// Copyright (c) 2016 The vulkano developers
// Licensed under the Apache License, Version 2.0
// <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT
// license <LICENSE-MIT or http://opensource.org/licenses/MIT>,
// at your option. All files in the project carrying such
// notice may not be copied, modified, or distributed except
// according to those terms.

use smallvec::SmallVec;
use std::any::Any;
use std::borrow::Cow;
use std::mem;
use std::ptr;
use std::sync::Arc;

use buffer::BufferAccess;
use command_buffer::CommandBuffer;
use command_buffer::synced::base::Command;
use command_buffer::synced::base::FinalCommand;
use command_buffer::synced::base::KeyTy;
use command_buffer::synced::base::SyncCommandBufferBuilder;
use command_buffer::synced::base::SyncCommandBufferBuilderError;
use command_buffer::sys::UnsafeCommandBufferBuilder;
use command_buffer::sys::UnsafeCommandBufferBuilderBindVertexBuffer;
use command_buffer::sys::UnsafeCommandBufferBuilderBufferImageCopy;
use command_buffer::sys::UnsafeCommandBufferBuilderColorImageClear;
use command_buffer::sys::UnsafeCommandBufferBuilderExecuteCommands;
use command_buffer::sys::UnsafeCommandBufferBuilderImageCopy;
use command_buffer::sys::UnsafeCommandBufferBuilderImageBlit;
use descriptor::descriptor::DescriptorDescTy;
use descriptor::descriptor::ShaderStages;
use descriptor::descriptor_set::DescriptorSet;
use descriptor::pipeline_layout::PipelineLayoutAbstract;
use format::ClearValue;
use framebuffer::FramebufferAbstract;
use framebuffer::SubpassContents;
use image::ImageAccess;
use image::ImageLayout;
use pipeline::ComputePipelineAbstract;
use pipeline::GraphicsPipelineAbstract;
use pipeline::input_assembly::IndexType;
use pipeline::viewport::Scissor;
use pipeline::viewport::Viewport;
use pipeline::depth_stencil::DynamicStencilValue;
use pipeline::depth_stencil::StencilFaceFlags;
use sampler::Filter;
use sync::AccessFlagBits;
use sync::Event;
use sync::PipelineStages;



impl<P> SyncCommandBufferBuilder<P> {
    /// Calls `vkBeginRenderPass` on the builder.
    // TODO: it shouldn't be possible to get an error if the framebuffer checked conflicts already
    // TODO: after begin_render_pass has been called, flushing should be forbidden and an error
    //       returned if conflict
    #[inline]
    pub unsafe fn begin_render_pass<F, I>(&mut self, framebuffer: F,
                                          subpass_contents: SubpassContents, clear_values: I)
                                          -> Result<(), SyncCommandBufferBuilderError>
        where F: FramebufferAbstract + Send + Sync + 'static,
              I: Iterator<Item = ClearValue> + Send + Sync + 'static
    {
        struct Cmd<F, I> {
            framebuffer: F,
            subpass_contents: SubpassContents,
            clear_values: Option<I>,
        }

        impl<P, F, I> Command<P> for Cmd<F, I>
            where F: FramebufferAbstract + Send + Sync + 'static,
                  I: Iterator<Item = ClearValue>
        {
            fn name(&self) -> &'static str {
                "vkCmdBeginRenderPass"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.begin_render_pass(&self.framebuffer,
                                      self.subpass_contents,
                                      self.clear_values.take().unwrap());
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                struct Fin<F>(F);
                impl<F> FinalCommand for Fin<F>
                    where F: FramebufferAbstract + Send + Sync + 'static
                {
                    fn name(&self) -> &'static str {
                        "vkCmdBeginRenderPass"
                    }
                    fn image(&self, num: usize) -> &dyn ImageAccess {
                        self.0.attached_image_view(num).unwrap().parent()
                    }
                    fn image_name(&self, num: usize) -> Cow<'static, str> {
                        format!("attachment {}", num).into()
                    }
                }
                Box::new(Fin(self.framebuffer))
            }

            fn image(&self, num: usize) -> &dyn ImageAccess {
                self.framebuffer.attached_image_view(num).unwrap().parent()
            }

            fn image_name(&self, num: usize) -> Cow<'static, str> {
                format!("attachment {}", num).into()
            }
        }

        let atch_desc = (0 .. framebuffer.num_attachments())
            .map(|atch| framebuffer.attachment_desc(atch).unwrap())
            .collect::<Vec<_>>();

        self.append_command(Cmd {
                                framebuffer,
                                subpass_contents,
                                clear_values: Some(clear_values),
                            });

        for (atch, desc) in atch_desc.into_iter().enumerate() {
            self.prev_cmd_resource(KeyTy::Image, atch, true,        // TODO: suboptimal ; note: remember to always pass true if desc.initial_layout != desc.final_layout
                                   PipelineStages {
                                       all_commands: true,
                                       .. PipelineStages::none()
                                   },       // TODO: wrong!
                                   AccessFlagBits {
                                       input_attachment_read: true,
                                       color_attachment_read: true,
                                       color_attachment_write: true,
                                       depth_stencil_attachment_read: true,
                                       depth_stencil_attachment_write: true,
                                       .. AccessFlagBits::none()
                                   },       // TODO: suboptimal
                                   desc.initial_layout, desc.final_layout)?;
        }

        self.prev_cmd_entered_render_pass();
        Ok(())
    }

    /// Calls `vkCmdBindIndexBuffer` on the builder.
    #[inline]
    pub unsafe fn bind_index_buffer<B>(&mut self, buffer: B, index_ty: IndexType)
                                       -> Result<(), SyncCommandBufferBuilderError>
        where B: BufferAccess + Send + Sync + 'static
    {
        struct Cmd<B> {
            buffer: B,
            index_ty: IndexType,
        }

        impl<P, B> Command<P> for Cmd<B>
            where B: BufferAccess + Send + Sync + 'static
        {
            fn name(&self) -> &'static str {
                "vkCmdBindIndexBuffer"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.bind_index_buffer(&self.buffer, self.index_ty);
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                struct Fin<B>(B);
                impl<B> FinalCommand for Fin<B>
                    where B: BufferAccess + Send + Sync + 'static
                {
                    fn name(&self) -> &'static str {
                        "vkCmdBindIndexBuffer"
                    }
                    fn buffer(&self, num: usize) -> &dyn BufferAccess {
                        assert_eq!(num, 0);
                        &self.0
                    }
                    fn buffer_name(&self, num: usize) -> Cow<'static, str> {
                        assert_eq!(num, 0);
                        "index buffer".into()
                    }
                }
                Box::new(Fin(self.buffer))
            }

            fn buffer(&self, num: usize) -> &dyn BufferAccess {
                assert_eq!(num, 0);
                &self.buffer
            }

            fn buffer_name(&self, num: usize) -> Cow<'static, str> {
                assert_eq!(num, 0);
                "index buffer".into()
            }
        }

        self.append_command(Cmd { buffer, index_ty });
        self.prev_cmd_resource(KeyTy::Buffer,
                               0,
                               false,
                               PipelineStages {
                                   vertex_input: true,
                                   ..PipelineStages::none()
                               },
                               AccessFlagBits {
                                   index_read: true,
                                   ..AccessFlagBits::none()
                               },
                               ImageLayout::Undefined,
                               ImageLayout::Undefined)?;
        Ok(())
    }

    /// Calls `vkCmdBindPipeline` on the builder with a graphics pipeline.
    #[inline]
    pub unsafe fn bind_pipeline_graphics<Gp>(&mut self, pipeline: Gp)
        where Gp: GraphicsPipelineAbstract + Send + Sync + 'static
    {
        struct Cmd<Gp> {
            pipeline: Gp,
        }

        impl<P, Gp> Command<P> for Cmd<Gp>
            where Gp: GraphicsPipelineAbstract + Send + Sync + 'static
        {
            fn name(&self) -> &'static str {
                "vkCmdBindPipeline"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.bind_pipeline_graphics(&self.pipeline);
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                struct Fin<Gp>(Gp);
                impl<Gp> FinalCommand for Fin<Gp>
                    where Gp: Send + Sync + 'static
                {
                    fn name(&self) -> &'static str {
                        "vkCmdBindPipeline"
                    }
                }
                Box::new(Fin(self.pipeline))
            }
        }

        self.append_command(Cmd { pipeline });
    }

    /// Calls `vkCmdBindPipeline` on the builder with a compute pipeline.
    #[inline]
    pub unsafe fn bind_pipeline_compute<Cp>(&mut self, pipeline: Cp)
        where Cp: ComputePipelineAbstract + Send + Sync + 'static
    {
        struct Cmd<Gp> {
            pipeline: Gp,
        }

        impl<P, Gp> Command<P> for Cmd<Gp>
            where Gp: ComputePipelineAbstract + Send + Sync + 'static
        {
            fn name(&self) -> &'static str {
                "vkCmdBindPipeline"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.bind_pipeline_compute(&self.pipeline);
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                struct Fin<Cp>(Cp);
                impl<Cp> FinalCommand for Fin<Cp>
                    where Cp: Send + Sync + 'static
                {
                    fn name(&self) -> &'static str {
                        "vkCmdBindPipeline"
                    }
                }
                Box::new(Fin(self.pipeline))
            }
        }

        self.append_command(Cmd { pipeline });
    }

    /// Starts the process of binding descriptor sets. Returns an intermediate struct which can be
    /// used to add the sets.
    #[inline]
    pub fn bind_descriptor_sets(&mut self) -> SyncCommandBufferBuilderBindDescriptorSets<P> {
        SyncCommandBufferBuilderBindDescriptorSets {
            builder: self,
            inner: SmallVec::new(),
        }
    }

    /// Starts the process of binding vertex buffers. Returns an intermediate struct which can be
    /// used to add the buffers.
    #[inline]
    pub fn bind_vertex_buffers(&mut self) -> SyncCommandBufferBuilderBindVertexBuffer<P> {
        SyncCommandBufferBuilderBindVertexBuffer {
            builder: self,
            inner: UnsafeCommandBufferBuilderBindVertexBuffer::new(),
            buffers: Vec::new(),
        }
    }

    /// Calls `vkCmdCopyImage` on the builder.
    ///
    /// Does nothing if the list of regions is empty, as it would be a no-op and isn't a valid
    /// usage of the command anyway.
    #[inline]
    pub unsafe fn copy_image<S, D, R>(&mut self, source: S, source_layout: ImageLayout,
                                      destination: D, destination_layout: ImageLayout, regions: R)
                                      -> Result<(), SyncCommandBufferBuilderError>
        where S: ImageAccess + Send + Sync + 'static,
              D: ImageAccess + Send + Sync + 'static,
              R: Iterator<Item = UnsafeCommandBufferBuilderImageCopy> + Send + Sync + 'static
    {
        struct Cmd<S, D, R> {
            source: Option<S>,
            source_layout: ImageLayout,
            destination: Option<D>,
            destination_layout: ImageLayout,
            regions: Option<R>,
        }

        impl<P, S, D, R> Command<P> for Cmd<S, D, R>
            where S: ImageAccess + Send + Sync + 'static,
                  D: ImageAccess + Send + Sync + 'static,
                  R: Iterator<Item = UnsafeCommandBufferBuilderImageCopy>
        {
            fn name(&self) -> &'static str {
                "vkCmdCopyImage"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.copy_image(self.source.as_ref().unwrap(),
                               self.source_layout,
                               self.destination.as_ref().unwrap(),
                               self.destination_layout,
                               self.regions.take().unwrap());
            }

            fn into_final_command(mut self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                struct Fin<S, D>(S, D);
                impl<S, D> FinalCommand for Fin<S, D>
                    where S: ImageAccess + Send + Sync + 'static,
                          D: ImageAccess + Send + Sync + 'static
                {
                    fn name(&self) -> &'static str {
                        "vkCmdCopyImage"
                    }
                    fn image(&self, num: usize) -> &dyn ImageAccess {
                        if num == 0 {
                            &self.0
                        } else if num == 1 {
                            &self.1
                        } else {
                            panic!()
                        }
                    }
                    fn image_name(&self, num: usize) -> Cow<'static, str> {
                        if num == 0 {
                            "source".into()
                        } else if num == 1 {
                            "destination".into()
                        } else {
                            panic!()
                        }
                    }
                }

                // Note: borrow checker somehow doesn't accept `self.source` and `self.destination`
                // without using an Option.
                Box::new(Fin(self.source.take().unwrap(),
                             self.destination.take().unwrap()))
            }

            fn image(&self, num: usize) -> &dyn ImageAccess {
                if num == 0 {
                    self.source.as_ref().unwrap()
                } else if num == 1 {
                    self.destination.as_ref().unwrap()
                } else {
                    panic!()
                }
            }

            fn image_name(&self, num: usize) -> Cow<'static, str> {
                if num == 0 {
                    "source".into()
                } else if num == 1 {
                    "destination".into()
                } else {
                    panic!()
                }
            }
        }

        self.append_command(Cmd {
                                source: Some(source),
                                source_layout,
                                destination: Some(destination),
                                destination_layout,
                                regions: Some(regions),
                            });
        self.prev_cmd_resource(KeyTy::Image,
                               0,
                               false,
                               PipelineStages {
                                   transfer: true,
                                   ..PipelineStages::none()
                               },
                               AccessFlagBits {
                                   transfer_read: true,
                                   ..AccessFlagBits::none()
                               },
                               source_layout,
                               source_layout)?;
        self.prev_cmd_resource(KeyTy::Image,
                               1,
                               true,
                               PipelineStages {
                                   transfer: true,
                                   ..PipelineStages::none()
                               },
                               AccessFlagBits {
                                   transfer_write: true,
                                   ..AccessFlagBits::none()
                               },
                               destination_layout,
                               destination_layout)?;
        Ok(())
    }

    /// Calls `vkCmdBlitImage` on the builder.
    ///
    /// Does nothing if the list of regions is empty, as it would be a no-op and isn't a valid
    /// usage of the command anyway.
    #[inline]
    pub unsafe fn blit_image<S, D, R>(&mut self, source: S, source_layout: ImageLayout,
                                      destination: D, destination_layout: ImageLayout, regions: R,
                                      filter: Filter)
                                      -> Result<(), SyncCommandBufferBuilderError>
        where S: ImageAccess + Send + Sync + 'static,
              D: ImageAccess + Send + Sync + 'static,
              R: Iterator<Item = UnsafeCommandBufferBuilderImageBlit> + Send + Sync + 'static
    {
        struct Cmd<S, D, R> {
            source: Option<S>,
            source_layout: ImageLayout,
            destination: Option<D>,
            destination_layout: ImageLayout,
            regions: Option<R>,
            filter: Filter,
        }

        impl<P, S, D, R> Command<P> for Cmd<S, D, R>
            where S: ImageAccess + Send + Sync + 'static,
                  D: ImageAccess + Send + Sync + 'static,
                  R: Iterator<Item = UnsafeCommandBufferBuilderImageBlit>
        {
            fn name(&self) -> &'static str {
                "vkCmdBlitImage"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.blit_image(self.source.as_ref().unwrap(),
                               self.source_layout,
                               self.destination.as_ref().unwrap(),
                               self.destination_layout,
                               self.regions.take().unwrap(),
                               self.filter);
            }

            fn into_final_command(mut self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                struct Fin<S, D>(S, D);
                impl<S, D> FinalCommand for Fin<S, D>
                    where S: ImageAccess + Send + Sync + 'static,
                          D: ImageAccess + Send + Sync + 'static
                {
                    fn name(&self) -> &'static str {
                        "vkCmdBlitImage"
                    }
                    fn image(&self, num: usize) -> &dyn ImageAccess {
                        if num == 0 {
                            &self.0
                        } else if num == 1 {
                            &self.1
                        } else {
                            panic!()
                        }
                    }
                    fn image_name(&self, num: usize) -> Cow<'static, str> {
                        if num == 0 {
                            "source".into()
                        } else if num == 1 {
                            "destination".into()
                        } else {
                            panic!()
                        }
                    }
                }

                // Note: borrow checker somehow doesn't accept `self.source` and `self.destination`
                // without using an Option.
                Box::new(Fin(self.source.take().unwrap(),
                             self.destination.take().unwrap()))
            }

            fn image(&self, num: usize) -> &dyn ImageAccess {
                if num == 0 {
                    self.source.as_ref().unwrap()
                } else if num == 1 {
                    self.destination.as_ref().unwrap()
                } else {
                    panic!()
                }
            }

            fn image_name(&self, num: usize) -> Cow<'static, str> {
                if num == 0 {
                    "source".into()
                } else if num == 1 {
                    "destination".into()
                } else {
                    panic!()
                }
            }
        }

        self.append_command(Cmd {
                                source: Some(source),
                                source_layout,
                                destination: Some(destination),
                                destination_layout,
                                regions: Some(regions),
                                filter,
                            });
        self.prev_cmd_resource(KeyTy::Image,
                               0,
                               false,
                               PipelineStages {
                                   transfer: true,
                                   ..PipelineStages::none()
                               },
                               AccessFlagBits {
                                   transfer_read: true,
                                   ..AccessFlagBits::none()
                               },
                               source_layout,
                               source_layout)?;
        self.prev_cmd_resource(KeyTy::Image,
                               1,
                               true,
                               PipelineStages {
                                   transfer: true,
                                   ..PipelineStages::none()
                               },
                               AccessFlagBits {
                                   transfer_write: true,
                                   ..AccessFlagBits::none()
                               },
                               destination_layout,
                               destination_layout)?;
        Ok(())
    }

    /// Calls `vkCmdClearColorImage` on the builder.
    ///
    /// Does nothing if the list of regions is empty, as it would be a no-op and isn't a valid
    /// usage of the command anyway.
    pub unsafe fn clear_color_image<I, R>(&mut self, image: I, layout: ImageLayout,
                                          color: ClearValue, regions: R)
                                          -> Result<(), SyncCommandBufferBuilderError>
        where I: ImageAccess + Send + Sync + 'static,
              R: Iterator<Item = UnsafeCommandBufferBuilderColorImageClear> + Send + Sync + 'static
    {
        struct Cmd<I, R> {
            image: Option<I>,
            layout: ImageLayout,
            color: ClearValue,
            regions: Option<R>,
        }

        impl<P, I, R> Command<P> for Cmd<I, R>
            where I: ImageAccess + Send + Sync + 'static,
                  R: Iterator<Item = UnsafeCommandBufferBuilderColorImageClear>
                         + Send
                         + Sync
                         + 'static
        {
            fn name(&self) -> &'static str {
                "vkCmdClearColorImage"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.clear_color_image(self.image.as_ref().unwrap(),
                                      self.layout,
                                      self.color,
                                      self.regions.take().unwrap());
            }

            fn into_final_command(mut self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                struct Fin<I>(I);
                impl<I> FinalCommand for Fin<I>
                    where I: ImageAccess + Send + Sync + 'static
                {
                    fn name(&self) -> &'static str {
                        "vkCmdClearColorImage"
                    }
                    fn image(&self, num: usize) -> &dyn ImageAccess {
                        assert_eq!(num, 0);
                        &self.0
                    }
                    fn image_name(&self, num: usize) -> Cow<'static, str> {
                        assert_eq!(num, 0);
                        "target".into()
                    }
                }

                // Note: borrow checker somehow doesn't accept `self.image` without using an Option.
                Box::new(Fin(self.image.take().unwrap()))
            }

            fn image(&self, num: usize) -> &dyn ImageAccess {
                assert_eq!(num, 0);
                self.image.as_ref().unwrap()
            }

            fn image_name(&self, num: usize) -> Cow<'static, str> {
                assert_eq!(num, 0);
                "target".into()
            }
        }

        self.append_command(Cmd {
                                image: Some(image),
                                layout,
                                color,
                                regions: Some(regions),
                            });
        self.prev_cmd_resource(KeyTy::Image,
                               0,
                               true,
                               PipelineStages {
                                   transfer: true,
                                   ..PipelineStages::none()
                               },
                               AccessFlagBits {
                                   transfer_write: true,
                                   ..AccessFlagBits::none()
                               },
                               layout,
                               layout)?;
        Ok(())
    }

    /// Calls `vkCmdCopyBuffer` on the builder.
    ///
    /// Does nothing if the list of regions is empty, as it would be a no-op and isn't a valid
    /// usage of the command anyway.
    #[inline]
    pub unsafe fn copy_buffer<S, D, R>(&mut self, source: S, destination: D, regions: R)
                                       -> Result<(), SyncCommandBufferBuilderError>
        where S: BufferAccess + Send + Sync + 'static,
              D: BufferAccess + Send + Sync + 'static,
              R: Iterator<Item = (usize, usize, usize)> + Send + Sync + 'static
    {
        struct Cmd<S, D, R> {
            source: Option<S>,
            destination: Option<D>,
            regions: Option<R>,
        }

        impl<P, S, D, R> Command<P> for Cmd<S, D, R>
            where S: BufferAccess + Send + Sync + 'static,
                  D: BufferAccess + Send + Sync + 'static,
                  R: Iterator<Item = (usize, usize, usize)>
        {
            fn name(&self) -> &'static str {
                "vkCmdCopyBuffer"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.copy_buffer(self.source.as_ref().unwrap(),
                                self.destination.as_ref().unwrap(),
                                self.regions.take().unwrap());
            }

            fn into_final_command(mut self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                struct Fin<S, D>(S, D);
                impl<S, D> FinalCommand for Fin<S, D>
                    where S: BufferAccess + Send + Sync + 'static,
                          D: BufferAccess + Send + Sync + 'static
                {
                    fn name(&self) -> &'static str {
                        "vkCmdCopyBuffer"
                    }
                    fn buffer(&self, num: usize) -> &dyn BufferAccess {
                        match num {
                            0 => &self.0,
                            1 => &self.1,
                            _ => panic!(),
                        }
                    }
                    fn buffer_name(&self, num: usize) -> Cow<'static, str> {
                        match num {
                            0 => "source".into(),
                            1 => "destination".into(),
                            _ => panic!(),
                        }
                    }
                }
                // Note: borrow checker somehow doesn't accept `self.source` and `self.destination`
                // without using an Option.
                Box::new(Fin(self.source.take().unwrap(),
                             self.destination.take().unwrap()))
            }

            fn buffer(&self, num: usize) -> &dyn BufferAccess {
                match num {
                    0 => self.source.as_ref().unwrap(),
                    1 => self.destination.as_ref().unwrap(),
                    _ => panic!(),
                }
            }

            fn buffer_name(&self, num: usize) -> Cow<'static, str> {
                match num {
                    0 => "source".into(),
                    1 => "destination".into(),
                    _ => panic!(),
                }
            }
        }

        self.append_command(Cmd {
                                source: Some(source),
                                destination: Some(destination),
                                regions: Some(regions),
                            });
        self.prev_cmd_resource(KeyTy::Buffer,
                               0,
                               false,
                               PipelineStages {
                                   transfer: true,
                                   ..PipelineStages::none()
                               },
                               AccessFlagBits {
                                   transfer_read: true,
                                   ..AccessFlagBits::none()
                               },
                               ImageLayout::Undefined,
                               ImageLayout::Undefined)?;
        self.prev_cmd_resource(KeyTy::Buffer,
                               1,
                               true,
                               PipelineStages {
                                   transfer: true,
                                   ..PipelineStages::none()
                               },
                               AccessFlagBits {
                                   transfer_write: true,
                                   ..AccessFlagBits::none()
                               },
                               ImageLayout::Undefined,
                               ImageLayout::Undefined)?;
        Ok(())
    }

    /// Calls `vkCmdCopyBufferToImage` on the builder.
    ///
    /// Does nothing if the list of regions is empty, as it would be a no-op and isn't a valid
    /// usage of the command anyway.
    #[inline]
    pub unsafe fn copy_buffer_to_image<S, D, R>(&mut self, source: S, destination: D,
                                                destination_layout: ImageLayout, regions: R)
                                                -> Result<(), SyncCommandBufferBuilderError>
        where S: BufferAccess + Send + Sync + 'static,
              D: ImageAccess + Send + Sync + 'static,
              R: Iterator<Item = UnsafeCommandBufferBuilderBufferImageCopy> + Send + Sync + 'static
    {
        struct Cmd<S, D, R> {
            source: Option<S>,
            destination: Option<D>,
            destination_layout: ImageLayout,
            regions: Option<R>,
        }

        impl<P, S, D, R> Command<P> for Cmd<S, D, R>
            where S: BufferAccess + Send + Sync + 'static,
                  D: ImageAccess + Send + Sync + 'static,
                  R: Iterator<Item = UnsafeCommandBufferBuilderBufferImageCopy>
        {
            fn name(&self) -> &'static str {
                "vkCmdCopyBufferToImage"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.copy_buffer_to_image(self.source.as_ref().unwrap(),
                                         self.destination.as_ref().unwrap(),
                                         self.destination_layout,
                                         self.regions.take().unwrap());
            }

            fn into_final_command(mut self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                struct Fin<S, D>(S, D);
                impl<S, D> FinalCommand for Fin<S, D>
                    where S: BufferAccess + Send + Sync + 'static,
                          D: ImageAccess + Send + Sync + 'static
                {
                    fn name(&self) -> &'static str {
                        "vkCmdCopyBufferToImage"
                    }
                    fn buffer(&self, num: usize) -> &dyn BufferAccess {
                        assert_eq!(num, 0);
                        &self.0
                    }
                    fn buffer_name(&self, num: usize) -> Cow<'static, str> {
                        assert_eq!(num, 0);
                        "source".into()
                    }
                    fn image(&self, num: usize) -> &dyn ImageAccess {
                        assert_eq!(num, 0);
                        &self.1
                    }
                    fn image_name(&self, num: usize) -> Cow<'static, str> {
                        assert_eq!(num, 0);
                        "destination".into()
                    }
                }

                // Note: borrow checker somehow doesn't accept `self.source` and `self.destination`
                // without using an Option.
                Box::new(Fin(self.source.take().unwrap(),
                             self.destination.take().unwrap()))
            }

            fn buffer(&self, num: usize) -> &dyn BufferAccess {
                assert_eq!(num, 0);
                self.source.as_ref().unwrap()
            }

            fn buffer_name(&self, num: usize) -> Cow<'static, str> {
                assert_eq!(num, 0);
                "source".into()
            }

            fn image(&self, num: usize) -> &dyn ImageAccess {
                assert_eq!(num, 0);
                self.destination.as_ref().unwrap()
            }

            fn image_name(&self, num: usize) -> Cow<'static, str> {
                assert_eq!(num, 0);
                "destination".into()
            }
        }

        self.append_command(Cmd {
                                source: Some(source),
                                destination: Some(destination),
                                destination_layout: destination_layout,
                                regions: Some(regions),
                            });
        self.prev_cmd_resource(KeyTy::Buffer,
                               0,
                               false,
                               PipelineStages {
                                   transfer: true,
                                   ..PipelineStages::none()
                               },
                               AccessFlagBits {
                                   transfer_read: true,
                                   ..AccessFlagBits::none()
                               },
                               ImageLayout::Undefined,
                               ImageLayout::Undefined)?;
        self.prev_cmd_resource(KeyTy::Image,
                               0,
                               true,
                               PipelineStages {
                                   transfer: true,
                                   ..PipelineStages::none()
                               },
                               AccessFlagBits {
                                   transfer_write: true,
                                   ..AccessFlagBits::none()
                               },
                               destination_layout,
                               destination_layout)?;
        Ok(())
    }

    /// Calls `vkCmdCopyImageToBuffer` on the builder.
    ///
    /// Does nothing if the list of regions is empty, as it would be a no-op and isn't a valid
    /// usage of the command anyway.
    #[inline]
    pub unsafe fn copy_image_to_buffer<S, D, R>(&mut self, source: S, source_layout: ImageLayout,
                                                destination: D, regions: R)
                                                -> Result<(), SyncCommandBufferBuilderError>
        where S: ImageAccess + Send + Sync + 'static,
              D: BufferAccess + Send + Sync + 'static,
              R: Iterator<Item = UnsafeCommandBufferBuilderBufferImageCopy> + Send + Sync + 'static
    {
        struct Cmd<S, D, R> {
            source: Option<S>,
            source_layout: ImageLayout,
            destination: Option<D>,
            regions: Option<R>,
        }

        impl<P, S, D, R> Command<P> for Cmd<S, D, R>
            where S: ImageAccess + Send + Sync + 'static,
                  D: BufferAccess + Send + Sync + 'static,
                  R: Iterator<Item = UnsafeCommandBufferBuilderBufferImageCopy>
        {
            fn name(&self) -> &'static str {
                "vkCmdCopyImageToBuffer"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.copy_image_to_buffer(self.source.as_ref().unwrap(),
                                         self.source_layout,
                                         self.destination.as_ref().unwrap(),
                                         self.regions.take().unwrap());
            }

            fn into_final_command(mut self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                struct Fin<S, D>(S, D);
                impl<S, D> FinalCommand for Fin<S, D>
                    where S: ImageAccess + Send + Sync + 'static,
                          D: BufferAccess + Send + Sync + 'static
                {
                    fn name(&self) -> &'static str {
                        "vkCmdCopyImageToBuffer"
                    }
                    fn buffer(&self, num: usize) -> &dyn BufferAccess {
                        assert_eq!(num, 0);
                        &self.1
                    }
                    fn buffer_name(&self, num: usize) -> Cow<'static, str> {
                        assert_eq!(num, 0);
                        "destination".into()
                    }
                    fn image(&self, num: usize) -> &dyn ImageAccess {
                        assert_eq!(num, 0);
                        &self.0
                    }
                    fn image_name(&self, num: usize) -> Cow<'static, str> {
                        assert_eq!(num, 0);
                        "source".into()
                    }
                }

                // Note: borrow checker somehow doesn't accept `self.source` and `self.destination`
                // without using an Option.
                Box::new(Fin(self.source.take().unwrap(),
                             self.destination.take().unwrap()))
            }

            fn buffer(&self, num: usize) -> &dyn BufferAccess {
                assert_eq!(num, 0);
                self.destination.as_ref().unwrap()
            }

            fn buffer_name(&self, num: usize) -> Cow<'static, str> {
                assert_eq!(num, 0);
                "destination".into()
            }

            fn image(&self, num: usize) -> &dyn ImageAccess {
                assert_eq!(num, 0);
                self.source.as_ref().unwrap()
            }

            fn image_name(&self, num: usize) -> Cow<'static, str> {
                assert_eq!(num, 0);
                "source".into()
            }
        }

        self.append_command(Cmd {
                                source: Some(source),
                                destination: Some(destination),
                                source_layout: source_layout,
                                regions: Some(regions),
                            });
        self.prev_cmd_resource(KeyTy::Image,
                               0,
                               false,
                               PipelineStages {
                                   transfer: true,
                                   ..PipelineStages::none()
                               },
                               AccessFlagBits {
                                   transfer_read: true,
                                   ..AccessFlagBits::none()
                               },
                               source_layout,
                               source_layout)?;
        self.prev_cmd_resource(KeyTy::Buffer,
                               0,
                               true,
                               PipelineStages {
                                   transfer: true,
                                   ..PipelineStages::none()
                               },
                               AccessFlagBits {
                                   transfer_write: true,
                                   ..AccessFlagBits::none()
                               },
                               ImageLayout::Undefined,
                               ImageLayout::Undefined)?;
        Ok(())
    }

    /// Calls `vkCmdDispatch` on the builder.
    #[inline]
    pub unsafe fn dispatch(&mut self, dimensions: [u32; 3]) {
        struct Cmd {
            dimensions: [u32; 3],
        }

        impl<P> Command<P> for Cmd {
            fn name(&self) -> &'static str {
                "vkCmdDispatch"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.dispatch(self.dimensions);
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                Box::new("vkCmdDispatch")
            }
        }

        self.append_command(Cmd { dimensions });
    }

    /// Calls `vkCmdDispatchIndirect` on the builder.
    #[inline]
    pub unsafe fn dispatch_indirect<B>(&mut self, buffer: B)
                                       -> Result<(), SyncCommandBufferBuilderError>
        where B: BufferAccess + Send + Sync + 'static
    {
        struct Cmd<B> {
            buffer: B,
        }

        impl<P, B> Command<P> for Cmd<B>
            where B: BufferAccess + Send + Sync + 'static
        {
            fn name(&self) -> &'static str {
                "vkCmdDispatchIndirect"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.dispatch_indirect(&self.buffer);
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                struct Fin<B>(B);
                impl<B> FinalCommand for Fin<B>
                    where B: BufferAccess + Send + Sync + 'static
                {
                    fn name(&self) -> &'static str {
                        "vkCmdDispatchIndirect"
                    }
                    fn buffer(&self, num: usize) -> &dyn BufferAccess {
                        assert_eq!(num, 0);
                        &self.0
                    }
                    fn buffer_name(&self, num: usize) -> Cow<'static, str> {
                        assert_eq!(num, 0);
                        "indirect buffer".into()
                    }
                }
                Box::new(Fin(self.buffer))
            }

            fn buffer(&self, num: usize) -> &dyn BufferAccess {
                assert_eq!(num, 0);
                &self.buffer
            }

            fn buffer_name(&self, num: usize) -> Cow<'static, str> {
                assert_eq!(num, 0);
                "indirect buffer".into()
            }
        }

        self.append_command(Cmd { buffer });
        self.prev_cmd_resource(KeyTy::Buffer,
                               0,
                               false,
                               PipelineStages {
                                   draw_indirect: true,
                                   ..PipelineStages::none()
                               }, // TODO: is draw_indirect correct?
                               AccessFlagBits {
                                   indirect_command_read: true,
                                   ..AccessFlagBits::none()
                               },
                               ImageLayout::Undefined,
                               ImageLayout::Undefined)?;
        Ok(())
    }

    /// Calls `vkCmdDraw` on the builder.
    #[inline]
    pub unsafe fn draw(&mut self, vertex_count: u32, instance_count: u32, first_vertex: u32,
                       first_instance: u32) {
        struct Cmd {
            vertex_count: u32,
            instance_count: u32,
            first_vertex: u32,
            first_instance: u32,
        }

        impl<P> Command<P> for Cmd {
            fn name(&self) -> &'static str {
                "vkCmdDraw"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.draw(self.vertex_count,
                         self.instance_count,
                         self.first_vertex,
                         self.first_instance);
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                Box::new("vkCmdDraw")
            }
        }

        self.append_command(Cmd {
                                vertex_count,
                                instance_count,
                                first_vertex,
                                first_instance,
                            });

    }

    /// Calls `vkCmdDrawIndexed` on the builder.
    #[inline]
    pub unsafe fn draw_indexed(&mut self, index_count: u32, instance_count: u32,
                               first_index: u32, vertex_offset: i32, first_instance: u32) {
        struct Cmd {
            index_count: u32,
            instance_count: u32,
            first_index: u32,
            vertex_offset: i32,
            first_instance: u32,
        }

        impl<P> Command<P> for Cmd {
            fn name(&self) -> &'static str {
                "vkCmdDrawIndexed"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.draw_indexed(self.index_count,
                                 self.instance_count,
                                 self.first_index,
                                 self.vertex_offset,
                                 self.first_instance);
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                Box::new("vkCmdDrawIndexed")
            }
        }

        self.append_command(Cmd {
                                index_count,
                                instance_count,
                                first_index,
                                vertex_offset,
                                first_instance,
                            });
    }

    /// Calls `vkCmdDrawIndirect` on the builder.
    #[inline]
    pub unsafe fn draw_indirect<B>(&mut self, buffer: B, draw_count: u32, stride: u32)
                                   -> Result<(), SyncCommandBufferBuilderError>
        where B: BufferAccess + Send + Sync + 'static
    {
        struct Cmd<B> {
            buffer: B,
            draw_count: u32,
            stride: u32,
        }

        impl<P, B> Command<P> for Cmd<B>
            where B: BufferAccess + Send + Sync + 'static
        {
            fn name(&self) -> &'static str {
                "vkCmdDrawIndirect"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.draw_indirect(&self.buffer, self.draw_count, self.stride);
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                struct Fin<B>(B);
                impl<B> FinalCommand for Fin<B>
                    where B: BufferAccess + Send + Sync + 'static
                {
                    fn name(&self) -> &'static str {
                        "vkCmdDrawIndirect"
                    }
                    fn buffer(&self, num: usize) -> &dyn BufferAccess {
                        assert_eq!(num, 0);
                        &self.0
                    }
                    fn buffer_name(&self, num: usize) -> Cow<'static, str> {
                        assert_eq!(num, 0);
                        "indirect buffer".into()
                    }
                }
                Box::new(Fin(self.buffer))
            }

            fn buffer(&self, num: usize) -> &dyn BufferAccess {
                assert_eq!(num, 0);
                &self.buffer
            }

            fn buffer_name(&self, num: usize) -> Cow<'static, str> {
                assert_eq!(num, 0);
                "indirect buffer".into()
            }
        }

        self.append_command(Cmd {
                                buffer,
                                draw_count,
                                stride,
                            });
        self.prev_cmd_resource(KeyTy::Buffer,
                               0,
                               false,
                               PipelineStages {
                                   draw_indirect: true,
                                   ..PipelineStages::none()
                               },
                               AccessFlagBits {
                                   indirect_command_read: true,
                                   ..AccessFlagBits::none()
                               },
                               ImageLayout::Undefined,
                               ImageLayout::Undefined)?;
        Ok(())
    }

    /// Calls `vkCmdDrawIndexedIndirect` on the builder.
    #[inline]
    pub unsafe fn draw_indexed_indirect<B>(&mut self, buffer: B, draw_count: u32, stride: u32)
                                           -> Result<(), SyncCommandBufferBuilderError>
        where B: BufferAccess + Send + Sync + 'static
    {
        struct Cmd<B> {
            buffer: B,
            draw_count: u32,
            stride: u32,
        }

        impl<P, B> Command<P> for Cmd<B>
            where B: BufferAccess + Send + Sync + 'static
        {
            fn name(&self) -> &'static str {
                "vkCmdDrawIndexedIndirect"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.draw_indexed_indirect(&self.buffer, self.draw_count, self.stride);
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                struct Fin<B>(B);
                impl<B> FinalCommand for Fin<B>
                    where B: BufferAccess + Send + Sync + 'static
                {
                    fn name(&self) -> &'static str {
                        "vkCmdDrawIndexedIndirect"
                    }
                    fn buffer(&self, num: usize) -> &dyn BufferAccess {
                        assert_eq!(num, 0);
                        &self.0
                    }
                    fn buffer_name(&self, num: usize) -> Cow<'static, str> {
                        assert_eq!(num, 0);
                        "indirect buffer".into()
                    }
                }
                Box::new(Fin(self.buffer))
            }

            fn buffer(&self, num: usize) -> &dyn BufferAccess {
                assert_eq!(num, 0);
                &self.buffer
            }

            fn buffer_name(&self, num: usize) -> Cow<'static, str> {
                assert_eq!(num, 0);
                "indirect buffer".into()
            }
        }

        self.append_command(Cmd {
                                buffer,
                                draw_count,
                                stride,
                            });
        self.prev_cmd_resource(KeyTy::Buffer,
                               0,
                               false,
                               PipelineStages {
                                   draw_indirect: true,
                                   ..PipelineStages::none()
                               },
                               AccessFlagBits {
                                   indirect_command_read: true,
                                   ..AccessFlagBits::none()
                               },
                               ImageLayout::Undefined,
                               ImageLayout::Undefined)?;
        Ok(())
    }

    /// Calls `vkCmdEndRenderPass` on the builder.
    #[inline]
    pub unsafe fn end_render_pass(&mut self) {
        struct Cmd;

        impl<P> Command<P> for Cmd {
            fn name(&self) -> &'static str {
                "vkCmdEndRenderPass"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.end_render_pass();
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                Box::new("vkCmdEndRenderPass")
            }
        }

        self.append_command(Cmd);
        self.prev_cmd_left_render_pass();
    }

    /// Starts the process of executing secondary command buffers. Returns an intermediate struct
    /// which can be used to add the command buffers.
    #[inline]
    pub unsafe fn execute_commands(&mut self) -> SyncCommandBufferBuilderExecuteCommands<P> {
        SyncCommandBufferBuilderExecuteCommands {
            builder: self,
            inner: UnsafeCommandBufferBuilderExecuteCommands::new(),
            command_buffers: Vec::new(),
        }
    }

    /// Calls `vkCmdFillBuffer` on the builder.
    #[inline]
    pub unsafe fn fill_buffer<B>(&mut self, buffer: B, data: u32)
        where B: BufferAccess + Send + Sync + 'static
    {
        struct Cmd<B> {
            buffer: B,
            data: u32,
        }

        impl<P, B> Command<P> for Cmd<B>
            where B: BufferAccess + Send + Sync + 'static
        {
            fn name(&self) -> &'static str {
                "vkCmdFillBuffer"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.fill_buffer(&self.buffer, self.data);
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                struct Fin<B>(B);
                impl<B> FinalCommand for Fin<B>
                    where B: BufferAccess + Send + Sync + 'static
                {
                    fn name(&self) -> &'static str {
                        "vkCmdFillBuffer"
                    }
                    fn buffer(&self, num: usize) -> &dyn BufferAccess {
                        assert_eq!(num, 0);
                        &self.0
                    }
                    fn buffer_name(&self, _: usize) -> Cow<'static, str> {
                        "destination".into()
                    }
                }
                Box::new(Fin(self.buffer))
            }

            fn buffer(&self, num: usize) -> &dyn BufferAccess {
                assert_eq!(num, 0);
                &self.buffer
            }

            fn buffer_name(&self, _: usize) -> Cow<'static, str> {
                "destination".into()
            }
        }

        self.append_command(Cmd { buffer, data });
        self.prev_cmd_resource(KeyTy::Buffer,
                               0,
                               true,
                               PipelineStages {
                                   transfer: true,
                                   ..PipelineStages::none()
                               },
                               AccessFlagBits {
                                   transfer_write: true,
                                   ..AccessFlagBits::none()
                               },
                               ImageLayout::Undefined,
                               ImageLayout::Undefined)
            .unwrap();
    }

    /// Calls `vkCmdNextSubpass` on the builder.
    #[inline]
    pub unsafe fn next_subpass(&mut self, subpass_contents: SubpassContents) {
        struct Cmd {
            subpass_contents: SubpassContents,
        }

        impl<P> Command<P> for Cmd {
            fn name(&self) -> &'static str {
                "vkCmdNextSubpass"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.next_subpass(self.subpass_contents);
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                Box::new("vkCmdNextSubpass")
            }
        }

        self.append_command(Cmd { subpass_contents });
    }

    /// Calls `vkCmdPushConstants` on the builder.
    #[inline]
    pub unsafe fn push_constants<Pl, D>(&mut self, pipeline_layout: Pl, stages: ShaderStages,
                                        offset: u32, size: u32, data: &D)
        where Pl: PipelineLayoutAbstract + Send + Sync + 'static,
              D: ?Sized + Send + Sync + 'static
    {
        struct Cmd<Pl> {
            pipeline_layout: Pl,
            stages: ShaderStages,
            offset: u32,
            size: u32,
            data: Box<[u8]>,
        }

        impl<P, Pl> Command<P> for Cmd<Pl>
            where Pl: PipelineLayoutAbstract + Send + Sync + 'static
        {
            fn name(&self) -> &'static str {
                "vkCmdPushConstants"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.push_constants::<_, [u8]>(&self.pipeline_layout,
                                              self.stages,
                                              self.offset,
                                              self.size,
                                              &self.data);
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                struct Fin<Pl>(Pl);
                impl<Pl> FinalCommand for Fin<Pl>
                    where Pl: Send + Sync + 'static
                {
                    fn name(&self) -> &'static str {
                        "vkCmdPushConstants"
                    }
                }
                Box::new(Fin(self.pipeline_layout))
            }
        }

        debug_assert!(mem::size_of_val(data) >= size as usize);

        let mut out = Vec::with_capacity(size as usize);
        ptr::copy::<u8>(data as *const D as *const u8,
                        out.as_mut_ptr(),
                        size as usize);
        out.set_len(size as usize);

        self.append_command(Cmd {
                                pipeline_layout,
                                stages,
                                offset,
                                size,
                                data: out.into(),
                            });
    }

    /// Calls `vkCmdResetEvent` on the builder.
    #[inline]
    pub unsafe fn reset_event(&mut self, event: Arc<Event>, stages: PipelineStages) {
        struct Cmd {
            event: Arc<Event>,
            stages: PipelineStages,
        }

        impl<P> Command<P> for Cmd {
            fn name(&self) -> &'static str {
                "vkCmdResetEvent"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.reset_event(&self.event, self.stages);
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                struct Fin(Arc<Event>);
                impl FinalCommand for Fin {
                    fn name(&self) -> &'static str {
                        "vkCmdResetEvent"
                    }
                }
                Box::new(Fin(self.event))
            }
        }

        self.append_command(Cmd { event, stages });
    }

    /// Calls `vkCmdSetBlendConstants` on the builder.
    #[inline]
    pub unsafe fn set_blend_constants(&mut self, constants: [f32; 4]) {
        struct Cmd {
            constants: [f32; 4],
        }

        impl<P> Command<P> for Cmd {
            fn name(&self) -> &'static str {
                "vkCmdSetBlendConstants"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.set_blend_constants(self.constants);
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                Box::new("vkCmdSetBlendConstants")
            }
        }

        self.append_command(Cmd { constants });
    }

    /// Calls `vkCmdSetDepthBias` on the builder.
    #[inline]
    pub unsafe fn set_depth_bias(&mut self, constant_factor: f32, clamp: f32, slope_factor: f32) {
        struct Cmd {
            constant_factor: f32,
            clamp: f32,
            slope_factor: f32,
        }

        impl<P> Command<P> for Cmd {
            fn name(&self) -> &'static str {
                "vkCmdSetDepthBias"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.set_depth_bias(self.constant_factor, self.clamp, self.slope_factor);
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                Box::new("vkCmdSetDepthBias")
            }
        }

        self.append_command(Cmd {
                                constant_factor,
                                clamp,
                                slope_factor,
                            });
    }

    /// Calls `vkCmdSetDepthBounds` on the builder.
    #[inline]
    pub unsafe fn set_depth_bounds(&mut self, min: f32, max: f32) {
        struct Cmd {
            min: f32,
            max: f32,
        }

        impl<P> Command<P> for Cmd {
            fn name(&self) -> &'static str {
                "vkCmdSetDepthBounds"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.set_depth_bounds(self.min, self.max);
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                Box::new("vkCmdSetDepthBounds")
            }
        }

        self.append_command(Cmd { min, max });
    }

    /// Calls `vkCmdSetEvent` on the builder.
    #[inline]
    pub unsafe fn set_event(&mut self, event: Arc<Event>, stages: PipelineStages) {
        struct Cmd {
            event: Arc<Event>,
            stages: PipelineStages,
        }

        impl<P> Command<P> for Cmd {
            fn name(&self) -> &'static str {
                "vkCmdSetEvent"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.set_event(&self.event, self.stages);
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                struct Fin(Arc<Event>);
                impl FinalCommand for Fin {
                    fn name(&self) -> &'static str {
                        "vkCmdSetEvent"
                    }
                }
                Box::new(Fin(self.event))
            }
        }

        self.append_command(Cmd { event, stages });
    }

    /// Calls `vkCmdSetLineWidth` on the builder.
    #[inline]
    pub unsafe fn set_line_width(&mut self, line_width: f32) {
        struct Cmd {
            line_width: f32,
        }

        impl<P> Command<P> for Cmd {
            fn name(&self) -> &'static str {
                "vkCmdSetLineWidth"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.set_line_width(self.line_width);
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                Box::new("vkCmdSetLineWidth")
            }
        }

        self.append_command(Cmd { line_width });
    }

    /// Calls `vkCmdSetStencilCompareMask` on the builder.
    #[inline]
    pub unsafe fn set_stencil_compare_mask(&mut self, compare_mask: DynamicStencilValue) {

        struct Cmd {
            face_mask: StencilFaceFlags,
            compare_mask: u32,
        }

        impl<P> Command<P> for Cmd {
            fn name(&self) -> &'static str {
                "vkCmdSetStencilCompareMask"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.set_stencil_compare_mask(self.face_mask, self.compare_mask);
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                Box::new("vkCmdSetStencilCompareMask")
            }
        }

        self.append_command(Cmd {
            face_mask: compare_mask.face,
            compare_mask: compare_mask.value,
        });
    }

    /// Calls `vkCmdSetStencilReference` on the builder.
    #[inline]
    pub unsafe fn set_stencil_reference(&mut self, reference: DynamicStencilValue) {

        struct Cmd {
            face_mask: StencilFaceFlags,
            reference: u32,
        }

        impl<P> Command<P> for Cmd {
            fn name(&self) -> &'static str {
                "vkCmdSetStencilReference"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.set_stencil_reference(self.face_mask, self.reference);
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                Box::new("vkCmdSetStencilReference")
            }
        }

        self.append_command(Cmd {
            face_mask: reference.face,
            reference: reference.value,
        });
    }

    /// Calls `vkCmdSetStencilWriteMask` on the builder.
    #[inline]
    pub unsafe fn set_stencil_write_mask(&mut self, write_mask: DynamicStencilValue) {

        struct Cmd {
            face_mask: StencilFaceFlags,
            write_mask: u32,
        }

        impl<P> Command<P> for Cmd {
            fn name(&self) -> &'static str {
                "vkCmdSetStencilWriteMask"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.set_stencil_write_mask(self.face_mask, self.write_mask);
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                Box::new("vkCmdSetStencilWriteMask")
            }
        }

        self.append_command(Cmd {
            face_mask: write_mask.face,
            write_mask: write_mask.value,
        });
    }

    /// Calls `vkCmdSetScissor` on the builder.
    ///
    /// If the list is empty then the command is automatically ignored.
    #[inline]
    pub unsafe fn set_scissor<I>(&mut self, first_scissor: u32, scissors: I)
        where I: Iterator<Item = Scissor> + Send + Sync + 'static
    {
        struct Cmd<I> {
            first_scissor: u32,
            scissors: Option<I>,
        }

        impl<P, I> Command<P> for Cmd<I>
            where I: Iterator<Item = Scissor>
        {
            fn name(&self) -> &'static str {
                "vkCmdSetScissor"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.set_scissor(self.first_scissor, self.scissors.take().unwrap());
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                Box::new("vkCmdSetScissor")
            }
        }

        self.append_command(Cmd {
            first_scissor,
            scissors: Some(scissors),
        });
    }

    /// Calls `vkCmdSetViewport` on the builder.
    ///
    /// If the list is empty then the command is automatically ignored.
    #[inline]
    pub unsafe fn set_viewport<I>(&mut self, first_viewport: u32, viewports: I)
        where I: Iterator<Item = Viewport> + Send + Sync + 'static
    {
        struct Cmd<I> {
            first_viewport: u32,
            viewports: Option<I>,
        }

        impl<P, I> Command<P> for Cmd<I>
            where I: Iterator<Item = Viewport>
        {
            fn name(&self) -> &'static str {
                "vkCmdSetViewport"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.set_viewport(self.first_viewport, self.viewports.take().unwrap());
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                Box::new("vkCmdSetViewport")
            }
        }

        self.append_command(Cmd {
                                first_viewport,
                                viewports: Some(viewports),
                            });
    }

    /// Calls `vkCmdUpdateBuffer` on the builder.
    #[inline]
    pub unsafe fn update_buffer<B, D>(&mut self, buffer: B, data: D)
        where B: BufferAccess + Send + Sync + 'static,
              D: Send + Sync + 'static
    {
        struct Cmd<B, D> {
            buffer: B,
            data: D,
        }

        impl<P, B, D> Command<P> for Cmd<B, D>
            where B: BufferAccess + Send + Sync + 'static,
                  D: Send + Sync + 'static
        {
            fn name(&self) -> &'static str {
                "vkCmdUpdateBuffer"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.update_buffer(&self.buffer, &self.data);
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                struct Fin<B>(B);
                impl<B> FinalCommand for Fin<B>
                    where B: BufferAccess + Send + Sync + 'static
                {
                    fn name(&self) -> &'static str {
                        "vkCmdUpdateBuffer"
                    }
                    fn buffer(&self, num: usize) -> &dyn BufferAccess {
                        assert_eq!(num, 0);
                        &self.0
                    }
                    fn buffer_name(&self, _: usize) -> Cow<'static, str> {
                        "destination".into()
                    }
                }
                Box::new(Fin(self.buffer))
            }

            fn buffer(&self, num: usize) -> &dyn BufferAccess {
                assert_eq!(num, 0);
                &self.buffer
            }

            fn buffer_name(&self, _: usize) -> Cow<'static, str> {
                "destination".into()
            }
        }

        self.append_command(Cmd { buffer, data });
        self.prev_cmd_resource(KeyTy::Buffer,
                               0,
                               true,
                               PipelineStages {
                                   transfer: true,
                                   ..PipelineStages::none()
                               },
                               AccessFlagBits {
                                   transfer_write: true,
                                   ..AccessFlagBits::none()
                               },
                               ImageLayout::Undefined,
                               ImageLayout::Undefined)
            .unwrap();
    }
}

pub struct SyncCommandBufferBuilderBindDescriptorSets<'b, P: 'b> {
    builder: &'b mut SyncCommandBufferBuilder<P>,
    inner: SmallVec<[Box<dyn DescriptorSet + Send + Sync>; 12]>,
}

impl<'b, P> SyncCommandBufferBuilderBindDescriptorSets<'b, P> {
    /// Adds a descriptor set to the list.
    #[inline]
    pub fn add<S>(&mut self, set: S)
        where S: DescriptorSet + Send + Sync + 'static
    {
        self.inner.push(Box::new(set));
    }

    #[inline]
    pub unsafe fn submit<Pl, I>(self, graphics: bool, pipeline_layout: Pl, first_binding: u32,
                                dynamic_offsets: I)
                                -> Result<(), SyncCommandBufferBuilderError>
        where Pl: PipelineLayoutAbstract + Send + Sync + 'static,
              I: Iterator<Item = u32> + Send + Sync + 'static
    {
        if self.inner.is_empty() {
            return Ok(());
        }

        struct Cmd<Pl, I> {
            inner: SmallVec<[Box<dyn DescriptorSet + Send + Sync>; 12]>,
            graphics: bool,
            pipeline_layout: Pl,
            first_binding: u32,
            dynamic_offsets: Option<I>,
        }

        impl<P, Pl, I> Command<P> for Cmd<Pl, I>
            where Pl: PipelineLayoutAbstract,
                  I: Iterator<Item = u32>
        {
            fn name(&self) -> &'static str {
                "vkCmdBindDescriptorSets"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.bind_descriptor_sets(self.graphics,
                                         &self.pipeline_layout,
                                         self.first_binding,
                                         self.inner.iter().map(|s| s.inner()),
                                         self.dynamic_offsets.take().unwrap());
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                struct Fin(SmallVec<[Box<dyn DescriptorSet + Send + Sync>; 12]>);
                impl FinalCommand for Fin {
                    fn name(&self) -> &'static str {
                        "vkCmdBindDescriptorSets"
                    }
                    fn buffer(&self, mut num: usize) -> &dyn BufferAccess {
                        for set in self.0.iter() {
                            if let Some(buf) = set.buffer(num) {
                                return buf.0;
                            }
                            num -= set.num_buffers();
                        }
                        panic!()
                    }
                    fn buffer_name(&self, mut num: usize) -> Cow<'static, str> {
                        for (set_num, set) in self.0.iter().enumerate() {
                            if let Some(buf) = set.buffer(num) {
                                return format!("Buffer bound to descriptor {} of set {}",
                                               buf.1,
                                               set_num)
                                    .into();
                            }
                            num -= set.num_buffers();
                        }
                        panic!()
                    }
                    fn image(&self, mut num: usize) -> &dyn ImageAccess {
                        for set in self.0.iter() {
                            if let Some(img) = set.image(num) {
                                return img.0.parent();
                            }
                            num -= set.num_images();
                        }
                        panic!()
                    }
                    fn image_name(&self, mut num: usize) -> Cow<'static, str> {
                        for (set_num, set) in self.0.iter().enumerate() {
                            if let Some(img) = set.image(num) {
                                return format!("Image bound to descriptor {} of set {}",
                                               img.1,
                                               set_num)
                                    .into();
                            }
                            num -= set.num_images();
                        }
                        panic!()
                    }
                }
                Box::new(Fin(self.inner))
            }

            fn buffer(&self, mut num: usize) -> &dyn BufferAccess {
                for set in self.inner.iter() {
                    if let Some(buf) = set.buffer(num) {
                        return buf.0;
                    }
                    num -= set.num_buffers();
                }
                panic!()
            }

            fn buffer_name(&self, mut num: usize) -> Cow<'static, str> {
                for (set_num, set) in self.inner.iter().enumerate() {
                    if let Some(buf) = set.buffer(num) {
                        return format!("Buffer bound to descriptor {} of set {}", buf.1, set_num)
                            .into();
                    }
                    num -= set.num_buffers();
                }
                panic!()
            }

            fn image(&self, mut num: usize) -> &dyn ImageAccess {
                for set in self.inner.iter() {
                    if let Some(img) = set.image(num) {
                        return img.0.parent();
                    }
                    num -= set.num_images();
                }
                panic!()
            }

            fn image_name(&self, mut num: usize) -> Cow<'static, str> {
                for (set_num, set) in self.inner.iter().enumerate() {
                    if let Some(img) = set.image(num) {
                        return format!("Image bound to descriptor {} of set {}", img.1, set_num)
                            .into();
                    }
                    num -= set.num_images();
                }
                panic!()
            }
        }

        let all_buffers = {
            let mut all_buffers = Vec::new();
            for ds in self.inner.iter() {
                for buf_num in 0 .. ds.num_buffers() {
                    let desc = ds.descriptor(ds.buffer(buf_num).unwrap().1 as usize)
                        .unwrap();
                    let write = !desc.readonly;
                    let (stages, access) = desc.pipeline_stages_and_access();
                    all_buffers.push((write, stages, access));
                }
            }
            all_buffers
        };

        let all_images = {
            let mut all_images = Vec::new();
            for ds in self.inner.iter() {
                for img_num in 0 .. ds.num_images() {
                    let (image_view, desc_num) = ds.image(img_num).unwrap();
                    let desc = ds.descriptor(desc_num as usize).unwrap();
                    let write = !desc.readonly;
                    let (stages, access) = desc.pipeline_stages_and_access();
                    let mut ignore_me_hack = false;
                    let layout = match desc.ty {
                        DescriptorDescTy::CombinedImageSampler(_) => {
                            image_view.descriptor_set_combined_image_sampler_layout()
                        },
                        DescriptorDescTy::Image(ref img) => {
                            if img.sampled {
                                image_view.descriptor_set_sampled_image_layout()
                            } else {
                                image_view.descriptor_set_storage_image_layout()
                            }
                        },
                        DescriptorDescTy::InputAttachment { .. } => {
                            // FIXME: This is tricky. Since we read from the input attachment
                            // and this input attachment is being written in an earlier pass,
                            // vulkano will think that it needs to put a pipeline barrier and will
                            // return a `Conflict` error. For now as a work-around we simply ignore
                            // input attachments.
                            ignore_me_hack = true;
                            image_view.descriptor_set_input_attachment_layout()
                        },
                        _ => panic!("Tried to bind an image to a non-image descriptor"),
                    };
                    all_images.push((write, stages, access, layout, ignore_me_hack));
                }
            }
            all_images
        };

        self.builder.append_command(Cmd {
                                        inner: self.inner,
                                        graphics,
                                        pipeline_layout,
                                        first_binding,
                                        dynamic_offsets: Some(dynamic_offsets),
                                    });

        for (n, (write, stages, access)) in all_buffers.into_iter().enumerate() {
            self.builder
                .prev_cmd_resource(KeyTy::Buffer,
                                   n,
                                   write,
                                   stages,
                                   access,
                                   ImageLayout::Undefined,
                                   ImageLayout::Undefined)?;
        }

        for (n, (write, stages, access, layout, ignore_me_hack)) in
            all_images.into_iter().enumerate()
        {
            if ignore_me_hack {
                continue;
            }
            self.builder
                .prev_cmd_resource(KeyTy::Image, n, write, stages, access, layout, layout)?;
        }

        Ok(())
    }
}

/// Prototype for a `vkCmdBindVertexBuffers`.
pub struct SyncCommandBufferBuilderBindVertexBuffer<'a, P: 'a> {
    builder: &'a mut SyncCommandBufferBuilder<P>,
    inner: UnsafeCommandBufferBuilderBindVertexBuffer,
    buffers: Vec<Box<dyn BufferAccess + Send + Sync>>,
}

impl<'a, P> SyncCommandBufferBuilderBindVertexBuffer<'a, P> {
    /// Adds a buffer to the list.
    #[inline]
    pub fn add<B>(&mut self, buffer: B)
        where B: BufferAccess + Send + Sync + 'static
    {
        self.inner.add(&buffer);
        self.buffers.push(Box::new(buffer));
    }

    #[inline]
    pub unsafe fn submit(self, first_binding: u32) -> Result<(), SyncCommandBufferBuilderError> {
        struct Cmd {
            first_binding: u32,
            inner: Option<UnsafeCommandBufferBuilderBindVertexBuffer>,
            buffers: Vec<Box<dyn BufferAccess + Send + Sync>>,
        }

        impl<P> Command<P> for Cmd {
            fn name(&self) -> &'static str {
                "vkCmdBindVertexBuffers"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.bind_vertex_buffers(self.first_binding, self.inner.take().unwrap());
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                struct Fin(Vec<Box<dyn BufferAccess + Send + Sync>>);
                impl FinalCommand for Fin {
                    fn name(&self) -> &'static str {
                        "vkCmdBindVertexBuffers"
                    }
                    fn buffer(&self, num: usize) -> &dyn BufferAccess {
                        &self.0[num]
                    }
                    fn buffer_name(&self, num: usize) -> Cow<'static, str> {
                        format!("Buffer #{}", num).into()
                    }
                }
                Box::new(Fin(self.buffers))
            }

            fn buffer(&self, num: usize) -> &dyn BufferAccess {
                &self.buffers[num]
            }

            fn buffer_name(&self, num: usize) -> Cow<'static, str> {
                format!("Buffer #{}", num).into()
            }
        }

        let num_buffers = self.buffers.len();

        self.builder.append_command(Cmd {
                                        first_binding,
                                        inner: Some(self.inner),
                                        buffers: self.buffers,
                                    });

        for n in 0 .. num_buffers {
            self.builder
                .prev_cmd_resource(KeyTy::Buffer,
                                   n,
                                   false,
                                   PipelineStages {
                                       vertex_input: true,
                                       ..PipelineStages::none()
                                   },
                                   AccessFlagBits {
                                       vertex_attribute_read: true,
                                       ..AccessFlagBits::none()
                                   },
                                   ImageLayout::Undefined,
                                   ImageLayout::Undefined)?;
        }

        Ok(())
    }
}

/// Prototype for a `vkCmdExecuteCommands`.
// FIXME: synchronization not implemented yet
pub struct SyncCommandBufferBuilderExecuteCommands<'a, P: 'a> {
    builder: &'a mut SyncCommandBufferBuilder<P>,
    inner: UnsafeCommandBufferBuilderExecuteCommands,
    command_buffers: Vec<Box<dyn Any + Send + Sync>>,
}

impl<'a, P> SyncCommandBufferBuilderExecuteCommands<'a, P> {
    /// Adds a command buffer to the list.
    #[inline]
    pub fn add<C>(&mut self, command_buffer: C)
        where C: CommandBuffer + Send + Sync + 'static
    {
        self.inner.add(&command_buffer);
        self.command_buffers
            .push(Box::new(command_buffer) as Box<_>);
    }

    #[inline]
    pub unsafe fn submit(self) -> Result<(), SyncCommandBufferBuilderError> {
        struct Cmd {
            inner: Option<UnsafeCommandBufferBuilderExecuteCommands>,
            command_buffers: Vec<Box<dyn Any + Send + Sync>>,
        }

        impl<P> Command<P> for Cmd {
            fn name(&self) -> &'static str {
                "vkCmdExecuteCommands"
            }

            unsafe fn send(&mut self, out: &mut UnsafeCommandBufferBuilder<P>) {
                out.execute_commands(self.inner.take().unwrap());
            }

            fn into_final_command(self: Box<Self>) -> Box<dyn FinalCommand + Send + Sync> {
                struct Fin(Vec<Box<dyn Any + Send + Sync>>);
                impl FinalCommand for Fin {
                    fn name(&self) -> &'static str {
                        "vkCmdExecuteCommands"
                    }
                }
                Box::new(Fin(self.command_buffers))
            }
        }

        self.builder.append_command(Cmd {
                                        inner: Some(self.inner),
                                        command_buffers: self.command_buffers,
                                    });
        Ok(())
    }
}