Module vulkano::pipeline::multisample

State of multisampling.

Multisampling allows you to ask the GPU to run the rasterizer to generate more than one sample per pixel.

For example, if rasterization_samples is 1 then the fragment shader, depth test and stencil test will be run once for each pixel. However if rasterization_samples is n, then the GPU will pick n different locations within each pixel and assign to each of these locations a different depth value. Depth and stencil test will then be run n times.

In addition to this, the sample_shading parameter is the proportion (between 0.0 and 1.0) or the samples that will be run through the fragment shader. For example if you set this to 1.0, then all the sub-pixel samples will run through the shader and get a different value. If you set this to 0.5, about half of the samples will run through the shader and the other half will get their values from the ones which went through the shader.

If alpha_to_coverage is true, then the alpha value of the fragment will be used in an implementation-defined way to determine which samples get disabled or not. For example if the alpha value is 0.5, then about half of the samples will be discarded. If you render to a multisample image, this means that the color will end up being mixed with whatever color was underneath, which gives the same effect as alpha blending.

If alpha_to_one is true, the alpha value of all the samples will be forced to 1.0 (or the maximum possible value) after the effects of alpha_to_coverage have been applied.

Structs

Multisample

Deprecated State of the multisampling.