Textures were suprisingly trivial with the plane intersection code hashed out

include/Hardware_Caster.h

@@ -55,6 +55,10 @@ public:
 	void assign_camera(Camera *camera) override;
 	void validate() override;
 
+	// TODO: Hoist this to the base class
+	void create_texture_atlas(sf::Texture *t, sf::Vector2i tile_dim);
+
+
 	// draw will abstract the gl sharing and software rendering
 	// methods of retrieving the screen buffer
 	void compute() override;
@@ -74,7 +78,7 @@ private:
 
 	int check_cl_khr_gl_sharing();
 
-	int create_image_buffer(std::string buffer_name, cl_uint size, void* data);
+	int create_image_buffer(std::string buffer_name, cl_uint size, sf::Texture* texture);
 	int create_buffer(std::string buffer_name, cl_uint size, void* data);
 	int create_buffer(std::string buffer_name, cl_uint size, void* data, cl_mem_flags flags);
 	int store_buffer(cl_mem, std::string buffer_name);

kernels/ray_caster_kernel.cl

@@ -23,13 +23,13 @@ float4 white_light(float4 input, float3 light, int3 mask) {
 float4 view_light(float4 in_color, float3 light, float3 view, int3 mask) {
 
 	float diffuse = max(dot(normalize(convert_float3(mask)), normalize(light)), 0.0f);
-	in_color += diffuse * 0.5;
+	in_color += diffuse * 0.2;
 
 	if (dot(light, normalize(convert_float3(mask))) > 0.0)
 	{
 		float3 halfwayVector = normalize(normalize(light) + normalize(view));
 		float specTmp = max(dot(normalize(convert_float3(mask)), halfwayVector), 0.0f);
-		in_color += pow(specTmp, 1.0f) * 0.1;
+		in_color += pow(specTmp, 1.0f) * 0.5;
 	}
 
 	//in_color += 0.02;
@@ -134,7 +134,10 @@ __kernel void raycaster(
 		global float* lights,
 		global int* light_count,
         __write_only image2d_t image,
-		global int* seed_memory
+		global int* seed_memory,
+		__read_only image2d_t texture_atlas,
+		global int2 *atlas_dim,
+		global int2 *tile_dim
 ){
 
 	int global_id = get_global_id(0);
@@ -230,27 +233,23 @@ __kernel void raycaster(
 
 		if (voxel_data != 0) {
 
+			// Determine where on the 2d plane the ray intersected
 
-			if (voxel_data == 6) {
-				voxel_color = (float4)(0.0, 0.239, 0.419, 0.3);
-			} 
-			else if (voxel_data == 5) {
-				voxel_color = (float4)(0.25, 0.52, 0.30, 0.1);
-			}
-			else if (voxel_data == 1) {
-				voxel_color = (float4)(0.929, 0.957, 0.027, 0.7);
-			}
-
-			// set to which face
 			float3 face_position = (float)(0);
+			float2 texture_position = (float)(0);
 
 
+			// First determine the percent of the way the ray is towards the next intersection_t
+			// in relation to the xyz position on the plane
 			if (face_mask.x == -1) {
 
 				float z_percent = (intersection_t.z - (intersection_t.x - delta_t.x)) / delta_t.z;
 				float y_percent = (intersection_t.y - (intersection_t.x - delta_t.x)) / delta_t.y;
 
+				// Since we intersected face x, we know that we are at the face (1.0)
+				// Not entirely sure what is causing the 1.0 vs 1.001 rendering bug
 				face_position = (float3)(1.001f, y_percent, z_percent);
+				texture_position = (float2)(y_percent, z_percent);
 			}
 			else if (face_mask.y == -1) {
 
@@ -258,7 +257,7 @@ __kernel void raycaster(
 				float z_percent = (intersection_t.z - (intersection_t.y - delta_t.y)) / delta_t.z;
 
 				face_position = (float3)(x_percent, 1.001f, z_percent);
-
+				texture_position = (float2)(x_percent, z_percent);
 			}
 
 			else if (face_mask.z == -1) {
@@ -267,28 +266,55 @@ __kernel void raycaster(
 				float y_percent = (intersection_t.y - (intersection_t.z - delta_t.z)) / delta_t.y;
 				
 				face_position = (float3)(x_percent, y_percent, 1.001f);
+				texture_position = (float2)(x_percent, y_percent);
 
 			}
 
+			// We now need to account for the ray wanting to skip the axis in which
+			// it flips its sign
 
-			if (ray_dir.x > 0)
-				face_position.x =  - face_position.x + 1;
+			// TODO: improve this
 
-			if (ray_dir.x < 0)
-				face_position.x = face_position.x + 0;
+			if (ray_dir.x > 0) {
+				face_position.x = -face_position.x + 1;
+				texture_position.x = -texture_position.x + 1.0;
+			}
+			//if (ray_dir.x < 0)
+			//	face_position.x = face_position.x + 0;
 
-			if (ray_dir.y > 0)
+			if (ray_dir.y > 0){
 				face_position.y =  - face_position.y + 1;
+				texture_position.y = -texture_position.y + 1.0;
+			}
 
-			if (ray_dir.y < 0)
-				face_position.y = face_position.y + 0;
+			//if (ray_dir.y < 0)
+			//	face_position.y = face_position.y + 0;
 
-			if (ray_dir.z > 0)
+			if (ray_dir.z > 0) {
 				face_position.z =  - face_position.z + 1;
+				texture_position.y = -texture_position.y + 1.0;
+			}
+
+			//if (ray_dir.z < 0)
+			//	face_position.z = face_position.z + 0;
+
 
-			if (ray_dir.z < 0)
-				face_position.z = face_position.z + 0;
+			// Now either use the face position to retrieve a texture sample, or
+			// just a plain color for the voxel color
+
+			if (voxel_data == 6) {
+				voxel_color = (float4)(0.0, 0.239, 0.419, 0.3);
+			}
+			else if (voxel_data == 5) {
+				float2 tile_size = convert_float2(*atlas_dim / *tile_dim);
+				voxel_color = read_imagef(texture_atlas, convert_int2(texture_position * tile_size) + convert_int2((float2)(3, 0) * tile_size));
+					//voxel_color = (float4)(0.25, 0.52, 0.30, 0.1);
+			}
+			else if (voxel_data == 1) {
+				voxel_color = (float4)(0.929, 0.957, 0.027, 0.7);
+			}
 
+			// 
 
 			if (cast_light_intersection_ray(
 				map,

src/Hardware_Caster.cpp

@@ -87,6 +87,9 @@ void Hardware_Caster::validate()
 		set_kernel_arg("raycaster", 7, "light_count");
 		set_kernel_arg("raycaster", 8, "image");
 		set_kernel_arg("raycaster", 9, "seed");
+		set_kernel_arg("raycaster", 10, "texture_atlas");
+		set_kernel_arg("raycaster", 11, "atlas_dim");
+		set_kernel_arg("raycaster", 12, "tile_dim");
 
 		//print_kernel_arguments();
 	}
@@ -94,6 +97,18 @@ void Hardware_Caster::validate()
 	
 }
 
+void Hardware_Caster::create_texture_atlas(sf::Texture *t, sf::Vector2i tile_dim) {
+	
+	create_image_buffer("texture_atlas", t->getSize().x * t->getSize().x * 4 * sizeof(float), t);
+	
+	// create_buffer observes arg 3's
+	
+	sf::Vector2u v = t->getSize();
+	create_buffer("atlas_dim", sizeof(sf::Vector2u) , &v);
+
+	create_buffer("tile_dim", sizeof(sf::Vector2i), &tile_dim);
+}
+
 void Hardware_Caster::compute()
 {
 	// correlating work size with texture size? good, bad?
@@ -177,7 +192,7 @@ void Hardware_Caster::create_viewport(int width, int height, float v_fov, float
 	viewport_sprite.setTexture(viewport_texture);
 
 	// Pass the buffer to opencl
-	create_image_buffer("image", sizeof(sf::Uint8) * width * height * 4, viewport_image);
+	create_image_buffer("image", sizeof(sf::Uint8) * width * height * 4, &viewport_texture);
 
 }
 
@@ -511,7 +526,7 @@ int Hardware_Caster::set_kernel_arg(
 
 }
 
-int Hardware_Caster::create_image_buffer(std::string buffer_name, cl_uint size, void* data) {
+int Hardware_Caster::create_image_buffer(std::string buffer_name, cl_uint size, sf::Texture* texture) {
 
 	// I can imagine overwriting buffers will be common, so I think
 	// this is safe to overwrite / release old buffers quietly
@@ -522,7 +537,7 @@ int Hardware_Caster::create_image_buffer(std::string buffer_name, cl_uint size,
 	int error;
 	cl_mem buff = clCreateFromGLTexture(
 		getContext(), CL_MEM_WRITE_ONLY, GL_TEXTURE_2D,
-		0, viewport_texture.getNativeHandle(), &error);
+		0, texture->getNativeHandle(), &error);
 
 	if (assert(error, "clCreateFromGLTexture"))
 		return OPENCL_ERROR;

src/main.cpp

@@ -124,10 +124,17 @@ int main() {
 	// *links* the lights to the GPU
 	raycaster->assign_lights(&light_vec);
 
-	// Checks to see if proper data was uploaded, then sets the kernel args
-	raycaster->validate();
+
+	// Load in the spritesheet texture
+	sf::Texture spritesheet;
+	spritesheet.loadFromFile("../assets/textures/minecraft_tiles.png");
+	spritesheet.getNativeHandle();
+	raycaster->create_texture_atlas(&spritesheet, sf::Vector2i(16, 16));
 
 
+	// Checks to see if proper data was uploaded, then sets the kernel args
+	// ALL DATA LOADING MUST BE FINISHED
+	raycaster->validate();
 
 	// ========== DEBUG ==========
     fps_counter fps;