[vulkan] Render object id to a buffer

Currently the instance id is written (with the idea that it can be
mapped back to entity in C). The plan is to use it for mouse picking.

libs/video/renderer/vulkan/device.c

@@ -155,6 +155,7 @@ QFV_CreateDevice (vulkan_ctx_t *ctx, const char **extensions)
 			.multiviewGeometryShader = 1,
 		};
 		VkPhysicalDeviceFeatures features = {
+			.independentBlend = 1,
 			.geometryShader = 1,
 			.multiViewport = 1,
 			.fragmentStoresAndAtomics = 1,

libs/video/renderer/vulkan/rp_main_def.plist

@@ -1012,6 +1012,11 @@ images = {
 		usage = color_attachment|input_attachment|sampled;
 		format = $render_output.format;
 	};
+
+	entid = {
+		@inherit = $image_base;
+		format = r32_uint;
+	}
 };
 imageviews = {
 	depth = {
@@ -1091,6 +1096,11 @@ imageviews = {
 		image = cube_output;
 		format = $render_output.format;
 	};
+
+	entid = {
+		@inherit = $view_base;
+		image = entid;
+	};
 };
 output = {
 	view = $output;
@@ -1499,7 +1509,7 @@ renderpasses = {
 						);
 						layout = $compose.layout;
 					};
-/*					debug = {
+					/*debug = {
 						@inherit = $compose_base;
 
 						color = $color.lights;
@@ -1594,6 +1604,16 @@ renderpasses = {
 			layers = 1;
 			attachments = {
 				output = $swapchain;
+				entid = {
+					@inherit = $attachment_base;
+					format = $images.entid.format;
+					loadOp = clear;
+					storeOp = store;
+					clearValue = {
+						color = { int32 = (-1, -1, -1, -1); };
+					};
+					view = entid;
+				};
 			};
 		};
 		subpasses = {
@@ -1652,6 +1672,26 @@ renderpasses = {
 						);
 						layout = $fisheye.layout;
 					};
+				};
+			};
+			slice = {
+				color = $color.slice;
+				dependencies = {
+					compose = $color_dependency;
+				};
+				attachments = {
+					color = {
+						output = {
+							layout = color_attachment_optimal;
+							blend = $alpha_blend;
+						};
+						entid = {
+							layout = color_attachment_optimal;
+							blend = $blend_disable;
+						};
+					};
+				};
+				pipelines = {
 					slice = {
 						@inherit = $compose_base;
 
@@ -1668,7 +1708,7 @@ renderpasses = {
 						inputAssembly = $slice.inputAssembly;
 						layout = $slice.layout;
 					};
-					lines = {
+					/*lines = {
 						@inherit = $compose_base;
 
 						color = $color.lines;
@@ -1683,7 +1723,7 @@ renderpasses = {
 						vertexInput = $lines.vertexInput;
 						inputAssembly = $lines.inputAssembly;
 						layout = $lines.layout;
-					};
+					};*/
 				};
 			};
 		};

libs/video/renderer/vulkan/shader/slice.vert

@@ -17,6 +17,7 @@ layout (location = 3) in vec2 glyph_offset;	// for 9-slice
 
 layout (location = 0) out vec2 uv;
 layout (location = 1) out vec4 color;
+layout (location = 2) out uint id;
 
 void
 main (void)
@@ -29,4 +30,5 @@ main (void)
 	// texture uv stored in glyph components 2 and 3
 	uv = glyph.pq;
 	color = glyph_color;
+	id = gl_InstanceIndex;
 }

libs/video/renderer/vulkan/shader/twod.frag

@@ -4,8 +4,10 @@ layout (set = 1, binding = 0) uniform sampler2D Texture;
 
 layout (location = 0) in vec2 st;
 layout (location = 1) in vec4 color;
+layout (location = 2) in flat uint id;
 
 layout (location = 0) out vec4 frag_color;
+layout (location = 1) out uint entid;
 
 void
 main (void)
@@ -14,4 +16,5 @@ main (void)
 
 	pix = texture (Texture, st);
 	frag_color = pix * color;
+	entid = id;
 }