Vulkan: Implement Component Swizzling

Component swizzling is part of an image view and localized in the code.
With component swizzling a different channel (or 0 or 1) can be read
when the component is accessed.

Pull Request: https://projects.blender.org/blender/blender/pulls/112273

source/blender/gpu/vulkan/vk_common.cc

@@ -729,17 +729,27 @@ VkImageViewType to_vk_image_view_type(const eGPUTextureType type, const eImageVi
   return VK_IMAGE_VIEW_TYPE_1D;
 }
 
-VkComponentMapping to_vk_component_mapping(const eGPUTextureFormat /*format*/)
+VkComponentSwizzle to_vk_component_swizzle(const char swizzle)
 {
-  /* TODO: this should map to OpenGL defaults based on the eGPUTextureFormat. The
-   * implementation of this function will be implemented when implementing other parts of
-   * VKTexture. */
-  VkComponentMapping component_mapping;
-  component_mapping.r = VK_COMPONENT_SWIZZLE_R;
-  component_mapping.g = VK_COMPONENT_SWIZZLE_G;
-  component_mapping.b = VK_COMPONENT_SWIZZLE_B;
-  component_mapping.a = VK_COMPONENT_SWIZZLE_A;
-  return component_mapping;
+  switch (swizzle) {
+    case '0':
+      return VK_COMPONENT_SWIZZLE_ZERO;
+    case '1':
+      return VK_COMPONENT_SWIZZLE_ONE;
+    case 'r':
+      return VK_COMPONENT_SWIZZLE_R;
+    case 'g':
+      return VK_COMPONENT_SWIZZLE_G;
+    case 'b':
+      return VK_COMPONENT_SWIZZLE_B;
+    case 'a':
+      return VK_COMPONENT_SWIZZLE_A;
+
+    default:
+      break;
+  }
+  BLI_assert_unreachable();
+  return VK_COMPONENT_SWIZZLE_IDENTITY;
 }
 
 template<typename T> void copy_color(T dst[4], const T *src)

source/blender/gpu/vulkan/vk_common.hh

@@ -47,7 +47,7 @@ VkFormat to_vk_format(const GPUVertCompType type,
                       const GPUVertFetchMode fetch_mode);
 VkFormat to_vk_format(const shader::Type type);
 
-VkComponentMapping to_vk_component_mapping(const eGPUTextureFormat format);
+VkComponentSwizzle to_vk_component_swizzle(const char swizzle);
 VkImageViewType to_vk_image_view_type(const eGPUTextureType type, eImageViewUsage view_type);
 VkImageType to_vk_image_type(const eGPUTextureType type);
 VkClearColorValue to_vk_clear_color_value(const eGPUDataFormat format, const void *data);

source/blender/gpu/vulkan/vk_image_view.cc

@@ -34,7 +34,7 @@ VKImageView::VKImageView(VKTexture &texture,
   image_view_info.image = texture.vk_image_handle();
   image_view_info.viewType = to_vk_image_view_type(texture.type_get(), usage);
   image_view_info.format = to_vk_format(texture.format_get());
-  image_view_info.components = to_vk_component_mapping(texture.format_get());
+  image_view_info.components = texture.vk_component_mapping_get();
   image_view_info.subresourceRange.aspectMask = image_aspect;
   image_view_info.subresourceRange.baseMipLevel = mip_range.first();
   image_view_info.subresourceRange.levelCount = mip_range.size();

source/blender/gpu/vulkan/vk_texture.cc

@@ -172,9 +172,14 @@ void VKTexture::clear_depth_stencil(const eGPUFrameBufferBits buffers,
                        Span<VkImageSubresourceRange>(&range, 1));
 }
 
-void VKTexture::swizzle_set(const char /*swizzle_mask*/[4])
+void VKTexture::swizzle_set(const char swizzle_mask[4])
 {
-  NOT_YET_IMPLEMENTED;
+  vk_component_mapping_.r = to_vk_component_swizzle(swizzle_mask[0]);
+  vk_component_mapping_.g = to_vk_component_swizzle(swizzle_mask[1]);
+  vk_component_mapping_.b = to_vk_component_swizzle(swizzle_mask[2]);
+  vk_component_mapping_.a = to_vk_component_swizzle(swizzle_mask[3]);
+
+  flags_ |= IMAGE_VIEW_DIRTY;
 }
 
 void VKTexture::mip_range_set(int min, int max)

source/blender/gpu/vulkan/vk_texture.hh

@@ -36,6 +36,11 @@ class VKTexture : public Texture, public VKBindableResource {
   int layer_offset_ = 0;
   bool use_stencil_ = false;
 
+  VkComponentMapping vk_component_mapping_ = {VK_COMPONENT_SWIZZLE_IDENTITY,
+                                              VK_COMPONENT_SWIZZLE_IDENTITY,
+                                              VK_COMPONENT_SWIZZLE_IDENTITY,
+                                              VK_COMPONENT_SWIZZLE_IDENTITY};
+
   enum eDirtyFlags {
     IMAGE_VIEW_DIRTY = (1 << 0),
   };
@@ -164,6 +169,11 @@ class VKTexture : public Texture, public VKBindableResource {
     return *image_view_;
   }
 
+  const VkComponentMapping &vk_component_mapping_get() const
+  {
+    return vk_component_mapping_;
+  }
+
  private:
   IndexRange mip_map_range() const;
   IndexRange layer_range() const;