CopyImageTexelToBuffer()

void Spices::VulkanImage::CopyImageTexelToBuffer	(	uint32_t	x,
		uint32_t	y,
		void *	out_rgba )

@breif Copy one texel data from a VkImage.

Parameters

[in]	x	The sampled position x.
[in]	y	The sampled position y.
[in]	out_rgba	The sampled data.

Todo

Support all type;

The temp buffer image date copy to.

Instance a VkBufferImageCopy.

Use Custom Cmd.

Write data to stagingbuffer.

Todo

Support all type;

The temp buffer image date copy to.

Instance a VkBufferImageCopy.

Use Custom Cmd.

Write data to stagingbuffer.

Definition at line 436 of file VulkanImage.cpp.

    {
        SPICES_PROFILE_ZONE;
 
        uint32_t channelize = 4;
 
        switch (m_Format)
        {
        case VK_FORMAT_B8G8R8A8_UNORM:           // 4 bytes.
            channelize = 4;                  
            break;                               
        case VK_FORMAT_R32_SFLOAT:               // 4 bytes.
            channelize = 4;
            break;
        case VK_FORMAT_R32G32B32A32_SFLOAT:      // 16 bytes.
            channelize = 16;
            break;
        default:
            break;
        }
 
        VulkanBuffer stagingBuffer(
            m_VulkanState, 
            "StagingBuffer",
            channelize,
            VK_BUFFER_USAGE_TRANSFER_DST_BIT,
            VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT
        );
 
        /*
        * @brief Transfer image layout from whatever to transfer src.
        */
        TransitionImageLayout(
            m_Format,
            VK_IMAGE_LAYOUT_UNDEFINED,
            VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL
        );
 
        VkBufferImageCopy                        region{};
        region.bufferOffset                    = 0;
        region.bufferRowLength                 = 0;
        region.bufferImageHeight               = 0;
 
        region.imageSubresource.aspectMask     = VK_IMAGE_ASPECT_COLOR_BIT;
        region.imageSubresource.mipLevel       = 0;
        region.imageSubresource.baseArrayLayer = 0;
        region.imageSubresource.layerCount     = m_Layers;
 
        region.imageOffset.x                   = static_cast<int32_t>(x);
        region.imageOffset.y                   = static_cast<int32_t>(y);
        region.imageExtent                     = { 1, 1, 1 };
 
        VulkanCommandBuffer::CustomGraphicCmd(m_VulkanState, [&](const VkCommandBuffer& commandBuffer) {
            vkCmdCopyImageToBuffer(commandBuffer, m_Image, VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL, stagingBuffer.Get(), 1, &region);
        });
 
        /*
        * @brief Transfer image layout from transfer src to shader read.
        * means only can get data from a shader read layout image.
        * @note In SpicesEngine, we need transform layout to shader read in scene compose renderer first,
        * and after that, you can do this here.
        */
        TransitionImageLayout(
            m_Format,
            VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL,
            VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL
        );
 
        stagingBuffer.WriteFromBuffer(out_rgba);
    }

References Spices::VulkanObject::m_VulkanState.