#include "Vulkan.h"

#include <sstream>


namespace love {
	namespace graphics {
		namespace vulkan {
			static uint32_t numShaderSwitches;

			void Vulkan::shaderSwitch() {
				numShaderSwitches++;
			}

			uint32_t Vulkan::getNumShaderSwitches() {
				return numShaderSwitches;
			}
			
			void Vulkan::resetShaderSwitches() {
				numShaderSwitches = 0;
			}

			VkFormat Vulkan::getVulkanVertexFormat(DataFormat format) {
				switch (format) {
				case DATAFORMAT_FLOAT:
					return VK_FORMAT_R32_SFLOAT;
				case DATAFORMAT_FLOAT_VEC2:
					return VK_FORMAT_R32G32_SFLOAT;
				case DATAFORMAT_FLOAT_VEC3:
					return VK_FORMAT_R32G32B32_SFLOAT;
				case DATAFORMAT_FLOAT_VEC4:
					return VK_FORMAT_R32G32B32A32_SFLOAT;

				case DATAFORMAT_FLOAT_MAT2X2:
				case DATAFORMAT_FLOAT_MAT2X3:
				case DATAFORMAT_FLOAT_MAT2X4:
				case DATAFORMAT_FLOAT_MAT3X2:
				case DATAFORMAT_FLOAT_MAT3X3:
				case DATAFORMAT_FLOAT_MAT3X4:
				case DATAFORMAT_FLOAT_MAT4X2:
				case DATAFORMAT_FLOAT_MAT4X3:
				case DATAFORMAT_FLOAT_MAT4X4:
					throw love::Exception("unimplemented data format (matnxm)");

				case DATAFORMAT_INT32:
					return VK_FORMAT_R32_SINT;
				case DATAFORMAT_INT32_VEC2:
					return VK_FORMAT_R32G32_SINT;
				case DATAFORMAT_INT32_VEC3:
					return VK_FORMAT_R32G32B32_SINT;
				case DATAFORMAT_INT32_VEC4:
					return VK_FORMAT_R32G32B32A32_SINT;

				case DATAFORMAT_UINT32:
					return VK_FORMAT_R32_UINT;
				case DATAFORMAT_UINT32_VEC2:
					return VK_FORMAT_R32G32_UINT;
				case DATAFORMAT_UINT32_VEC3:
					return VK_FORMAT_R32G32B32_UINT;
				case DATAFORMAT_UINT32_VEC4:
					return VK_FORMAT_R32G32B32A32_UINT;

				case DATAFORMAT_SNORM8_VEC4:
					return VK_FORMAT_R8G8B8A8_SNORM;
				case DATAFORMAT_UNORM8_VEC4:
					return VK_FORMAT_R8G8B8A8_UNORM;
				case DATAFORMAT_INT8_VEC4:
					return VK_FORMAT_R8G8B8A8_SINT;
				case DATAFORMAT_UINT8_VEC4:
					return VK_FORMAT_R8G8B8A8_UINT;

				case DATAFORMAT_SNORM16_VEC2:
					return VK_FORMAT_R16G16_SNORM;
				case DATAFORMAT_SNORM16_VEC4:
					return VK_FORMAT_R16G16B16A16_SNORM;
				case DATAFORMAT_UNORM16_VEC2:
					return VK_FORMAT_R16G16_UNORM;
				case DATAFORMAT_UNORM16_VEC4:
					return VK_FORMAT_R16G16B16A16_UNORM;

				case DATAFORMAT_INT16_VEC2:
					return VK_FORMAT_R16G16_SINT;
				case DATAFORMAT_INT16_VEC4:
					return VK_FORMAT_R16G16B16A16_SINT;

				case DATAFORMAT_UINT16:
					return VK_FORMAT_R16_UINT;
				case DATAFORMAT_UINT16_VEC2:
					return VK_FORMAT_R16G16_UINT;
				case DATAFORMAT_UINT16_VEC4:
					return VK_FORMAT_R16G16B16A16_UINT;

				case DATAFORMAT_BOOL:
				case DATAFORMAT_BOOL_VEC2:
				case DATAFORMAT_BOOL_VEC3:
				case DATAFORMAT_BOOL_VEC4:
					throw love::Exception("unimplemented data format (bool)");

				default:
					throw love::Exception("unknown data format");
				}
			}

			TextureFormat Vulkan::getTextureFormat(PixelFormat format) {
				TextureFormat textureFormat{};

				switch (format) {
					case PIXELFORMAT_UNKNOWN:
						throw love::Exception("unknown pixel format");
					case PIXELFORMAT_NORMAL:
						textureFormat.internalFormat = VK_FORMAT_R8G8B8A8_SRGB;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_FLOAT;
						break;
					case PIXELFORMAT_HDR:
						throw love::Exception("unimplemented pixel format: hdr");
					case PIXELFORMAT_R8_UNORM:
						textureFormat.internalFormat = VK_FORMAT_R8_UNORM;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_FLOAT;
						break;
					case PIXELFORMAT_R8_INT:
						textureFormat.internalFormat = VK_FORMAT_R8_SINT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_SINT;
						break;
					case PIXELFORMAT_R8_UINT:
						textureFormat.internalFormat = VK_FORMAT_R8_UINT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_UINT;
						break;
					case PIXELFORMAT_R16_UNORM:
						textureFormat.internalFormat = VK_FORMAT_R16_UNORM;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_FLOAT;
						break;
					case PIXELFORMAT_R16_FLOAT:
						textureFormat.internalFormat = VK_FORMAT_R16_SFLOAT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_FLOAT;
						break;
					case PIXELFORMAT_R16_INT:
						textureFormat.internalFormat = VK_FORMAT_R16_SINT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_SINT;
						break;
					case PIXELFORMAT_R16_UINT:
						textureFormat.internalFormat = VK_FORMAT_R16_UINT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_UINT;
						break;
					case PIXELFORMAT_R32_FLOAT:
						textureFormat.internalFormat = VK_FORMAT_R32_SFLOAT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_FLOAT;
						break;
					case PIXELFORMAT_R32_INT:
						textureFormat.internalFormat = VK_FORMAT_R32_SINT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_SINT;
						break;
					case PIXELFORMAT_R32_UINT:
						textureFormat.internalFormat = VK_FORMAT_R32_UINT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_UINT;
						break;
					case PIXELFORMAT_RG8_UNORM:
						textureFormat.internalFormat = VK_FORMAT_R8G8_UNORM;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_FLOAT;
						break;
					case PIXELFORMAT_RG8_INT:
						textureFormat.internalFormat = VK_FORMAT_R8G8_SINT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_SINT;
						break;
					case PIXELFORMAT_RG8_UINT:
						textureFormat.internalFormat = VK_FORMAT_R8G8_UINT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_UINT;
						break;
					case PIXELFORMAT_LA8_UNORM: // Same as RG8: but accessed as (L: L: L: A)
						textureFormat.internalFormat = VK_FORMAT_R8G8_UNORM;
						textureFormat.swizzleR = VK_COMPONENT_SWIZZLE_R;
						textureFormat.swizzleG = VK_COMPONENT_SWIZZLE_R;
						textureFormat.swizzleB = VK_COMPONENT_SWIZZLE_R;
						textureFormat.swizzleA = VK_COMPONENT_SWIZZLE_G;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_FLOAT;
						break;
					case PIXELFORMAT_RG16_UNORM:
						textureFormat.internalFormat = VK_FORMAT_R16G16_UNORM;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_FLOAT;
						break;
					case PIXELFORMAT_RG16_FLOAT:
						textureFormat.internalFormat = VK_FORMAT_R16G16_SFLOAT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_FLOAT;
						break;
					case PIXELFORMAT_RG16_INT:
						textureFormat.internalFormat = VK_FORMAT_R16G16_SINT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_SINT;
						break;
					case PIXELFORMAT_RG16_UINT:
						textureFormat.internalFormat = VK_FORMAT_R16G16_UINT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_UINT;
						break;
					case PIXELFORMAT_RG32_FLOAT:
						textureFormat.internalFormat = VK_FORMAT_R32G32_SFLOAT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_FLOAT;
						break;
					case PIXELFORMAT_RG32_INT:
						textureFormat.internalFormat = VK_FORMAT_R32G32_SINT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_SINT;
						break;
					case PIXELFORMAT_RG32_UINT:
						textureFormat.internalFormat = VK_FORMAT_R32G32_UINT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_UINT;
						break;
					case PIXELFORMAT_RGBA8_UNORM:
						textureFormat.internalFormat = VK_FORMAT_R8G8B8A8_UNORM;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_FLOAT;
						break;
					case PIXELFORMAT_RGBA8_UNORM_sRGB:
						textureFormat.internalFormat = VK_FORMAT_R8G8B8A8_SRGB;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_FLOAT;
						break;
					case PIXELFORMAT_BGRA8_UNORM:
						textureFormat.internalFormat = VK_FORMAT_B8G8R8A8_UNORM;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_FLOAT;
						break;
					case PIXELFORMAT_BGRA8_UNORM_sRGB:
						textureFormat.internalFormat = VK_FORMAT_B8G8R8A8_SRGB;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_FLOAT;
						break;
					case PIXELFORMAT_RGBA8_INT:
						textureFormat.internalFormat = VK_FORMAT_R8G8B8A8_SINT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_SINT;
						break;
					case PIXELFORMAT_RGBA8_UINT:
						textureFormat.internalFormat = VK_FORMAT_R8G8B8A8_UINT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_UINT;
						break;
					case PIXELFORMAT_RGBA16_UNORM:
						textureFormat.internalFormat = VK_FORMAT_R16G16B16A16_UNORM;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_FLOAT;
						break;
					case PIXELFORMAT_RGBA16_FLOAT:
						textureFormat.internalFormat = VK_FORMAT_R16G16B16A16_SFLOAT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_FLOAT;
						break;
					case PIXELFORMAT_RGBA16_INT:
						textureFormat.internalFormat = VK_FORMAT_R16G16B16A16_SINT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_SINT;
						break;
					case PIXELFORMAT_RGBA16_UINT:
						textureFormat.internalFormat = VK_FORMAT_R16G16B16A16_UINT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_UINT;
						break;
					case PIXELFORMAT_RGBA32_FLOAT:
						textureFormat.internalFormat = VK_FORMAT_R32G32B32A32_SFLOAT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_FLOAT;
						break;
					case PIXELFORMAT_RGBA32_INT:
						textureFormat.internalFormat = VK_FORMAT_R32G32B32A32_SINT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_SINT;
						break;
					case PIXELFORMAT_RGBA32_UINT:
						textureFormat.internalFormat = VK_FORMAT_R32G32B32A32_UINT;
						textureFormat.internalFormatRepresentation = FORMATREPRESENTATION_UINT;
						break;
					case PIXELFORMAT_RGBA4_UNORM:    // LSB->MSB: [a: b: g: r]
					case PIXELFORMAT_RGB5A1_UNORM:   // LSB->MSB: [a: b: g: r]
					case PIXELFORMAT_RGB565_UNORM:   // LSB->MSB: [b: g: r]
					case PIXELFORMAT_RGB10A2_UNORM:  // LSB->MSB: [r: g: b: a]
					case PIXELFORMAT_RG11B10_FLOAT:  // LSB->MSB: [r: g: b]
					case PIXELFORMAT_STENCIL8:
					case PIXELFORMAT_DEPTH16_UNORM:
					case PIXELFORMAT_DEPTH24_UNORM:
					case PIXELFORMAT_DEPTH32_FLOAT:
					case PIXELFORMAT_DEPTH24_UNORM_STENCIL8:
					case PIXELFORMAT_DEPTH32_FLOAT_STENCIL8:
					case PIXELFORMAT_DXT1_UNORM:
					case PIXELFORMAT_DXT3_UNORM:
					case PIXELFORMAT_DXT5_UNORM:
					case PIXELFORMAT_BC4_UNORM:
					case PIXELFORMAT_BC4_SNORM:
					case PIXELFORMAT_BC5_UNORM:
					case PIXELFORMAT_BC5_SNORM:
					case PIXELFORMAT_BC6H_UFLOAT:
					case PIXELFORMAT_BC6H_FLOAT:
					case PIXELFORMAT_BC7_UNORM:
					case PIXELFORMAT_PVR1_RGB2_UNORM:
					case PIXELFORMAT_PVR1_RGB4_UNORM:
					case PIXELFORMAT_PVR1_RGBA2_UNORM:
					case PIXELFORMAT_PVR1_RGBA4_UNORM:
					case PIXELFORMAT_ETC1_UNORM:
					case PIXELFORMAT_ETC2_RGB_UNORM:
					case PIXELFORMAT_ETC2_RGBA_UNORM:
					case PIXELFORMAT_ETC2_RGBA1_UNORM:
					case PIXELFORMAT_EAC_R_UNORM:
					case PIXELFORMAT_EAC_R_SNORM:
					case PIXELFORMAT_EAC_RG_UNORM:
					case PIXELFORMAT_EAC_RG_SNORM:
					case PIXELFORMAT_ASTC_4x4:
					case PIXELFORMAT_ASTC_5x4:
					case PIXELFORMAT_ASTC_5x5:
					case PIXELFORMAT_ASTC_6x5:
					case PIXELFORMAT_ASTC_6x6:
					case PIXELFORMAT_ASTC_8x5:
					case PIXELFORMAT_ASTC_8x6:
					case PIXELFORMAT_ASTC_8x8:
					case PIXELFORMAT_ASTC_10x5:
					case PIXELFORMAT_ASTC_10x6:
					case PIXELFORMAT_ASTC_10x8:
					case PIXELFORMAT_ASTC_10x10:
					case PIXELFORMAT_ASTC_12x10:
					case PIXELFORMAT_ASTC_12x12:
						throw love::Exception("unimplemented pixel format");
				}

				return textureFormat;
			}

			// values taken from https://pcisig.com/membership/member-companies
			// as specified at https://www.khronos.org/registry/vulkan/specs/1.3-extensions/man/html/VkPhysicalDeviceProperties.html
			std::string Vulkan::getVendorName(uint32_t vendorId) {
				switch (vendorId) {
				case 4130:
					return "AMD";
				case 4318:
					return "Nvidia";
				case 8086:
					return "Intel";
				case 4203:
					return "Apple";
				case 5140:
					return "Microsoft";
				case 5045:
					return "ARM";
				case 20803:
					return "Qualcomm";
				case 5348:
					return "Broadcom";
				default:
					return "unknown";
				}
			}

			std::string Vulkan::getVulkanApiVersion(uint32_t version) {
				std::stringstream ss;

				ss << VK_API_VERSION_MAJOR(version) 
				   << "." << VK_API_VERSION_MINOR(version) 
				   << "." << VK_API_VERSION_PATCH(version);

				return ss.str();
			}

			VkPrimitiveTopology Vulkan::getPrimitiveTypeTopology(graphics::PrimitiveType primitiveType) {
				switch (primitiveType) {
				case PRIMITIVE_POINTS:
					return VK_PRIMITIVE_TOPOLOGY_POINT_LIST;
				case PRIMITIVE_TRIANGLES:
					return VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST;
				case PRIMITIVE_TRIANGLE_FAN:
					return VK_PRIMITIVE_TOPOLOGY_TRIANGLE_FAN;
				case PRIMITIVE_TRIANGLE_STRIP:
					return VK_PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP;
				default:
					throw love::Exception("unknown primitive type");
				}
			}

			VkBlendFactor Vulkan::getBlendFactor(BlendFactor blendFactor) {
				switch (blendFactor) {
				case BLENDFACTOR_ZERO:
					return VK_BLEND_FACTOR_ZERO;
				case BLENDFACTOR_ONE:
					return VK_BLEND_FACTOR_ONE;
				case BLENDFACTOR_SRC_COLOR:
					return VK_BLEND_FACTOR_SRC_COLOR;
				case BLENDFACTOR_ONE_MINUS_SRC_COLOR:
					return VK_BLEND_FACTOR_ONE_MINUS_SRC_COLOR;
				case BLENDFACTOR_SRC_ALPHA:
					return VK_BLEND_FACTOR_SRC_ALPHA;
				case BLENDFACTOR_ONE_MINUS_SRC_ALPHA:
					return VK_BLEND_FACTOR_ONE_MINUS_SRC_ALPHA;
				case BLENDFACTOR_DST_COLOR:
					return VK_BLEND_FACTOR_DST_COLOR;
				case BLENDFACTOR_ONE_MINUS_DST_COLOR:
					return VK_BLEND_FACTOR_ONE_MINUS_DST_COLOR;
				case BLENDFACTOR_DST_ALPHA:
					return VK_BLEND_FACTOR_DST_ALPHA;
				case BLENDFACTOR_ONE_MINUS_DST_ALPHA:
					return VK_BLEND_FACTOR_ONE_MINUS_DST_ALPHA;
				case BLENDFACTOR_SRC_ALPHA_SATURATED:
					return VK_BLEND_FACTOR_SRC_ALPHA_SATURATE;
				default:
					throw love::Exception("unknown blend factor");
				}
			}

			VkBlendOp Vulkan::getBlendOp(BlendOperation op) {
				switch (op) {
				case BLENDOP_ADD:
					return VK_BLEND_OP_ADD;
				case BLENDOP_MAX:
					return VK_BLEND_OP_MAX;
				case BLENDOP_MIN:
					return VK_BLEND_OP_MIN;
				case BLENDOP_SUBTRACT:
					return VK_BLEND_OP_SUBTRACT;
				case BLENDOP_REVERSE_SUBTRACT:
					return VK_BLEND_OP_REVERSE_SUBTRACT;
				default:
					throw love::Exception("unknown blend operation");
				}
			}

			VkBool32 Vulkan::getBool(bool b) {
				if (b) {
					return VK_TRUE;
				} else {
					return VK_FALSE;
				}
			}

			VkColorComponentFlags Vulkan::getColorMask(ColorChannelMask mask) {
				VkColorComponentFlags flags = 0;

				if (mask.r) {
					flags |= VK_COLOR_COMPONENT_R_BIT;
				}
				if (mask.g) {
					flags |= VK_COLOR_COMPONENT_G_BIT;
				}
				if (mask.b) {
					flags |= VK_COLOR_COMPONENT_B_BIT;
				}
				if (mask.a) {
					flags |= VK_COLOR_COMPONENT_A_BIT;
				}

				return flags;
			}

			VkFrontFace Vulkan::getFrontFace(Winding winding) {
				switch (winding) {
				case WINDING_CW:
					return VK_FRONT_FACE_CLOCKWISE;
				case WINDING_CCW:
					return VK_FRONT_FACE_COUNTER_CLOCKWISE;
				default:
					throw love::Exception("unknown winding");
				}
			}

			VkCullModeFlags Vulkan::getCullMode(CullMode cullmode) {
				switch (cullmode) {
				case CULL_BACK:
					return VK_CULL_MODE_BACK_BIT;
				case CULL_FRONT:
					return VK_CULL_MODE_FRONT_BIT;
				case CULL_NONE:
					return VK_CULL_MODE_NONE;
				default:
					throw love::Exception("unknown cull mode");
				}
			}

			void Vulkan::cmdTransitionImageLayout(VkCommandBuffer commandBuffer, VkImage image, VkImageLayout oldLayout, VkImageLayout newLayout) {
				VkImageMemoryBarrier barrier{};
				barrier.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
				barrier.oldLayout = oldLayout;
				barrier.newLayout = newLayout;
				barrier.srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
				barrier.dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
				barrier.image = image;
				barrier.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
				barrier.subresourceRange.baseMipLevel = 0;
				barrier.subresourceRange.levelCount = 1;
				barrier.subresourceRange.baseArrayLayer = 0;
				barrier.subresourceRange.layerCount = 1;

				VkPipelineStageFlags sourceStage;
				VkPipelineStageFlags destinationStage;

				if (oldLayout == VK_IMAGE_LAYOUT_UNDEFINED && newLayout == VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL) {
					barrier.srcAccessMask = 0;
					barrier.dstAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;

					sourceStage = VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT;
					destinationStage = VK_PIPELINE_STAGE_TRANSFER_BIT;
				}
				else if (oldLayout == VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL && newLayout == VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL) {
					barrier.srcAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;
					barrier.dstAccessMask = VK_ACCESS_SHADER_READ_BIT;

					sourceStage = VK_PIPELINE_STAGE_TRANSFER_BIT;
					destinationStage = VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT;
				}
				else if (oldLayout == VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL && newLayout == VK_IMAGE_LAYOUT_GENERAL) {
					barrier.srcAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;
					barrier.dstAccessMask = VK_ACCESS_SHADER_READ_BIT;

					sourceStage = VK_PIPELINE_STAGE_TRANSFER_BIT;
					destinationStage = VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT;
				}
				else if (oldLayout == VK_IMAGE_LAYOUT_GENERAL && newLayout == VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL) {
					barrier.srcAccessMask = VK_ACCESS_SHADER_READ_BIT;
					barrier.dstAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;

					sourceStage = VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT;
					destinationStage = VK_PIPELINE_STAGE_TRANSFER_BIT;
				}
				else if (oldLayout == VK_IMAGE_LAYOUT_UNDEFINED && newLayout == VK_IMAGE_LAYOUT_GENERAL) {
					barrier.srcAccessMask = 0;
					barrier.dstAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT | VK_ACCESS_SHADER_READ_BIT;

					sourceStage = VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT | VK_PIPELINE_STAGE_TRANSFER_BIT;
					destinationStage = VK_PIPELINE_STAGE_TRANSFER_BIT | VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT;
				}
				else if (oldLayout == VK_IMAGE_LAYOUT_UNDEFINED && newLayout == VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL) {
					barrier.srcAccessMask = 0;
					barrier.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;

					sourceStage = VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
					destinationStage = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
				}
				else if (oldLayout == VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL && newLayout == VK_IMAGE_LAYOUT_PRESENT_SRC_KHR) {
					barrier.srcAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
					barrier.dstAccessMask = 0;

					sourceStage = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
					destinationStage = VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
				}
				else if (oldLayout == VK_IMAGE_LAYOUT_GENERAL && newLayout == VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL) {
					barrier.srcAccessMask = 0;
					barrier.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;

					sourceStage = VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
					destinationStage = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
				}
				else if (oldLayout == VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL && newLayout == VK_IMAGE_LAYOUT_GENERAL) {
					barrier.srcAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
					barrier.dstAccessMask = 0;

					sourceStage = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
					destinationStage = VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
				}
				else {
					throw std::invalid_argument("unsupported layout transition!");
				}

				vkCmdPipelineBarrier(
					commandBuffer,
					sourceStage, destinationStage,
					0,
					0, nullptr,
					0, nullptr,
					1, &barrier
				);
			}
		}
	}
}