// Copyright (c) 2019-2022 Andrew Depke

#pragma once

#include <dxgiformat.h>

// Returns the format size in bits.
inline uint32_t GetResourceFormatSize(DXGI_FORMAT format)
{
	switch (format)
	{
	case DXGI_FORMAT_R32G32B32A32_TYPELESS:
	case DXGI_FORMAT_R32G32B32A32_FLOAT:
	case DXGI_FORMAT_R32G32B32A32_UINT:
	case DXGI_FORMAT_R32G32B32A32_SINT:
		return 128;

	case DXGI_FORMAT_R32G32B32_TYPELESS:
	case DXGI_FORMAT_R32G32B32_FLOAT:
	case DXGI_FORMAT_R32G32B32_UINT:
	case DXGI_FORMAT_R32G32B32_SINT:
		return 96;

	case DXGI_FORMAT_R16G16B16A16_TYPELESS:
	case DXGI_FORMAT_R16G16B16A16_FLOAT:
	case DXGI_FORMAT_R16G16B16A16_UNORM:
	case DXGI_FORMAT_R16G16B16A16_UINT:
	case DXGI_FORMAT_R16G16B16A16_SNORM:
	case DXGI_FORMAT_R16G16B16A16_SINT:
		return 64;

	case DXGI_FORMAT_R32G32_TYPELESS:
	case DXGI_FORMAT_R32G32_FLOAT:
	case DXGI_FORMAT_R32G32_UINT:
	case DXGI_FORMAT_R32G32_SINT:
		return 64;

	case DXGI_FORMAT_R32G8X24_TYPELESS:
	case DXGI_FORMAT_D32_FLOAT_S8X24_UINT:
	case DXGI_FORMAT_R32_FLOAT_X8X24_TYPELESS:
	case DXGI_FORMAT_X32_TYPELESS_G8X24_UINT:
		return 64;

	case DXGI_FORMAT_R10G10B10A2_TYPELESS:
	case DXGI_FORMAT_R10G10B10A2_UNORM:
	case DXGI_FORMAT_R10G10B10A2_UINT:
	case DXGI_FORMAT_R11G11B10_FLOAT:
		return 32;

	case DXGI_FORMAT_R8G8B8A8_TYPELESS:
	case DXGI_FORMAT_R8G8B8A8_UNORM:
	case DXGI_FORMAT_R8G8B8A8_UNORM_SRGB:
	case DXGI_FORMAT_R8G8B8A8_UINT:
	case DXGI_FORMAT_R8G8B8A8_SNORM:
	case DXGI_FORMAT_R8G8B8A8_SINT:
		return 32;

	case DXGI_FORMAT_R16G16_TYPELESS:
	case DXGI_FORMAT_R16G16_FLOAT:
	case DXGI_FORMAT_R16G16_UNORM:
	case DXGI_FORMAT_R16G16_UINT:
	case DXGI_FORMAT_R16G16_SNORM:
	case DXGI_FORMAT_R16G16_SINT:
		return 32;

	case DXGI_FORMAT_R32_TYPELESS:
	case DXGI_FORMAT_D32_FLOAT:
	case DXGI_FORMAT_R32_FLOAT:
	case DXGI_FORMAT_R32_UINT:
	case DXGI_FORMAT_R32_SINT:
		return 32;

	case DXGI_FORMAT_R24G8_TYPELESS:
	case DXGI_FORMAT_D24_UNORM_S8_UINT:
	case DXGI_FORMAT_R24_UNORM_X8_TYPELESS:
	case DXGI_FORMAT_X24_TYPELESS_G8_UINT:
		return 32;

	case DXGI_FORMAT_R8G8_TYPELESS:
	case DXGI_FORMAT_R8G8_UNORM:
	case DXGI_FORMAT_R8G8_UINT:
	case DXGI_FORMAT_R8G8_SNORM:
	case DXGI_FORMAT_R8G8_SINT:
		return 16;

	case DXGI_FORMAT_R16_TYPELESS:
	case DXGI_FORMAT_R16_FLOAT:
	case DXGI_FORMAT_D16_UNORM:
	case DXGI_FORMAT_R16_UNORM:
	case DXGI_FORMAT_R16_UINT:
	case DXGI_FORMAT_R16_SNORM:
	case DXGI_FORMAT_R16_SINT:
		return 16;

	case DXGI_FORMAT_R8_TYPELESS:
	case DXGI_FORMAT_R8_UNORM:
	case DXGI_FORMAT_R8_UINT:
	case DXGI_FORMAT_R8_SNORM:
	case DXGI_FORMAT_R8_SINT:
	case DXGI_FORMAT_A8_UNORM:
		return 8;

	case DXGI_FORMAT_R1_UNORM:
		return 1;

	case DXGI_FORMAT_R8G8_B8G8_UNORM:
	case DXGI_FORMAT_G8R8_G8B8_UNORM:
		return 32;

	case DXGI_FORMAT_B8G8R8A8_UNORM:
	case DXGI_FORMAT_B8G8R8X8_UNORM:
	case DXGI_FORMAT_B8G8R8A8_TYPELESS:
	case DXGI_FORMAT_B8G8R8A8_UNORM_SRGB:
	case DXGI_FORMAT_B8G8R8X8_TYPELESS:
	case DXGI_FORMAT_B8G8R8X8_UNORM_SRGB:
		return 32;
	}

	return 0;
}

inline bool IsResourceFormatSRGB(DXGI_FORMAT format)
{
	switch (format)
	{
	case DXGI_FORMAT_R8G8B8A8_UNORM_SRGB:
	case DXGI_FORMAT_BC1_UNORM_SRGB:
	case DXGI_FORMAT_BC2_UNORM_SRGB:
	case DXGI_FORMAT_BC3_UNORM_SRGB:
	case DXGI_FORMAT_B8G8R8A8_UNORM_SRGB:
	case DXGI_FORMAT_B8G8R8X8_UNORM_SRGB:
	case DXGI_FORMAT_BC7_UNORM_SRGB:
		return true;
	default:
		return false;
	}
}

inline DXGI_FORMAT ConvertResourceFormatToSRGB(DXGI_FORMAT linearFormat)
{
	switch (linearFormat)
	{
	case DXGI_FORMAT_R8G8B8A8_UNORM: return DXGI_FORMAT_R8G8B8A8_UNORM_SRGB;
	case DXGI_FORMAT_BC1_UNORM: return DXGI_FORMAT_BC1_UNORM_SRGB;
	case DXGI_FORMAT_BC2_UNORM: return DXGI_FORMAT_BC2_UNORM_SRGB;
	case DXGI_FORMAT_BC3_UNORM: return DXGI_FORMAT_BC3_UNORM_SRGB;
	case DXGI_FORMAT_B8G8R8A8_UNORM: return DXGI_FORMAT_B8G8R8A8_UNORM_SRGB;
	case DXGI_FORMAT_B8G8R8X8_UNORM: return DXGI_FORMAT_B8G8R8X8_UNORM_SRGB;
	case DXGI_FORMAT_BC7_UNORM: return DXGI_FORMAT_BC7_UNORM_SRGB;
	}

	return DXGI_FORMAT_UNKNOWN;
}

inline DXGI_FORMAT ConvertResourceFormatToLinear(DXGI_FORMAT sRGBFormat)
{
	switch (sRGBFormat)
	{
	case DXGI_FORMAT_R8G8B8A8_UNORM_SRGB: return DXGI_FORMAT_R8G8B8A8_UNORM;
	case DXGI_FORMAT_BC1_UNORM_SRGB: return DXGI_FORMAT_BC1_UNORM;
	case DXGI_FORMAT_BC2_UNORM_SRGB: return DXGI_FORMAT_BC2_UNORM;
	case DXGI_FORMAT_BC3_UNORM_SRGB: return DXGI_FORMAT_BC3_UNORM;
	case DXGI_FORMAT_B8G8R8A8_UNORM_SRGB: return DXGI_FORMAT_B8G8R8A8_UNORM;
	case DXGI_FORMAT_B8G8R8X8_UNORM_SRGB: return DXGI_FORMAT_B8G8R8X8_UNORM;
	case DXGI_FORMAT_BC7_UNORM_SRGB: return DXGI_FORMAT_BC7_UNORM;
	}

	return DXGI_FORMAT_UNKNOWN;
}

inline DXGI_FORMAT ConvertResourceFormatToTypedDepth(DXGI_FORMAT typelessDepthFormat)
{
	// If the given format is typeless, we need to convert it to typed depth.
	switch (typelessDepthFormat)
	{
	case DXGI_FORMAT_R32_TYPELESS: return DXGI_FORMAT_D32_FLOAT;
	case DXGI_FORMAT_R24G8_TYPELESS: return DXGI_FORMAT_D24_UNORM_S8_UINT;
	default: return typelessDepthFormat;
	}
}

inline DXGI_FORMAT ConvertResourceFormatToTypedNonDepth(DXGI_FORMAT typelessDepthFormat)
{
	// If the given format is typeless, we need to convert it to typed non-depth.
	switch (typelessDepthFormat)
	{
	case DXGI_FORMAT_R32_TYPELESS: return DXGI_FORMAT_R32_FLOAT;
	case DXGI_FORMAT_R24G8_TYPELESS: return DXGI_FORMAT_R24_UNORM_X8_TYPELESS;
	default: return typelessDepthFormat;
	}
}