Function TinyDDS_EncodeFormat

encoder/3rdparty/tinydds.h:1737–1960

#define TDDS_EF_BUMP_RGBA(bits, rm, gm, bm, am) TDDS_EF(bits, rm, gm, bm, am, TINYDDS_DDPF_BUMPLUMINANCE | TINYDDS_DDPF_ALPHAPIXELS)

static bool TinyDDS_EncodeFormat(TinyDDS_Format fmt, TinyDDS_Header* header, TinyDDS_HeaderDX10* headerDx10) {
	// lets start with the easy part. if its real DXGI_FORMAT we can just fill in the Dx10 part
	if(fmt < TDDS_SYNTHESISED_DXGIFORMATS) {
		headerDx10->DXGIFormat = (TinyImageFormat_DXGI_FORMAT)fmt;
		header->formatFourCC = TINYDDS_MAKE_RIFFCODE('D','X','1','0');
		header->formatFlags = TINYDDS_DDPF_FOURCC;
	} else {
		headerDx10->DXGIFormat = TIF_DXGI_FORMAT_UNKNOWN;
	}
	// now lets try synthesising if possible
	// if we can reset the DX10 fourCC but leave the format in place
	// that way if we have slices which can only be DXGI_FORMAT we can use it
	switch(fmt) {
	case TDDS_UNDEFINED: break;

	case TDDS_R1_UNORM: TDDS_EF_RGB(1, 0x1, 0, 0)
	case TDDS_R4G4_UNORM: TDDS_EF_RGB(8, 0x0F, 0xF0, 0)
	case TDDS_G4R4_UNORM: TDDS_EF_RGB(8, 0xF0, 0x0F, 0)
	case TDDS_B2G3R3_UNORM: TDDS_EF_RGB(8, 0x3, 0x7, 0x7 )
	case TDDS_R8_UNORM: TDDS_EF_RGB(8, 0xFF, 0, 0 );
	case TDDS_A8_UNORM: TDDS_EF_ALPHA( 8, 0xFF);

	case TDDS_R16_UNORM:TDDS_EF_RGB( 16,0x0000FFFF, 0, 0)
	case TDDS_A4B4G4R4_UNORM:
		TDDS_EF_RGBA(16, 0xF000, 0x0F00, 0x00F0, 0x000F);
	case TDDS_X4B4G4R4_UNORM:
		TDDS_EF_RGBA(16, 0xF000, 0x0F00, 0x00F0, 0x0000);
	case TDDS_B4G4R4A4_UNORM:
		TDDS_EF_RGBA(16, 0x0F00, 0x00F0, 0x000F, 0xF000);
	case TDDS_B4G4R4X4_UNORM:
		TDDS_EF_RGBA(16, 0x0F00, 0x00F0, 0x000F, 0x0000);
	case TDDS_A4R4G4B4_UNORM:
		TDDS_EF_RGBA(16, 0x00F0, 0x0F00, 0xF000, 0x000F);
	case TDDS_X4R4G4B4_UNORM:
		TDDS_EF_RGBA(16, 0x00F0, 0x0F00, 0xF000, 0x0000);
	case TDDS_R4G4B4A4_UNORM:
		TDDS_EF_RGBA(16, 0x000F, 0x00F0, 0x0F00, 0xF000);
	case TDDS_R4G4B4X4_UNORM:
		TDDS_EF_RGBA(16, 0x000F, 0x00F0, 0x0F00, 0x0000);

	case TDDS_B5G5R5A1_UNORM:
		TDDS_EF_RGBA(16, 0x7C00, 0x03E0, 0x001F, 0x8000);
	case TDDS_B5G5R5X1_UNORM:
		TDDS_EF_RGBA(16, 0x7C00, 0x03E0, 0x001F, 0x0000);

	case TDDS_R5G5B5A1_UNORM:
	TDDS_EF_RGBA(16, 0x001F, 0x03E0, 0x7C00, 0x8000);
	case TDDS_R5G5B5X1_UNORM:
	TDDS_EF_RGBA(16, 0x001F, 0x03E0, 0x7C00, 0x0000);

	case TDDS_A1R5G5B5_UNORM:
		TDDS_EF_RGBA(16, 0x003E, 0x07C0, 0xF800, 0x0001);
	case TDDS_X1R5G5B5_UNORM:
		TDDS_EF_RGBA(16, 0x003E, 0x07C0, 0xF800, 0x0000);
	case TDDS_A1B5G5R5_UNORM:
		TDDS_EF_RGBA(16, 0xF800, 0x07C0, 0x003E, 0x0001);
	case TDDS_X1B5G5R5_UNORM:
		TDDS_EF_RGBA(16, 0xF800, 0x07C0, 0x003E, 0x0000);