ezResult ezBmpFileFormat::WriteImage(ezStreamWriterBase& stream, const ezImage& image, ezLogInterface* pLog) const
{
// Technically almost arbitrary formats are supported, but we only use the common ones.
ezImageFormat::Enum compatibleFormats[] =
{
ezImageFormat::B8G8R8X8_UNORM,
ezImageFormat::B8G8R8A8_UNORM,
ezImageFormat::B8G8R8_UNORM,
ezImageFormat::B5G5R5X1_UNORM,
ezImageFormat::B5G6R5_UNORM,
};
// Find a compatible format closest to the one the image currently has
ezImageFormat::Enum format = ezImageConversionBase::FindClosestCompatibleFormat(image.GetImageFormat(), compatibleFormats);
if (format == ezImageFormat::UNKNOWN)
{
ezLog::Error(pLog, "No conversion from format '%s' to a format suitable for BMP files known.", ezImageFormat::GetName(image.GetImageFormat()));
return EZ_FAILURE;
}
// Convert if not already in a compatible format
if (format != image.GetImageFormat())
{
ezImage convertedImage;
if (ezImageConversionBase::Convert(image, convertedImage, format) != EZ_SUCCESS)
{
// This should never happen
EZ_ASSERT_DEV(false, "ezImageConversion::Convert failed even though the conversion was to the format returned by FindClosestCompatibleFormat.");
return EZ_FAILURE;
}
return WriteImage(stream, convertedImage, pLog);
}
ezUInt32 uiRowPitch = image.GetRowPitch(0);
ezUInt32 uiHeight = image.GetHeight(0);
int dataSize = uiRowPitch * uiHeight;
ezBmpFileInfoHeader fileInfoHeader;
fileInfoHeader.m_width = image.GetWidth(0);
fileInfoHeader.m_height = uiHeight;
fileInfoHeader.m_planes = 1;
fileInfoHeader.m_bitCount = ezImageFormat::GetBitsPerPixel(format);
fileInfoHeader.m_sizeImage = 0; // Can be zero unless we store the data compressed
fileInfoHeader.m_xPelsPerMeter = 0;
fileInfoHeader.m_yPelsPerMeter = 0;
fileInfoHeader.m_clrUsed = 0;
fileInfoHeader.m_clrImportant = 0;
bool bWriteColorMask = false;
// Prefer to write a V3 header
ezUInt32 uiHeaderVersion = 3;
switch (format)
{
case ezImageFormat::B8G8R8X8_UNORM:
case ezImageFormat::B5G5R5X1_UNORM:
case ezImageFormat::B8G8R8_UNORM:
fileInfoHeader.m_compression = RGB;
break;
case ezImageFormat::B8G8R8A8_UNORM:
fileInfoHeader.m_compression = BITFIELDS;
uiHeaderVersion = 4;
break;
case ezImageFormat::B5G6R5_UNORM:
fileInfoHeader.m_compression = BITFIELDS;
bWriteColorMask = true;
break;
default:
return EZ_FAILURE;
}
EZ_ASSERT_DEV(!bWriteColorMask || uiHeaderVersion <= 3, "Internal bug");
ezUInt32 uiFileInfoHeaderSize = sizeof(ezBmpFileInfoHeader);
ezUInt32 uiHeaderSize = sizeof(ezBmpFileHeader);
if (uiHeaderVersion >= 4)
{
uiFileInfoHeaderSize += sizeof(ezBmpFileInfoHeaderV4);
}
else if (bWriteColorMask)
{
uiHeaderSize += 3 * sizeof(ezUInt32);
}
uiHeaderSize += uiFileInfoHeaderSize;
fileInfoHeader.m_size = uiFileInfoHeaderSize;
ezBmpFileHeader header;
header.m_type = ezBmpFileMagic;
header.m_size = uiHeaderSize + dataSize;
header.m_reserved1 = 0;
header.m_reserved2 = 0;
header.m_offBits = uiHeaderSize;
const void* dataPtr = image.GetDataPointer<void>();
// Write all data
if (stream.WriteBytes(&header, sizeof(header)) != EZ_SUCCESS)
{
ezLog::Error(pLog, "Failed to write header.");
return EZ_FAILURE;
}
if (stream.WriteBytes(&fileInfoHeader, sizeof(fileInfoHeader)) != EZ_SUCCESS)
{
ezLog::Error(pLog, "Failed to write fileInfoHeader.");
return EZ_FAILURE;
}
if (uiHeaderVersion >= 4)
{
ezBmpFileInfoHeaderV4 fileInfoHeaderV4;
memset(&fileInfoHeaderV4, 0, sizeof(fileInfoHeaderV4));
fileInfoHeaderV4.m_redMask = ezImageFormat::GetRedMask(format);
fileInfoHeaderV4.m_greenMask = ezImageFormat::GetGreenMask(format);
fileInfoHeaderV4.m_blueMask = ezImageFormat::GetBlueMask(format);
fileInfoHeaderV4.m_alphaMask = ezImageFormat::GetAlphaMask(format);
if (stream.WriteBytes(&fileInfoHeaderV4, sizeof(fileInfoHeaderV4)) != EZ_SUCCESS)
{
ezLog::Error(pLog, "Failed to write fileInfoHeaderV4.");
return EZ_FAILURE;
}
}
else if (bWriteColorMask)
{
struct
{
ezUInt32 m_red;
ezUInt32 m_green;
ezUInt32 m_blue;
} colorMask;
colorMask.m_red = ezImageFormat::GetRedMask(format);
colorMask.m_green = ezImageFormat::GetGreenMask(format);
colorMask.m_blue = ezImageFormat::GetBlueMask(format);
if (stream.WriteBytes(&colorMask, sizeof(colorMask)) != EZ_SUCCESS)
{
ezLog::Error(pLog, "Failed to write colorMask.");
return EZ_FAILURE;
}
}
const ezUInt32 uiPaddedRowPitch = ((uiRowPitch - 1) / 4 + 1) * 4;
// Write rows in reverse order
for (ezInt32 iRow = uiHeight - 1; iRow >= 0; iRow--)
{
if (stream.WriteBytes(image.GetPixelPointer<void>(0, 0, 0, 0, iRow, 0), uiPaddedRowPitch) != EZ_SUCCESS)
{
ezLog::Error(pLog, "Failed to write data.");
return EZ_FAILURE;
}
}
return EZ_SUCCESS;
}
ezResult ezBmpFileFormat::ReadImage(ezStreamReaderBase& stream, ezImage& image, ezLogInterface* pLog) const
{
ezBmpFileHeader fileHeader;
if (stream.ReadBytes(&fileHeader, sizeof(ezBmpFileHeader)) != sizeof(ezBmpFileHeader))
{
ezLog::Error(pLog, "Failed to read header data.");
return EZ_FAILURE;
}
// Some very old BMP variants may have different magic numbers, but we don't support them.
if (fileHeader.m_type != ezBmpFileMagic)
{
ezLog::Error(pLog, "The file is not a recognized BMP file.");
return EZ_FAILURE;
}
// We expect at least header version 3
ezUInt32 uiHeaderVersion = 3;
ezBmpFileInfoHeader fileInfoHeader;
if (stream.ReadBytes(&fileInfoHeader, sizeof(ezBmpFileInfoHeader)) != sizeof(ezBmpFileInfoHeader))
{
ezLog::Error(pLog, "Failed to read header data (V3).");
return EZ_FAILURE;
}
int remainingHeaderBytes = fileInfoHeader.m_size - sizeof(fileInfoHeader);
// File header shorter than expected - happens with corrupt files or e.g. with OS/2 BMP files which may have shorter headers
if (remainingHeaderBytes < 0)
{
ezLog::Error(pLog, "The file header was shorter than expected.");
return EZ_FAILURE;
}
// Newer files may have a header version 4 (required for transparency)
ezBmpFileInfoHeaderV4 fileInfoHeaderV4;
if (remainingHeaderBytes >= sizeof(ezBmpFileInfoHeaderV4))
{
uiHeaderVersion = 4;
if (stream.ReadBytes(&fileInfoHeaderV4, sizeof(ezBmpFileInfoHeaderV4)) != sizeof(ezBmpFileInfoHeaderV4))
{
ezLog::Error(pLog, "Failed to read header data (V4).");
return EZ_FAILURE;
}
remainingHeaderBytes -= sizeof(ezBmpFileInfoHeaderV4);
}
// Skip rest of header
if (stream.SkipBytes(remainingHeaderBytes) != remainingHeaderBytes)
{
ezLog::Error(pLog, "Failed to skip remaining header data.");
return EZ_FAILURE;
}
ezUInt32 uiBpp = fileInfoHeader.m_bitCount;
// Find target format to load the image
ezImageFormat::Enum format = ezImageFormat::UNKNOWN;
bool bIndexed = false;
bool bCompressed = false;
switch (fileInfoHeader.m_compression)
{
// RGB or indexed data
case RGB:
switch (uiBpp)
{
case 1:
case 4:
case 8:
bIndexed = true;
// We always decompress indexed to BGRX, since the palette is specified in this format
format = ezImageFormat::B8G8R8X8_UNORM;
break;
case 16:
format = ezImageFormat::B5G5R5X1_UNORM;
break;
case 24:
format = ezImageFormat::B8G8R8_UNORM;
break;
case 32:
format = ezImageFormat::B8G8R8X8_UNORM;
}
break;
// RGB data, but with the color masks specified in place of the palette
case BITFIELDS:
switch (uiBpp)
{
case 16:
case 32:
// In case of old headers, the color masks appear after the header (and aren't counted as part of it)
if (uiHeaderVersion < 4)
{
// Color masks (w/o alpha channel)
struct
{
ezUInt32 m_red;
ezUInt32 m_green;
ezUInt32 m_blue;
} colorMask;
if (stream.ReadBytes(&colorMask, sizeof(colorMask)) != sizeof(colorMask))
{
return EZ_FAILURE;
}
format = ezImageFormat::FromPixelMask(colorMask.m_red, colorMask.m_green, colorMask.m_blue, 0);
}
else
{
// For header version four and higher, the color masks are part of the header
format = ezImageFormat::FromPixelMask(
fileInfoHeaderV4.m_redMask, fileInfoHeaderV4.m_greenMask,
fileInfoHeaderV4.m_blueMask, fileInfoHeaderV4.m_alphaMask);
}
break;
}
break;
case RLE4:
if (uiBpp == 4)
{
bIndexed = true;
bCompressed = true;
format = ezImageFormat::B8G8R8X8_UNORM;
}
break;
case RLE8:
if (uiBpp == 8)
{
bIndexed = true;
bCompressed = true;
format = ezImageFormat::B8G8R8X8_UNORM;
}
break;
}
if (format == ezImageFormat::UNKNOWN)
{
ezLog::Error(pLog, "Unknown or unsupported BMP encoding.");
return EZ_FAILURE;
}
const ezUInt32 uiWidth = fileInfoHeader.m_width;
if (uiWidth > 65536)
{
ezLog::Error(pLog, "Image specifies width > 65536. Header corrupted?");
return EZ_FAILURE;
}
const ezUInt32 uiHeight = fileInfoHeader.m_height;
if (uiHeight > 65536)
{
ezLog::Error(pLog, "Image specifies height > 65536. Header corrupted?");
return EZ_FAILURE;
}
ezUInt32 uiDataSize = fileInfoHeader.m_sizeImage;
if (uiDataSize > 1024 * 1024 * 1024)
{
ezLog::Error(pLog, "Image specifies data size > 1GiB. Header corrupted?");
return EZ_FAILURE;
}
int uiRowPitchIn = (uiWidth * uiBpp + 31) / 32 * 4;
if (uiDataSize == 0)
{
if (fileInfoHeader.m_compression != RGB)
{
ezLog::Error(pLog, "The data size wasn't specified in the header.");
return EZ_FAILURE;
}
uiDataSize = uiRowPitchIn * uiHeight;
}
// Set image data
image.SetImageFormat(format);
image.SetNumMipLevels(1);
image.SetNumArrayIndices(1);
image.SetNumFaces(1);
image.SetWidth(uiWidth);
image.SetHeight(uiHeight);
image.SetDepth(1);
image.AllocateImageData();
ezUInt32 uiRowPitch = image.GetRowPitch(0);
if (bIndexed)
{
// If no palette size was specified, the full available palette size will be used
ezUInt32 paletteSize = fileInfoHeader.m_clrUsed;
if (paletteSize == 0)
{
paletteSize = 1U << uiBpp;
}
else if(paletteSize > 65536)
{
ezLog::Error(pLog, "Palette size > 65536.");
return EZ_FAILURE;
}
ezDynamicArray<ezBmpBgrxQuad> palette;
palette.SetCount(paletteSize);
if (stream.ReadBytes(&palette[0], paletteSize * sizeof(ezBmpBgrxQuad)) != paletteSize * sizeof(ezBmpBgrxQuad))
{
ezLog::Error(pLog, "Failed to read palette data.");
return EZ_FAILURE;
}
if (bCompressed)
{
// Compressed data is always in pairs of bytes
if (uiDataSize % 2 != 0)
{
ezLog::Error(pLog, "The data size is not a multiple of 2 bytes in an RLE-compressed file.");
return EZ_FAILURE;
}
ezDynamicArray<ezUInt8> compressedData;
compressedData.SetCount(uiDataSize);
if (stream.ReadBytes(&compressedData[0], uiDataSize) != uiDataSize)
{
ezLog::Error(pLog, "Failed to read data.");
return EZ_FAILURE;
}
const ezUInt8* pIn = &compressedData[0];
const ezUInt8* pInEnd = pIn + uiDataSize;
// Current output position
ezUInt32 uiRow = uiHeight - 1;
ezUInt32 uiCol = 0;
ezBmpBgrxQuad* pLine = image.GetPixelPointer<ezBmpBgrxQuad>(0, 0, 0, 0, uiRow, 0);
// Decode RLE data directly to RGBX
while(pIn < pInEnd)
{
ezUInt32 uiByte1 = *pIn++;
ezUInt32 uiByte2 = *pIn++;
// Relative mode - the first byte specified a number of indices to be repeated, the second one the indices
if (uiByte1 > 0)
{
// Clamp number of repetitions to row width.
// The spec isn't clear on this point, but some files pad the number of encoded indices for some reason.
uiByte1 = ezMath::Min(uiByte1, uiWidth - uiCol);
if (uiBpp == 4)
{
// Alternate between two indices.
for (ezUInt32 uiRep = 0; uiRep < uiByte1 / 2; uiRep++)
{
pLine[uiCol++] = palette[uiByte2 >> 4];
pLine[uiCol++] = palette[uiByte2 & 0x0F];
}
// Repeat the first index for odd numbers of repetitions.
if (uiByte1 & 1)
{
pLine[uiCol++] = palette[uiByte2 >> 4];
}
}
else /* if (uiBpp == 8) */
{
// Repeat a single index.
for (ezUInt32 uiRep = 0; uiRep < uiByte1; uiRep++)
{
pLine[uiCol++] = palette[uiByte2];
}
}
}
else
{
// Absolute mode - the first byte specifies a number of indices encoded separately, or is a special marker
switch (uiByte2)
ezResult ezImageConversion::ConvertSingleStepDecompress(const ezImageView& source, ezImage& target, ezImageFormat::Enum sourceFormat,
ezImageFormat::Enum targetFormat, const ezImageConversionStep* pStep)
{
for (ezUInt32 arrayIndex = 0; arrayIndex < source.GetNumArrayIndices(); arrayIndex++)
{
for (ezUInt32 face = 0; face < source.GetNumFaces(); face++)
{
for (ezUInt32 mipLevel = 0; mipLevel < source.GetNumMipLevels(); mipLevel++)
{
const ezUInt32 width = target.GetWidth(mipLevel);
const ezUInt32 height = target.GetHeight(mipLevel);
const ezUInt32 blockSizeX = ezImageFormat::GetBlockWidth(sourceFormat);
const ezUInt32 blockSizeY = ezImageFormat::GetBlockHeight(sourceFormat);
const ezUInt32 numBlocksX = source.GetNumBlocksX(mipLevel);
const ezUInt32 numBlocksY = source.GetNumBlocksY(mipLevel);
const ezUInt32 targetRowPitch = target.GetRowPitch(mipLevel);
const ezUInt32 targetBytesPerPixel = ezImageFormat::GetBitsPerPixel(targetFormat) / 8;
const ezUInt32 blockSizeInBytes = ezImageFormat::GetBitsPerBlock(sourceFormat) / 8;
// Decompress into a temp memory block so we don't have to explicitly handle the case where the image is not a multiple of the block
// size
ezHybridArray<ezUInt8, 256> tempBuffer;
tempBuffer.SetCount(numBlocksX * blockSizeX * blockSizeY * targetBytesPerPixel);
for (ezUInt32 slice = 0; slice < source.GetDepth(mipLevel); slice++)
{
for (ezUInt32 blockY = 0; blockY < numBlocksY; blockY++)
{
ezImageView sourceRowView = source.GetRowView(mipLevel, face, arrayIndex, blockY, slice);
if (static_cast<const ezImageConversionStepDecompressBlocks*>(pStep)
->DecompressBlocks(sourceRowView.GetArrayPtr<void>(), ezArrayPtr<void>(tempBuffer.GetData(), tempBuffer.GetCount()),
numBlocksX, sourceFormat, targetFormat)
.Failed())
{
return EZ_FAILURE;
}
for (ezUInt32 blockX = 0; blockX < numBlocksX; blockX++)
{
ezUInt8* targetPointer =
target.GetPixelPointer<ezUInt8>(mipLevel, face, arrayIndex, blockX * blockSizeX, blockY * blockSizeY, slice);
// Copy into actual target, clamping to image dimensions
ezUInt32 copyWidth = ezMath::Min(blockSizeX, width - blockX * blockSizeX);
ezUInt32 copyHeight = ezMath::Min(blockSizeY, height - blockY * blockSizeY);
for (ezUInt32 row = 0; row < copyHeight; row++)
{
memcpy(targetPointer, &tempBuffer[(blockX * blockSizeX + row) * blockSizeY * targetBytesPerPixel],
copyWidth * targetBytesPerPixel);
targetPointer += targetRowPitch;
}
}
}
}
}
}
}
return EZ_SUCCESS;
}