OPENMPT_NAMESPACE_BEGIN
PNG::Bitmap *PNG::ReadPNG(FileReader &file)
//-----------------------------------------
{
file.Rewind();
if(!file.ReadMagic("\211PNG\r\n\032\n"))
{
return nullptr;
}
uint32_t width = 0;
uint32_t height = 0;
uint8_t bitDepth;
uint8_t colorType;
uint8_t compressionMethod;
uint8_t filterMethod;
uint8_t interlaceMethod;
std::vector<uint8_t> dataIn;
std::vector<Pixel> palette;
while(file.AreBytesLeft())
{
uint32_t chunkLength = file.ReadUint32BE();
char magic[4];
file.ReadArray(magic);
FileReader chunk = file.ReadChunk(chunkLength);
file.Skip(4); // CRC32
if(!memcmp(magic, "IHDR", 4))
{
// Image header
width = chunk.ReadUint32BE();
height = chunk.ReadUint32BE();
bitDepth = chunk.ReadUint8();
colorType = chunk.ReadUint8();
compressionMethod = chunk.ReadUint8();
filterMethod = chunk.ReadUint8();
interlaceMethod = chunk.ReadUint8();
ASSERT(!filterMethod && !interlaceMethod);
} else if(!memcmp(magic, "IDAT", 4))
{
// Data block(s)
z_stream strm;
strm.zalloc = Z_NULL;
strm.zfree = Z_NULL;
strm.opaque = Z_NULL;
strm.avail_in = static_cast<uInt>(chunk.GetLength());
strm.next_in = (Bytef *)(chunk.GetRawData());
if(inflateInit2(&strm, 15) != Z_OK)
{
break;
}
int retVal;
do
{
dataIn.resize(dataIn.size() + 4096);
strm.avail_out = 4096;
strm.next_out = (Bytef *)&dataIn[dataIn.size() - 4096];
retVal = inflate(&strm, Z_NO_FLUSH);
} while(retVal == Z_OK);
inflateEnd(&strm);
} else if(!memcmp(magic, "PLTE", 4))
{
// Palette for <= 8-bit images
palette.resize(256);
size_t numEntries = std::min<size_t>(256u, chunk.GetLength() / 3u);
for(size_t i = 0; i < numEntries; i++)
{
uint8_t p[3];
chunk.ReadArray(p);
palette[i] = Pixel(p[0], p[1], p[2], 255);
}
}
}
// LUT for translating the color type into a number of color samples
const uint32_t sampleTable[] =
{
1, // 0: Grayscale
0,
3, // 2: RGB
1, // 3: Palette bitmap
2, // 4: Grayscale + Alpha
0,
4 // 6: RGBA
};
const uint32_t bitsPerPixel = colorType < CountOf(sampleTable) ? sampleTable[colorType] * bitDepth : 0;
if(!width || !height || !bitsPerPixel
|| (colorType != 2 && colorType != 3 && colorType != 6) || bitDepth != 8 // Only RGB(A) and 8-bit palette PNGs for now.
|| compressionMethod || interlaceMethod
|| (colorType == 3 && palette.empty())
|| dataIn.size() < (bitsPerPixel * width * height) / 8 + height) // Enough data present?
{
return nullptr;
}
Bitmap *bitmap = new (std::nothrow) Bitmap(width, height);
Pixel *pixelOut = bitmap->GetPixels();
uint32_t x = 0, y = 0;
size_t offset = 0;
while(y < height)
{
if(x == 0)
{
filterMethod = dataIn[offset++];
ASSERT(!filterMethod);
}
if(colorType == 6)
{
// RGBA
pixelOut->r = dataIn[offset++];
pixelOut->g = dataIn[offset++];
pixelOut->b = dataIn[offset++];
pixelOut->a = dataIn[offset++];
} else if(colorType == 2)
{
// RGB
pixelOut->r = dataIn[offset++];
pixelOut->g = dataIn[offset++];
pixelOut->b = dataIn[offset++];
pixelOut->a = 255;
} else if(colorType == 3)
{
// Palette
*pixelOut = palette[dataIn[offset++]];
}
pixelOut++;
x++;
if(x == width)
{
y++;
x = 0;
}
}
return bitmap;
}
VSTPresets::ErrorCode VSTPresets::LoadFile(FileReader &file, CVstPlugin &plugin)
//------------------------------------------------------------------------------
{
const bool firstChunk = file.GetPosition() == 0;
ChunkHeader header;
if(!file.ReadConvertEndianness(header) || header.chunkMagic != cMagic)
{
return invalidFile;
}
if(header.fxID != plugin.GetUID())
{
return wrongPlugin;
}
if(header.fxMagic == fMagic || header.fxMagic == chunkPresetMagic)
{
// Program
PlugParamIndex numParams = file.ReadUint32BE();
VstPatchChunkInfo info;
info.version = 1;
info.pluginUniqueID = header.fxID;
info.pluginVersion = header.fxVersion;
info.numElements = numParams;
MemsetZero(info.future);
plugin.Dispatch(effBeginLoadProgram, 0, 0, &info, 0.0f);
plugin.Dispatch(effBeginSetProgram, 0, 0, nullptr, 0.0f);
char prgName[28];
file.ReadString<mpt::String::maybeNullTerminated>(prgName, 28);
plugin.Dispatch(effSetProgramName, 0, 0, prgName, 0.0f);
if(header.fxMagic == fMagic)
{
if(plugin.GetNumParameters() != numParams)
{
return wrongParameters;
}
for(PlugParamIndex p = 0; p < numParams; p++)
{
plugin.SetParameter(p, file.ReadFloatBE());
}
} else
{
FileReader chunk = file.ReadChunk(file.ReadUint32BE());
plugin.Dispatch(effSetChunk, 1, chunk.GetLength(), const_cast<char *>(chunk.GetRawData()), 0);
}
plugin.Dispatch(effEndSetProgram, 0, 0, nullptr, 0.0f);
} else if((header.fxMagic == bankMagic || header.fxMagic == chunkBankMagic) && firstChunk)
{
// Bank - only read if it's the first chunk in the file, not if it's a sub chunk.
uint32 numProgs = file.ReadUint32BE();
uint32 currentProgram = file.ReadUint32BE();
file.Skip(124);
VstPatchChunkInfo info;
info.version = 1;
info.pluginUniqueID = header.fxID;
info.pluginVersion = header.fxVersion;
info.numElements = numProgs;
MemsetZero(info.future);
plugin.Dispatch(effBeginLoadBank, 0, 0, &info, 0.0f);
if(header.fxMagic == bankMagic)
{
VstInt32 oldCurrentProgram = plugin.GetCurrentProgram();
for(uint32 p = 0; p < numProgs; p++)
{
plugin.Dispatch(effBeginSetProgram, 0, 0, nullptr, 0.0f);
plugin.Dispatch(effSetProgram, 0, 0, nullptr, 0.0f);
ErrorCode retVal = LoadFile(file, plugin);
if(retVal != noError)
{
return retVal;
}
plugin.Dispatch(effEndSetProgram, 0, 0, nullptr, 0.0f);
}
plugin.SetCurrentProgram(oldCurrentProgram);
} else
{
FileReader chunk = file.ReadChunk(file.ReadUint32BE());
plugin.Dispatch(effSetChunk, 0, chunk.GetLength(), const_cast<char *>(chunk.GetRawData()), 0);
}
if(header.version >= 2)
{
plugin.SetCurrentProgram(currentProgram);
}
}
return noError;
}
