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ioq3quest/code/renderercommon/tr_image_png.c
Edward Betts fe42b8653d Correct spelling mistakes.
2017-11-22 01:40:20 -06:00

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/*
===========================================================================
ioquake3 png decoder
Copyright (C) 2007,2008 Joerg Dietrich
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
===========================================================================
*/
#include "tr_common.h"
#include "../qcommon/puff.h"
// we could limit the png size to a lower value here
#ifndef INT_MAX
#define INT_MAX 0x1fffffff
#endif
/*
=================
PNG LOADING
=================
*/
/*
* Quake 3 image format : RGBA
*/
#define Q3IMAGE_BYTESPERPIXEL (4)
/*
* PNG specifications
*/
/*
* The first 8 Bytes of every PNG-File are a fixed signature
* to identify the file as a PNG.
*/
#define PNG_Signature "\x89\x50\x4E\x47\xD\xA\x1A\xA"
#define PNG_Signature_Size (8)
/*
* After the signature diverse chunks follow.
* A chunk consists of a header and if Length
* is bigger than 0 a body and a CRC of the body follow.
*/
struct PNG_ChunkHeader
{
uint32_t Length;
uint32_t Type;
};
#define PNG_ChunkHeader_Size (8)
typedef uint32_t PNG_ChunkCRC;
#define PNG_ChunkCRC_Size (4)
/*
* We use the following ChunkTypes.
* All others are ignored.
*/
#define MAKE_CHUNKTYPE(a,b,c,d) (((a) << 24) | ((b) << 16) | ((c) << 8) | ((d)))
#define PNG_ChunkType_IHDR MAKE_CHUNKTYPE('I', 'H', 'D', 'R')
#define PNG_ChunkType_PLTE MAKE_CHUNKTYPE('P', 'L', 'T', 'E')
#define PNG_ChunkType_IDAT MAKE_CHUNKTYPE('I', 'D', 'A', 'T')
#define PNG_ChunkType_IEND MAKE_CHUNKTYPE('I', 'E', 'N', 'D')
#define PNG_ChunkType_tRNS MAKE_CHUNKTYPE('t', 'R', 'N', 'S')
/*
* Per specification the first chunk after the signature SHALL be IHDR.
*/
struct PNG_Chunk_IHDR
{
uint32_t Width;
uint32_t Height;
uint8_t BitDepth;
uint8_t ColourType;
uint8_t CompressionMethod;
uint8_t FilterMethod;
uint8_t InterlaceMethod;
};
#define PNG_Chunk_IHDR_Size (13)
/*
* ColourTypes
*/
#define PNG_ColourType_Grey (0)
#define PNG_ColourType_True (2)
#define PNG_ColourType_Indexed (3)
#define PNG_ColourType_GreyAlpha (4)
#define PNG_ColourType_TrueAlpha (6)
/*
* number of colour components
*
* Grey : 1 grey
* True : 1 R, 1 G, 1 B
* Indexed : 1 index
* GreyAlpha : 1 grey, 1 alpha
* TrueAlpha : 1 R, 1 G, 1 B, 1 alpha
*/
#define PNG_NumColourComponents_Grey (1)
#define PNG_NumColourComponents_True (3)
#define PNG_NumColourComponents_Indexed (1)
#define PNG_NumColourComponents_GreyAlpha (2)
#define PNG_NumColourComponents_TrueAlpha (4)
/*
* For the different ColourTypes
* different BitDepths are specified.
*/
#define PNG_BitDepth_1 ( 1)
#define PNG_BitDepth_2 ( 2)
#define PNG_BitDepth_4 ( 4)
#define PNG_BitDepth_8 ( 8)
#define PNG_BitDepth_16 (16)
/*
* Only one valid CompressionMethod is standardized.
*/
#define PNG_CompressionMethod_0 (0)
/*
* Only one valid FilterMethod is currently standardized.
*/
#define PNG_FilterMethod_0 (0)
/*
* This FilterMethod defines 5 FilterTypes
*/
#define PNG_FilterType_None (0)
#define PNG_FilterType_Sub (1)
#define PNG_FilterType_Up (2)
#define PNG_FilterType_Average (3)
#define PNG_FilterType_Paeth (4)
/*
* Two InterlaceMethods are standardized :
* 0 - NonInterlaced
* 1 - Interlaced
*/
#define PNG_InterlaceMethod_NonInterlaced (0)
#define PNG_InterlaceMethod_Interlaced (1)
/*
* The Adam7 interlace method uses 7 passes.
*/
#define PNG_Adam7_NumPasses (7)
/*
* The compressed data starts with a header ...
*/
struct PNG_ZlibHeader
{
uint8_t CompressionMethod;
uint8_t Flags;
};
#define PNG_ZlibHeader_Size (2)
/*
* ... and is followed by a check value
*/
#define PNG_ZlibCheckValue_Size (4)
/*
* Some support functions for buffered files follow.
*/
/*
* buffered file representation
*/
struct BufferedFile
{
byte *Buffer;
int Length;
byte *Ptr;
int BytesLeft;
};
/*
* Read a file into a buffer.
*/
static struct BufferedFile *ReadBufferedFile(const char *name)
{
struct BufferedFile *BF;
union {
byte *b;
void *v;
} buffer;
/*
* input verification
*/
if(!name)
{
return(NULL);
}
/*
* Allocate control struct.
*/
BF = ri.Malloc(sizeof(struct BufferedFile));
if(!BF)
{
return(NULL);
}
/*
* Initialize the structs components.
*/
BF->Length = 0;
BF->Buffer = NULL;
BF->Ptr = NULL;
BF->BytesLeft = 0;
/*
* Read the file.
*/
BF->Length = ri.FS_ReadFile((char *) name, &buffer.v);
BF->Buffer = buffer.b;
/*
* Did we get it? Is it big enough?
*/
if(!(BF->Buffer && (BF->Length > 0)))
{
ri.Free(BF);
return(NULL);
}
/*
* Set the pointers and counters.
*/
BF->Ptr = BF->Buffer;
BF->BytesLeft = BF->Length;
return(BF);
}
/*
* Close a buffered file.
*/
static void CloseBufferedFile(struct BufferedFile *BF)
{
if(BF)
{
if(BF->Buffer)
{
ri.FS_FreeFile(BF->Buffer);
}
ri.Free(BF);
}
}
/*
* Get a pointer to the requested bytes.
*/
static void *BufferedFileRead(struct BufferedFile *BF, unsigned Length)
{
void *RetVal;
/*
* input verification
*/
if(!(BF && Length))
{
return(NULL);
}
/*
* not enough bytes left
*/
if(Length > BF->BytesLeft)
{
return(NULL);
}
/*
* the pointer to the requested data
*/
RetVal = BF->Ptr;
/*
* Raise the pointer and counter.
*/
BF->Ptr += Length;
BF->BytesLeft -= Length;
return(RetVal);
}
/*
* Rewind the buffer.
*/
static qboolean BufferedFileRewind(struct BufferedFile *BF, unsigned Offset)
{
unsigned BytesRead;
/*
* input verification
*/
if(!BF)
{
return(qfalse);
}
/*
* special trick to rewind to the beginning of the buffer
*/
if(Offset == (unsigned)-1)
{
BF->Ptr = BF->Buffer;
BF->BytesLeft = BF->Length;
return(qtrue);
}
/*
* How many bytes do we have already read?
*/
BytesRead = BF->Ptr - BF->Buffer;
/*
* We can only rewind to the beginning of the BufferedFile.
*/
if(Offset > BytesRead)
{
return(qfalse);
}
/*
* lower the pointer and counter.
*/
BF->Ptr -= Offset;
BF->BytesLeft += Offset;
return(qtrue);
}
/*
* Skip some bytes.
*/
static qboolean BufferedFileSkip(struct BufferedFile *BF, unsigned Offset)
{
/*
* input verification
*/
if(!BF)
{
return(qfalse);
}
/*
* We can only skip to the end of the BufferedFile.
*/
if(Offset > BF->BytesLeft)
{
return(qfalse);
}
/*
* lower the pointer and counter.
*/
BF->Ptr += Offset;
BF->BytesLeft -= Offset;
return(qtrue);
}
/*
* Find a chunk
*/
static qboolean FindChunk(struct BufferedFile *BF, uint32_t ChunkType)
{
struct PNG_ChunkHeader *CH;
uint32_t Length;
uint32_t Type;
/*
* input verification
*/
if(!BF)
{
return(qfalse);
}
/*
* cycle trough the chunks
*/
while(qtrue)
{
/*
* Read the chunk-header.
*/
CH = BufferedFileRead(BF, PNG_ChunkHeader_Size);
if(!CH)
{
return(qfalse);
}
/*
* Do not swap the original types
* they might be needed later.
*/
Length = BigLong(CH->Length);
Type = BigLong(CH->Type);
/*
* We found it!
*/
if(Type == ChunkType)
{
/*
* Rewind to the start of the chunk.
*/
BufferedFileRewind(BF, PNG_ChunkHeader_Size);
break;
}
else
{
/*
* Skip the rest of the chunk.
*/
if(Length)
{
if(!BufferedFileSkip(BF, Length + PNG_ChunkCRC_Size))
{
return(qfalse);
}
}
}
}
return(qtrue);
}
/*
* Decompress all IDATs
*/
static uint32_t DecompressIDATs(struct BufferedFile *BF, uint8_t **Buffer)
{
uint8_t *DecompressedData;
uint32_t DecompressedDataLength;
uint8_t *CompressedData;
uint8_t *CompressedDataPtr;
uint32_t CompressedDataLength;
struct PNG_ChunkHeader *CH;
uint32_t Length;
uint32_t Type;
int BytesToRewind;
int32_t puffResult;
uint8_t *puffDest;
uint32_t puffDestLen;
uint8_t *puffSrc;
uint32_t puffSrcLen;
/*
* input verification
*/
if(!(BF && Buffer))
{
return(-1);
}
/*
* some zeroing
*/
DecompressedData = NULL;
*Buffer = DecompressedData;
CompressedData = NULL;
CompressedDataLength = 0;
BytesToRewind = 0;
/*
* Find the first IDAT chunk.
*/
if(!FindChunk(BF, PNG_ChunkType_IDAT))
{
return(-1);
}
/*
* Count the size of the uncompressed data
*/
while(qtrue)
{
/*
* Read chunk header
*/
CH = BufferedFileRead(BF, PNG_ChunkHeader_Size);
if(!CH)
{
/*
* Rewind to the start of this adventure
* and return unsuccessful
*/
BufferedFileRewind(BF, BytesToRewind);
return(-1);
}
/*
* Length and Type of chunk
*/
Length = BigLong(CH->Length);
Type = BigLong(CH->Type);
/*
* We have reached the end of the IDAT chunks
*/
if(!(Type == PNG_ChunkType_IDAT))
{
BufferedFileRewind(BF, PNG_ChunkHeader_Size);
break;
}
/*
* Add chunk header to count.
*/
BytesToRewind += PNG_ChunkHeader_Size;
/*
* Skip to next chunk
*/
if(Length)
{
if(!BufferedFileSkip(BF, Length + PNG_ChunkCRC_Size))
{
BufferedFileRewind(BF, BytesToRewind);
return(-1);
}
BytesToRewind += Length + PNG_ChunkCRC_Size;
CompressedDataLength += Length;
}
}
BufferedFileRewind(BF, BytesToRewind);
CompressedData = ri.Malloc(CompressedDataLength);
if(!CompressedData)
{
return(-1);
}
CompressedDataPtr = CompressedData;
/*
* Collect the compressed Data
*/
while(qtrue)
{
/*
* Read chunk header
*/
CH = BufferedFileRead(BF, PNG_ChunkHeader_Size);
if(!CH)
{
ri.Free(CompressedData);
return(-1);
}
/*
* Length and Type of chunk
*/
Length = BigLong(CH->Length);
Type = BigLong(CH->Type);
/*
* We have reached the end of the IDAT chunks
*/
if(!(Type == PNG_ChunkType_IDAT))
{
BufferedFileRewind(BF, PNG_ChunkHeader_Size);
break;
}
/*
* Copy the Data
*/
if(Length)
{
uint8_t *OrigCompressedData;
OrigCompressedData = BufferedFileRead(BF, Length);
if(!OrigCompressedData)
{
ri.Free(CompressedData);
return(-1);
}
if(!BufferedFileSkip(BF, PNG_ChunkCRC_Size))
{
ri.Free(CompressedData);
return(-1);
}
memcpy(CompressedDataPtr, OrigCompressedData, Length);
CompressedDataPtr += Length;
}
}
/*
* Let puff() calculate the decompressed data length.
*/
puffDest = NULL;
puffDestLen = 0;
/*
* The zlib header and checkvalue don't belong to the compressed data.
*/
puffSrc = CompressedData + PNG_ZlibHeader_Size;
puffSrcLen = CompressedDataLength - PNG_ZlibHeader_Size - PNG_ZlibCheckValue_Size;
/*
* first puff() to calculate the size of the uncompressed data
*/
puffResult = puff(puffDest, &puffDestLen, puffSrc, &puffSrcLen);
if(!((puffResult == 0) && (puffDestLen > 0)))
{
ri.Free(CompressedData);
return(-1);
}
/*
* Allocate the buffer for the uncompressed data.
*/
DecompressedData = ri.Malloc(puffDestLen);
if(!DecompressedData)
{
ri.Free(CompressedData);
return(-1);
}
/*
* Set the input again in case something was changed by the last puff() .
*/
puffDest = DecompressedData;
puffSrc = CompressedData + PNG_ZlibHeader_Size;
puffSrcLen = CompressedDataLength - PNG_ZlibHeader_Size - PNG_ZlibCheckValue_Size;
/*
* decompression puff()
*/
puffResult = puff(puffDest, &puffDestLen, puffSrc, &puffSrcLen);
/*
* The compressed data is not needed anymore.
*/
ri.Free(CompressedData);
/*
* Check if the last puff() was successful.
*/
if(!((puffResult == 0) && (puffDestLen > 0)))
{
ri.Free(DecompressedData);
return(-1);
}
/*
* Set the output of this function.
*/
DecompressedDataLength = puffDestLen;
*Buffer = DecompressedData;
return(DecompressedDataLength);
}
/*
* the Paeth predictor
*/
static uint8_t PredictPaeth(uint8_t a, uint8_t b, uint8_t c)
{
/*
* a == Left
* b == Up
* c == UpLeft
*/
uint8_t Pr;
int p;
int pa, pb, pc;
p = ((int) a) + ((int) b) - ((int) c);
pa = abs(p - ((int) a));
pb = abs(p - ((int) b));
pc = abs(p - ((int) c));
if((pa <= pb) && (pa <= pc))
{
Pr = a;
}
else if(pb <= pc)
{
Pr = b;
}
else
{
Pr = c;
}
return(Pr);
}
/*
* Reverse the filters.
*/
static qboolean UnfilterImage(uint8_t *DecompressedData,
uint32_t ImageHeight,
uint32_t BytesPerScanline,
uint32_t BytesPerPixel)
{
uint8_t *DecompPtr;
uint8_t FilterType;
uint8_t *PixelLeft, *PixelUp, *PixelUpLeft;
uint32_t w, h, p;
/*
* some zeros for the filters
*/
uint8_t Zeros[8] = {0, 0, 0, 0, 0, 0, 0, 0};
/*
* input verification
*/
if(!(DecompressedData && BytesPerPixel))
{
return(qfalse);
}
/*
* ImageHeight and BytesPerScanline can be zero in small interlaced images.
*/
if((!ImageHeight) || (!BytesPerScanline))
{
return(qtrue);
}
/*
* Set the pointer to the start of the decompressed Data.
*/
DecompPtr = DecompressedData;
/*
* Un-filtering is done in place.
*/
/*
* Go trough all scanlines.
*/
for(h = 0; h < ImageHeight; h++)
{
/*
* Every scanline starts with a FilterType byte.
*/
FilterType = *DecompPtr;
DecompPtr++;
/*
* Left pixel of the first byte in a scanline is zero.
*/
PixelLeft = Zeros;
/*
* Set PixelUp to previous line only if we are on the second line or above.
*
* Plus one byte for the FilterType
*/
if(h > 0)
{
PixelUp = DecompPtr - (BytesPerScanline + 1);
}
else
{
PixelUp = Zeros;
}
/*
* The pixel left to the first pixel of the previous scanline is zero too.
*/
PixelUpLeft = Zeros;
/*
* Cycle trough all pixels of the scanline.
*/
for(w = 0; w < (BytesPerScanline / BytesPerPixel); w++)
{
/*
* Cycle trough the bytes of the pixel.
*/
for(p = 0; p < BytesPerPixel; p++)
{
switch(FilterType)
{
case PNG_FilterType_None :
{
/*
* The byte is unfiltered.
*/
break;
}
case PNG_FilterType_Sub :
{
DecompPtr[p] += PixelLeft[p];
break;
}
case PNG_FilterType_Up :
{
DecompPtr[p] += PixelUp[p];
break;
}
case PNG_FilterType_Average :
{
DecompPtr[p] += ((uint8_t) ((((uint16_t) PixelLeft[p]) + ((uint16_t) PixelUp[p])) / 2));
break;
}
case PNG_FilterType_Paeth :
{
DecompPtr[p] += PredictPaeth(PixelLeft[p], PixelUp[p], PixelUpLeft[p]);
break;
}
default :
{
return(qfalse);
}
}
}
PixelLeft = DecompPtr;
/*
* We only have an upleft pixel if we are on the second line or above.
*/
if(h > 0)
{
PixelUpLeft = DecompPtr - (BytesPerScanline + 1);
}
/*
* Skip to the next pixel.
*/
DecompPtr += BytesPerPixel;
/*
* We only have a previous line if we are on the second line and above.
*/
if(h > 0)
{
PixelUp = DecompPtr - (BytesPerScanline + 1);
}
}
}
return(qtrue);
}
/*
* Convert a raw input pixel to Quake 3 RGA format.
*/
static qboolean ConvertPixel(struct PNG_Chunk_IHDR *IHDR,
byte *OutPtr,
uint8_t *DecompPtr,
qboolean HasTransparentColour,
uint8_t *TransparentColour,
uint8_t *OutPal)
{
/*
* input verification
*/
if(!(IHDR && OutPtr && DecompPtr && TransparentColour && OutPal))
{
return(qfalse);
}
switch(IHDR->ColourType)
{
case PNG_ColourType_Grey :
{
switch(IHDR->BitDepth)
{
case PNG_BitDepth_1 :
case PNG_BitDepth_2 :
case PNG_BitDepth_4 :
{
uint8_t Step;
uint8_t GreyValue;
Step = 0xFF / ((1 << IHDR->BitDepth) - 1);
GreyValue = DecompPtr[0] * Step;
OutPtr[0] = GreyValue;
OutPtr[1] = GreyValue;
OutPtr[2] = GreyValue;
OutPtr[3] = 0xFF;
/*
* Grey supports full transparency for one specified colour
*/
if(HasTransparentColour)
{
if(TransparentColour[1] == DecompPtr[0])
{
OutPtr[3] = 0x00;
}
}
break;
}
case PNG_BitDepth_8 :
case PNG_BitDepth_16 :
{
OutPtr[0] = DecompPtr[0];
OutPtr[1] = DecompPtr[0];
OutPtr[2] = DecompPtr[0];
OutPtr[3] = 0xFF;
/*
* Grey supports full transparency for one specified colour
*/
if(HasTransparentColour)
{
if(IHDR->BitDepth == PNG_BitDepth_8)
{
if(TransparentColour[1] == DecompPtr[0])
{
OutPtr[3] = 0x00;
}
}
else
{
if((TransparentColour[0] == DecompPtr[0]) && (TransparentColour[1] == DecompPtr[1]))
{
OutPtr[3] = 0x00;
}
}
}
break;
}
default :
{
return(qfalse);
}
}
break;
}
case PNG_ColourType_True :
{
switch(IHDR->BitDepth)
{
case PNG_BitDepth_8 :
{
OutPtr[0] = DecompPtr[0];
OutPtr[1] = DecompPtr[1];
OutPtr[2] = DecompPtr[2];
OutPtr[3] = 0xFF;
/*
* True supports full transparency for one specified colour
*/
if(HasTransparentColour)
{
if((TransparentColour[1] == DecompPtr[0]) &&
(TransparentColour[3] == DecompPtr[1]) &&
(TransparentColour[5] == DecompPtr[2]))
{
OutPtr[3] = 0x00;
}
}
break;
}
case PNG_BitDepth_16 :
{
/*
* We use only the upper byte.
*/
OutPtr[0] = DecompPtr[0];
OutPtr[1] = DecompPtr[2];
OutPtr[2] = DecompPtr[4];
OutPtr[3] = 0xFF;
/*
* True supports full transparency for one specified colour
*/
if(HasTransparentColour)
{
if((TransparentColour[0] == DecompPtr[0]) && (TransparentColour[1] == DecompPtr[1]) &&
(TransparentColour[2] == DecompPtr[2]) && (TransparentColour[3] == DecompPtr[3]) &&
(TransparentColour[4] == DecompPtr[4]) && (TransparentColour[5] == DecompPtr[5]))
{
OutPtr[3] = 0x00;
}
}
break;
}
default :
{
return(qfalse);
}
}
break;
}
case PNG_ColourType_Indexed :
{
OutPtr[0] = OutPal[DecompPtr[0] * Q3IMAGE_BYTESPERPIXEL + 0];
OutPtr[1] = OutPal[DecompPtr[0] * Q3IMAGE_BYTESPERPIXEL + 1];
OutPtr[2] = OutPal[DecompPtr[0] * Q3IMAGE_BYTESPERPIXEL + 2];
OutPtr[3] = OutPal[DecompPtr[0] * Q3IMAGE_BYTESPERPIXEL + 3];
break;
}
case PNG_ColourType_GreyAlpha :
{
switch(IHDR->BitDepth)
{
case PNG_BitDepth_8 :
{
OutPtr[0] = DecompPtr[0];
OutPtr[1] = DecompPtr[0];
OutPtr[2] = DecompPtr[0];
OutPtr[3] = DecompPtr[1];
break;
}
case PNG_BitDepth_16 :
{
/*
* We use only the upper byte.
*/
OutPtr[0] = DecompPtr[0];
OutPtr[1] = DecompPtr[0];
OutPtr[2] = DecompPtr[0];
OutPtr[3] = DecompPtr[2];
break;
}
default :
{
return(qfalse);
}
}
break;
}
case PNG_ColourType_TrueAlpha :
{
switch(IHDR->BitDepth)
{
case PNG_BitDepth_8 :
{
OutPtr[0] = DecompPtr[0];
OutPtr[1] = DecompPtr[1];
OutPtr[2] = DecompPtr[2];
OutPtr[3] = DecompPtr[3];
break;
}
case PNG_BitDepth_16 :
{
/*
* We use only the upper byte.
*/
OutPtr[0] = DecompPtr[0];
OutPtr[1] = DecompPtr[2];
OutPtr[2] = DecompPtr[4];
OutPtr[3] = DecompPtr[6];
break;
}
default :
{
return(qfalse);
}
}
break;
}
default :
{
return(qfalse);
}
}
return(qtrue);
}
/*
* Decode a non-interlaced image.
*/
static qboolean DecodeImageNonInterlaced(struct PNG_Chunk_IHDR *IHDR,
byte *OutBuffer,
uint8_t *DecompressedData,
uint32_t DecompressedDataLength,
qboolean HasTransparentColour,
uint8_t *TransparentColour,
uint8_t *OutPal)
{
uint32_t IHDR_Width;
uint32_t IHDR_Height;
uint32_t BytesPerScanline, BytesPerPixel, PixelsPerByte;
uint32_t w, h, p;
byte *OutPtr;
uint8_t *DecompPtr;
/*
* input verification
*/
if(!(IHDR && OutBuffer && DecompressedData && DecompressedDataLength && TransparentColour && OutPal))
{
return(qfalse);
}
/*
* byte swapping
*/
IHDR_Width = BigLong(IHDR->Width);
IHDR_Height = BigLong(IHDR->Height);
/*
* information for un-filtering
*/
switch(IHDR->ColourType)
{
case PNG_ColourType_Grey :
{
switch(IHDR->BitDepth)
{
case PNG_BitDepth_1 :
case PNG_BitDepth_2 :
case PNG_BitDepth_4 :
{
BytesPerPixel = 1;
PixelsPerByte = 8 / IHDR->BitDepth;
break;
}
case PNG_BitDepth_8 :
case PNG_BitDepth_16 :
{
BytesPerPixel = (IHDR->BitDepth / 8) * PNG_NumColourComponents_Grey;
PixelsPerByte = 1;
break;
}
default :
{
return(qfalse);
}
}
break;
}
case PNG_ColourType_True :
{
switch(IHDR->BitDepth)
{
case PNG_BitDepth_8 :
case PNG_BitDepth_16 :
{
BytesPerPixel = (IHDR->BitDepth / 8) * PNG_NumColourComponents_True;
PixelsPerByte = 1;
break;
}
default :
{
return(qfalse);
}
}
break;
}
case PNG_ColourType_Indexed :
{
switch(IHDR->BitDepth)
{
case PNG_BitDepth_1 :
case PNG_BitDepth_2 :
case PNG_BitDepth_4 :
{
BytesPerPixel = 1;
PixelsPerByte = 8 / IHDR->BitDepth;
break;
}
case PNG_BitDepth_8 :
{
BytesPerPixel = PNG_NumColourComponents_Indexed;
PixelsPerByte = 1;
break;
}
default :
{
return(qfalse);
}
}
break;
}
case PNG_ColourType_GreyAlpha :
{
switch(IHDR->BitDepth)
{
case PNG_BitDepth_8 :
case PNG_BitDepth_16 :
{
BytesPerPixel = (IHDR->BitDepth / 8) * PNG_NumColourComponents_GreyAlpha;
PixelsPerByte = 1;
break;
}
default :
{
return(qfalse);
}
}
break;
}
case PNG_ColourType_TrueAlpha :
{
switch(IHDR->BitDepth)
{
case PNG_BitDepth_8 :
case PNG_BitDepth_16 :
{
BytesPerPixel = (IHDR->BitDepth / 8) * PNG_NumColourComponents_TrueAlpha;
PixelsPerByte = 1;
break;
}
default :
{
return(qfalse);
}
}
break;
}
default :
{
return(qfalse);
}
}
/*
* Calculate the size of one scanline
*/
BytesPerScanline = (IHDR_Width * BytesPerPixel + (PixelsPerByte - 1)) / PixelsPerByte;
/*
* Check if we have enough data for the whole image.
*/
if(!(DecompressedDataLength == ((BytesPerScanline + 1) * IHDR_Height)))
{
return(qfalse);
}
/*
* Unfilter the image.
*/
if(!UnfilterImage(DecompressedData, IHDR_Height, BytesPerScanline, BytesPerPixel))
{
return(qfalse);
}
/*
* Set the working pointers to the beginning of the buffers.
*/
OutPtr = OutBuffer;
DecompPtr = DecompressedData;
/*
* Create the output image.
*/
for(h = 0; h < IHDR_Height; h++)
{
/*
* Count the pixels on the scanline for those multipixel bytes
*/
uint32_t CurrPixel;
/*
* skip FilterType
*/
DecompPtr++;
/*
* Reset the pixel count.
*/
CurrPixel = 0;
for(w = 0; w < (BytesPerScanline / BytesPerPixel); w++)
{
if(PixelsPerByte > 1)
{
uint8_t Mask;
uint32_t Shift;
uint8_t SinglePixel;
for(p = 0; p < PixelsPerByte; p++)
{
if(CurrPixel < IHDR_Width)
{
Mask = (1 << IHDR->BitDepth) - 1;
Shift = (PixelsPerByte - 1 - p) * IHDR->BitDepth;
SinglePixel = ((DecompPtr[0] & (Mask << Shift)) >> Shift);
if(!ConvertPixel(IHDR, OutPtr, &SinglePixel, HasTransparentColour, TransparentColour, OutPal))
{
return(qfalse);
}
OutPtr += Q3IMAGE_BYTESPERPIXEL;
CurrPixel++;
}
}
}
else
{
if(!ConvertPixel(IHDR, OutPtr, DecompPtr, HasTransparentColour, TransparentColour, OutPal))
{
return(qfalse);
}
OutPtr += Q3IMAGE_BYTESPERPIXEL;
}
DecompPtr += BytesPerPixel;
}
}
return(qtrue);
}
/*
* Decode an interlaced image.
*/
static qboolean DecodeImageInterlaced(struct PNG_Chunk_IHDR *IHDR,
byte *OutBuffer,
uint8_t *DecompressedData,
uint32_t DecompressedDataLength,
qboolean HasTransparentColour,
uint8_t *TransparentColour,
uint8_t *OutPal)
{
uint32_t IHDR_Width;
uint32_t IHDR_Height;
uint32_t BytesPerScanline[PNG_Adam7_NumPasses], BytesPerPixel, PixelsPerByte;
uint32_t PassWidth[PNG_Adam7_NumPasses], PassHeight[PNG_Adam7_NumPasses];
uint32_t WSkip[PNG_Adam7_NumPasses], WOffset[PNG_Adam7_NumPasses], HSkip[PNG_Adam7_NumPasses], HOffset[PNG_Adam7_NumPasses];
uint32_t w, h, p, a;
byte *OutPtr;
uint8_t *DecompPtr;
uint32_t TargetLength;
/*
* input verification
*/
if(!(IHDR && OutBuffer && DecompressedData && DecompressedDataLength && TransparentColour && OutPal))
{
return(qfalse);
}
/*
* byte swapping
*/
IHDR_Width = BigLong(IHDR->Width);
IHDR_Height = BigLong(IHDR->Height);
/*
* Skip and Offset for the passes.
*/
WSkip[0] = 8;
WOffset[0] = 0;
HSkip[0] = 8;
HOffset[0] = 0;
WSkip[1] = 8;
WOffset[1] = 4;
HSkip[1] = 8;
HOffset[1] = 0;
WSkip[2] = 4;
WOffset[2] = 0;
HSkip[2] = 8;
HOffset[2] = 4;
WSkip[3] = 4;
WOffset[3] = 2;
HSkip[3] = 4;
HOffset[3] = 0;
WSkip[4] = 2;
WOffset[4] = 0;
HSkip[4] = 4;
HOffset[4] = 2;
WSkip[5] = 2;
WOffset[5] = 1;
HSkip[5] = 2;
HOffset[5] = 0;
WSkip[6] = 1;
WOffset[6] = 0;
HSkip[6] = 2;
HOffset[6] = 1;
/*
* Calculate the sizes of the passes.
*/
PassWidth[0] = (IHDR_Width + 7) / 8;
PassHeight[0] = (IHDR_Height + 7) / 8;
PassWidth[1] = (IHDR_Width + 3) / 8;
PassHeight[1] = (IHDR_Height + 7) / 8;
PassWidth[2] = (IHDR_Width + 3) / 4;
PassHeight[2] = (IHDR_Height + 3) / 8;
PassWidth[3] = (IHDR_Width + 1) / 4;
PassHeight[3] = (IHDR_Height + 3) / 4;
PassWidth[4] = (IHDR_Width + 1) / 2;
PassHeight[4] = (IHDR_Height + 1) / 4;
PassWidth[5] = (IHDR_Width + 0) / 2;
PassHeight[5] = (IHDR_Height + 1) / 2;
PassWidth[6] = (IHDR_Width + 0) / 1;
PassHeight[6] = (IHDR_Height + 0) / 2;
/*
* information for un-filtering
*/
switch(IHDR->ColourType)
{
case PNG_ColourType_Grey :
{
switch(IHDR->BitDepth)
{
case PNG_BitDepth_1 :
case PNG_BitDepth_2 :
case PNG_BitDepth_4 :
{
BytesPerPixel = 1;
PixelsPerByte = 8 / IHDR->BitDepth;
break;
}
case PNG_BitDepth_8 :
case PNG_BitDepth_16 :
{
BytesPerPixel = (IHDR->BitDepth / 8) * PNG_NumColourComponents_Grey;
PixelsPerByte = 1;
break;
}
default :
{
return(qfalse);
}
}
break;
}
case PNG_ColourType_True :
{
switch(IHDR->BitDepth)
{
case PNG_BitDepth_8 :
case PNG_BitDepth_16 :
{
BytesPerPixel = (IHDR->BitDepth / 8) * PNG_NumColourComponents_True;
PixelsPerByte = 1;
break;
}
default :
{
return(qfalse);
}
}
break;
}
case PNG_ColourType_Indexed :
{
switch(IHDR->BitDepth)
{
case PNG_BitDepth_1 :
case PNG_BitDepth_2 :
case PNG_BitDepth_4 :
{
BytesPerPixel = 1;
PixelsPerByte = 8 / IHDR->BitDepth;
break;
}
case PNG_BitDepth_8 :
{
BytesPerPixel = PNG_NumColourComponents_Indexed;
PixelsPerByte = 1;
break;
}
default :
{
return(qfalse);
}
}
break;
}
case PNG_ColourType_GreyAlpha :
{
switch(IHDR->BitDepth)
{
case PNG_BitDepth_8 :
case PNG_BitDepth_16 :
{
BytesPerPixel = (IHDR->BitDepth / 8) * PNG_NumColourComponents_GreyAlpha;
PixelsPerByte = 1;
break;
}
default :
{
return(qfalse);
}
}
break;
}
case PNG_ColourType_TrueAlpha :
{
switch(IHDR->BitDepth)
{
case PNG_BitDepth_8 :
case PNG_BitDepth_16 :
{
BytesPerPixel = (IHDR->BitDepth / 8) * PNG_NumColourComponents_TrueAlpha;
PixelsPerByte = 1;
break;
}
default :
{
return(qfalse);
}
}
break;
}
default :
{
return(qfalse);
}
}
/*
* Calculate the size of the scanlines per pass
*/
for(a = 0; a < PNG_Adam7_NumPasses; a++)
{
BytesPerScanline[a] = (PassWidth[a] * BytesPerPixel + (PixelsPerByte - 1)) / PixelsPerByte;
}
/*
* Calculate the size of all passes
*/
TargetLength = 0;
for(a = 0; a < PNG_Adam7_NumPasses; a++)
{
TargetLength += ((BytesPerScanline[a] + (BytesPerScanline[a] ? 1 : 0)) * PassHeight[a]);
}
/*
* Check if we have enough data for the whole image.
*/
if(!(DecompressedDataLength == TargetLength))
{
return(qfalse);
}
/*
* Unfilter the image.
*/
DecompPtr = DecompressedData;
for(a = 0; a < PNG_Adam7_NumPasses; a++)
{
if(!UnfilterImage(DecompPtr, PassHeight[a], BytesPerScanline[a], BytesPerPixel))
{
return(qfalse);
}
DecompPtr += ((BytesPerScanline[a] + (BytesPerScanline[a] ? 1 : 0)) * PassHeight[a]);
}
/*
* Set the working pointers to the beginning of the buffers.
*/
DecompPtr = DecompressedData;
/*
* Create the output image.
*/
for(a = 0; a < PNG_Adam7_NumPasses; a++)
{
for(h = 0; h < PassHeight[a]; h++)
{
/*
* Count the pixels on the scanline for those multipixel bytes
*/
uint32_t CurrPixel;
/*
* skip FilterType
* but only when the pass has a width bigger than zero
*/
if(BytesPerScanline[a])
{
DecompPtr++;
}
/*
* Reset the pixel count.
*/
CurrPixel = 0;
for(w = 0; w < (BytesPerScanline[a] / BytesPerPixel); w++)
{
if(PixelsPerByte > 1)
{
uint8_t Mask;
uint32_t Shift;
uint8_t SinglePixel;
for(p = 0; p < PixelsPerByte; p++)
{
if(CurrPixel < PassWidth[a])
{
Mask = (1 << IHDR->BitDepth) - 1;
Shift = (PixelsPerByte - 1 - p) * IHDR->BitDepth;
SinglePixel = ((DecompPtr[0] & (Mask << Shift)) >> Shift);
OutPtr = OutBuffer + (((((h * HSkip[a]) + HOffset[a]) * IHDR_Width) + ((CurrPixel * WSkip[a]) + WOffset[a])) * Q3IMAGE_BYTESPERPIXEL);
if(!ConvertPixel(IHDR, OutPtr, &SinglePixel, HasTransparentColour, TransparentColour, OutPal))
{
return(qfalse);
}
CurrPixel++;
}
}
}
else
{
OutPtr = OutBuffer + (((((h * HSkip[a]) + HOffset[a]) * IHDR_Width) + ((w * WSkip[a]) + WOffset[a])) * Q3IMAGE_BYTESPERPIXEL);
if(!ConvertPixel(IHDR, OutPtr, DecompPtr, HasTransparentColour, TransparentColour, OutPal))
{
return(qfalse);
}
}
DecompPtr += BytesPerPixel;
}
}
}
return(qtrue);
}
/*
* The PNG loader
*/
void R_LoadPNG(const char *name, byte **pic, int *width, int *height)
{
struct BufferedFile *ThePNG;
byte *OutBuffer;
uint8_t *Signature;
struct PNG_ChunkHeader *CH;
uint32_t ChunkHeaderLength;
uint32_t ChunkHeaderType;
struct PNG_Chunk_IHDR *IHDR;
uint32_t IHDR_Width;
uint32_t IHDR_Height;
PNG_ChunkCRC *CRC;
uint8_t *InPal;
uint8_t *DecompressedData;
uint32_t DecompressedDataLength;
uint32_t i;
/*
* palette with 256 RGBA entries
*/
uint8_t OutPal[1024];
/*
* transparent colour from the tRNS chunk
*/
qboolean HasTransparentColour = qfalse;
uint8_t TransparentColour[6] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
/*
* input verification
*/
if(!(name && pic))
{
return;
}
/*
* Zero out return values.
*/
*pic = NULL;
if(width)
{
*width = 0;
}
if(height)
{
*height = 0;
}
/*
* Read the file.
*/
ThePNG = ReadBufferedFile(name);
if(!ThePNG)
{
return;
}
/*
* Read the siganture of the file.
*/
Signature = BufferedFileRead(ThePNG, PNG_Signature_Size);
if(!Signature)
{
CloseBufferedFile(ThePNG);
return;
}
/*
* Is it a PNG?
*/
if(memcmp(Signature, PNG_Signature, PNG_Signature_Size))
{
CloseBufferedFile(ThePNG);
return;
}
/*
* Read the first chunk-header.
*/
CH = BufferedFileRead(ThePNG, PNG_ChunkHeader_Size);
if(!CH)
{
CloseBufferedFile(ThePNG);
return;
}
/*
* PNG multi-byte types are in Big Endian
*/
ChunkHeaderLength = BigLong(CH->Length);
ChunkHeaderType = BigLong(CH->Type);
/*
* Check if the first chunk is an IHDR.
*/
if(!((ChunkHeaderType == PNG_ChunkType_IHDR) && (ChunkHeaderLength == PNG_Chunk_IHDR_Size)))
{
CloseBufferedFile(ThePNG);
return;
}
/*
* Read the IHDR.
*/
IHDR = BufferedFileRead(ThePNG, PNG_Chunk_IHDR_Size);
if(!IHDR)
{
CloseBufferedFile(ThePNG);
return;
}
/*
* Read the CRC for IHDR
*/
CRC = BufferedFileRead(ThePNG, PNG_ChunkCRC_Size);
if(!CRC)
{
CloseBufferedFile(ThePNG);
return;
}
/*
* Here we could check the CRC if we wanted to.
*/
/*
* multi-byte type swapping
*/
IHDR_Width = BigLong(IHDR->Width);
IHDR_Height = BigLong(IHDR->Height);
/*
* Check if Width and Height are valid.
*/
if(!((IHDR_Width > 0) && (IHDR_Height > 0))
|| IHDR_Width > INT_MAX / Q3IMAGE_BYTESPERPIXEL / IHDR_Height)
{
CloseBufferedFile(ThePNG);
ri.Printf( PRINT_WARNING, "%s: invalid image size\n", name );
return;
}
/*
* Do we need to check if the dimensions of the image are valid for Quake3?
*/
/*
* Check if CompressionMethod and FilterMethod are valid.
*/
if(!((IHDR->CompressionMethod == PNG_CompressionMethod_0) && (IHDR->FilterMethod == PNG_FilterMethod_0)))
{
CloseBufferedFile(ThePNG);
return;
}
/*
* Check if InterlaceMethod is valid.
*/
if(!((IHDR->InterlaceMethod == PNG_InterlaceMethod_NonInterlaced) || (IHDR->InterlaceMethod == PNG_InterlaceMethod_Interlaced)))
{
CloseBufferedFile(ThePNG);
return;
}
/*
* Read palette for an indexed image.
*/
if(IHDR->ColourType == PNG_ColourType_Indexed)
{
/*
* We need the palette first.
*/
if(!FindChunk(ThePNG, PNG_ChunkType_PLTE))
{
CloseBufferedFile(ThePNG);
return;
}
/*
* Read the chunk-header.
*/
CH = BufferedFileRead(ThePNG, PNG_ChunkHeader_Size);
if(!CH)
{
CloseBufferedFile(ThePNG);
return;
}
/*
* PNG multi-byte types are in Big Endian
*/
ChunkHeaderLength = BigLong(CH->Length);
ChunkHeaderType = BigLong(CH->Type);
/*
* Check if the chunk is a PLTE.
*/
if(!(ChunkHeaderType == PNG_ChunkType_PLTE))
{
CloseBufferedFile(ThePNG);
return;
}
/*
* Check if Length is divisible by 3
*/
if(ChunkHeaderLength % 3)
{
CloseBufferedFile(ThePNG);
return;
}
/*
* Read the raw palette data
*/
InPal = BufferedFileRead(ThePNG, ChunkHeaderLength);
if(!InPal)
{
CloseBufferedFile(ThePNG);
return;
}
/*
* Read the CRC for the palette
*/
CRC = BufferedFileRead(ThePNG, PNG_ChunkCRC_Size);
if(!CRC)
{
CloseBufferedFile(ThePNG);
return;
}
/*
* Set some default values.
*/
for(i = 0; i < 256; i++)
{
OutPal[i * Q3IMAGE_BYTESPERPIXEL + 0] = 0x00;
OutPal[i * Q3IMAGE_BYTESPERPIXEL + 1] = 0x00;
OutPal[i * Q3IMAGE_BYTESPERPIXEL + 2] = 0x00;
OutPal[i * Q3IMAGE_BYTESPERPIXEL + 3] = 0xFF;
}
/*
* Convert to the Quake3 RGBA-format.
*/
for(i = 0; i < (ChunkHeaderLength / 3); i++)
{
OutPal[i * Q3IMAGE_BYTESPERPIXEL + 0] = InPal[i*3+0];
OutPal[i * Q3IMAGE_BYTESPERPIXEL + 1] = InPal[i*3+1];
OutPal[i * Q3IMAGE_BYTESPERPIXEL + 2] = InPal[i*3+2];
OutPal[i * Q3IMAGE_BYTESPERPIXEL + 3] = 0xFF;
}
}
/*
* transparency information is sometimes stored in a tRNS chunk
*/
/*
* Let's see if there is a tRNS chunk
*/
if(FindChunk(ThePNG, PNG_ChunkType_tRNS))
{
uint8_t *Trans;
/*
* Read the chunk-header.
*/
CH = BufferedFileRead(ThePNG, PNG_ChunkHeader_Size);
if(!CH)
{
CloseBufferedFile(ThePNG);
return;
}
/*
* PNG multi-byte types are in Big Endian
*/
ChunkHeaderLength = BigLong(CH->Length);
ChunkHeaderType = BigLong(CH->Type);
/*
* Check if the chunk is a tRNS.
*/
if(!(ChunkHeaderType == PNG_ChunkType_tRNS))
{
CloseBufferedFile(ThePNG);
return;
}
/*
* Read the transparency information.
*/
Trans = BufferedFileRead(ThePNG, ChunkHeaderLength);
if(!Trans)
{
CloseBufferedFile(ThePNG);
return;
}
/*
* Read the CRC.
*/
CRC = BufferedFileRead(ThePNG, PNG_ChunkCRC_Size);
if(!CRC)
{
CloseBufferedFile(ThePNG);
return;
}
/*
* Only for Grey, True and Indexed ColourType should tRNS exist.
*/
switch(IHDR->ColourType)
{
case PNG_ColourType_Grey :
{
if(ChunkHeaderLength != 2)
{
CloseBufferedFile(ThePNG);
return;
}
HasTransparentColour = qtrue;
/*
* Grey can have one colour which is completely transparent.
* This colour is always stored in 16 bits.
*/
TransparentColour[0] = Trans[0];
TransparentColour[1] = Trans[1];
break;
}
case PNG_ColourType_True :
{
if(ChunkHeaderLength != 6)
{
CloseBufferedFile(ThePNG);
return;
}
HasTransparentColour = qtrue;
/*
* True can have one colour which is completely transparent.
* This colour is always stored in 16 bits.
*/
TransparentColour[0] = Trans[0];
TransparentColour[1] = Trans[1];
TransparentColour[2] = Trans[2];
TransparentColour[3] = Trans[3];
TransparentColour[4] = Trans[4];
TransparentColour[5] = Trans[5];
break;
}
case PNG_ColourType_Indexed :
{
/*
* Maximum of 256 one byte transparency entries.
*/
if(ChunkHeaderLength > 256)
{
CloseBufferedFile(ThePNG);
return;
}
HasTransparentColour = qtrue;
/*
* alpha values for palette entries
*/
for(i = 0; i < ChunkHeaderLength; i++)
{
OutPal[i * Q3IMAGE_BYTESPERPIXEL + 3] = Trans[i];
}
break;
}
/*
* All other ColourTypes should not have tRNS chunks
*/
default :
{
CloseBufferedFile(ThePNG);
return;
}
}
}
/*
* Rewind to the start of the file.
*/
if(!BufferedFileRewind(ThePNG, -1))
{
CloseBufferedFile(ThePNG);
return;
}
/*
* Skip the signature
*/
if(!BufferedFileSkip(ThePNG, PNG_Signature_Size))
{
CloseBufferedFile(ThePNG);
return;
}
/*
* Decompress all IDAT chunks
*/
DecompressedDataLength = DecompressIDATs(ThePNG, &DecompressedData);
if(!(DecompressedDataLength && DecompressedData))
{
CloseBufferedFile(ThePNG);
return;
}
/*
* Allocate output buffer.
*/
OutBuffer = ri.Malloc(IHDR_Width * IHDR_Height * Q3IMAGE_BYTESPERPIXEL);
if(!OutBuffer)
{
ri.Free(DecompressedData);
CloseBufferedFile(ThePNG);
return;
}
/*
* Interlaced and Non-interlaced images need to be handled differently.
*/
switch(IHDR->InterlaceMethod)
{
case PNG_InterlaceMethod_NonInterlaced :
{
if(!DecodeImageNonInterlaced(IHDR, OutBuffer, DecompressedData, DecompressedDataLength, HasTransparentColour, TransparentColour, OutPal))
{
ri.Free(OutBuffer);
ri.Free(DecompressedData);
CloseBufferedFile(ThePNG);
return;
}
break;
}
case PNG_InterlaceMethod_Interlaced :
{
if(!DecodeImageInterlaced(IHDR, OutBuffer, DecompressedData, DecompressedDataLength, HasTransparentColour, TransparentColour, OutPal))
{
ri.Free(OutBuffer);
ri.Free(DecompressedData);
CloseBufferedFile(ThePNG);
return;
}
break;
}
default :
{
ri.Free(OutBuffer);
ri.Free(DecompressedData);
CloseBufferedFile(ThePNG);
return;
}
}
/*
* update the pointer to the image data
*/
*pic = OutBuffer;
/*
* Fill width and height.
*/
if(width)
{
*width = IHDR_Width;
}
if(height)
{
*height = IHDR_Height;
}
/*
* DecompressedData is not needed anymore.
*/
ri.Free(DecompressedData);
/*
* We have all data, so close the file.
*/
CloseBufferedFile(ThePNG);
}
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