FasTC/IO/src/ImageLoaderPNG.cpp
2014-04-02 13:57:17 -04:00

287 lines
9.3 KiB
C++

/* FasTC
* Copyright (c) 2012 University of North Carolina at Chapel Hill. All rights reserved.
*
* Permission to use, copy, modify, and distribute this software and its documentation for educational,
* research, and non-profit purposes, without fee, and without a written agreement is hereby granted,
* provided that the above copyright notice, this paragraph, and the following four paragraphs appear
* in all copies.
*
* Permission to incorporate this software into commercial products may be obtained by contacting the
* authors or the Office of Technology Development at the University of North Carolina at Chapel Hill <otd@unc.edu>.
*
* This software program and documentation are copyrighted by the University of North Carolina at Chapel Hill.
* The software program and documentation are supplied "as is," without any accompanying services from the
* University of North Carolina at Chapel Hill or the authors. The University of North Carolina at Chapel Hill
* and the authors do not warrant that the operation of the program will be uninterrupted or error-free. The
* end-user understands that the program was developed for research purposes and is advised not to rely
* exclusively on the program for any reason.
*
* IN NO EVENT SHALL THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL OR THE AUTHORS BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING OUT OF THE
* USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL OR THE
* AUTHORS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL AND THE AUTHORS SPECIFICALLY DISCLAIM ANY WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE AND ANY
* STATUTORY WARRANTY OF NON-INFRINGEMENT. THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY
* OF NORTH CAROLINA AT CHAPEL HILL AND THE AUTHORS HAVE NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
* ENHANCEMENTS, OR MODIFICATIONS.
*
* Please send all BUG REPORTS to <pavel@cs.unc.edu>.
*
* The authors may be contacted via:
*
* Pavel Krajcevski
* Dept of Computer Science
* 201 S Columbia St
* Frederick P. Brooks, Jr. Computer Science Bldg
* Chapel Hill, NC 27599-3175
* USA
*
* <http://gamma.cs.unc.edu/FasTC/>
*/
#include "ImageLoaderPNG.h"
#include <algorithm>
#include <cassert>
#include <cstdio>
#include <cstring>
#include <png.h>
static void ReportError(const char *msg) {
fprintf(stderr, "ERROR: ImageLoaderPNG -- %s\n", msg);
}
class PNGStreamReader {
public:
static void ReadDataFromStream(png_structp png_ptr,
png_bytep outBytes, png_size_t byteCountToRead
) {
png_voidp io_ptr = png_get_io_ptr( png_ptr );
if( io_ptr == NULL ) {
ReportError("Read callback had invalid io pointer.\n");
return;
}
ImageLoaderPNG &loader = *(ImageLoaderPNG *)(io_ptr);
const unsigned char *stream = &(loader.m_RawData[loader.m_StreamPosition]);
memcpy(outBytes, stream, byteCountToRead);
loader.m_StreamPosition += byteCountToRead;
}
};
ImageLoaderPNG::ImageLoaderPNG(const unsigned char *rawData)
: ImageLoader(rawData)
, m_StreamPosition(8) // We start at position 8 because of PNG header.
{
}
bool ImageLoaderPNG::ReadData() {
const int kNumSigBytesToRead = 8;
uint8 pngSigBuf[kNumSigBytesToRead];
memcpy(pngSigBuf, m_RawData, kNumSigBytesToRead);
const int numSigNoMatch = png_sig_cmp(pngSigBuf, 0, kNumSigBytesToRead);
if(numSigNoMatch) {
ReportError("Incorrect PNG signature");
return false;
}
png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if(!png_ptr) {
ReportError("Could not create read struct");
return false;
}
png_infop info_ptr = png_create_info_struct(png_ptr);
if(!info_ptr) {
ReportError("Could not create info struct");
png_destroy_read_struct(&png_ptr, NULL, NULL);
return false;
}
// Read from our buffer, not a file pointer...
png_set_read_fn(png_ptr, this, PNGStreamReader::ReadDataFromStream);
// Make sure to tell libpng how many bytes we've read...
png_set_sig_bytes(png_ptr, kNumSigBytesToRead);
png_read_info(png_ptr, info_ptr);
int bitDepth = 0;
int colorType = -1;
if( 1 != png_get_IHDR(png_ptr, info_ptr,
(png_uint_32 *)(&m_Width), (png_uint_32 *)(&m_Height),
&bitDepth, &colorType,
NULL, NULL, NULL)
) {
ReportError("Could not read PNG header");
png_destroy_read_struct(&png_ptr, NULL, NULL);
return false;
}
if(bitDepth != 8) {
ReportError("Only 8-bit images currently supported.");
png_destroy_read_struct(&png_ptr, NULL, NULL);
return false;
}
const int numPixels = m_Width * m_Height;
png_size_t bpr = png_get_rowbytes(png_ptr, info_ptr);
png_bytep rowData = new png_byte[bpr];
switch(colorType) {
default:
ReportError("PNG color type unsupported");
png_destroy_read_struct(&png_ptr, NULL, NULL);
return false;
case PNG_COLOR_TYPE_PALETTE:
{
m_RedChannelPrecision = bitDepth;
m_RedData = new unsigned char[numPixels];
m_GreenChannelPrecision = bitDepth;
m_GreenData = new unsigned char[numPixels];
m_BlueChannelPrecision = bitDepth;
m_BlueData = new unsigned char[numPixels];
png_colorp palette;
int nPaletteEntries;
png_uint_32 ret = png_get_PLTE(png_ptr, info_ptr, &palette, &nPaletteEntries);
if(ret != PNG_INFO_PLTE) {
memset(m_BlueData, 0, numPixels);
memset(m_RedData, 0, numPixels);
memset(m_GreenData, 0, numPixels);
assert(!"Couldn't find PLTE chunk");
break;
}
for(uint32 i = 0; i < m_Height; i++) {
png_read_row(png_ptr, rowData, NULL);
unsigned int rowOffset = i * m_Width;
for(uint32 j = 0; j < m_Width; j++) {
assert(rowData[j] < nPaletteEntries);
const png_color &c = palette[::std::min<unsigned char>(rowData[j], nPaletteEntries - 1)];
m_RedData[rowOffset + j] = c.red;
m_GreenData[rowOffset + j] = c.green;
m_BlueData[rowOffset + j] = c.blue;
}
}
}
break;
case PNG_COLOR_TYPE_GRAY: {
m_RedChannelPrecision = bitDepth;
m_RedData = new unsigned char[numPixels];
m_GreenChannelPrecision = bitDepth;
m_GreenData = new unsigned char[numPixels];
m_BlueChannelPrecision = bitDepth;
m_BlueData = new unsigned char[numPixels];
for(uint32 i = 0; i < m_Height; i++) {
png_read_row(png_ptr, rowData, NULL);
unsigned int rowOffset = i * m_Width;
unsigned int byteIdx = 0;
for(uint32 j = 0; j < m_Width; j++) {
m_RedData[rowOffset + j] = rowData[byteIdx];
m_GreenData[rowOffset + j] = rowData[byteIdx];
m_BlueData[rowOffset + j] = rowData[byteIdx];
byteIdx++;
}
assert(byteIdx == bpr);
}
}
break;
case PNG_COLOR_TYPE_RGB:
m_RedChannelPrecision = bitDepth;
m_RedData = new unsigned char[numPixels];
m_GreenChannelPrecision = bitDepth;
m_GreenData = new unsigned char[numPixels];
m_BlueChannelPrecision = bitDepth;
m_BlueData = new unsigned char[numPixels];
for(uint32 i = 0; i < m_Height; i++) {
png_read_row(png_ptr, rowData, NULL);
unsigned int rowOffset = i * m_Width;
unsigned int byteIdx = 0;
for(uint32 j = 0; j < m_Width; j++) {
m_RedData[rowOffset + j] = rowData[byteIdx++];
m_GreenData[rowOffset + j] = rowData[byteIdx++];
m_BlueData[rowOffset + j] = rowData[byteIdx++];
}
assert(byteIdx == bpr);
}
break;
case PNG_COLOR_TYPE_RGB_ALPHA:
m_RedChannelPrecision = bitDepth;
m_RedData = new unsigned char[numPixels];
m_GreenChannelPrecision = bitDepth;
m_GreenData = new unsigned char[numPixels];
m_BlueChannelPrecision = bitDepth;
m_BlueData = new unsigned char[numPixels];
m_AlphaChannelPrecision = bitDepth;
m_AlphaData = new unsigned char[numPixels];
for(uint32 i = 0; i < m_Height; i++) {
png_read_row(png_ptr, rowData, NULL);
unsigned int rowOffset = i * m_Width;
unsigned int byteIdx = 0;
for(uint32 j = 0; j < m_Width; j++) {
m_RedData[rowOffset + j] = rowData[byteIdx++];
m_GreenData[rowOffset + j] = rowData[byteIdx++];
m_BlueData[rowOffset + j] = rowData[byteIdx++];
m_AlphaData[rowOffset + j] = rowData[byteIdx++];
}
assert(byteIdx == bpr);
}
break;
case PNG_COLOR_TYPE_GRAY_ALPHA:
m_RedChannelPrecision = bitDepth;
m_RedData = new unsigned char[numPixels];
m_AlphaChannelPrecision = bitDepth;
m_AlphaData = new unsigned char[numPixels];
for(uint32 i = 0; i < m_Height; i++) {
png_read_row(png_ptr, rowData, NULL);
unsigned int rowOffset = i * m_Width;
unsigned int byteIdx = 0;
for(uint32 j = 0; j < m_Width; j++) {
m_RedData[rowOffset + j] = rowData[byteIdx++];
m_AlphaData[rowOffset + j] = rowData[byteIdx++];
}
assert(byteIdx == bpr);
}
break;
}
// Cleanup
delete [] rowData;
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
return true;
}