MegaGlest/source/shared_lib/sources/graphics/JPGReader.cpp
2010-10-21 07:20:17 +00:00

226 lines
6.9 KiB
C++

// ==============================================================
// This file is part of Glest Shared Library (www.glest.org)
//
// Copyright (C) 2001-2010 Martiño Figueroa and others
//
// You can redistribute this code 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
// ==============================================================
#include "JPGReader.h"
#include "FileReader.h"
#include "types.h"
#include "pixmap.h"
#include <stdexcept>
#include <jpeglib.h>
#include <setjmp.h>
#include "leak_dumper.h"
using std::runtime_error;
using std::ios;
/**Used things from CImageLoaderJPG.cpp from Irrlicht*/
namespace Shared{ namespace Graphics{
// =====================================================
// Methods used for JPG-Decompression
// =====================================================
//Methods used by jpeglib
static void init_source(j_decompress_ptr cinfo) {
//It already is initialized
}
static boolean fill_input_buffer (j_decompress_ptr cinfo) {
//it is already filled
return true;
}
static void skip_input_data (j_decompress_ptr cinfo, long num_bytes) {
if (num_bytes > 0) {
jpeg_source_mgr* This = cinfo->src;
This->bytes_in_buffer-= num_bytes;
This->next_input_byte+= num_bytes;
}
}
static void term_source (j_decompress_ptr cinfo) {
}
// =====================================================
// class JPGReader
// =====================================================
/**Return an array containing the used extensions,
* initialized*/
//static inline const string* getExtensions() {
//static const string extensions[] = {"jpg", "jpeg", ""};
static inline std::vector<string> getExtensions() {
static std::vector<string> extensions;
if(extensions.size() == 0) {
extensions.push_back("jpg");
extensions.push_back("jpeg");
}
return extensions;
}
JPGReader::JPGReader(): FileReader<Pixmap2D>(getExtensions()) {}
Pixmap2D* JPGReader::read(ifstream& is, const string& path, Pixmap2D* ret) const {
//Read file
is.seekg(0, ios::end);
size_t length = is.tellg();
if (length < 8) {
return NULL;
}
is.seekg(0, ios::beg);
uint8 *buffer = new uint8[length];
is.read((char*)buffer, (std::streamsize)length);
//Check buffer (weak jpeg check)
//if (buffer[0] != 0x46 || buffer[1] != 0xA0) {
// Proper header check found from: http://www.fastgraph.com/help/jpeg_header_format.html
if (buffer[0] != 0xFF || buffer[1] != 0xD8) {
std::cout << "0 = [" << std::hex << (int)buffer[0] << "] 1 = [" << std::hex << (int)buffer[1] << "]" << std::endl;
delete[] buffer;
return NULL;
}
struct jpeg_decompress_struct cinfo;
struct jpeg_error_mgr jerr;
JSAMPROW row_pointer[1];
row_pointer[0] = NULL;
cinfo.err = jpeg_std_error( &jerr ); //Standard error handler
jpeg_create_decompress( &cinfo ); //Create decompressing structure
struct jpeg_source_mgr source;
jmp_buf error_buffer; //Used for saving/restoring context
// Set up data pointer
source.bytes_in_buffer = length;
source.next_input_byte = (JOCTET*)buffer;
cinfo.src = &source;
if (setjmp(error_buffer)) { //Longjump was called --> an exception was thrown
delete[] buffer;
jpeg_destroy_decompress(&cinfo);
if (row_pointer[0] != NULL) {
delete[] row_pointer[0];
}
return NULL;
}
source.init_source = init_source;
source.fill_input_buffer = fill_input_buffer;
source.resync_to_restart = jpeg_resync_to_restart;
source.skip_input_data = skip_input_data;
source.term_source = term_source;
/* reading the image header which contains image information */
if (jpeg_read_header( &cinfo, TRUE ) != JPEG_HEADER_OK) {
delete[] buffer;
jpeg_destroy_decompress(&cinfo);
return NULL;
}
/*std::cout << "JPEG FILE Information: " << std::endl;
std::cout << "Image width and height: " << cinfo.image_width <<" pixels and " << cinfo.image_height <<" pixels." << std::endl;
std::cout << "Color components per fixel: " << cinfo.num_components << std::endl;
std::cout << "Color space: " << cinfo.jpeg_color_space << std::endl;*/
int picComponents = (ret->getComponents() == -1)?cinfo.num_components:ret->getComponents();
//std::cout << "JPG-Components: Pic: " << picComponents << " old: " << (ret->getComponents()) << " File: " << cinfo.num_components << std::endl;
//picComponents = 4;
//TODO: Irrlicht has some special CMYK-handling - maybe needed too?
/* Start decompression jpeg here */
jpeg_start_decompress( &cinfo );
ret->init(cinfo.image_width, cinfo.image_height, picComponents);
uint8* pixels = ret->getPixels();
//std::cout << "output width and height: " << cinfo.output_width <<" pixels and " << cinfo.output_height <<" pixels." << std::endl;
/* now actually read the jpeg into the raw buffer */
row_pointer[0] = new unsigned char[cinfo.output_width*cinfo.num_components];
size_t location = 0; //Current pixel
/* read one scan line at a time */
/* Again you need to invert the lines unfortunately*/
while( cinfo.output_scanline < cinfo.output_height )
{
jpeg_read_scanlines( &cinfo, row_pointer, 1 );
location = (cinfo.output_height - cinfo.output_scanline)*cinfo.output_width*picComponents;
if (picComponents == cinfo.num_components) {
memcpy(pixels+location,row_pointer[0],cinfo.output_width*cinfo.num_components);
} else {
int r,g,b,a,l;
for (unsigned int xPic = 0, xFile = 0; xPic < cinfo.output_width*picComponents; xPic+= picComponents, xFile+= cinfo.num_components) {
switch(cinfo.num_components) {
case 3:
r = row_pointer[0][xFile];
g = row_pointer[0][xFile+1];
b = row_pointer[0][xFile+2];
l = (r+g+b+2)/3;
a = 255;
break;
case 4:
r = row_pointer[0][xFile];
g = row_pointer[0][xFile+1];
b = row_pointer[0][xFile+2];
l = (r+g+b+2)/3;
a = row_pointer[0][xFile+3];
break;
default:
//TODO: Error
case 1:
r = g = b = l = row_pointer[0][xFile];
a = 255;
break;
}
switch (picComponents) {
case 1:
pixels[location+xPic] = l;
break;
case 4:
pixels[location+xPic+3] = a; //Next case
case 3:
pixels[location+xPic] = r;
pixels[location+xPic+1] = g;
pixels[location+xPic+2] = b;
break;
default:
//just so at least something works
for (int i = 0; i < picComponents; ++i) {
pixels[location+xPic+i] = l;
}
//TODO: Error
}
}
}
}
/*for(int i = 0; i < cinfo.image_width*cinfo.image_height*picComponents; ++i) {
if (i%39 == 0) std::cout << std::endl;
int first = pixels[i]/16;
if (first < 10)
std:: cout << first;
else
std::cout << (char)('A'+(first-10));
first = pixels[i]%16;
if (first < 10)
std:: cout << first;
else
std::cout << (char)('A'+(first-10));
std::cout << " ";
}*/
/* wrap up decompression, destroy objects, free pointers and close open files */
jpeg_finish_decompress( &cinfo );
jpeg_destroy_decompress( &cinfo );
delete[] row_pointer[0];
delete[] buffer;
return ret;
}
}} //end namespace