/* NIGHTFALL OpenGL Interface                                              */
/* Copyright (C) 2001 Rainer Wichmann & Markus Kuster                      */
/*                                                                         */
/*  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., 675 Mass Ave, Cambridge, MA 02139, USA.              */

/* ANSI C forbids an empty source file, so put this outside                */
/* do nothing here if we don't have OpenGL                                 */

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "Light.h"

#ifdef  _WITH_OPENGL
#include <setjmp.h>
#include <GL/glut.h>

struct my_error_mgr {
  struct jpeg_error_mgr pub;	/* "public" fields */
  jmp_buf setjmp_buffer;	/* for return to caller */
};

typedef struct my_error_mgr * my_error_ptr;

/*
 * Here's the routine that will replace the standard error_exit method:
 */

METHODDEF(void)
my_error_exit (j_common_ptr cinfo)
{
  /* cinfo->err really points to a my_error_mgr struct, so coerce pointer */
  my_error_ptr myerr = (my_error_ptr) cinfo->err;

  /* Always display the message. */
  /* We could postpone this until after returning, if we chose. */
  (*cinfo->err->output_message) (cinfo);

  /* Return control to the setjmp point */
  longjmp(myerr->setjmp_buffer, 1);
}

/******************************************************************
 @package   nightfall
 @author    Markus Kuster (kuster@astro.uni-tuebingen.de)
 @version   1.0
 @short     Read a JPEG coded image file
 @param     (char) *filename   the name of the image file 
            (int)  *width      pointer to the variable to store the 
                               width of the image
	    (int)  *height     pointer to the variable to store the 
                               height of the image
	    (int)  *components number of color components per pixel
 @return    (GLubyte) *buffer  pointer to the image buffer 
                               containing the image
 @heading Read a JPEG image from a file and decompress it. This code
          is based on the example code example.c included in the
          jpeg-library libjpeg-6.2.0.
*******************************************************************/
GLubyte *ReadJPEGFile(char *filename, int *width, int *height, int *components)
{
  /* This struct contains the JPEG decompression parameters and pointers to
   * working space (which is allocated as needed by the JPEG library).
   */
  struct jpeg_decompress_struct cinfo;
  /* We use our private extension JPEG error handler.
   * Note that this struct must live as long as the main JPEG parameter
   * struct, to avoid dangling-pointer problems.
   */
  struct my_error_mgr jerr;
  /* More stuff */
  FILE * infile;		/* source file */
  JSAMPARRAY buffer;		/* Output row buffer */
  JSAMPLE *image_buffer;        /* Array of R,G,B-order data */
  char ErrMsg[256];             /* error message          */ 

  int row_stride;		/* physical row width in output buffer */
  long cont;
  
  /* In this example we want to open the input file before doing anything else,
   * so that the setjmp() error recovery below can assume the file is open.
   * VERY IMPORTANT: use "b" option to fopen() if you are on a machine that
   * requires it in order to read binary files.
   */
  
  if (!(infile = fopen(filename, "rb"))) {
    sprintf(ErrMsg,_("Can't open jpeg file: %s \n"),filename);
    WARNING (ErrMsg);
    return(FALSE);
  }
  
  /* Step 1: allocate and initialize JPEG decompression object */
  
  /* We set up the normal JPEG error routines, then override error_exit. */
  cinfo.err = jpeg_std_error(&jerr.pub);
  jerr.pub.error_exit = my_error_exit;
  /* Establish the setjmp return context for my_error_exit to use. */

  if (setjmp(jerr.setjmp_buffer)) {
    /* If we get here, the JPEG code has signaled an error.
     * We need to clean up the JPEG object, close the input file, and return.
     */
    sprintf(ErrMsg,_("JPEG code has signaled an error ! \n"));
    WARNING (ErrMsg);

    jpeg_destroy_decompress(&cinfo);
    fclose(infile);
    return(FALSE);
  }
  /* Now we can initialize the JPEG decompression object. */
  jpeg_create_decompress(&cinfo);
  
  /* Step 2: specify data source (eg, a file) */
  
  jpeg_stdio_src(&cinfo, infile);
  
  /* Step 3: read file parameters with jpeg_read_header() */
  
  (void) jpeg_read_header(&cinfo, TRUE);
  
  /* We can ignore the return value from jpeg_read_header since
   *   (a) suspension is not possible with the stdio data source, and
   *   (b) we passed TRUE to reject a tables-only JPEG file as an error.
   * See libjpeg.doc for more info.
   */
  
  /* Step 4: set parameters for decompression */
  
  /* In this example, we don't need to change any of the defaults set by
   * jpeg_read_header(), so we do nothing here.
   */
  
  /* Step 5: Start decompressor */
  
  (void) jpeg_start_decompress(&cinfo);
  /* We can ignore the return value since suspension is not possible
   * with the stdio data source.
   */
  
  /* We may need to do some setup of our own at this point before reading
   * the data.  After jpeg_start_decompress() we have the correct scaled
   * output image dimensions available, as well as the output colormap
   * if we asked for color quantization.
   * In this example, we need to make an output work buffer of the right size.
   */ 
  /* JSAMPLEs per row in output buffer */
  row_stride = cinfo.output_width * cinfo.output_components;

  /* Make a one-row-high sample array that will go away when done with image */
  buffer = (*cinfo.mem->alloc_sarray)
    ((j_common_ptr) &cinfo, JPOOL_IMAGE, row_stride, 1);
  
  /* Allocate buffer for the full image */
  image_buffer=(JSAMPLE *) malloc(cinfo.image_width*cinfo.image_height*cinfo.output_components);
  if (!image_buffer) {
    sprintf(ErrMsg,_("Can't allocate memory for image buffer !\n"));
    WARNING (ErrMsg);
    /* clean up and return savely */
    jpeg_destroy_decompress(&cinfo);
    fclose(infile);
    return(FALSE);
  }

  /* Step 6: while (scan lines remain to be read) */
  /*           jpeg_read_scanlines(...); */
  
  /* Here we use the library's state variable cinfo.output_scanline as the
   * loop counter, so that we don't have to keep track ourselves.
   */
  
  cont=cinfo.output_height-1;
  while (cinfo.output_scanline < cinfo.output_height) {
    /* jpeg_read_scanlines expects an array of pointers to scanlines.
     * Here the array is only one element long, but you could ask for
     * more than one scanline at a time if that's more convenient.
     */
    (void) jpeg_read_scanlines(&cinfo, buffer, 1);
    /* copy buffer to the image storage area */
    memcpy(image_buffer+cinfo.image_width*cinfo.output_components*cont,buffer[0],row_stride);
    cont--;
  }
  
  /* Step 7: Finish decompression */
  
  (void) jpeg_finish_decompress(&cinfo);
  /* We can ignore the return value since suspension is not possible
   * with the stdio data source.
   */
  
  /* Step 8: Release JPEG decompression object */
  
  /* This is an important step since it will release a good deal of memory. */
  jpeg_destroy_decompress(&cinfo);
  
  /* After finish_decompress, we can close the input file.
   * Here we postpone it until after no more JPEG errors are possible,
   * so as to simplify the setjmp error logic above.  (Actually, I don't
   * think that jpeg_destroy can do an error exit, but why assume anything...)
   */
  if (infile) {
    fclose(infile);
  }
  
  /* store number of color components per pixel */
  *components=cinfo.output_components;

  /* store image width and height */ 
  *width=cinfo.image_width;
  *height=cinfo.image_height;
  
  
  /* At this point you may want to check to see whether any corrupt-data
   * warnings occurred (test whether jerr.pub.num_warnings is nonzero).
   */
  
  /* And we're done! */
  return image_buffer;
}

/******************************************************************
 @package   nightfall
 @author    Markus Kuster (kuster@astro.uni-tuebingen.de)
 @version   1.0
 @short     Write a JPEG coded image file
 @param     (char) *filename   the name of the image file 
            (int)  *width      pointer to the variable to store the 
                               width of the image
	    (int)  *height     pointer to the variable to store the 
                               height of the image
	    (int)  *components number of color components per pixel
 @return    (GLubyte) *buffer  pointer to the image buffer 
                               containing the image
 @heading Compress a byte image and write it as jpeg file. This code
          is based on the example code example.c included in the
          jpeg-library libjpeg-6.2.0.
*******************************************************************/
int WriteJPEGFile(JSAMPLE * imgbuff, char *filename, int imgwidth, 
		    int imgheight, int components, int quality)
{  
  /* This struct contains the JPEG compression parameters and pointers to
   * working space (which is allocated as needed by the JPEG library).
   * It is possible to have several such structures, representing multiple
   * compression/decompression processes, in existence at once.  We refer
   * to any one struct (and its associated working data) as a "JPEG object".
   */
  struct jpeg_compress_struct cinfo;
  /* This struct represents a JPEG error handler. It is declared separately
   * because applications often want to supply a specialized error handler
   * (see the second half of this file for an example).  But here we just
   * take the easy way out and use the standard error handler, which will
   * print a message on stderr and call exit() if compression fails.
   * Note that this struct must live as long as the main JPEG parameter
   * struct, to avoid dangling-pointer problems.
   */
  struct my_error_mgr jerr;
  JSAMPROW row_pointer[1];      /* pointer to JSAMPLE row[s] */
  int row_stride,line;          /* physical row width in image buffer */
  FILE *outfile;                /* image file */
  char ErrMsg[256];             /* error message          */ 

  /* open output file */
  if (!(outfile = fopen(filename, "wb"))) {
    sprintf(ErrMsg,_("Can't write jpeg file: %s \n"),filename);
    WARNING (ErrMsg);
    return(FALSE);
  }

  /* Step 1: allocate and initialize JPEG compression object */

  /* We have to set up the error handler first, in case the initialization
   * step fails.  (Unlikely, but it could happen if you are out of memory.)
   * This routine fills in the contents of struct jerr, and returns jerr's
   * address which we place into the link field in cinfo.
   */

  /* need an error handler b/o MPI - cannot exit() without killing
   * all parallel processes   R.W.
   */
  cinfo.err = jpeg_std_error(&jerr.pub);
  jerr.pub.error_exit = my_error_exit;

  if (setjmp(jerr.setjmp_buffer)) {
    /* If we get here, the JPEG code has signaled an error.
     * We need to clean up the JPEG object, close the input file, and return.
     */
    sprintf(ErrMsg,_("JPEG code has signaled an error ! \n"));
    WARNING (ErrMsg);

    jpeg_destroy_compress(&cinfo);
    fclose(outfile);
    return(FALSE);
  }

  /* Now we can initialize the JPEG compression object. */
  jpeg_create_compress(&cinfo);

  jpeg_stdio_dest(&cinfo, outfile);

  /* Step 3: set parameters for compression */

  /* First we supply a description of the input image.
   * Four fields of the cinfo struct must be filled in:
   */
  cinfo.image_width = imgwidth;      /* image width and height, in pixels */
  cinfo.image_height = imgheight;
  cinfo.input_components = 3;           /* # of color components per pixel */
  cinfo.in_color_space = JCS_RGB;       /* colorspace of input image */
   
  /* Now use the library's routine to set default compression parameters.
   * (You must set at least cinfo.in_color_space before calling this,
   * since the defaults depend on the source color space.)
   */
  jpeg_set_defaults(&cinfo);
  /* Now you can set any non-default parameters you wish to.
   * Here we just illustrate the use of quality (quantization table) scaling:
   */
  jpeg_set_quality(&cinfo, quality, TRUE ); /* limit to baseline-JPEG values */
  
  /* Step 4: Start compressor */

  /* TRUE ensures that we will write a complete interchange-JPEG file.
   * Pass TRUE unless you are very sure of what you're doing.
   */
  jpeg_start_compress(&cinfo, TRUE);

  /* Step 5: while (scan lines remain to be written) */
  /*           jpeg_write_scanlines(...); */

  /* Here we use the library's state variable cinfo.next_scanline as the
   * loop counter, so that we don't have to keep track ourselves.
   * To keep things simple, we pass one scanline per call; you can pass
   * more if you wish, though.
   */
  row_stride = imgwidth * 3; /* JSAMPLEs per row in imgbuff */
  line = cinfo.image_height-1;
  while (line >= 0) {
    /* jpeg_write_scanlines expects an array of pointers to scanlines.
     * Here the array is only one element long, but you could pass
     * more than one scanline at a time if that's more convenient.
     */
    row_pointer[0] = & imgbuff[row_stride*line];
    (void) jpeg_write_scanlines(&cinfo, row_pointer, 1);
    line--;
  }

  /* Step 6: Finish compression */
  jpeg_finish_compress(&cinfo);

  if (outfile) {
    /* After finish_compress, we can close the output file. */
    fclose(outfile);
  }

  /* Step 7: release JPEG compression object */

  /* This is an important step since it will release a good deal of memory. */
  jpeg_destroy_compress(&cinfo);
  /* And we're done! */

  return(TRUE);
}

#endif /* OpenGL end */


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