#ifndef TEXTURELOADER_H_
#define TEXTURELOADER_H_

#include <GL/glut.h>

/* glmReadPPM: read a PPM raw (type P6) file.  The PPM file has a header
 * that should look something like:
 *
 *    P6
 *    # comment
 *    width height max_value
 *    rgbrgbrgb...
 *
 * where "P6" is the magic cookie which identifies the file type and
 * should be the only characters on the first line followed by a
 * carriage return.  Any line starting with a # mark will be treated
 * as a comment and discarded.   After the magic cookie, three integer
 * values are expected: width, height of the image and the maximum
 * value for a pixel (max_value must be < 256 for PPM raw files).  The
 * data section consists of width*height rgb triplets (one byte each)
 * in binary format (i.e., such as that written with fwrite() or
 * equivalent).
 *
 * The rgb data is returned as an array of unsigned chars (packed
 * rgb).  The malloc()'d memory should be free()'d by the caller.  If
 * an error occurs, an error message is sent to stderr and NULL is
 * returned.
 *
 * filename   - name of the .ppm file.
 * width      - will contain the width of the image on return.
 * height     - will contain the height of the image on return.
 *
 */
GLubyte* glmReadPPM(char* filename, int* width, int* height) {
  FILE* fp;
  int i, w, h, d;
  unsigned char* image;
  char head[70]; /* max line <= 70 in PPM (per spec). */

  fp = fopen(filename, "rb");
  if (!fp) {
    perror(filename);
    return NULL;
  }

  /* grab first two chars of the file and make sure that it has the
   correct magic cookie for a raw PPM file. */
  fgets(head, 70, fp);
  if (strncmp(head, "P6", 2)) {
    fprintf(stderr, "%s: Not a raw PPM file\n", filename);
    return NULL;
  }

  /* grab the three elements in the header (width, height, maxval). */
  i = 0;
  while (i < 3) {
    fgets(head, 70, fp);
    if (head[0] == '#') /* skip comments. */
      continue;
    if (i == 0)
      i += sscanf(head, "%d %d %d", &w, &h, &d);
    else if (i == 1)
      i += sscanf(head, "%d %d", &h, &d);
    else if (i == 2)
      i += sscanf(head, "%d", &d);
  }

  /* grab all the image data in one fell swoop. */
  image = (unsigned char*)malloc(sizeof(unsigned char)*w*h*3);
  fread(image, sizeof(unsigned char), w*h*3, fp);
  fclose(fp);

  *width = w;
  *height = h;
  return image;
}


#endif /*TEXTURELOADER_H_*/