#include <windows.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include <stdio.h>

#include "bitmap.h"

#define BITMAP_FILESIZE 0x02
#define BITMAP_OFFSET 0x0a
#define BITMAP_HEADERSIZE 0x0e
#define BITMAP_WIDTH 0x12
#define BITMAP_HEIGHT 0x16

void load_image(char *filename)
{
  GLuint texture;
  FILE *bitmap;

  // try to open the file
  bitmap = fopen(filename, "rb");

  // does the bitmap exist?
  if (bitmap > 0)
  {
    unsigned int dataoffset, filesize;
    GLsizei width, height;
    unsigned char *imagedata;

    fseek(bitmap, BITMAP_FILESIZE, SEEK_SET);
    fread(&filesize, 4, 1, bitmap);
    fseek(bitmap, BITMAP_OFFSET, SEEK_SET);
    fread(&dataoffset, 4, 1, bitmap);
    fseek(bitmap, BITMAP_WIDTH, SEEK_SET);
    fread(&width, 4, 1, bitmap);
    fread(&height, 4, 1, bitmap);

    imagedata = (unsigned char *)malloc((size_t)(filesize -dataoffset));

    fseek(bitmap, dataoffset, SEEK_SET);
    fread(imagedata, (size_t)(filesize -dataoffset), 1, bitmap);

    glGenTextures(1, &texture);
    glBindTexture(GL_TEXTURE_2D, texture);
    gluBuild2DMipmaps(GL_TEXTURE_2D, GL_RGB, width, height, GL_RGB, GL_UNSIGNED_BYTE, imagedata);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

    free(imagedata);
    fclose(bitmap);
  }
}