#include <windows.h>
#include <gl/gl.h>
#include <gl/glut.h>
#include <stdio.h>

struct image
{
  int depth;
  int width;
  int height;
  int components;
  GLubyte *data;
};
struct image img;


// Borrowed from ATI ImageIO library
int load_tga (struct image *img, char *filename)
{
  FILE *fp;
  GLubyte tmp;
  unsigned char header [18];

  if (!(fp = fopen(filename, "rb")))
  {
    return 1;
  }

  fread(header, 18, 1, fp);
  if (header[2] != 2)
  {
    fclose(fp);
    return 1;
  }

  if (header[16] < 24)
  {
    fclose(fp);
    return 1;
  }

  img->depth = 1;
  img->width = header[12] + (header[13] << 8);
  img->height = header[14] + (header[15] << 8);
  img->components = header[16] / 8;
  img->data = new GLubyte[img->width * img->height * img->components];

  fseek(fp, header[0], SEEK_CUR);
  fread(img->data, img->width * img->height * img->components, 1, fp);
  fclose(fp);

  for (int i = 0; i < img->width * img->height * img->components; i += img->components)
  {
    tmp = img->data[i];
    img->data[i] = img->data[i+2];
    img->data[i+2] = tmp;
  }

  return 0;
}


void draw ()
{
  glClear(GL_COLOR_BUFFER_BIT);

  glBegin(GL_POINTS);
  for (int i = 0; i < img.width; i++)
    for (int j = 0; j < img.height; j++)
    {
      glColor3ubv(&(img.data[j * (img.width * img.components) + (i * img.components)]));
      glVertex2f(i, j);
    }
  glEnd();

  glFlush();
}


int main (int argc, char **argv)
{
  if (load_tga(&img, "wood.tga"))
    printf("File Not Found\n");

  glutInit(&argc, argv);
  glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE);
  glutInitWindowSize(img.width, img.height);
  glutCreateWindow("Basic 2D Drawing");

  glutDisplayFunc(draw);

  glMatrixMode(GL_PROJECTION);
  glOrtho(0, img.width, 0, img.height, -1000, 1000);

  glutMainLoop();
  return 0;
}