#include <GL/glut.h>
#include <stdlib.h>
#include <stdio.h>
#include <math.h>

#define WINDSIZEX 100
#define WINDSIZEY 100


void init(void)
{
   glEnable(GL_DEPTH_TEST);
   glDepthFunc(GL_ALWAYS);
}

static void test(void)
{    
   GLfloat srcFloatPixels[32*32];
   GLushort srcUShortPixels[32*32];
   GLfloat results[32*32];
   int i;

   glRasterPos2f(0.25, 0.25);
   for (i=0; i<1024; i++){
      srcUShortPixels[i] = 61042;
      srcFloatPixels[i] = 61042.0 / 65536;
   }
   //glDrawPixels(32, 32, GL_DEPTH_COMPONENT, GL_FLOAT, srcFloatPixels);
   glDrawPixels(32, 32, GL_DEPTH_COMPONENT, GL_UNSIGNED_SHORT, srcUShortPixels);

   glDisable(GL_DEPTH_TEST);
   glReadPixels(0, 0, 32, 32, GL_DEPTH_COMPONENT, GL_FLOAT, results);
   for (i=0; i<1024; i++){
      if (fabsf(results[i] - srcFloatPixels[i]) > 0.0001){
	 printf("result is %f, src is %f at %d\n", results[i], srcFloatPixels[i], i);
	 exit(1);
      }
   }
   printf("PASS!\n");
   exit(0);
}

void display(void)
{
   glViewport(0, 0, WINDSIZEX, WINDSIZEY);
   glMatrixMode(GL_PROJECTION);
   glLoadIdentity();
   gluOrtho2D(0, WINDSIZEX, 0, WINDSIZEY);
   glMatrixMode(GL_MODELVIEW);
   glLoadIdentity();

   test();
}

int main(int argc, char** argv)
{
   glutInit(&argc, argv);
   glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
   glutInitWindowSize(WINDSIZEX, WINDSIZEY);
   glutInitWindowPosition(100, 100);
   glutCreateWindow(argv[0]);
   init();
   glutDisplayFunc(display);
   glutMainLoop();
   return 0; 
}