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

#define WINDSIZEX 100
#define WINDSIZEY 100


void
init (void)
{
    int i;
    GLfloat white[] = { 1.0, 1.0, 1.0, 1.0 };

    glClearColor (0.0, 0.0, 0.0, 1.0);
    glColor4fv (white);
    glDisable (GL_DITHER);
}

#define TEXTURE_SIZE 4
void
MakeTexture (GLubyte * image)
{
    int i;

    for (i = 0; i < TEXTURE_SIZE * TEXTURE_SIZE * 3; i++)
    {
        image[i] = 1;
    }
}

static void
test (void)
{
    int i;
    int texName;
    GLubyte image[TEXTURE_SIZE * TEXTURE_SIZE * 3];
    GLubyte image2[TEXTURE_SIZE * TEXTURE_SIZE * 3];

    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
    glPixelStorei(GL_PACK_ALIGNMENT, 1);


    glClear (GL_COLOR_BUFFER_BIT);
    glColor3f (1.0, 1.0, 1.0);
    glGenTextures (1, &texName);
    glBindTexture (GL_TEXTURE_2D, texName);

    MakeTexture (image);
    glTexImage2D (GL_TEXTURE_2D, 0, GL_SRGB_EXT, TEXTURE_SIZE,
                  TEXTURE_SIZE, 0, GL_RGB, GL_UNSIGNED_BYTE, image);
    glGetTexImage (GL_TEXTURE_2D, 0, GL_RGB, GL_UNSIGNED_BYTE, image2);

    for (i = 0; i < TEXTURE_SIZE * TEXTURE_SIZE * 3; i++)
    {
        printf ("image2[%d] = %d\n", i, image2[i]);
    }

}

void
display (void)
{
    glMatrixMode (GL_PROJECTION);
    glLoadIdentity ();
    glOrtho (-50, 50, -50, 50, 0, 2048);

    test ();
}

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