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

#define WINDSIZEX 100
#define WINDSIZEY 100


void init(void)
{
glClearColor(0.0, 0.0, 0.0, 0.0);
}

static void test(void)
{   
    static GLfloat t[] = {
        0.0, 1.0, 0.0,  0.0, 1.0, 0.0,  0.0, 1.0, 0.0,  0.0, 1.0, 0.0,
        1.0, 0.0, 1.0,  1.0, 0.0, 1.0,  1.0, 0.0, 1.0,  1.0, 0.0, 1.0,

        0.0, 1.0, 0.0,  0.0, 1.0, 0.0,  0.0, 1.0, 0.0,  0.0, 1.0, 0.0,
        1.0, 0.0, 1.0,  1.0, 0.0, 1.0,  1.0, 0.0, 1.0,  1.0, 0.0, 1.0,

        0.0, 1.0, 0.0,  0.0, 1.0, 0.0,  0.0, 1.0, 0.0,  0.0, 1.0, 0.0,
        1.0, 0.0, 1.0,  1.0, 0.0, 1.0,  1.0, 0.0, 1.0,  1.0, 0.0, 1.0,

        0.0, 1.0, 0.0,  0.0, 1.0, 0.0,  0.0, 1.0, 0.0,  0.0, 1.0, 0.0,
        1.0, 0.0, 1.0,  1.0, 0.0, 1.0,  1.0, 0.0, 1.0,  1.0, 0.0, 1.0,
    };


    glTexImage2D(GL_TEXTURE_2D, 0, 3, 8, 4, 0, GL_RGB, GL_FLOAT,
                 (unsigned char *)t);
    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);

    glColor3f(0.0, 0.0, 1.0);
    glClear(GL_COLOR_BUFFER_BIT);
    glEnable(GL_TEXTURE_2D);
    glBegin(GL_QUAD_STRIP);
        glTexCoord2f(0.25, 0.25);
        glVertex2i(25, 25);
        glTexCoord2f(0.25, 0.75);
        glVertex2i(25, 75);
        glTexCoord2f(0.75, 0.25);
        glVertex2i(75, 25);
        glTexCoord2f(0.75, 0.75);
        glVertex2i(75, 75);
    glEnd();

    glCopyTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 20, 20, 8, 4, 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);
   glutInitWindowSize(WINDSIZEX, WINDSIZEY);
   glutInitWindowPosition(100, 100);
   glutCreateWindow(argv[0]);
   init();
   glutDisplayFunc(display);
   glutMainLoop();
   return 0; 
}