void setUpTexture()
{
    unsigned char grass[512 * 512 * 3];
    FILE* f = fopen("grass.raw", "r");
    fread(grass, 512 * 512 * 3, 1, f);
    fclose(f);

    glEnable(GL_TEXTURE_2D);

    //Here 1 is the texture id
    glBindTexture(GL_TEXTURE_2D, 1);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    glTexImage2D(GL_TEXTURE_2D, 0, 3, 512, 512, 0, GL_RGB, GL_UNSIGNED_BYTE,grass);

    glDisable(GL_TEXTURE_2D);
}
void grass()
{
    glEnable(GL_TEXTURE_2D);
    glBindTexture(GL_TEXTURE_2D,3);
    glBegin(GL_QUADS);
    glColor4f(1,1,1,0.1);
    glTexCoord2d(0,0);  glVertex3f(2, 1, 2);
    glTexCoord2d(1,0);  glVertex3f(-2, 1, 2);
    glTexCoord2d(1,1);  glVertex3f(-2, 1, -2);
    glTexCoord2d(0,1);  glVertex3f(2, 1, -2);
    glEnd();
    glDisable(GL_TEXTURE_2D);
}