OpenGL / Allegro 5.1 gluSphere()

Another snippet to document for posterity. I have been very busy working the last few days, but try to keep my hand in whenever I can. Here's what I tried.

#include "allegro5/allegro.h" 
#include "allegro5/allegro_opengl.h" 
#include "allegro5/allegro_image.h" 
#include "GL/glu.h"

const int SCREEN_X = 800;
const int SCREEN_Y = 600;

int main(int argc, char *argv[])
{
ALLEGRO_DISPLAY *display = NULL;
ALLEGRO_BITMAP *bmp_earth = NULL;
GLuint tex_bmp = 0;

al_init();
al_init_image_addon();

al_set_new_display_flags(ALLEGRO_OPENGL);
display = al_create_display(SCREEN_X, SCREEN_Y);
bmp_earth = al_load_bitmap("dry_world.jpg");
tex_bmp = al_get_opengl_texture(bmp_earth);

GLUquadricObj *gl_quad_obj;
gl_quad_obj=gluNewQuadric();

glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(35.0f, (GLdouble)SCREEN_X / (GLdouble)SCREEN_Y, 1.0f, 200.0f);
glRotatef(23.0f, 0.0f,0.0f, 1.0f); // Trick photography; rotate the camera...

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();

glTranslatef(0.0f,0.0f,-20.0f);
glRotatef(-90.0f, 1.0f, 0.0f, 0.0f);

//glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

glEnable(GL_DEPTH_TEST);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, tex_bmp);

//gluQuadricNormals(gl_quad_obj, GLU_SMOOTH);
gluQuadricTexture(gl_quad_obj, GL_TRUE);
gluSphere(gl_quad_obj,5.0f,32,32);

glDisable(GL_DEPTH_TEST);
glDisable(GL_TEXTURE_2D);

al_flip_display();
al_rest(5.0);

glDeleteTextures(1, &tex_bmp);
gluDeleteQuadric(gl_quad_obj);
al_destroy_display(display);
al_destroy_bitmap(bmp_earth);
return 0;
}

Short and sweet. I had some curiosity about using the glu extension for something other than gluPerspective(), and as I had a hankering to make a planet, I experimented with gluSphere(). Turns out it works okay with Allegro 5.1. The above is pretty minimalistic, just enough to get results.

Here's the map I used, from Celestia...

In this one, it became pretty important to enable the GL_DEPTH_TEST. Otherwise, you WILL get some funny effects. Note also, in the above code, the demo of how to rotate the camera!

Of course, gluSphere() this is not the only gluQuadricObject that OpenGL can do. Again, the main reference OpenGL Manual. Scroll the index on the left to glu, and there you have it; lots of cool stuff.