/* Lab exercise on texture mapping

   Scott D. Anderson
   Fall 2004
*/

#include <math.h>
#include <stdio.h>
#include <tw.h>

/* ================================================================ */

const GLfloat width=1, height=1; // of the texture, in texture space

const int NUM_TEXTURES = 6;
GLuint textureIDs[NUM_TEXTURES];

void texinit() {
    glGenTextures(NUM_TEXTURES,textureIDs);
    twLoadTexture(textureIDs[0],"buffy256.ppm");
    twLoadTexture(textureIDs[1],"angel256.ppm");
    twLoadTexture(textureIDs[2],"willow256.ppm");
    twLoadTexture(textureIDs[3],"xander256.ppm");
    twLoadTexture(textureIDs[4],"giles256.ppm");
    twLoadTexture(textureIDs[5],"spike256.ppm");
}    

void display() {
    twDisplayInit();
    twCamera();

    glEnable(GL_TEXTURE_2D);

    // front is buffy
    glBindTexture(GL_TEXTURE_2D,textureIDs[0]);
    glBegin(GL_QUADS);
    glTexCoord2f(0,0);          glVertex3f( 0,1,1); 
    glTexCoord2f(0,width);      glVertex3f( 0,0,1); 
    glTexCoord2f(height,width); glVertex3f( 1,0,1); 
    glTexCoord2f(height,0);     glVertex3f( 1,1,1); 
    glEnd();

    // top is angel
    glBindTexture(GL_TEXTURE_2D,textureIDs[1]);
    glBegin(GL_QUADS);
    glTexCoord2f(0,0);          glVertex3f( 0,1,1); 
    glTexCoord2f(0,width);      glVertex3f( 1,1,1); 
    glTexCoord2f(height,width); glVertex3f( 1,1,0); 
    glTexCoord2f(height,0);     glVertex3f( 0,1,0); 
    glEnd();

    // left is willow
    glBindTexture(GL_TEXTURE_2D,textureIDs[2]);
    glBegin(GL_QUADS);
    glTexCoord2f(0,0);          glVertex3f( 0,1,1); 
    glTexCoord2f(0,width);      glVertex3f( 0,1,0); 
    glTexCoord2f(height,width); glVertex3f( 0,0,0); 
    glTexCoord2f(height,0);     glVertex3f( 0,0,1); 
    glEnd();

    // right is xander
    glBindTexture(GL_TEXTURE_2D,textureIDs[3]);
    glBegin(GL_QUADS);
    glTexCoord2f(0,0);          glVertex3f( 1,0,0); 
    glTexCoord2f(0,width);      glVertex3f( 1,0,1); 
    glTexCoord2f(height,width); glVertex3f( 1,1,1); 
    glTexCoord2f(height,0);     glVertex3f( 1,1,0); 
    glEnd();

    // back is giles
    glBindTexture(GL_TEXTURE_2D,textureIDs[4]);
    glBegin(GL_QUADS);
    glTexCoord2f(0,0);          glVertex3f( 1,0,0); 
    glTexCoord2f(0,width);      glVertex3f( 1,1,0); 
    glTexCoord2f(height,width); glVertex3f( 0,1,0); 
    glTexCoord2f(height,0);     glVertex3f( 0,0,0); 
    glEnd();

    // bottom is spike
    glBindTexture(GL_TEXTURE_2D,textureIDs[5]);
    glBegin(GL_QUADS);
    glTexCoord2f(0,0);          glVertex3f( 1,0,0); 
    glTexCoord2f(0,width);      glVertex3f( 0,0,0); 
    glTexCoord2f(height,width); glVertex3f( 0,1,0); 
    glTexCoord2f(height,0);     glVertex3f( 1,1,0); 
    glEnd();

    glFlush();
    glutSwapBuffers();
}

/* ================================================================ */
int main(int argc, char **argv) {
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
    twInitWindowSize(500, 500);
    glutCreateWindow(argv[0]);
    glutDisplayFunc(display);
    twBoundingBox(0,1,0,1,0,1);
    twMainInit();
    texinit();
    glutMainLoop();                   
}