/* Just throws up a torus.

Implemented Fall 2007
Scott D. Anderson
*/

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

GLdouble InnerRadius = 0.5;     // If you slice through the torus to get a
                                // circular section, this is the radius of
                                // that circular cross-section.

GLdouble OuterRadius = 2.0;     // If you think of the torus as a circle,
                                // it's the radius of the circle

GLint Nsides = 5;               // If you slice through the torus to get a
                                // circular section, this is how many
                                // sides that polygonal approximation has.

GLint Rings  = 3;               // If you think of the torus as a
                                // polygonal approx to a circle, this is
                                // how many sides the polygon has.

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

    glPushMatrix();
    glTranslatef(-OuterRadius,0,0); // move left
    glutSolidTorus(InnerRadius,OuterRadius,Nsides,Rings);
    glTranslatef(OuterRadius*2.0,0,0); // move right
    glutWireTorus(InnerRadius,OuterRadius,Nsides,Rings);
    glPopMatrix();

    glFlush();
    glutSwapBuffers();
}

void keys(unsigned char key, int x, int y) {
    switch(key) {
        case 'n':  Nsides--; break;
        case 'N':  Nsides++; break;
        case 'r':  Rings--; break;
        case 'R':  Rings++; break;
        case 'i':  InnerRadius -= 0.1; break;
        case 'I':  InnerRadius += 0.1; break;
        case 'o':  OuterRadius -= 0.1; break;
        case 'O':  OuterRadius += 0.1; break;
    }
    glutPostRedisplay();
}

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(-5,5,-5,5,-5,5);  // 10x10x10 cube around origin
  twMainInit();            
  twKeyCallback('n',keys,"decrease Nsides");
  twKeyCallback('N',keys,"increase Nsides");
  twKeyCallback('r',keys,"decrease Rings");
  twKeyCallback('R',keys,"increase Rings");
  twKeyCallback('i',keys,"decrease InnerRadius");
  twKeyCallback('I',keys,"increase InnerRadius");
  twKeyCallback('o',keys,"decrease OuterRadius");
  twKeyCallback('O',keys,"increase OuterRadius");
  glutMainLoop();
  return 0;
}