/* Creates a ``TeddyBear'' object.  Demonstrates affine transforms,
   including nested transformations, and the new twColor convenience.

The body is 4 x 6 x 3, the head is a sphere of unit radius, sitting on
top.  The arms are 2.5 units long and are 1 unit from the midline, so the
span is 7 total.  The legs are 3 units long and are rotated twice, so
calculating the endpoint is in principal complex.  However, because the
arms are long enough, we only have to worry about Y, not X.

60 degrees around x, so endpoint drops to z=-1.5-3*sqrt(3)/2

Thus, the whole bear is 7 units wide, 6.5+3*sqrt(3)/2 = 9.1 units high,
and 3 units deep.  Plus, it sticks out of the bounding box a little.

Written by Caroline Geiersbach and Scott D. Anderson
scott.anderson@acm.org
Summer 2003
*/

#include <stdio.h>
#include <math.h>                // for the sqrt in the bb calc.
#include <tw.h>

bool wirep = true;                // true if you want wire-frame body and head

void drawBear() {
    twTriple bodyColor = {0.8,0.5,0.3};
    twTriple headColor = {0.7,0.4,0.2};

    glPushMatrix();
  
    // draw body
    twColor(bodyColor,0,0);
    glPushMatrix();
    glScalef(2,3,1.5);
    // body
    if(wirep)
        glutWireSphere(1,20,20);
    else
        glutSolidSphere(1,20,20);
    glPopMatrix();
  
    // limbs are in the head color
    twColor(headColor,0,0); // dark brown

    // draw right arm
    glPushMatrix();
    glTranslatef(1,2,0);
    glRotatef(90,0,1,0);
    twTube(0.5,0.4,2.5,20,1); 
    glPopMatrix();

    // draw left arm
    glPushMatrix();
    glTranslatef(-1,2,0);
    glRotatef(-90,0,1,0);
    twTube(0.5,0.4,2.5,20,1); 
    glPopMatrix();

    // draw right leg.  
    glPushMatrix();
    glTranslatef(1,-1.5,0);        // hip joint here
    glRotatef(30,0,1,0);        // rotate around y
    glRotatef(60,1,0,0);        // and around x
    twTube(0.7,0.6,3,20,1);
    glPopMatrix();
  
    // draw left leg
    glPushMatrix();
    glTranslatef(-1,-1.5,0);        // hip joint here
    glRotatef(-30,0,1,0);        // rotate around y
    glRotatef(60,1,0,0);        // and around x
    twTube(0.7,0.6,3,20,1);
    glPopMatrix();

    // draw head
    twColor(headColor,0,0);

    glPushMatrix();                // head coordinate system
    glTranslatef(0,4,0);
    // head
    if(wirep)
        glutWireSphere(1,20,20);
    else
        glutSolidSphere(1,20,20);

    twColorName(TW_BLACK);        // eyes and nose in black

    glPushMatrix();
    glTranslatef(-0.4,0,0.9);
    glutSolidSphere(0.12,10,10);  // left eye
    glTranslatef(0.8,0,0);
    glutSolidSphere(0.12,10,10);  // right eye
    glPopMatrix();

    glPushMatrix();
    glTranslatef(0,-0.4,0.9);
    glutSolidSphere(0.2,10,10);   // nose
    glPopMatrix();

    twColor(bodyColor,0,0);        // ears are in body color

    glPushMatrix();
    glTranslatef(-0.6,0.7,0.2);
    glScalef(1,1,0.5);
    glutSolidSphere(0.4,20,20);  // left ear
    glPopMatrix();

    glPushMatrix();
    glTranslatef(0.6,0.7,0.2);
    glScalef(1,1,0.5);
    glutSolidSphere(0.4,20,20);  // right ear
    glPopMatrix();

    glPopMatrix();                // end of head coordinate system
    glPopMatrix();                // final pop
}

void display(void) {
    twDisplayInit();
    twCamera(); // sets up camera based on bounding box coords.

    drawBear();

    glFlush();
    glutSwapBuffers();
}

void wireToggle(unsigned char k, int x, int y) {
    wirep = ! wirep;
    glutPostRedisplay();
}

int main(int argc, char** argv) {
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
    twInitWindowSize(650,650);
    glutCreateWindow(argv[0]);
    twBoundingBox(-3.5,3.5,-1.5-3*sqrt(3)/2,3+2,-1.5,1.5);
    twMainInit(); 
    twKeyCallback('w',wireToggle,"toggle wire-frame bear body and head");
    glutDisplayFunc(display);
    glutMainLoop();
    return 0;
}