/* Demo of the color interpolation

Implemented Fall 2003
Scott D. Anderson
*/

#include <stdio.h>
#include <GL/glut.h>
#include <tw.h>

twTriple Tri[3] = 
    {
        {0,0,0},
        {3,-2,0},
        {1,4,0}
    };

twTriple Quad[4] =
    {
        {5,0,0},
        {7,-2,0},
        {9,1,0},
        {6,3,0}
    };

void drawTri() {
    glBegin(GL_TRIANGLES);
    {
        glColor3f(1,0,0);
        glVertex3fv(Tri[0]);
        glColor3f(1,0,1);
        glVertex3fv(Tri[1]);
        glColor3f(1,1,0);
        glVertex3fv(Tri[2]);
    }
    glEnd();
}

void drawQuad() {
    glBegin(GL_TRIANGLES);
    {
        glColor3f(0,0,1);        glVertex3fv(Quad[0]);
        glColor3f(0.1,0.7,0.4);        glVertex3fv(Quad[1]);
        glColor3f(0.6,0.6,0.6);        glVertex3fv(Quad[2]);

        glColor3f(0.6,0.6,0.6);        glVertex3fv(Quad[2]);
        glColor3f(0.1,0.8,0.5);        glVertex3fv(Quad[3]);
        glColor3f(0,0,1);        glVertex3fv(Quad[0]);
    }

    glEnd();
}

void drawQuad2() {
    glBegin(GL_TRIANGLES);
    {
        glColor3f(0.1,0.7,0.4);        glVertex3fv(Quad[1]);
        glColor3f(0.6,0.6,0.6);        glVertex3fv(Quad[2]);
        glColor3f(0.1,0.8,0.5);        glVertex3fv(Quad[3]);

        glColor3f(0.1,0.8,0.5);        glVertex3fv(Quad[3]);
        glColor3f(0,0,1);        glVertex3fv(Quad[0]);
        glColor3f(0.1,0.7,0.4);        glVertex3fv(Quad[1]);
    }

    glEnd();
}

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

    glShadeModel(GL_SMOOTH);
    drawTri();
    drawQuad();
    for(int i=0; i<4; i++) Quad[i][0] += 4;
    drawQuad2();
    for(int i=0; i<4; i++) Quad[i][0] -= 4;

    glFlush();
    glutSwapBuffers();
}

int main(int argc, char** argv) {
  glutInit(&argc, argv);
  glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
  twInitWindowSize(800,500);
  glutCreateWindow(argv[0]);
  glutDisplayFunc(display);
  twBoundingBox(0,9,-2,3,-1,1);
  twMainInit();            
  glutMainLoop();
  return 0;
}