//primitives   
//  rotation of the square and filled square
//  introducing new versions of fundamental draw-functions
// T. Kosaka CS TNCT 2001

#include <stdio.h>
#include <math.h>
#include <GL/glut.h>
#include "drawShape2D.h"

void userdraw(void);

void display(void)
{
    glClear( GL_COLOR_BUFFER_BIT);
    userdraw();
    glutSwapBuffers();
}

void userdraw(void)
{
    static int tick=0;
    point2D_t pnt[4];
    color_t color0={0,1,1};
    color_t color[4]={
        {1,0,1},{1,0,0},{0,1,0},{0,0,1}
    };
    pnt[0].x=200.*cos((float)tick*.005)+320;
    pnt[0].y=200.*sin((float)tick*.005)+240;
    pnt[1].x=200.*cos((float)tick*.005+3.1415926535*.5)+320;
    pnt[1].y=200.*sin((float)tick*.005+3.1415926535*.5)+240;
    pnt[2].x=200.*cos((float)tick*.005+3.1415926535)+320;
    pnt[2].y=200.*sin((float)tick*.005+3.1415926535)+240;
    pnt[3].x=200.*cos((float)tick*.005+3.1415926535*1.5)+320;
    pnt[3].y=200.*sin((float)tick*.005+3.1415926535*1.5)+240;
    if ((tick/100)%3==0) {
        glutSetWindowTitle("primitives - drawPolygon");
        setColor(color0);
        drawPolygon(pnt,4);
    } else if ((tick/100)%3==1) {
        glutSetWindowTitle("primitives - fillPolygon");
        fillPolygon(pnt,4,color0);
    } else {
        glutSetWindowTitle("primitives - gradatePolygon");
        gradatePolygon(pnt,color,4);
    }
    tick++;
}

int main(int argc, char **argv)
{
    glutInit(&argc,argv);
    glutInitDisplayMode ( GLUT_DOUBLE | GLUT_RGB );
    glutInitWindowPosition(100,100);
    glutInitWindowSize(640,480);
    glutCreateWindow ("primitives");
    glClearColor(0.0, 0.0, 0.0, 0.0);
    gluOrtho2D(0., 640., 0., 480.0);
      // Define the dimensions of the Orthographic Viewing Volume
    glutIdleFunc(display); // idle event call back
    glutDisplayFunc(display);
    glutMainLoop();
    return 0;
}