//hitKey
//  Drawing a circle at the position of the pointer when key 'A' is hit.
//  Drawing a square at the position of the pointer when key 'B' is hit.
//  glutKeyboardFunc(onKeyboard); // keyboard event call back
//  void onKeyboard(unsigned char key, int x, int y_inv)
// T. Kosaka CS TNCT 2001

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

#ifndef M_PI
#define M_PI 3.141592653589793
#endif

void userdraw(void);

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

unsigned int GlobalTick=1000;
point2D_t CurrentPoint;
int circle;

void onKeyboard(unsigned char key, int x, int y_inv)
{
    int y=480-y_inv-1;  // device coordinate -> view coordinate
    switch (key) {
    case 'A':
    case 'a':
        GlobalTick=10;
        CurrentPoint.x=x;
        CurrentPoint.y=y;
        circle=1;
        break;
    case 'B':
    case 'b':
        GlobalTick=10;
        CurrentPoint.x=x;
        CurrentPoint.y=y;
        circle=0;
        break;
    default:
        break;
    }
}

void userdraw(void)
{
    float r;
    int num;
    int i;
    color_t cyan={0.,1.,1.};
    point2D_t p[600];
    if (GlobalTick<400) {
        r=GlobalTick;
        if (circle==1) {
            num=GlobalTick/20+30;
        } else {
            num=4;
        }
        for (i=0;i<num;i++) {
            p[i].x=r*cos(2.*M_PI*i/num)+CurrentPoint.x;
            p[i].y=r*sin(2.*M_PI*i/num)+CurrentPoint.y;
        }
        setColor(cyan);
        drawPolygon(p,num);
    }
    GlobalTick++;
    if (50000<GlobalTick) GlobalTick=1000;
}

int main(int argc, char **argv)
{
    glutInit(&argc,argv);
    glutInitDisplayMode ( GLUT_DOUBLE | GLUT_RGB );
    glutInitWindowPosition(100,100);
    glutInitWindowSize(640,480);
    glutCreateWindow ("hitKey  !!! Push 'A' or 'B' key with the mouse moving. !!!");
    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);
    glutKeyboardFunc(onKeyboard); // keyboard event call back
    glutMainLoop();
    return 0;
}