OpenGL - 클릭 시 원 그리기

Visual Studio 2012 에서 Glut 라이브러리를 사용하여 마우스 클릭 시 원 그리는 소스 입니다.

#include "DrawCircle.h"
 
void drawCircle(int argc, char** argv) {
    glutInit(&argc, argv);
 
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
 
    glutInitWindowSize(640, 480);
 
    glutInitWindowPosition(100, 100);
 
    glutCreateWindow("Interactive drawing");
 
    init();
 
    glutDisplayFunc(display);
 
    glutMouseFunc(mouse);
 
    glutKeyboardFunc(keyboard);
 
    glutMainLoop();
}
 
void keyboard (unsigned char key, int x, int y)
{
    switch(key)
    {
    case 'q':
    case 'Q':
        exit(0);   
        break;
 
    default:
        break;
    }
}
 
void mouse (int button, int state, int x, int y)
{ 
    if(button == GLUT_LEFT_BUTTON && state == GLUT_DOWN)
    {
        if( num_pts < 100 )
        {
            pts[num_pts][0] = x;
            pts[num_pts][1] = y;
            num_pts++;
        }
    }
 
    glutPostRedisplay();
}
 
void init (void)
{
    glClearColor(1.0f, 1.0f, 1.0f,1.0f);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(0.0, 640.0, 480.0 , 0.0 );
}
 
void display(void)
{
 
    float radius = 25.0f;
 
    //  clear all pixels
    glClear(GL_COLOR_BUFFER_BIT);
    glClearColor(1.0f, 1.0f, 1.0f,1.0f);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    glColor3f(1.0f, 0.0f, 1.0f);
 
    for(int i=0 ; i < num_pts ; i++)
    {
        glPushMatrix();
        glTranslatef(pts[i][0],pts[i][1],0.0f);
 
        glBegin(GL_POLYGON);
        for(float fAngle = 0.f ; fAngle < 360.f; fAngle+= 1.0f ) {
            glVertex2f(cos(fAngle) * radius , sin(fAngle) * radius);
 
        }
        glEnd();
        glPopMatrix();
    }
 
    glFlush();
 
}
 
 

풀 소스는 아래 경로 에 있습니다.

https://github.com/cepiloth/LearningOpenGL/blob/master/DrawOpenGL/sample/DrawCircle.cpp