OpenGL滑鼠響應事件

注意滑鼠響應事件的實現方法:
#include <GL/glut.h>
#include <stdlib.h>

static GLfloat spin = 0.0;

void display(void)
{
   glClear(GL_COLOR_BUFFER_BIT);
   glPushMatrix();
   glRotatef(spin, 0.0, 0.0, 1.0);
   glColor3f(1.0, 1.0, 1.0);
   glRectf(-25.0, -25.0, 25.0, 25.0);
   glPopMatrix();

   glutSwapBuffers();
}

void spinDisplay(void)
{
   spin = spin + 2.0;
   if (spin > 360.0)
      spin = spin - 360.0;
   glutPostRedisplay();
}

void init(void)
{
   glClearColor (0.0, 0.0, 0.0, 0.0);
   glShadeModel (GL_FLAT);
}

void reshape(int w, int h)
{
   glViewport (0, 0, (GLsizei) w, (GLsizei) h);
   glMatrixMode(GL_PROJECTION);
   glLoadIdentity();
   glOrtho(-50.0, 50.0, -50.0, 50.0, -1.0, 1.0);
   glMatrixMode(GL_MODELVIEW);
   glLoadIdentity();
}

void mouse(int button, int state, int x, int y)
{
   switch (button) {
      case GLUT_LEFT_BUTTON:
         if (state == GLUT_DOWN)
            glutIdleFunc(spinDisplay);
         break;
      case GLUT_MIDDLE_BUTTON:
      case GLUT_RIGHT_BUTTON:
         if (state == GLUT_DOWN)
            glutIdleFunc(NULL);
         break;
      default:
         break;
   }
}
   

int main(int argc, char** argv)
{
   glutInit(&argc, argv);
   glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB);