/*----------------------------------------------------------------------------------------
* This is the main display callback function. It sets up the drawing for
* The 3D scene first then calls the Draw3D() function. After that it switches to
* an orthographic projection and calls Draw2D().
*/
void Draw(void)
{
/*
* Clear the background
*/
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
/*
* Allow drawing in full region of the screen
*/
glViewport(0,0,winw,winh);
glPushMatrix();
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glMatrixMode(GL_PROJECTION);
glPushMatrix();
glLoadIdentity();
gluOrtho2D(0, winw, 0, winh);
poly.Shrink(40);
glLineWidth(1);
poly.draw(Vector2f(0,0));
glLineWidth(3);
poly.handleShrinkErrors();
poly.draw(Vector2f(640,0));
glPopMatrix();
glPopMatrix();
glMatrixMode(GL_MODELVIEW);
/*
* Bring the back buffer to the front and vice-versa.
*/
glutSwapBuffers();
}
/*----------------------------------------------------------------------------------------
* \brief This function is called whenever a mouse button is pressed or released
* \param button - GLUT_LEFT_BUTTON, GLUT_RIGHT_BUTTON, or GLUT_MIDDLE_BUTTON
* \param state - GLUT_UP or GLUT_DOWN depending on whether the mouse was released
* or pressed respectivly.
* \param x - the x-coord of the mouse cursor.
* \param y - the y-coord of the mouse cursor.
*/
void MouseButton(int button,int state,int x, int y)
{
/*
* update the mouse position
*/
TheMouse.x = x;
TheMouse.y = y;
/*
* has the button been pressed or released?
*/
if (state == GLUT_DOWN)
{
/*
* This holds the location of the first mouse click
*/
if ( !(TheMouse.lmb || TheMouse.mmb || TheMouse.rmb) )
{
TheMouse.xpress = x;
TheMouse.ypress = y;
poly.Add(Vector2f(x,winh-y));
poly.Shrink(20);
}
/*
* Which button was pressed?
*/
switch(button)
{
case GLUT_LEFT_BUTTON:
TheMouse.lmb = 1;
break;
case GLUT_MIDDLE_BUTTON:
poly.vert.clear();
poly.shrink.clear();
TheMouse.mmb = 1;
break;
case GLUT_RIGHT_BUTTON:
TheMouse.rmb = 1;
break;
}
}
else
{
/*
* Which button was released?
*/
switch(button)
{
case GLUT_LEFT_BUTTON:
TheMouse.lmb = 0;
break;
case GLUT_MIDDLE_BUTTON:
TheMouse.mmb = 0;
break;
case GLUT_RIGHT_BUTTON:
TheMouse.rmb = 0;
break;
}
}
/*
* Force a redraw of the screen. If we later want interactions with the mouse
* and the 3D scene, we will need to redraw the changes.
*/
glutPostRedisplay();
}
