bool Component::setupClipping(Graphics* const Graphics) const
{
if(getClipping())
{
//Get Clipping initial settings
Pnt2f ClipTopLeft,ClipBottomRight;
getClipBounds(ClipTopLeft,ClipBottomRight);
Vec4d LeftPlaneEquation (1.0,0.0,0.0, -ClipTopLeft.x() + Graphics->getClipPlaneOffset()),
RightPlaneEquation (-1.0,0.0,0.0, ClipBottomRight.x() + Graphics->getClipPlaneOffset()),
TopPlaneEquation (0.0,1.0,0.0, -ClipTopLeft.y() + Graphics->getClipPlaneOffset()),
BottomPlaneEquation(0.0,-1.0,0.0, ClipBottomRight.y() + Graphics->getClipPlaneOffset());
//glClipPlane
//Clip with the Intersection of this components RenderingSurface bounds
//and its parents RenderingSurface bounds
if(ClipBottomRight.x()-ClipTopLeft.x() <= 0 || ClipBottomRight.y()-ClipTopLeft.y()<= 0)
{
return false;
}
if(!glIsEnabled(GL_CLIP_PLANE0)) { glEnable(GL_CLIP_PLANE0); }
if(!glIsEnabled(GL_CLIP_PLANE1)) { glEnable(GL_CLIP_PLANE1); }
if(!glIsEnabled(GL_CLIP_PLANE2)) { glEnable(GL_CLIP_PLANE2); }
if(!glIsEnabled(GL_CLIP_PLANE3)) { glEnable(GL_CLIP_PLANE3); }
//Clip Plane Equations
//Clip Planes get transformed by the ModelViewMatrix when set
//So we can rely on the fact that our current coordinate space
//is relative to the this components position
glClipPlane(GL_CLIP_PLANE0,LeftPlaneEquation.getValues());
glClipPlane(GL_CLIP_PLANE1,RightPlaneEquation.getValues());
glClipPlane(GL_CLIP_PLANE2,TopPlaneEquation.getValues());
glClipPlane(GL_CLIP_PLANE3,BottomPlaneEquation.getValues());
}
else
{
if(glIsEnabled(GL_CLIP_PLANE0)) { glDisable(GL_CLIP_PLANE0); }
if(glIsEnabled(GL_CLIP_PLANE1)) { glDisable(GL_CLIP_PLANE1); }
if(glIsEnabled(GL_CLIP_PLANE2)) { glDisable(GL_CLIP_PLANE2); }
if(glIsEnabled(GL_CLIP_PLANE3)) { glDisable(GL_CLIP_PLANE3); }
}
return true;
}
