ogre世界座標魚螢幕座標相互轉換

bool worldCoordToScreen(Vector3 objPos, Camera* cam, Vector2 screenRect,  Vector2& screenPos)

{

Matrix4 viewMatrix = cam->getViewMatrix();

Matrix4 projMatrix = cam->getProjectionMatrix();

 

Vector4 in = Vector4(objPos.x, objPos.y, objPos.z, 1.0);

Vector4 out = viewMatrix * in;

out = projMatrix * out;

 

if(out.w <= 0.0) return false;    // out.w<0時，objPos 在攝像機背面

 

out.x /= out.w;

out.y /= out.w;

out.z /= out.w;

 

// Map x, y and z to range 0-1

out.x = out.x * 0.5 + 0.5;

out.y = out.y * 0.5 + 0.5;

out.z = out.z * 0.5 + 0.5;

 

// Map x,y to viewport

out.x = out.x * screenRect.x;

out.y = (1-out.y) * screenRect.y;

 

screenPos.x = out.x;

screenPos.y = out.y;

 

return true;

}

 

  virtual void mousePressed(MouseEvent* e)
    {
        // Left mouse button down
        if (e->getButtonID() & MouseEvent::khyJh"@BUTTON0_MASK)
        {
            // Setup the ray scene query
            Ray mouseRay = mCamera->getCameraToViewportRay( e->getX(), e->getY() );
            mRaySceneQuery->setRay( mouseRay );

            // Execute query
            RaySceneQueryResult &result = mRaySceneQuery->execute();
            RaySceneQueryResult::iterator itr = result.begin( );

            // Get results, create a node/entity on the position
            if ( itr != result.end() && itr-&gkhyJh"@t;worldFragment )
            {
                char name[16];
                sprintf( name, "Robot%d", mCount++ );

                Entity *ent = mSceneMgr->createEntity( name, "robot.mesh" );
                mCurrentObject = mSceneMgr->getRootSceneNode( )->createChildSceneNode( String(name) + "Node", itr->worldFragment->singleIntersection );
                mCurrentObject->attachObject( ent );
                mCurrekhyJh"@ntObject->setScale( 0.1f, 0.1f, 0.1f );
            } // if

            mLMouseDown = true;
        } // if

        // Right mouse button down
        else if (e->getButtonID() & MouseEvent::BUTTON1_MASK)
        {
            mRMouseDown = true;
            CEGUI::MouseCursor::getSingleton().hide( );
        } // else if
    } // mousePressed