sgMaskCheckCollision
\brief Check the collision between two masks
\param m1 The first mask to test
\param x1 First mask's x position
\param y1 First mask's y position
\param m2 The second mask to test
\param x2 Second mask's x position
\param y2 Second mask's y position
\return SG_TRUE if the masks collide, SG_FALSE otherwise.