class mrpt::opengl::mrptEventGLPreRender

An event sent by an mrpt::opengl::Viewport just after clearing the viewport and setting the GL_PROJECTION matrix, and before calling the scene OpenGL drawing primitives.

While handling this event you can call OpenGL glDraw(), etc.

IMPORTANTE NOTICE: Event handlers in your observer class will most likely be invoked from an internal GUI thread of MRPT, so all your code in the handler must be thread safe.

#include <mrpt/opengl/Viewport.h>

class mrptEventGLPreRender: public mrpt::system::mrptEvent
{
public:
    //
fields

    const Viewport*const source_viewport;

    // construction

    mrptEventGLPreRender(const Viewport* obj);
};