ClassGL 3.6 Library Reference

COpenGL::DrawBegin

void DrawBegin( BOOL ClearFlag = TRUE );

Parameters

ClearFlag

Specifies whether the COpenGL object’s rendering context should be cleared by the OpenGL glClear( GetClearValue () ) function.

Remarks

The DrawBegin method function prepares the COpenGL object for drawing operations into associated rendering context.

Each call to DrawBegin must have a corresponding call to the DrawEnd method function. It is possible to call the DrawBegin function when another object’s DrawBegin call is not ‘finished’ with its corresponding DrawEnd call. However, in this case, only the first object’s DrawBegin call stores the current OpenGL rendering context internally and sets the current rendering context to the object’s rendering context. The next such object’s DrawBegin calls have no effect.

If a different operation than that which DrawBegin, DrawEnd provides is required then the application must handle the object’s rendering context activation itself using the wglMakeCurrent calls.