Save the current OpenGL render states and matrices.
This function can be used when you mix SFML drawing and direct OpenGL
rendering. Combined with PopGLStates, it ensures that:
DSFML's internal states are not messed up by your OpenGL code
your OpenGL states are not modified by a call to an SFML function
$(PARA More specifically, it must be used around the code that calls
`draw` functions.
Note that this function is quite expensive: it saves all the possible
* OpenGL states and matrices, even the ones you don't care about.Therefore
* it should be used wisely. It is provided for convenience, but the best
* results will be achieved if you handle OpenGL states yourself (because
* you know which states have really changed, and need to be saved and
* restored). Take a look at the `resetGLStates` function if you do so.)
Save the current OpenGL render states and matrices.
This function can be used when you mix SFML drawing and direct OpenGL rendering. Combined with PopGLStates, it ensures that:
$(PARA More specifically, it must be used around the code that calls `draw` functions. Note that this function is quite expensive: it saves all the possible * OpenGL states and matrices, even the ones you don't care about.Therefore * it should be used wisely. It is provided for convenience, but the best * results will be achieved if you handle OpenGL states yourself (because * you know which states have really changed, and need to be saved and * restored). Take a look at the `resetGLStates` function if you do so.)