EnableDirectAccess

Enables direct access to framebuffer memory.

Declaration

void NAPI GA_2DStateFuncs::EnableDirectAccess(void)

Prototype In

snap/graphics.h

Description

This function disables the accelerator and turns on direct framebuffer access. The primary purpose of this function is to correctly arbitrate video memory access between the accelerator and the CPU. You must call this function before you perform any direct rendering to the video memory if the function pointer for this function is not NULL. If the function pointer is NULL, then the controller does not need to arbitrate access and this function is not necessary (instead simply call WaitTillIdle before accessing the framebuffer memory).

Note that if you are using the buffer manager functions, you should avoid using this function but instead use the LockBuffer and UnlockBuffer functions to hide the complexity of managing offscreen memory blocks.

Note: This function does an implicit WaitTillIdle when it is called to ensure that the graphics accelerator has finished all current rendering operations before enabling direct access to display memory.

See Also

DisableDirectAccess, WaitTillIdle, LockBuffer

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