metal: Add hint to select low power device instead of the default one (#8182)

On some system like MacBook Pro Intel with AMD card, asking for the default device will always return the AMD GPU.
This is not an issue for 99% of the case when the renderer context is here to provide the maximum performance level like for game.
However, for video application using GPU for 1 quad and 1 texture, using the discrete GPU for that lead to an important power consumption (4 to 8W), heat increase, and fan noise.
With this patch, I successfully amend ffplay to only use the integrated GPU (i.e. the Intel one), instead of the discrete GPU (i.e. the AMD one).
This commit is contained in:
Jeremy Demeule 2023-08-31 10:23:45 +02:00 committed by Sam Lantinga
parent 0b995f21e7
commit aa7ba62978
2 changed files with 27 additions and 2 deletions

View file

@ -1474,6 +1474,17 @@ extern "C" {
*/ */
#define SDL_HINT_RENDER_VSYNC "SDL_RENDER_VSYNC" #define SDL_HINT_RENDER_VSYNC "SDL_RENDER_VSYNC"
/**
* \brief A variable controlling whether the Metal render driver select low power device over default one
*
* This variable can be set to the following values:
* "0" - Use the prefered OS device
* "1" - Select a low power one
*
* By default the prefered OS device is used.
*/
#define SDL_HINT_RENDER_METAL_PREFER_LOW_POWER_DEVICE "SDL_RENDER_METAL_PREFER_LOW_POWER_DEVICE"
/** /**
* \brief A variable controlling if VSYNC is automatically disable if doesn't reach the enough FPS * \brief A variable controlling if VSYNC is automatically disable if doesn't reach the enough FPS
* *

View file

@ -1654,8 +1654,22 @@ static SDL_Renderer *METAL_CreateRenderer(SDL_Window * window, Uint32 flags)
return NULL; return NULL;
} }
// !!! FIXME: MTLCopyAllDevices() can find other GPUs on macOS... #ifdef __MACOSX__
if (SDL_GetHintBoolean(SDL_HINT_RENDER_METAL_PREFER_LOW_POWER_DEVICE, SDL_TRUE)) {
NSArray<id<MTLDevice>> *devices = MTLCopyAllDevices();
for (id<MTLDevice> device in devices) {
if (device.isLowPower) {
mtldevice = device;
break;
}
}
}
#endif
if (mtldevice == nil) {
mtldevice = MTLCreateSystemDefaultDevice(); mtldevice = MTLCreateSystemDefaultDevice();
}
if (mtldevice == nil) { if (mtldevice == nil) {
SDL_free(renderer); SDL_free(renderer);