stats->gpuMemoryUsed always returns -INT64_MAX

[tracer0707]

Hi,
I'm trying to get a frame statistics and i using the bgfx::getStats() function as in examples.
Everything works fine except gpuMemoryUsed. It always returns -INT64_MAX value.
I calling this function before the bgfx::frame().

This is my code:

const bgfx::Stats* stats = bgfx::getStats();
double toMsCpu = 1000.0 / stats->cpuTimerFreq;
cpuTime = double(stats->cpuTimeEnd - stats->cpuTimeBegin) * toMsCpu;

double toMsGpu = 1000.0 / stats->gpuTimerFreq;
gpuTime = double(stats->gpuTimeEnd - stats->gpuTimeBegin) * toMsGpu;

frameMs = double(stats->cpuTimeFrame) * toMsCpu;
numDrawCalls = stats->numDraw;
numTriangles = stats->numPrims[bgfx::Topology::TriList];

if (-INT64_MAX != stats->gpuMemoryUsed)
{
	gpuMemUsed = stats->gpuMemoryUsed;
}

What am I doing wrong?
Thanks.

[bkaradzic]

You're not doing anything wrong. The feature on some backends depends on NVAPI. Which might not be installed. And on some backends is completely unavailable. I just need to improve docs about it.

[tracer0707]

Thanks for the answer.
Is it means that I need to calc GPU used memory manually?
What the proper way to do it? Sum each loaded texture size + framebuffers + index/vertex buffers and so on?

[bkaradzic]

What the proper way to do it? Sum each loaded texture size + framebuffers + index/vertex buffers and so on?

Yes, that would give you approximate, but probably good enough result.

[tracer0707]

Thank you!