sceSystemServiceGetHdrToneMapLuminance was NotImplemented. Titles read
it at startup to set up their HDR tone mapping.
The presenter always outputs through a B8G8R8A8 sRGB-nonlinear swapchain,
so the display range the title has to map into is SDR: the maximum and
full-frame maximum luminance are the 100 cd/m2 SDR reference white and
the minimum is 0. A null output pointer returns
SYSTEM_SERVICE_ERROR_PARAMETER like the other getters here.
Dean Galvin