Get the properties associated with a surface.
SDL_PropertiesID SDL_GetSurfaceProperties(SDL_Surface *surface);
|the SDL_Surface structure to query
Returns a valid property ID on success or 0 on failure; call SDL_GetError() for more information.
The following properties are understood by SDL:
SDL_PROP_SURFACE_COLORSPACE_NUMBER: an SDL_ColorSpace value describing the surface colorspace, defaults to SDL_COLORSPACE_SRGB_LINEAR for floating point formats, SDL_COLORSPACE_HDR10 for 10-bit formats, SDL_COLORSPACE_SRGB for other RGB surfaces and SDL_COLORSPACE_BT709_FULL for YUV surfaces.
SDL_PROP_SURFACE_MAXCLL_NUMBER: MaxCLL (Maximum Content Light Level) indicates the maximum light level of any single pixel (in cd/m2 or nits) of the content. MaxCLL is usually measured off the final delivered content after mastering. If one uses the full light level of the HDR mastering display and adds a hard clip at its maximum value, MaxCLL would be equal to the peak luminance of the mastering monitor. This defaults to 400 for HDR10 surfaces.
SDL_PROP_SURFACE_MAXFALL_NUMBER: MaxFALL (Maximum Frame Average Light Level) indicates the maximum value of the frame average light level (in cd/m2 or nits) of the content. MaxFALL is calculated by averaging the decoded luminance values of all the pixels within a frame. MaxFALL is usually much lower than MaxCLL.
SDL_PROP_SURFACE_SDR_WHITE_POINT_FLOAT: for HDR10 and floating point surfaces, this defines the value of 100% diffuse white, with higher values being displayed in the High Dynamic Range headroom. This defaults to 100 for HDR10 surfaces and 1.0 for other surfaces.
SDL_PROP_SURFACE_HDR_HEADROOM_FLOAT: for HDR10 and floating point surfaces, this defines the maximum dynamic range used by the content, in terms of the SDR white point. This defaults to SDL_PROP_SURFACE_MAXCLL_NUMBER / SDL_PROP_SURFACE_SDR_WHITE_POINT_FLOAT, or 4.0, for HDR10 surfaces.
SDL_PROP_SURFACE_TONEMAP_OPERATOR_STRING: the tone mapping operator used when compressing from a surface with high dynamic range to another with lower dynamic range. Currently this supports "chrome", which uses the same tone mapping that Chrome uses for HDR content, the form "*=N", where N is a floating point scale factor applied in linear space, and "none", which disables tone mapping. This defaults to "chrome".
This function is available since SDL 3.0.0.