a pixel value.
a pointer to SDL_PixelFormatDetails describing the pixel format.
an optional palette for indexed formats, may be NULL.
a pointer filled in with the red component, may be NULL.
a pointer filled in with the green component, may be NULL.
a pointer filled in with the blue component, may be NULL.
a pointer filled in with the alpha component, may be NULL.
Threadsafety: It is safe to call this function from any thread, as long as the palette is not modified.
Get RGBA values from a pixel in the specified format.
This function uses the entire 8-bit [0..255] range when converting color components from pixel formats with less than 8-bits per RGB component (e.g., a completely white pixel in 16-bit RGB565 format would return [0xff, 0xff, 0xff] not [0xf8, 0xfc, 0xf8]).
If the surface has no alpha component, the alpha will be returned as 0xff (100% opaque).