SDL2 texture blend help

[Ivan Trombley]

On Tuesday, 12 December 2017 at 03:34:51 UTC, Dmitry wrote:
> On Tuesday, 12 December 2017 at 03:32:05 UTC, Ivan Trombley 
> wrote:
>> It turns out that it's an issue with the color channels being 
>> in sRGB color space and the alpha channel being linear. I 
>> verified this by doing a software blend of the images and then 
>> doing another software blend using gamma corrected values.
>>
>> There's a setting in opengl to correct for it, 
>> glEnable(GL_FRAMEBUFFER_SRGB), but I haven't tried this yet.
>
> BTW, also you could use bleeding (for example, 
> https://github.com/dmi7ry/alpha-bleeding-d )

This isn't a scaling problem (which is totally solved by 
pre-multiplying the alpha with the colors BTW). This is a gamma 
correction problem which is solved only by converting the color 
values to linear color space before compositing and then 
converting the final pixel back to sRGB.