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.
