Gamma

Quick rules of thumb, since I can never remember which is which:

• RGB = linear space
• sRGB = gamma space
• most image files store sRGB
• sRGB is unfit for blending

The corollary is:

• Image files loaded as textures should be converted from sRGB to RGB (but some decoders do this for you!)
• The shader responsible for putting the final pixels on the screen should have a gamma correction step doing:

const float gamma = 2.2;

out vec4 color;

void main()
{
    // ...

    color = pow(color, 1. / gamma);
}

See also

• https://blog.johnnovak.net/2016/09/21/what-every-coder-should-know-about-gamma/
• https://en.wikipedia.org/wiki/Gamma_correction
• https://www.cambridgeincolour.com/tutorials/gamma-correction.htm