blend mode 'overlay' for GLSL
npm install glsl-blend-soft-light
Photoshop-like "soft light" blend mode for GLSL.
``glsl
#pragma glslify: blend = require(../)
void main() {
vec4 bgColor = texture2D(bg, vUv);
vec4 fgColor = texture2D(foreground, vUv);
vec3 color = blend(bgColor.rgb, fgColor.rgb);
gl_FragColor = vec4(color, 1.0);
}
`

#### blend(vec3 base, vec3 blend)
Blends background and foreground with an "soft light" blend mode. The algorithm for each channel is as follows:
```
(blend < 0.5) ? (2.0 base blend + base base (1.0 - 2.0 blend)) : (sqrt(base) (2.0 blend - 1.0) + 2.0 base * (1.0 - blend))
See stackgl/contributing.
MIT. See LICENSE.md for details.