mirror of
https://github.com/italicsjenga/slang-shaders.git
synced 2024-11-25 08:51:32 +11:00
22 lines
714 B
Plaintext
22 lines
714 B
Plaintext
|
/*
|
||
|
|
Gauss-4tap v1.0 by fishku
|
||
|
|
Copyright (C) 2023
|
||
|
|
Public domain license (CC0)
|
||
|
|
|
||
|
|
Simple two-pass Gaussian blur filter which does two taps per pass.
|
||
|
|
Idea based on:
|
||
|
|
https://www.rastergrid.com/blog/2010/09/efficient-gaussian-blur-with-linear-sampling/
|
||
|
|
|
||
|
|
Changelog:
|
||
|
|
v1.0: Initial release.
|
||
|
|
*/
|
||
|
|
|
||
|
|
// Finds the offset so that two samples drawn with linear filtering at that
|
||
|
|
// offset from a central pixel, multiplied with 1/2 each, sum up to a 3-sample
|
||
|
|
// approximation of the Gaussian sampled at pixel centers.
|
||
|
|
float get_offset(float sigma) {
|
||
|
|
// Weight at x = 0 evaluates to 1 for all values of sigma.
|
||
|
|
const float w = exp(-1.0 / (sigma * sigma));
|
||
|
|
return 2.0 * w / (2.0 * w + 1.0);
|
||
|
|
}
|