mirror of
https://github.com/psychopy/psychojs.git
synced 2025-05-11 16:18:10 +00:00
37 lines
1.1 KiB
GLSL
37 lines
1.1 KiB
GLSL
/**
|
|
* Radial grating.
|
|
*
|
|
* @author Nikita Agafonov
|
|
* @copyright (c) 2020-2022 Open Science Tools Ltd. (https://opensciencetools.org)
|
|
* @license Distributed under the terms of the MIT License
|
|
* @description Creates 2d radial grating image. Based on https://www.shadertoy.com/view/wtjGzt
|
|
* @usedby GratingStim.js
|
|
*/
|
|
|
|
#version 300 es
|
|
precision mediump float;
|
|
|
|
in vec2 vUvs;
|
|
out vec4 shaderOut;
|
|
uniform float uFreq;
|
|
uniform float uPhase;
|
|
uniform vec3 uColor;
|
|
uniform float uAlpha;
|
|
|
|
#define M_PI 3.14159265358979
|
|
#define PI2 2.* M_PI
|
|
|
|
float aastep(float x) { // --- antialiased step(.5)
|
|
float w = fwidth(x); // pixel width. NB: x must not be discontinuous or factor discont out
|
|
return smoothstep(.7,-.7,(abs(fract(x-.25)-.5)-.25)/w); // just use (offseted) smooth squares
|
|
}
|
|
|
|
void main() {
|
|
vec2 uv = vUvs * 2. - 1.;
|
|
// converting first to [-1, 1] space to get the proper color functionality
|
|
// then back to [0, 1]
|
|
float v = uFreq * atan(uv.y, uv.x) / 6.28;
|
|
float s = aastep(v) * 2. - 1.;
|
|
shaderOut = vec4(vec3(s) * uColor * .5 + .5, 1.0) * uAlpha;
|
|
}
|