phaser4-rex-plugins/plugins/shaders/fisheye/fisheye-frag.js

Plugins of phaser4

const frag = `\
#pragma phaserTemplate(shaderName)

#ifdef GL_FRAGMENT_PRECISION_HIGH
#define highmedp highp
#else
#define highmedp mediump
#endif
precision highmedp float;

// Scene buffer
uniform sampler2D uMainSampler; 
varying vec2 outTexCoord;

// Effect parameters
uniform vec3 config;
uniform vec2 texSize;
uniform vec2 center;

#pragma phaserTemplate(fragmentHeader)

void main (void) {
  float mode = config.x;
  float radius = config.y;
  float intensity = config.z;

  vec2 tc = outTexCoord * texSize;  
  tc -= center;
  float dist = length(tc) / radius;
  if (dist < 1.0) {
    float factor;
    if (mode > 0.0) {
      factor = sin(dist * 1.570795);
    } else {
      factor = asin(dist) / 1.570795;
    }
    tc *= mix(1.0, factor, intensity);
  }

  tc += center;
  gl_FragColor = texture2D(uMainSampler, tc / texSize);

}
`;

export default frag;