@luma.gl/effects/dist/passes/postprocessing/image-blur-filters/triangleblur.js

Post-processing effects for luma.gl

// luma.gl
// SPDX-License-Identifier: MIT
// Copyright (c) vis.gl contributors
import { random } from '@luma.gl/shadertools';
const source = /* wgsl */ `\
uniform triangleBlurUniforms {
  radius: f32,
  delta: vec2f,
}

@group(0) @binding(1) var<uniform> triangleBlur: triangleBlurUniforms;

vec4 triangleBlur_sampleColor(sampler2D source, vec2 texSize, vec2 texCoord) {
  vec2 adjustedDelta = triangleBlur.delta * triangleBlur.radius / texSize;

  vec4 color = vec4(0.0);
  float total = 0.0;

  /* randomize the lookup values to hide the fixed number of samples */
  float offset = random(vec3(12.9898, 78.233, 151.7182), 0.0);

  for (float t = -30.0; t <= 30.0; t++) {
    float percent = (t + offset - 0.5) / 30.0;
    float weight = 1.0 - abs(percent);
    vec4 offsetColor = texture(source, texCoord + adjustedDelta * percent);

    /* switch to pre-multiplied alpha to correctly blur transparent images */
    offsetColor.rgb *= offsetColor.a;

    color += offsetColor * weight;
    total += weight;
  }

  color = color / total;

  /* switch back from pre-multiplied alpha */
  color.rgb /= color.a + 0.00001;

  return color;
}
`;
const fs = /* glsl */ `\
uniform triangleBlurUniforms {
  float radius;
  vec2 delta;
} triangleBlur;

vec4 triangleBlur_sampleColor(sampler2D source, vec2 texSize, vec2 texCoord) {
  vec2 adjustedDelta = triangleBlur.delta * triangleBlur.radius / texSize;

  vec4 color = vec4(0.0);
  float total = 0.0;

  /* randomize the lookup values to hide the fixed number of samples */
  float offset = random(vec3(12.9898, 78.233, 151.7182), 0.0);

  for (float t = -30.0; t <= 30.0; t++) {
    float percent = (t + offset - 0.5) / 30.0;
    float weight = 1.0 - abs(percent);
    vec4 offsetColor = texture(source, texCoord + adjustedDelta * percent);

    /* switch to pre-multiplied alpha to correctly blur transparent images */
    offsetColor.rgb *= offsetColor.a;

    color += offsetColor * weight;
    total += weight;
  }

  color = color / total;

  /* switch back from pre-multiplied alpha */
  color.rgb /= color.a + 0.00001;

  return color;
}
`;
/**
 * @filter       Triangle Blur
 * @description  This is the most basic blur filter, which convolves the image with a
 *               pyramid filter. The pyramid filter is separable and is applied as two
 *               perpendicular triangle filters.
 */
export const triangleBlur = {
    name: 'triangleBlur',
    dependencies: [random],
    source,
    fs,
    props: {},
    uniforms: {},
    uniformTypes: {
        radius: 'f32',
        delta: 'vec2<f32>'
    },
    propTypes: {
        radius: { value: 20, min: 0, softMax: 100 },
        delta: { value: [1, 0], private: true }
    },
    passes: [
        { sampler: true, uniforms: { delta: [1, 0] } },
        { sampler: true, uniforms: { delta: [0, 1] } }
    ]
};
//# sourceMappingURL=triangleblur.js.map