// deck.gl
// SPDX-License-Identifier: MIT
// Copyright (c) vis.gl contributors

export default `\
#version 300 es
#define SHADER_NAME triangle-layer-fragment-shader

precision highp float;

uniform sampler2D weightsTexture;
uniform sampler2D colorTexture;

in vec2 vTexCoords;
in float vIntensityMin;
in float vIntensityMax;

out vec4 fragColor;

vec4 getLinearColor(float value) {
  float factor = clamp(value * vIntensityMax, 0., 1.);
  vec4 color = texture(colorTexture, vec2(factor, 0.5));
  color.a *= min(value * vIntensityMin, 1.0);
  return color;
}

void main(void) {
  vec4 weights = texture(weightsTexture, vTexCoords);
  float weight = weights.r;

  if (triangle.aggregationMode > 0.5) {
    weight /= max(1.0, weights.a);
  }

  // discard pixels with 0 weight.
  if (weight <= 0.) {
     discard;
  }

  vec4 linearColor = getLinearColor(weight);
  linearColor.a *= layer.opacity;
  fragColor = linearColor;
}
`;