kepler.gl/src/deckgl-layers/dist/raster/raster-layer/raster-layer-webgl2.fs.d.ts

kepler.gl is a webgl based application to visualize large scale location data in the browser

declare const _default: "#version 300 es\n#define SHADER_NAME raster-layer-fragment-shader\n\n// Ref https://www.khronos.org/registry/OpenGL/specs/es/3.0/GLSL_ES_Specification_3.00.pdf#page=60\nprecision mediump float;\nprecision mediump int;\nprecision mediump usampler2D;\n\nin vec2 vTexCoord;\nin vec2 vTexPos;\n\nout vec4 color;\n\nuniform float desaturate;\nuniform vec4 transparentColor;\nuniform vec3 tintColor;\nuniform float opacity;\n\nuniform float coordinateConversion;\nuniform vec4 bounds;\n\n/* projection utils */\nconst float TILE_SIZE = 512.0;\nconst float PI = 3.1415926536;\nconst float WORLD_SCALE = TILE_SIZE / PI / 2.0;\n\n// from degrees to Web Mercator\nvec2 lnglat_to_mercator(vec2 lnglat) {\n  float x = lnglat.x;\n  float y = clamp(lnglat.y, -89.9, 89.9);\n  return vec2(\n    radians(x) + PI,\n    PI + log(tan(PI * 0.25 + radians(y) * 0.5))\n  ) * WORLD_SCALE;\n}\n\n// from Web Mercator to degrees\nvec2 mercator_to_lnglat(vec2 xy) {\n  xy /= WORLD_SCALE;\n  return degrees(vec2(\n    xy.x - PI,\n    atan(exp(xy.y - PI)) * 2.0 - PI * 0.5\n  ));\n}\n/* End projection utils */\n\n// apply desaturation\nvec3 color_desaturate(vec3 color) {\n  float luminance = (color.r + color.g + color.b) * 0.333333333;\n  return mix(color, vec3(luminance), desaturate);\n}\n\n// apply tint\nvec3 color_tint(vec3 color) {\n  return color * tintColor;\n}\n\n// blend with background color\nvec4 apply_opacity(vec3 color, float alpha) {\n  if (transparentColor.a == 0.0) {\n    return vec4(color, alpha);\n  }\n  float blendedAlpha = alpha + transparentColor.a * (1.0 - alpha);\n  float highLightRatio = alpha / blendedAlpha;\n  vec3 blendedRGB = mix(transparentColor.rgb, color, highLightRatio);\n  return vec4(blendedRGB, blendedAlpha);\n}\n\nvec2 getUV(vec2 pos) {\n  return vec2(\n    (pos.x - bounds[0]) / (bounds[2] - bounds[0]),\n    (pos.y - bounds[3]) / (bounds[1] - bounds[3])\n  );\n}\n\nvoid main(void) {\n  vec2 uv = vTexCoord;\n  if (coordinateConversion < -0.5) {\n    vec2 lnglat = mercator_to_lnglat(vTexPos);\n    uv = getUV(lnglat);\n  } else if (coordinateConversion > 0.5) {\n    vec2 commonPos = lnglat_to_mercator(vTexPos);\n    uv = getUV(commonPos);\n  }\n\n  vec4 image;\n  DECKGL_CREATE_COLOR(image, vTexCoord);\n\n  DECKGL_MUTATE_COLOR(image, vTexCoord);\n\n  color = apply_opacity(color_tint(color_desaturate(image.rgb)), opacity);\n\n  geometry.uv = uv;\n  DECKGL_FILTER_COLOR(color, geometry);\n}\n";
export default _default;