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molstar

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A comprehensive macromolecular library.

github.com/molstar/molstar

molstar/molstar

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/** * Copyright (c) 2020 mol* contributors, licensed under MIT, See LICENSE file for more info. * * @author David Sehnal <david.sehnal@gmail.com> */ export declare const float_to_rgba = "\n // floatToRgba adapted from https://github.com/equinor/glsl-float-to-rgba\n // MIT License, Copyright (c) 2020 Equinor\n\n float shiftRight (float v, float amt) {\n v = floor(v) + 0.5;\n return floor(v / exp2(amt));\n }\n float shiftLeft (float v, float amt) {\n return floor(v * exp2(amt) + 0.5);\n }\n float maskLast (float v, float bits) {\n return mod(v, shiftLeft(1.0, bits));\n }\n float extractBits (float num, float from, float to) {\n from = floor(from + 0.5); to = floor(to + 0.5);\n return maskLast(shiftRight(num, from), to - from);\n }\n\n vec4 floatToRgba(float texelFloat, bool littleEndian) {\n if (texelFloat == 0.0) return vec4(0.0, 0.0, 0.0, 0.0);\n float sign = texelFloat > 0.0 ? 0.0 : 1.0;\n texelFloat = abs(texelFloat);\n float exponent = floor(log2(texelFloat));\n float biased_exponent = exponent + 127.0;\n float fraction = ((texelFloat / exp2(exponent)) - 1.0) * 8388608.0;\n float t = biased_exponent / 2.0;\n float last_bit_of_biased_exponent = fract(t) * 2.0;\n float remaining_bits_of_biased_exponent = floor(t);\n float byte4 = extractBits(fraction, 0.0, 8.0) / 255.0;\n float byte3 = extractBits(fraction, 8.0, 16.0) / 255.0;\n float byte2 = (last_bit_of_biased_exponent * 128.0 + extractBits(fraction, 16.0, 23.0)) / 255.0;\n float byte1 = (sign * 128.0 + remaining_bits_of_biased_exponent) / 255.0;\n return (\n littleEndian\n ? vec4(byte4, byte3, byte2, byte1)\n : vec4(byte1, byte2, byte3, byte4)\n );\n }\n";