56 lines
2.3 KiB
GLSL
56 lines
2.3 KiB
GLSL
/**
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*
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* RenderPipeline
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*
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* Copyright (c) 2014-2016 tobspr <tobias.springer1@gmail.com>
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*
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*/
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#pragma once
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uniform sampler3D IESDatasetTex;
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// The ies profiles give us candela values, which we can directly convert to lumens
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const float IES_SCALE = 1.0 /* lumens */;
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// Computes the IES factor from a given light vector and profile.
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// A profile < 0 means no light profile.
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float get_ies_factor(vec3 light_vector, int profile) {
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if (profile < 0)
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return 1.0;
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light_vector = normalize(light_vector);
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float horiz_angle = acos(light_vector.z) / M_PI;
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float vert_angle = fma(atan(light_vector.x, light_vector.y), 1.0 / TWO_PI, 0.5);
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float profile_coord = (profile+0.5) / MAX_IES_PROFILES;
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float data = textureLod(IESDatasetTex, vec3(horiz_angle, vert_angle, profile_coord), 0).x;
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return data * IES_SCALE;
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}
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// Computes the IES factor from a given spherical coordinate and profile.
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// theta and phi should range from 0 to 1.
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float get_ies_factor(int profile, float theta, float phi) {
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if (profile < 0)
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return 1.0;
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float profile_coord = (profile+0.5) / MAX_IES_PROFILES;
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float data = textureLod(IESDatasetTex, vec3(theta * 0.5 + 0.5, phi, profile_coord), 0).x;
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return data * IES_SCALE;
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}
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