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/*
* Copyright 2011-2020 Blender Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
float safe_divide(float a, float b)
{
return (b != 0.0) ? a / b : 0.0;
}
vector safe_divide(vector a, vector b)
{
return vector((b[0] != 0.0) ? a[0] / b[0] : 0.0,
(b[1] != 0.0) ? a[1] / b[1] : 0.0,
(b[2] != 0.0) ? a[2] / b[2] : 0.0);
}
float safe_modulo(float a, float b)
{
return (b != 0.0) ? fmod(a, b) : 0.0;
}
float fract(float a)
{
return a - floor(a);
}
/* See: https://www.iquilezles.org/www/articles/smin/smin.htm. */
float smoothmin(float a, float b, float c)
{
if (c != 0.0) {
float h = max(c - abs(a - b), 0.0) / c;
return min(a, b) - h * h * h * c * (1.0 / 6.0);
}
else {
return min(a, b);
}
}
float pingpong(float a, float b)
{
return (b != 0.0) ? abs(fract((a - b) / (b * 2.0)) * b * 2.0 - b) : 0.0;
}
float safe_sqrt(float a)
{
return (a > 0.0) ? sqrt(a) : 0.0;
}
float safe_log(float a, float b)
{
return (a > 0.0 && b > 0.0) ? log(a) / log(b) : 0.0;
}
vector project(vector v, vector v_proj)
{
float lenSquared = dot(v_proj, v_proj);
return (lenSquared != 0.0) ? (dot(v, v_proj) / lenSquared) * v_proj : vector(0.0);
}
vector snap(vector a, vector b)
{
return floor(safe_divide(a, b)) * b;
}
/* Adapted from GODOT-engine math_funcs.h. */
float wrap(float value, float max, float min)
{
float range = max - min;
return (range != 0.0) ? value - (range * floor((value - min) / range)) : min;
}
point wrap(point value, point max, point min)
{
return point(wrap(value[0], max[0], min[0]),
wrap(value[1], max[1], min[1]),
wrap(value[2], max[2], min[2]));
}
/* Built in OSL faceforward is `(dot(I, Nref) > 0) ? -N : N;` which is different to
* GLSL `dot(Nref, I) < 0 ? N : -N` for zero values. */
point compatible_faceforward(point vec, point incident, point reference)
{
return dot(reference, incident) < 0.0 ? vec : -vec;
}
matrix euler_to_mat(point euler)
{
float cx = cos(euler[0]);
float cy = cos(euler[1]);
float cz = cos(euler[2]);
float sx = sin(euler[0]);
float sy = sin(euler[1]);
float sz = sin(euler[2]);
matrix mat = matrix(1.0);
mat[0][0] = cy * cz;
mat[0][1] = cy * sz;
mat[0][2] = -sy;
mat[1][0] = sy * sx * cz - cx * sz;
mat[1][1] = sy * sx * sz + cx * cz;
mat[1][2] = cy * sx;
+mat[2][0] = sy * cx * cz + sx * sz;
mat[2][1] = sy * cx * sz - sx * cz;
mat[2][2] = cy * cx;
return mat;
}
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