Viridis colormap

Former-commit-id: e14f89b6103d56e884d57d4ed39ce602e1c64d52

include/igl/viridis.cpp

@@ -0,0 +1,361 @@
+// This file is part of libigl, a simple c++ geometry processing library.
+//
+// Copyright (C) 2017 Joe Graus <jgraus@gmu.edu>, Alec Jacobson <alecjacobson@gmail.com>
+//
+// This Source Code Form is subject to the terms of the Mozilla Public License
+// v. 2.0. If a copy of the MPL was not distributed with this file, You can
+// obtain one at http://mozilla.org/MPL/2.0/.
+#include "viridis.h"
+#include "colon.h"
+
+// One of the new matplotlib colormaps by Nathaniel J.Smith, Stefan van der Walt, and (in the case of viridis) Eric Firing.
+// Released under the CC0 license / public domain dedication
+static const unsigned int pal = 256;
+
+static float viridis_cm[pal][3] = {
+	{ 0.267004, 0.004874, 0.329415 },
+	{ 0.268510, 0.009605, 0.335427 },
+	{ 0.269944, 0.014625, 0.341379 },
+	{ 0.271305, 0.019942, 0.347269 },
+	{ 0.272594, 0.025563, 0.353093 },
+	{ 0.273809, 0.031497, 0.358853 },
+	{ 0.274952, 0.037752, 0.364543 },
+	{ 0.276022, 0.044167, 0.370164 },
+	{ 0.277018, 0.050344, 0.375715 },
+	{ 0.277941, 0.056324, 0.381191 },
+	{ 0.278791, 0.062145, 0.386592 },
+	{ 0.279566, 0.067836, 0.391917 },
+	{ 0.280267, 0.073417, 0.397163 },
+	{ 0.280894, 0.078907, 0.402329 },
+	{ 0.281446, 0.084320, 0.407414 },
+	{ 0.281924, 0.089666, 0.412415 },
+	{ 0.282327, 0.094955, 0.417331 },
+	{ 0.282656, 0.100196, 0.422160 },
+	{ 0.282910, 0.105393, 0.426902 },
+	{ 0.283091, 0.110553, 0.431554 },
+	{ 0.283197, 0.115680, 0.436115 },
+	{ 0.283229, 0.120777, 0.440584 },
+	{ 0.283187, 0.125848, 0.444960 },
+	{ 0.283072, 0.130895, 0.449241 },
+	{ 0.282884, 0.135920, 0.453427 },
+	{ 0.282623, 0.140926, 0.457517 },
+	{ 0.282290, 0.145912, 0.461510 },
+	{ 0.281887, 0.150881, 0.465405 },
+	{ 0.281412, 0.155834, 0.469201 },
+	{ 0.280868, 0.160771, 0.472899 },
+	{ 0.280255, 0.165693, 0.476498 },
+	{ 0.279574, 0.170599, 0.479997 },
+	{ 0.278826, 0.175490, 0.483397 },
+	{ 0.278012, 0.180367, 0.486697 },
+	{ 0.277134, 0.185228, 0.489898 },
+	{ 0.276194, 0.190074, 0.493001 },
+	{ 0.275191, 0.194905, 0.496005 },
+	{ 0.274128, 0.199721, 0.498911 },
+	{ 0.273006, 0.204520, 0.501721 },
+	{ 0.271828, 0.209303, 0.504434 },
+	{ 0.270595, 0.214069, 0.507052 },
+	{ 0.269308, 0.218818, 0.509577 },
+	{ 0.267968, 0.223549, 0.512008 },
+	{ 0.266580, 0.228262, 0.514349 },
+	{ 0.265145, 0.232956, 0.516599 },
+	{ 0.263663, 0.237631, 0.518762 },
+	{ 0.262138, 0.242286, 0.520837 },
+	{ 0.260571, 0.246922, 0.522828 },
+	{ 0.258965, 0.251537, 0.524736 },
+	{ 0.257322, 0.256130, 0.526563 },
+	{ 0.255645, 0.260703, 0.528312 },
+	{ 0.253935, 0.265254, 0.529983 },
+	{ 0.252194, 0.269783, 0.531579 },
+	{ 0.250425, 0.274290, 0.533103 },
+	{ 0.248629, 0.278775, 0.534556 },
+	{ 0.246811, 0.283237, 0.535941 },
+	{ 0.244972, 0.287675, 0.537260 },
+	{ 0.243113, 0.292092, 0.538516 },
+	{ 0.241237, 0.296485, 0.539709 },
+	{ 0.239346, 0.300855, 0.540844 },
+	{ 0.237441, 0.305202, 0.541921 },
+	{ 0.235526, 0.309527, 0.542944 },
+	{ 0.233603, 0.313828, 0.543914 },
+	{ 0.231674, 0.318106, 0.544834 },
+	{ 0.229739, 0.322361, 0.545706 },
+	{ 0.227802, 0.326594, 0.546532 },
+	{ 0.225863, 0.330805, 0.547314 },
+	{ 0.223925, 0.334994, 0.548053 },
+	{ 0.221989, 0.339161, 0.548752 },
+	{ 0.220057, 0.343307, 0.549413 },
+	{ 0.218130, 0.347432, 0.550038 },
+	{ 0.216210, 0.351535, 0.550627 },
+	{ 0.214298, 0.355619, 0.551184 },
+	{ 0.212395, 0.359683, 0.551710 },
+	{ 0.210503, 0.363727, 0.552206 },
+	{ 0.208623, 0.367752, 0.552675 },
+	{ 0.206756, 0.371758, 0.553117 },
+	{ 0.204903, 0.375746, 0.553533 },
+	{ 0.203063, 0.379716, 0.553925 },
+	{ 0.201239, 0.383670, 0.554294 },
+	{ 0.199430, 0.387607, 0.554642 },
+	{ 0.197636, 0.391528, 0.554969 },
+	{ 0.195860, 0.395433, 0.555276 },
+	{ 0.194100, 0.399323, 0.555565 },
+	{ 0.192357, 0.403199, 0.555836 },
+	{ 0.190631, 0.407061, 0.556089 },
+	{ 0.188923, 0.410910, 0.556326 },
+	{ 0.187231, 0.414746, 0.556547 },
+	{ 0.185556, 0.418570, 0.556753 },
+	{ 0.183898, 0.422383, 0.556944 },
+	{ 0.182256, 0.426184, 0.557120 },
+	{ 0.180629, 0.429975, 0.557282 },
+	{ 0.179019, 0.433756, 0.557430 },
+	{ 0.177423, 0.437527, 0.557565 },
+	{ 0.175841, 0.441290, 0.557685 },
+	{ 0.174274, 0.445044, 0.557792 },
+	{ 0.172719, 0.448791, 0.557885 },
+	{ 0.171176, 0.452530, 0.557965 },
+	{ 0.169646, 0.456262, 0.558030 },
+	{ 0.168126, 0.459988, 0.558082 },
+	{ 0.166617, 0.463708, 0.558119 },
+	{ 0.165117, 0.467423, 0.558141 },
+	{ 0.163625, 0.471133, 0.558148 },
+	{ 0.162142, 0.474838, 0.558140 },
+	{ 0.160665, 0.478540, 0.558115 },
+	{ 0.159194, 0.482237, 0.558073 },
+	{ 0.157729, 0.485932, 0.558013 },
+	{ 0.156270, 0.489624, 0.557936 },
+	{ 0.154815, 0.493313, 0.557840 },
+	{ 0.153364, 0.497000, 0.557724 },
+	{ 0.151918, 0.500685, 0.557587 },
+	{ 0.150476, 0.504369, 0.557430 },
+	{ 0.149039, 0.508051, 0.557250 },
+	{ 0.147607, 0.511733, 0.557049 },
+	{ 0.146180, 0.515413, 0.556823 },
+	{ 0.144759, 0.519093, 0.556572 },
+	{ 0.143343, 0.522773, 0.556295 },
+	{ 0.141935, 0.526453, 0.555991 },
+	{ 0.140536, 0.530132, 0.555659 },
+	{ 0.139147, 0.533812, 0.555298 },
+	{ 0.137770, 0.537492, 0.554906 },
+	{ 0.136408, 0.541173, 0.554483 },
+	{ 0.135066, 0.544853, 0.554029 },
+	{ 0.133743, 0.548535, 0.553541 },
+	{ 0.132444, 0.552216, 0.553018 },
+	{ 0.131172, 0.555899, 0.552459 },
+	{ 0.129933, 0.559582, 0.551864 },
+	{ 0.128729, 0.563265, 0.551229 },
+	{ 0.127568, 0.566949, 0.550556 },
+	{ 0.126453, 0.570633, 0.549841 },
+	{ 0.125394, 0.574318, 0.549086 },
+	{ 0.124395, 0.578002, 0.548287 },
+	{ 0.123463, 0.581687, 0.547445 },
+	{ 0.122606, 0.585371, 0.546557 },
+	{ 0.121831, 0.589055, 0.545623 },
+	{ 0.121148, 0.592739, 0.544641 },
+	{ 0.120565, 0.596422, 0.543611 },
+	{ 0.120092, 0.600104, 0.542530 },
+	{ 0.119738, 0.603785, 0.541400 },
+	{ 0.119512, 0.607464, 0.540218 },
+	{ 0.119423, 0.611141, 0.538982 },
+	{ 0.119483, 0.614817, 0.537692 },
+	{ 0.119699, 0.618490, 0.536347 },
+	{ 0.120081, 0.622161, 0.534946 },
+	{ 0.120638, 0.625828, 0.533488 },
+	{ 0.121380, 0.629492, 0.531973 },
+	{ 0.122312, 0.633153, 0.530398 },
+	{ 0.123444, 0.636809, 0.528763 },
+	{ 0.124780, 0.640461, 0.527068 },
+	{ 0.126326, 0.644107, 0.525311 },
+	{ 0.128087, 0.647749, 0.523491 },
+	{ 0.130067, 0.651384, 0.521608 },
+	{ 0.132268, 0.655014, 0.519661 },
+	{ 0.134692, 0.658636, 0.517649 },
+	{ 0.137339, 0.662252, 0.515571 },
+	{ 0.140210, 0.665859, 0.513427 },
+	{ 0.143303, 0.669459, 0.511215 },
+	{ 0.146616, 0.673050, 0.508936 },
+	{ 0.150148, 0.676631, 0.506589 },
+	{ 0.153894, 0.680203, 0.504172 },
+	{ 0.157851, 0.683765, 0.501686 },
+	{ 0.162016, 0.687316, 0.499129 },
+	{ 0.166383, 0.690856, 0.496502 },
+	{ 0.170948, 0.694384, 0.493803 },
+	{ 0.175707, 0.697900, 0.491033 },
+	{ 0.180653, 0.701402, 0.488189 },
+	{ 0.185783, 0.704891, 0.485273 },
+	{ 0.191090, 0.708366, 0.482284 },
+	{ 0.196571, 0.711827, 0.479221 },
+	{ 0.202219, 0.715272, 0.476084 },
+	{ 0.208030, 0.718701, 0.472873 },
+	{ 0.214000, 0.722114, 0.469588 },
+	{ 0.220124, 0.725509, 0.466226 },
+	{ 0.226397, 0.728888, 0.462789 },
+	{ 0.232815, 0.732247, 0.459277 },
+	{ 0.239374, 0.735588, 0.455688 },
+	{ 0.246070, 0.738910, 0.452024 },
+	{ 0.252899, 0.742211, 0.448284 },
+	{ 0.259857, 0.745492, 0.444467 },
+	{ 0.266941, 0.748751, 0.440573 },
+	{ 0.274149, 0.751988, 0.436601 },
+	{ 0.281477, 0.755203, 0.432552 },
+	{ 0.288921, 0.758394, 0.428426 },
+	{ 0.296479, 0.761561, 0.424223 },
+	{ 0.304148, 0.764704, 0.419943 },
+	{ 0.311925, 0.767822, 0.415586 },
+	{ 0.319809, 0.770914, 0.411152 },
+	{ 0.327796, 0.773980, 0.406640 },
+	{ 0.335885, 0.777018, 0.402049 },
+	{ 0.344074, 0.780029, 0.397381 },
+	{ 0.352360, 0.783011, 0.392636 },
+	{ 0.360741, 0.785964, 0.387814 },
+	{ 0.369214, 0.788888, 0.382914 },
+	{ 0.377779, 0.791781, 0.377939 },
+	{ 0.386433, 0.794644, 0.372886 },
+	{ 0.395174, 0.797475, 0.367757 },
+	{ 0.404001, 0.800275, 0.362552 },
+	{ 0.412913, 0.803041, 0.357269 },
+	{ 0.421908, 0.805774, 0.351910 },
+	{ 0.430983, 0.808473, 0.346476 },
+	{ 0.440137, 0.811138, 0.340967 },
+	{ 0.449368, 0.813768, 0.335384 },
+	{ 0.458674, 0.816363, 0.329727 },
+	{ 0.468053, 0.818921, 0.323998 },
+	{ 0.477504, 0.821444, 0.318195 },
+	{ 0.487026, 0.823929, 0.312321 },
+	{ 0.496615, 0.826376, 0.306377 },
+	{ 0.506271, 0.828786, 0.300362 },
+	{ 0.515992, 0.831158, 0.294279 },
+	{ 0.525776, 0.833491, 0.288127 },
+	{ 0.535621, 0.835785, 0.281908 },
+	{ 0.545524, 0.838039, 0.275626 },
+	{ 0.555484, 0.840254, 0.269281 },
+	{ 0.565498, 0.842430, 0.262877 },
+	{ 0.575563, 0.844566, 0.256415 },
+	{ 0.585678, 0.846661, 0.249897 },
+	{ 0.595839, 0.848717, 0.243329 },
+	{ 0.606045, 0.850733, 0.236712 },
+	{ 0.616293, 0.852709, 0.230052 },
+	{ 0.626579, 0.854645, 0.223353 },
+	{ 0.636902, 0.856542, 0.216620 },
+	{ 0.647257, 0.858400, 0.209861 },
+	{ 0.657642, 0.860219, 0.203082 },
+	{ 0.668054, 0.861999, 0.196293 },
+	{ 0.678489, 0.863742, 0.189503 },
+	{ 0.688944, 0.865448, 0.182725 },
+	{ 0.699415, 0.867117, 0.175971 },
+	{ 0.709898, 0.868751, 0.169257 },
+	{ 0.720391, 0.870350, 0.162603 },
+	{ 0.730889, 0.871916, 0.156029 },
+	{ 0.741388, 0.873449, 0.149561 },
+	{ 0.751884, 0.874951, 0.143228 },
+	{ 0.762373, 0.876424, 0.137064 },
+	{ 0.772852, 0.877868, 0.131109 },
+	{ 0.783315, 0.879285, 0.125405 },
+	{ 0.793760, 0.880678, 0.120005 },
+	{ 0.804182, 0.882046, 0.114965 },
+	{ 0.814576, 0.883393, 0.110347 },
+	{ 0.824940, 0.884720, 0.106217 },
+	{ 0.835270, 0.886029, 0.102646 },
+	{ 0.845561, 0.887322, 0.099702 },
+	{ 0.855810, 0.888601, 0.097452 },
+	{ 0.866013, 0.889868, 0.095953 },
+	{ 0.876168, 0.891125, 0.095250 },
+	{ 0.886271, 0.892374, 0.095374 },
+	{ 0.896320, 0.893616, 0.096335 },
+	{ 0.906311, 0.894855, 0.098125 },
+	{ 0.916242, 0.896091, 0.100717 },
+	{ 0.926106, 0.897330, 0.104071 },
+	{ 0.935904, 0.898570, 0.108131 },
+	{ 0.945636, 0.899815, 0.112838 },
+	{ 0.955300, 0.901065, 0.118128 },
+	{ 0.964894, 0.902323, 0.123941 },
+	{ 0.974417, 0.903590, 0.130215 },
+	{ 0.983868, 0.904867, 0.136897 },
+	{ 0.993248, 0.906157, 0.143936 }
+};
+
+template <typename T>
+static float hue(float delta, T r, T g, T b) {
+	float h = 0.0f;
+
+	if (delta != 0.0f) {
+		if (r > g && r > b) {
+			h = 60.0f * std::fmod(g - b / delta, 6.0);
+		} else if (g > b) {
+			h = 60.0f * ((b - r / delta) + 2.0);
+		} else {
+			h = 60.0f * ((r - g / delta) + 4.0);
+		}
+	}
+
+	return h;
+}
+
+template <typename T>
+IGL_INLINE void igl::viridis(const T x, T * rgb)
+{
+  return viridis(x,rgb[0],rgb[1],rgb[2]);
+}
+
+template <typename T>
+IGL_INLINE void igl::viridis(const T x_in, T & r, T & g, T & b)
+{
+	T x_in_clamped = static_cast<T>(std::max(0.0, std::min(1.0, x_in)));
+
+	// simple rgb lerp from palette 
+	unsigned int least = std::floor(x_in_clamped * static_cast<T>(pal - 1));
+	unsigned int most = std::ceil(x_in_clamped * static_cast<T>(pal - 1));
+
+	T _r[2] = { viridis_cm[least][0], viridis_cm[most][0] };
+	T _g[2] = { viridis_cm[least][1], viridis_cm[most][1] };
+	T _b[2] = { viridis_cm[least][2], viridis_cm[most][2] };
+
+	float t = std::max(0.0, std::min(1.0, fmod(x_in_clamped * static_cast<T>(pal), 1.0f)));
+
+	r = std::max(0.0, std::min(1.0, (1.0f - t) * _r[0] + t * _r[1]));
+	g = std::max(0.0, std::min(1.0, (1.0f - t) * _g[0] + t * _g[1]));
+	b = std::max(0.0, std::min(1.0, (1.0f - t) * _b[0] + t * _b[1]));
+}
+
+template <typename DerivedZ, typename DerivedC>
+IGL_INLINE void igl::viridis(
+  const Eigen::PlainObjectBase<DerivedZ> & Z,
+  const bool normalize,
+  Eigen::PlainObjectBase<DerivedC> & C)
+{
+  const double min_z = (normalize ? Z.minCoeff()) :  0;
+  const double max_z = (normalize ? Z.maxCoeff()) : -1;
+  return viridis(Z, min_z, max_z, C);
+}
+
+template <typename DerivedZ, typename DerivedC>
+IGL_INLINE void igl::viridis(
+  const Eigen::PlainObjectBase<DerivedZ> & Z,
+  const double min_z,
+  const double max_z,
+  Eigen::PlainObjectBase<DerivedC> & C)
+{
+  C.resize(Z.rows(),3);
+  double denom = (max_z - min_z);
+  denom = (denom == 0) ? 1 : denom;
+  for(int r = 0; r < Z.rows(); ++r) {
+    viridis(
+      (typename DerivedC::Scalar)((-min_z + Z(r,0)) / denom),
+      C(r,0),
+      C(r,1),
+      C(r,2));
+  }
+}
+
+#ifdef IGL_STATIC_LIBRARY
+// Explicit template instantiation
+// generated by autoexplicit.sh
+template void igl::viridis<Eigen::Matrix<double, -1, 1, 0, -1, 1>, Eigen::Matrix<double, -1, -1, 0, -1, -1> >(Eigen::PlainObjectBase<Eigen::Matrix<double, -1, 1, 0, -1, 1> > const&, bool, Eigen::PlainObjectBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> >&);
+template void igl::viridis<double>(double, double*);
+template void igl::viridis<double>(double, double&, double&, double&);
+template void igl::viridis<float>(float, float*);
+template void igl::viridis<Eigen::Array<double, -1, 1, 0, -1, 1>, Eigen::Matrix<double, -1, -1, 0, -1, -1> >(Eigen::PlainObjectBase<Eigen::Array<double, -1, 1, 0, -1, 1> > const&, bool, Eigen::PlainObjectBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> >&);
+template void igl::viridis<Eigen::Matrix<int, -1, 1, 0, -1, 1>, Eigen::Matrix<double, -1, -1, 0, -1, -1> >(Eigen::PlainObjectBase<Eigen::Matrix<int, -1, 1, 0, -1, 1> > const&, bool, Eigen::PlainObjectBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> >&);
+template void igl::viridis<Eigen::Matrix<double, -1, -1, 0, -1, -1>, Eigen::Matrix<double, -1, -1, 0, -1, -1> >(Eigen::PlainObjectBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> > const&, bool, Eigen::PlainObjectBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> >&);
+template void igl::viridis<float>(float, float&, float&, float&);
+template void igl::viridis<Eigen::Matrix<float, -1, 1, 0, -1, 1>, Eigen::Matrix<double, -1, -1, 0, -1, -1> >(Eigen::PlainObjectBase<Eigen::Matrix<float, -1, 1, 0, -1, 1> > const&, double, double, Eigen::PlainObjectBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> >&);
+template void igl::viridis<Eigen::Matrix<double, -1, 1, 0, -1, 1>, Eigen::Matrix<double, -1, -1, 0, -1, -1> >(Eigen::PlainObjectBase<Eigen::Matrix<double, -1, 1, 0, -1, 1> > const&, double, double, Eigen::PlainObjectBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> >&);
+template void igl::viridis<Eigen::Matrix<double, -1, -1, 0, -1, -1>, Eigen::Matrix<double, -1, -1, 0, -1, -1> >(Eigen::PlainObjectBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> > const&, double, double, Eigen::PlainObjectBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> >&);
+#endif

include/igl/viridis.h

@@ -0,0 +1,61 @@
+// This file is part of libigl, a simple c++ geometry processing library.
+// 
+// Copyright (C) 2017 Joe Graus <jgraus@gmu.edu>, Alec Jacobson <alecjacobson@gmail.com>
+// 
+// This Source Code Form is subject to the terms of the Mozilla Public License 
+// v. 2.0. If a copy of the MPL was not distributed with this file, You can 
+// obtain one at http://mozilla.org/MPL/2.0/.
+
+#ifndef IGL_VIRIDIS_H
+#define IGL_VIRIDIS_H
+#include "igl_inline.h"
+
+#include <Eigen/Dense>
+
+namespace igl {
+  // Viridis colormap -- a perceptually uniform sequential colormap
+  //
+  // Inputs:
+  //   m  number of colors 
+  // Outputs:
+  //   J  m by list of RGB colors between 0 and 1
+  //
+  // Wrapper for directly computing [r,g,b] values for a given factor f between
+  // 0 and 1
+  //
+  // Inputs:
+  //   f  factor determining color value as if 0 was min and 1 was max
+  // Outputs:
+  //   r  red value
+  //   g  green value
+  //   b  blue value
+  template <typename T>
+  IGL_INLINE void viridis(const T f, T * rgb);
+  template <typename T>
+  IGL_INLINE void viridis(const T f, T & r, T & g, T & b);
+  // Inputs:
+  //   Z  #Z list of factors
+  //   normalize  whether to normalize Z to be tightly between [0,1]
+  // Outputs:
+  //   C  #C by 3 list of rgb colors
+  template <typename DerivedZ, typename DerivedC>
+  IGL_INLINE void viridis(
+    const Eigen::PlainObjectBase<DerivedZ> & Z,
+    const bool normalize,
+    Eigen::PlainObjectBase<DerivedC> & C);
+  // Inputs:
+  //   min_z  value at black
+  //   max_z  value at yellow
+  template <typename DerivedZ, typename DerivedC>
+  IGL_INLINE void viridis(
+    const Eigen::PlainObjectBase<DerivedZ> & Z,
+    const double min_Z,
+    const double max_Z,
+    Eigen::PlainObjectBase<DerivedC> & C);
+};
+
+#ifndef IGL_STATIC_LIBRARY
+#  include "viridis.cpp"
+#endif
+
+#endif