Magma colormap

Former-commit-id: 3b395e8b5847ad1f663ff6fe62bacb164e4720db

include/igl/magma.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 "magma.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 magma_cm[pal][3] = {
+	{ 0.001462, 0.000466, 0.013866 },
+	{ 0.002258, 0.001295, 0.018331 },
+	{ 0.003279, 0.002305, 0.023708 },
+	{ 0.004512, 0.003490, 0.029965 },
+	{ 0.005950, 0.004843, 0.037130 },
+	{ 0.007588, 0.006356, 0.044973 },
+	{ 0.009426, 0.008022, 0.052844 },
+	{ 0.011465, 0.009828, 0.060750 },
+	{ 0.013708, 0.011771, 0.068667 },
+	{ 0.016156, 0.013840, 0.076603 },
+	{ 0.018815, 0.016026, 0.084584 },
+	{ 0.021692, 0.018320, 0.092610 },
+	{ 0.024792, 0.020715, 0.100676 },
+	{ 0.028123, 0.023201, 0.108787 },
+	{ 0.031696, 0.025765, 0.116965 },
+	{ 0.035520, 0.028397, 0.125209 },
+	{ 0.039608, 0.031090, 0.133515 },
+	{ 0.043830, 0.033830, 0.141886 },
+	{ 0.048062, 0.036607, 0.150327 },
+	{ 0.052320, 0.039407, 0.158841 },
+	{ 0.056615, 0.042160, 0.167446 },
+	{ 0.060949, 0.044794, 0.176129 },
+	{ 0.065330, 0.047318, 0.184892 },
+	{ 0.069764, 0.049726, 0.193735 },
+	{ 0.074257, 0.052017, 0.202660 },
+	{ 0.078815, 0.054184, 0.211667 },
+	{ 0.083446, 0.056225, 0.220755 },
+	{ 0.088155, 0.058133, 0.229922 },
+	{ 0.092949, 0.059904, 0.239164 },
+	{ 0.097833, 0.061531, 0.248477 },
+	{ 0.102815, 0.063010, 0.257854 },
+	{ 0.107899, 0.064335, 0.267289 },
+	{ 0.113094, 0.065492, 0.276784 },
+	{ 0.118405, 0.066479, 0.286321 },
+	{ 0.123833, 0.067295, 0.295879 },
+	{ 0.129380, 0.067935, 0.305443 },
+	{ 0.135053, 0.068391, 0.315000 },
+	{ 0.140858, 0.068654, 0.324538 },
+	{ 0.146785, 0.068738, 0.334011 },
+	{ 0.152839, 0.068637, 0.343404 },
+	{ 0.159018, 0.068354, 0.352688 },
+	{ 0.165308, 0.067911, 0.361816 },
+	{ 0.171713, 0.067305, 0.370771 },
+	{ 0.178212, 0.066576, 0.379497 },
+	{ 0.184801, 0.065732, 0.387973 },
+	{ 0.191460, 0.064818, 0.396152 },
+	{ 0.198177, 0.063862, 0.404009 },
+	{ 0.204935, 0.062907, 0.411514 },
+	{ 0.211718, 0.061992, 0.418647 },
+	{ 0.218512, 0.061158, 0.425392 },
+	{ 0.225302, 0.060445, 0.431742 },
+	{ 0.232077, 0.059889, 0.437695 },
+	{ 0.238826, 0.059517, 0.443256 },
+	{ 0.245543, 0.059352, 0.448436 },
+	{ 0.252220, 0.059415, 0.453248 },
+	{ 0.258857, 0.059706, 0.457710 },
+	{ 0.265447, 0.060237, 0.461840 },
+	{ 0.271994, 0.060994, 0.465660 },
+	{ 0.278493, 0.061978, 0.469190 },
+	{ 0.284951, 0.063168, 0.472451 },
+	{ 0.291366, 0.064553, 0.475462 },
+	{ 0.297740, 0.066117, 0.478243 },
+	{ 0.304081, 0.067835, 0.480812 },
+	{ 0.310382, 0.069702, 0.483186 },
+	{ 0.316654, 0.071690, 0.485380 },
+	{ 0.322899, 0.073782, 0.487408 },
+	{ 0.329114, 0.075972, 0.489287 },
+	{ 0.335308, 0.078236, 0.491024 },
+	{ 0.341482, 0.080564, 0.492631 },
+	{ 0.347636, 0.082946, 0.494121 },
+	{ 0.353773, 0.085373, 0.495501 },
+	{ 0.359898, 0.087831, 0.496778 },
+	{ 0.366012, 0.090314, 0.497960 },
+	{ 0.372116, 0.092816, 0.499053 },
+	{ 0.378211, 0.095332, 0.500067 },
+	{ 0.384299, 0.097855, 0.501002 },
+	{ 0.390384, 0.100379, 0.501864 },
+	{ 0.396467, 0.102902, 0.502658 },
+	{ 0.402548, 0.105420, 0.503386 },
+	{ 0.408629, 0.107930, 0.504052 },
+	{ 0.414709, 0.110431, 0.504662 },
+	{ 0.420791, 0.112920, 0.505215 },
+	{ 0.426877, 0.115395, 0.505714 },
+	{ 0.432967, 0.117855, 0.506160 },
+	{ 0.439062, 0.120298, 0.506555 },
+	{ 0.445163, 0.122724, 0.506901 },
+	{ 0.451271, 0.125132, 0.507198 },
+	{ 0.457386, 0.127522, 0.507448 },
+	{ 0.463508, 0.129893, 0.507652 },
+	{ 0.469640, 0.132245, 0.507809 },
+	{ 0.475780, 0.134577, 0.507921 },
+	{ 0.481929, 0.136891, 0.507989 },
+	{ 0.488088, 0.139186, 0.508011 },
+	{ 0.494258, 0.141462, 0.507988 },
+	{ 0.500438, 0.143719, 0.507920 },
+	{ 0.506629, 0.145958, 0.507806 },
+	{ 0.512831, 0.148179, 0.507648 },
+	{ 0.519045, 0.150383, 0.507443 },
+	{ 0.525270, 0.152569, 0.507192 },
+	{ 0.531507, 0.154739, 0.506895 },
+	{ 0.537755, 0.156894, 0.506551 },
+	{ 0.544015, 0.159033, 0.506159 },
+	{ 0.550287, 0.161158, 0.505719 },
+	{ 0.556571, 0.163269, 0.505230 },
+	{ 0.562866, 0.165368, 0.504692 },
+	{ 0.569172, 0.167454, 0.504105 },
+	{ 0.575490, 0.169530, 0.503466 },
+	{ 0.581819, 0.171596, 0.502777 },
+	{ 0.588158, 0.173652, 0.502035 },
+	{ 0.594508, 0.175701, 0.501241 },
+	{ 0.600868, 0.177743, 0.500394 },
+	{ 0.607238, 0.179779, 0.499492 },
+	{ 0.613617, 0.181811, 0.498536 },
+	{ 0.620005, 0.183840, 0.497524 },
+	{ 0.626401, 0.185867, 0.496456 },
+	{ 0.632805, 0.187893, 0.495332 },
+	{ 0.639216, 0.189921, 0.494150 },
+	{ 0.645633, 0.191952, 0.492910 },
+	{ 0.652056, 0.193986, 0.491611 },
+	{ 0.658483, 0.196027, 0.490253 },
+	{ 0.664915, 0.198075, 0.488836 },
+	{ 0.671349, 0.200133, 0.487358 },
+	{ 0.677786, 0.202203, 0.485819 },
+	{ 0.684224, 0.204286, 0.484219 },
+	{ 0.690661, 0.206384, 0.482558 },
+	{ 0.697098, 0.208501, 0.480835 },
+	{ 0.703532, 0.210638, 0.479049 },
+	{ 0.709962, 0.212797, 0.477201 },
+	{ 0.716387, 0.214982, 0.475290 },
+	{ 0.722805, 0.217194, 0.473316 },
+	{ 0.729216, 0.219437, 0.471279 },
+	{ 0.735616, 0.221713, 0.469180 },
+	{ 0.742004, 0.224025, 0.467018 },
+	{ 0.748378, 0.226377, 0.464794 },
+	{ 0.754737, 0.228772, 0.462509 },
+	{ 0.761077, 0.231214, 0.460162 },
+	{ 0.767398, 0.233705, 0.457755 },
+	{ 0.773695, 0.236249, 0.455289 },
+	{ 0.779968, 0.238851, 0.452765 },
+	{ 0.786212, 0.241514, 0.450184 },
+	{ 0.792427, 0.244242, 0.447543 },
+	{ 0.798608, 0.247040, 0.444848 },
+	{ 0.804752, 0.249911, 0.442102 },
+	{ 0.810855, 0.252861, 0.439305 },
+	{ 0.816914, 0.255895, 0.436461 },
+	{ 0.822926, 0.259016, 0.433573 },
+	{ 0.828886, 0.262229, 0.430644 },
+	{ 0.834791, 0.265540, 0.427671 },
+	{ 0.840636, 0.268953, 0.424666 },
+	{ 0.846416, 0.272473, 0.421631 },
+	{ 0.852126, 0.276106, 0.418573 },
+	{ 0.857763, 0.279857, 0.415496 },
+	{ 0.863320, 0.283729, 0.412403 },
+	{ 0.868793, 0.287728, 0.409303 },
+	{ 0.874176, 0.291859, 0.406205 },
+	{ 0.879464, 0.296125, 0.403118 },
+	{ 0.884651, 0.300530, 0.400047 },
+	{ 0.889731, 0.305079, 0.397002 },
+	{ 0.894700, 0.309773, 0.393995 },
+	{ 0.899552, 0.314616, 0.391037 },
+	{ 0.904281, 0.319610, 0.388137 },
+	{ 0.908884, 0.324755, 0.385308 },
+	{ 0.913354, 0.330052, 0.382563 },
+	{ 0.917689, 0.335500, 0.379915 },
+	{ 0.921884, 0.341098, 0.377376 },
+	{ 0.925937, 0.346844, 0.374959 },
+	{ 0.929845, 0.352734, 0.372677 },
+	{ 0.933606, 0.358764, 0.370541 },
+	{ 0.937221, 0.364929, 0.368567 },
+	{ 0.940687, 0.371224, 0.366762 },
+	{ 0.944006, 0.377643, 0.365136 },
+	{ 0.947180, 0.384178, 0.363701 },
+	{ 0.950210, 0.390820, 0.362468 },
+	{ 0.953099, 0.397563, 0.361438 },
+	{ 0.955849, 0.404400, 0.360619 },
+	{ 0.958464, 0.411324, 0.360014 },
+	{ 0.960949, 0.418323, 0.359630 },
+	{ 0.963310, 0.425390, 0.359469 },
+	{ 0.965549, 0.432519, 0.359529 },
+	{ 0.967671, 0.439703, 0.359810 },
+	{ 0.969680, 0.446936, 0.360311 },
+	{ 0.971582, 0.454210, 0.361030 },
+	{ 0.973381, 0.461520, 0.361965 },
+	{ 0.975082, 0.468861, 0.363111 },
+	{ 0.976690, 0.476226, 0.364466 },
+	{ 0.978210, 0.483612, 0.366025 },
+	{ 0.979645, 0.491014, 0.367783 },
+	{ 0.981000, 0.498428, 0.369734 },
+	{ 0.982279, 0.505851, 0.371874 },
+	{ 0.983485, 0.513280, 0.374198 },
+	{ 0.984622, 0.520713, 0.376698 },
+	{ 0.985693, 0.528148, 0.379371 },
+	{ 0.986700, 0.535582, 0.382210 },
+	{ 0.987646, 0.543015, 0.385210 },
+	{ 0.988533, 0.550446, 0.388365 },
+	{ 0.989363, 0.557873, 0.391671 },
+	{ 0.990138, 0.565296, 0.395122 },
+	{ 0.990871, 0.572706, 0.398714 },
+	{ 0.991558, 0.580107, 0.402441 },
+	{ 0.992196, 0.587502, 0.406299 },
+	{ 0.992785, 0.594891, 0.410283 },
+	{ 0.993326, 0.602275, 0.414390 },
+	{ 0.993834, 0.609644, 0.418613 },
+	{ 0.994309, 0.616999, 0.422950 },
+	{ 0.994738, 0.624350, 0.427397 },
+	{ 0.995122, 0.631696, 0.431951 },
+	{ 0.995480, 0.639027, 0.436607 },
+	{ 0.995810, 0.646344, 0.441361 },
+	{ 0.996096, 0.653659, 0.446213 },
+	{ 0.996341, 0.660969, 0.451160 },
+	{ 0.996580, 0.668256, 0.456192 },
+	{ 0.996775, 0.675541, 0.461314 },
+	{ 0.996925, 0.682828, 0.466526 },
+	{ 0.997077, 0.690088, 0.471811 },
+	{ 0.997186, 0.697349, 0.477182 },
+	{ 0.997254, 0.704611, 0.482635 },
+	{ 0.997325, 0.711848, 0.488154 },
+	{ 0.997351, 0.719089, 0.493755 },
+	{ 0.997351, 0.726324, 0.499428 },
+	{ 0.997341, 0.733545, 0.505167 },
+	{ 0.997285, 0.740772, 0.510983 },
+	{ 0.997228, 0.747981, 0.516859 },
+	{ 0.997138, 0.755190, 0.522806 },
+	{ 0.997019, 0.762398, 0.528821 },
+	{ 0.996898, 0.769591, 0.534892 },
+	{ 0.996727, 0.776795, 0.541039 },
+	{ 0.996571, 0.783977, 0.547233 },
+	{ 0.996369, 0.791167, 0.553499 },
+	{ 0.996162, 0.798348, 0.559820 },
+	{ 0.995932, 0.805527, 0.566202 },
+	{ 0.995680, 0.812706, 0.572645 },
+	{ 0.995424, 0.819875, 0.579140 },
+	{ 0.995131, 0.827052, 0.585701 },
+	{ 0.994851, 0.834213, 0.592307 },
+	{ 0.994524, 0.841387, 0.598983 },
+	{ 0.994222, 0.848540, 0.605696 },
+	{ 0.993866, 0.855711, 0.612482 },
+	{ 0.993545, 0.862859, 0.619299 },
+	{ 0.993170, 0.870024, 0.626189 },
+	{ 0.992831, 0.877168, 0.633109 },
+	{ 0.992440, 0.884330, 0.640099 },
+	{ 0.992089, 0.891470, 0.647116 },
+	{ 0.991688, 0.898627, 0.654202 },
+	{ 0.991332, 0.905763, 0.661309 },
+	{ 0.990930, 0.912915, 0.668481 },
+	{ 0.990570, 0.920049, 0.675675 },
+	{ 0.990175, 0.927196, 0.682926 },
+	{ 0.989815, 0.934329, 0.690198 },
+	{ 0.989434, 0.941470, 0.697519 },
+	{ 0.989077, 0.948604, 0.704863 },
+	{ 0.988717, 0.955742, 0.712242 },
+	{ 0.988367, 0.962878, 0.719649 },
+	{ 0.988033, 0.970012, 0.727077 },
+	{ 0.987691, 0.977154, 0.734536 },
+	{ 0.987387, 0.984288, 0.742002 },
+	{ 0.987053, 0.991438, 0.749504 }
+};
+
+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::magma(const T x, T * rgb)
+{
+  return magma(x,rgb[0],rgb[1],rgb[2]);
+}
+
+template <typename T>
+IGL_INLINE void igl::magma(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] = { magma_cm[least][0], magma_cm[most][0] };
+	T _g[2] = { magma_cm[least][1], magma_cm[most][1] };
+	T _b[2] = { magma_cm[least][2], magma_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::magma(
+  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 magma(Z, min_z, max_z, C);
+}
+
+template <typename DerivedZ, typename DerivedC>
+IGL_INLINE void igl::magma(
+  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) {
+    magma(
+      (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::magma<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::magma<double>(double, double*);
+template void igl::magma<double>(double, double&, double&, double&);
+template void igl::magma<float>(float, float*);
+template void igl::magma<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::magma<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::magma<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::magma<float>(float, float&, float&, float&);
+template void igl::magma<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::magma<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::magma<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/magma.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_MAGMA_H
+#define IGL_MAGMA_H
+#include "igl_inline.h"
+
+#include <Eigen/Dense>
+
+namespace igl {
+  // Magma 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 magma(const T f, T * rgb);
+  template <typename T>
+  IGL_INLINE void magma(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 magma(
+    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 magma(
+    const Eigen::PlainObjectBase<DerivedZ> & Z,
+    const double min_Z,
+    const double max_Z,
+    Eigen::PlainObjectBase<DerivedC> & C);
+};
+
+#ifndef IGL_STATIC_LIBRARY
+#  include "magma.cpp"
+#endif
+
+#endif