tools/llvm-xray/xray-color-helper.cc

   1 //===-- xray-graph.cc - XRay Function Call Graph Renderer -----------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // A class to get a color from a specified gradient.
  11 //
  12 //===----------------------------------------------------------------------===//
  13 #include <algorithm>
  14 #include <iostream>
  15
  16 #include "xray-color-helper.h"
  17 #include "llvm/Support/FormatVariadic.h"
  18 #include "llvm/Support/raw_ostream.h"
  19
  20 using namespace llvm;
  21 using namespace xray;
  22
  23 //  Sequential ColorMaps, which are used to represent information
  24 //  from some minimum to some maximum.
  25
  26 static const std::tuple<uint8_t, uint8_t, uint8_t> SequentialMaps[][9] = {
  27     {// The greys color scheme from http://colorbrewer2.org/
  28      std::make_tuple(255, 255, 255), std::make_tuple(240, 240, 240),
  29      std::make_tuple(217, 217, 217), std::make_tuple(189, 189, 189),
  30      std::make_tuple(150, 150, 150), std::make_tuple(115, 115, 115),
  31      std::make_tuple(82, 82, 82), std::make_tuple(37, 37, 37),
  32      std::make_tuple(0, 0, 0)},
  33     {// The OrRd color scheme from http://colorbrewer2.org/
  34      std::make_tuple(255, 247, 236), std::make_tuple(254, 232, 200),
  35      std::make_tuple(253, 212, 158), std::make_tuple(253, 187, 132),
  36      std::make_tuple(252, 141, 89), std::make_tuple(239, 101, 72),
  37      std::make_tuple(215, 48, 31), std::make_tuple(179, 0, 0),
  38      std::make_tuple(127, 0, 0)},
  39     {// The PuBu color scheme from http://colorbrewer2.org/
  40      std::make_tuple(255, 247, 251), std::make_tuple(236, 231, 242),
  41      std::make_tuple(208, 209, 230), std::make_tuple(166, 189, 219),
  42      std::make_tuple(116, 169, 207), std::make_tuple(54, 144, 192),
  43      std::make_tuple(5, 112, 176), std::make_tuple(4, 90, 141),
  44      std::make_tuple(2, 56, 88)}};
  45
  46 // Sequential Maps extend the last colors given out of range inputs.
  47 static const std::tuple<uint8_t, uint8_t, uint8_t> SequentialBounds[][2] = {
  48     {// The Bounds for the greys color scheme
  49      std::make_tuple(255, 255, 255), std::make_tuple(0, 0, 0)},
  50     {// The Bounds for the OrRd color Scheme
  51      std::make_tuple(255, 247, 236), std::make_tuple(127, 0, 0)},
  52     {// The Bounds for the PuBu color Scheme
  53      std::make_tuple(255, 247, 251), std::make_tuple(2, 56, 88)}};
  54
  55 ColorHelper::ColorHelper(ColorHelper::SequentialScheme S)
  56     : MinIn(0.0), MaxIn(1.0), ColorMap(SequentialMaps[static_cast<int>(S)]),
  57       BoundMap(SequentialBounds[static_cast<int>(S)]) {}
  58
  59 // Diverging ColorMaps, which are used to represent information
  60 // representing differenes, or a range that goes from negative to positive.
  61 // These take an input in the range [-1,1].
  62
  63 static const std::tuple<uint8_t, uint8_t, uint8_t> DivergingCoeffs[][11] = {
  64     {// The PiYG color scheme from http://colorbrewer2.org/
  65      std::make_tuple(142, 1, 82), std::make_tuple(197, 27, 125),
  66      std::make_tuple(222, 119, 174), std::make_tuple(241, 182, 218),
  67      std::make_tuple(253, 224, 239), std::make_tuple(247, 247, 247),
  68      std::make_tuple(230, 245, 208), std::make_tuple(184, 225, 134),
  69      std::make_tuple(127, 188, 65), std::make_tuple(77, 146, 33),
  70      std::make_tuple(39, 100, 25)}};
  71
  72 // Diverging maps use out of bounds ranges to show missing data. Missing Right
  73 // Being below min, and missing left being above max.
  74 static const std::tuple<uint8_t, uint8_t, uint8_t> DivergingBounds[][2] = {
  75     {// The PiYG color scheme has green and red for missing right and left
  76      // respectively.
  77      std::make_tuple(255, 0, 0), std::make_tuple(0, 255, 0)}};
  78
  79 ColorHelper::ColorHelper(ColorHelper::DivergingScheme S)
  80     : MinIn(-1.0), MaxIn(1.0), ColorMap(DivergingCoeffs[static_cast<int>(S)]),
  81       BoundMap(DivergingBounds[static_cast<int>(S)]) {}
  82
  83 // Takes a tuple of uint8_ts representing a color in RGB and converts them to
  84 // HSV represented by a tuple of doubles
  85 static std::tuple<double, double, double>
  86 convertToHSV(const std::tuple<uint8_t, uint8_t, uint8_t> &Color) {
  87   double Scaled[3] = {std::get<0>(Color) / 255.0, std::get<1>(Color) / 255.0,
  88                       std::get<2>(Color) / 255.0};
  89   int Min = 0;
  90   int Max = 0;
  91   for (int i = 1; i < 3; ++i) {
  92     if (Scaled[i] < Scaled[Min])
  93       Min = i;
  94     if (Scaled[i] > Scaled[Max])
  95       Max = i;
  96   }
  97
  98   double C = Scaled[Max] - Scaled[Min];
  99
 100   double HPrime =
 101       (C == 0) ? 0 : (Scaled[(Max + 1) % 3] - Scaled[(Max + 2) % 3]) / C;
 102   HPrime = HPrime + 2.0 * Max;
 103
 104   double H = (HPrime < 0) ? (HPrime + 6.0) * 60
 105                           : HPrime * 60; // Scale to between 0 and 360
 106   double V = Scaled[Max];
 107
 108   double S = (V == 0.0) ? 0.0 : C / V;
 109
 110   return std::make_tuple(H, S, V);
 111 }
 112
 113 // Takes a double precision number, clips it between 0 and 1 and then converts
 114 // that to an integer between 0x00 and 0xFF with proxpper rounding.
 115 static uint8_t unitIntervalTo8BitChar(double B) {
 116   double n = std::max(std::min(B, 1.0), 0.0);
 117   return static_cast<uint8_t>(255 * n + 0.5);
 118 }
 119
 120 // Takes a typle of doubles representing a color in HSV and converts them to
 121 // RGB represented as a tuple of uint8_ts
 122 static std::tuple<uint8_t, uint8_t, uint8_t>
 123 convertToRGB(const std::tuple<double, double, double> &Color) {
 124   const double &H = std::get<0>(Color);
 125   const double &S = std::get<1>(Color);
 126   const double &V = std::get<2>(Color);
 127
 128   double C = V * S;
 129
 130   double HPrime = H / 60;
 131   double X = C * (1 - std::abs(std::fmod(HPrime, 2.0) - 1));
 132
 133   double RGB1[3];
 134   int HPrimeInt = static_cast<int>(HPrime);
 135   if (HPrimeInt % 2 == 0) {
 136     RGB1[(HPrimeInt / 2) % 3] = C;
 137     RGB1[(HPrimeInt / 2 + 1) % 3] = X;
 138     RGB1[(HPrimeInt / 2 + 2) % 3] = 0.0;
 139   } else {
 140     RGB1[(HPrimeInt / 2) % 3] = X;
 141     RGB1[(HPrimeInt / 2 + 1) % 3] = C;
 142     RGB1[(HPrimeInt / 2 + 2) % 3] = 0.0;
 143   }
 144
 145   double Min = V - C;
 146   double RGB2[3] = {RGB1[0] + Min, RGB1[1] + Min, RGB1[2] + Min};
 147
 148   return std::make_tuple(unitIntervalTo8BitChar(RGB2[0]),
 149                          unitIntervalTo8BitChar(RGB2[1]),
 150                          unitIntervalTo8BitChar(RGB2[2]));
 151 }
 152
 153 // The Hue component of the HSV interpolation Routine
 154 static double interpolateHue(double H0, double H1, double T) {
 155   double D = H1 - H0;
 156   if (H0 > H1) {
 157     std::swap(H0, H1);
 158
 159     D = -D;
 160     T = 1 - T;
 161   }
 162
 163   if (D <= 180) {
 164     return H0 + T * (H1 - H0);
 165   } else {
 166     H0 = H0 + 360;
 167     return std::fmod(H0 + T * (H1 - H0) + 720, 360);
 168   }
 169 }
 170
 171 // Interpolates between two HSV Colors both represented as a tuple of doubles
 172 // Returns an HSV Color represented as a tuple of doubles
 173 static std::tuple<double, double, double>
 174 interpolateHSV(const std::tuple<double, double, double> &C0,
 175                const std::tuple<double, double, double> &C1, double T) {
 176   double H = interpolateHue(std::get<0>(C0), std::get<0>(C1), T);
 177   double S = std::get<1>(C0) + T * (std::get<1>(C1) - std::get<1>(C0));
 178   double V = std::get<2>(C0) + T * (std::get<2>(C1) - std::get<2>(C0));
 179   return std::make_tuple(H, S, V);
 180 }
 181
 182 // Get the Color as a tuple of uint8_ts
 183 std::tuple<uint8_t, uint8_t, uint8_t>
 184 ColorHelper::getColorTuple(double Point) const {
 185   assert(!ColorMap.empty() && "ColorMap must not be empty!");
 186   assert(!BoundMap.empty() && "BoundMap must not be empty!");
 187
 188   if (Point < MinIn)
 189     return BoundMap[0];
 190   if (Point > MaxIn)
 191     return BoundMap[1];
 192
 193   size_t MaxIndex = ColorMap.size() - 1;
 194   double IntervalWidth = MaxIn - MinIn;
 195   double OffsetP = Point - MinIn;
 196   double SectionWidth = IntervalWidth / static_cast<double>(MaxIndex);
 197   size_t SectionNo = std::floor(OffsetP / SectionWidth);
 198   double T = (OffsetP - SectionNo * SectionWidth) / SectionWidth;
 199
 200   auto &RGBColor0 = ColorMap[SectionNo];
 201   auto &RGBColor1 = ColorMap[std::min(SectionNo + 1, MaxIndex)];
 202
 203   auto HSVColor0 = convertToHSV(RGBColor0);
 204   auto HSVColor1 = convertToHSV(RGBColor1);
 205
 206   auto InterpolatedHSVColor = interpolateHSV(HSVColor0, HSVColor1, T);
 207   return convertToRGB(InterpolatedHSVColor);
 208 }
 209
 210 // A helper method to convert a color represented as tuple of uint8s to a hex
 211 // string.
 212 std::string
 213 ColorHelper::getColorString(std::tuple<uint8_t, uint8_t, uint8_t> t) {
 214   return llvm::formatv("#{0:X-2}{1:X-2}{2:X-2}", std::get<0>(t), std::get<1>(t),
 215                        std::get<2>(t));
 216 }
 217
 218 // Gets a color in a gradient given a number in the interval [0,1], it does this
 219 // by evaluating a polynomial which maps [0, 1] -> [0, 1] for each of the R G
 220 // and B values in the color. It then converts this [0,1] colors to a 24 bit
 221 // color as a hex string.
 222 std::string ColorHelper::getColorString(double Point) const {
 223   return getColorString(getColorTuple(Point));
 224 }