1 files changed, 198 insertions, 0 deletions
diff --git a/tools/llvm-xray/xray-color-helper.cc b/tools/llvm-xray/xray-color-helper.cc
new file mode 100644
index 000000000000..925bb7483d8f
--- /dev/null
+++ b/tools/llvm-xray/xray-color-helper.cc
@@ -0,0 +1,198 @@
+//===-- xray-graph.cc - XRay Function Call Graph Renderer -----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// A class to get a color from a specified gradient.
+//
+//===----------------------------------------------------------------------===//
+#include <algorithm>
+
+#include "xray-color-helper.h"
+#include "llvm/Support/FormatVariadic.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+using namespace xray;
+
+//  Sequential ColorMaps, which are used to represent information
+//  from some minimum to some maximum.
+
+static const std::tuple<uint8_t, uint8_t, uint8_t> SequentialMaps[][9] = {
+    {// The greys color scheme from http://colorbrewer2.org/
+     std::make_tuple(255, 255, 255), std::make_tuple(240, 240, 240),
+     std::make_tuple(217, 217, 217), std::make_tuple(189, 189, 189),
+     std::make_tuple(150, 150, 150), std::make_tuple(115, 115, 115),
+     std::make_tuple(82, 82, 82), std::make_tuple(37, 37, 37),
+     std::make_tuple(0, 0, 0)},
+    {// The OrRd color scheme from http://colorbrewer2.org/
+     std::make_tuple(255, 247, 236), std::make_tuple(254, 232, 200),
+     std::make_tuple(253, 212, 158), std::make_tuple(253, 187, 132),
+     std::make_tuple(252, 141, 89), std::make_tuple(239, 101, 72),
+     std::make_tuple(215, 48, 31), std::make_tuple(179, 0, 0),
+     std::make_tuple(127, 0, 0)},
+    {// The PuBu color scheme from http://colorbrewer2.org/
+     std::make_tuple(255, 247, 251), std::make_tuple(236, 231, 242),
+     std::make_tuple(208, 209, 230), std::make_tuple(166, 189, 219),
+     std::make_tuple(116, 169, 207), std::make_tuple(54, 144, 192),
+     std::make_tuple(5, 112, 176), std::make_tuple(4, 90, 141),
+     std::make_tuple(2, 56, 88)}};
+
+ColorHelper::ColorHelper(ColorHelper::SequentialScheme S)
+    : MinIn(0.0), MaxIn(1.0), ColorMap(SequentialMaps[static_cast<int>(S)]) {}
+
+// Diverging ColorMaps, which are used to represent information
+// representing differenes, or a range that goes from negative to positive.
+// These take an input in the range [-1,1].
+
+static const std::tuple<uint8_t, uint8_t, uint8_t> DivergingCoeffs[][11] = {
+    {// The PiYG color scheme from http://colorbrewer2.org/
+     std::make_tuple(142, 1, 82), std::make_tuple(197, 27, 125),
+     std::make_tuple(222, 119, 174), std::make_tuple(241, 182, 218),
+     std::make_tuple(253, 224, 239), std::make_tuple(247, 247, 247),
+     std::make_tuple(230, 245, 208), std::make_tuple(184, 225, 134),
+     std::make_tuple(127, 188, 65), std::make_tuple(77, 146, 33),
+     std::make_tuple(39, 100, 25)}};
+
+ColorHelper::ColorHelper(ColorHelper::DivergingScheme S)
+    : MinIn(-1.0), MaxIn(1.0), ColorMap(DivergingCoeffs[static_cast<int>(S)]) {}
+
+// Takes a tuple of uint8_ts representing a color in RGB and converts them to
+// HSV represented by a tuple of doubles
+static std::tuple<double, double, double>
+convertToHSV(const std::tuple<uint8_t, uint8_t, uint8_t> &Color) {
+  double Scaled[3] = {std::get<0>(Color) / 255.0, std::get<1>(Color) / 255.0,
+                      std::get<2>(Color) / 255.0};
+  int Min = 0;
+  int Max = 0;
+  for (int i = 1; i < 3; ++i) {
+    if (Scaled[i] < Scaled[Min])
+      Min = i;
+    if (Scaled[i] > Scaled[Max])
+      Max = i;
+  }
+
+  double C = Scaled[Max] - Scaled[Min];
+
+  double HPrime = (Scaled[(Max + 1) % 3] - Scaled[(Max + 2) % 3]) / C;
+  HPrime = HPrime + 2.0 * Max;
+
+  double H = (HPrime < 0) ? (HPrime + 6.0) * 60
+                          : HPrime * 60; // Scale to between 0 and 360
+
+  double V = Scaled[Max];
+
+  double S = (V == 0.0) ? 0.0 : C / V;
+
+  return std::make_tuple(H, S, V);
+}
+
+// Takes a double precision number, clips it between 0 and 1 and then converts
+// that to an integer between 0x00 and 0xFF with proxpper rounding.
+static uint8_t unitIntervalTo8BitChar(double B) {
+  double n = std::max(std::min(B, 1.0), 0.0);
+  return static_cast<uint8_t>(255 * n + 0.5);
+}
+
+// Takes a typle of doubles representing a color in HSV and converts them to
+// RGB represented as a tuple of uint8_ts
+static std::tuple<uint8_t, uint8_t, uint8_t>
+convertToRGB(const std::tuple<double, double, double> &Color) {
+  const double &H = std::get<0>(Color);
+  const double &S = std::get<1>(Color);
+  const double &V = std::get<2>(Color);
+
+  double C = V * S;
+
+  double HPrime = H / 60;
+  double X = C * (1 - std::abs(std::fmod(HPrime, 2.0) - 1));
+
+  double RGB1[3];
+  int HPrimeInt = static_cast<int>(HPrime);
+  if (HPrimeInt % 2 == 0) {
+    RGB1[(HPrimeInt / 2) % 3] = C;
+    RGB1[(HPrimeInt / 2 + 1) % 3] = X;
+    RGB1[(HPrimeInt / 2 + 2) % 3] = 0.0;
+  } else {
+    RGB1[(HPrimeInt / 2) % 3] = X;
+    RGB1[(HPrimeInt / 2 + 1) % 3] = C;
+    RGB1[(HPrimeInt / 2 + 2) % 3] = 0.0;
+  }
+
+  double Min = V - C;
+  double RGB2[3] = {RGB1[0] + Min, RGB1[1] + Min, RGB1[2] + Min};
+
+  return std::make_tuple(unitIntervalTo8BitChar(RGB2[0]),
+                         unitIntervalTo8BitChar(RGB2[1]),
+                         unitIntervalTo8BitChar(RGB2[2]));
+}
+
+// The Hue component of the HSV interpolation Routine
+static double interpolateHue(double H0, double H1, double T) {
+  double D = H1 - H0;
+  if (H0 > H1) {
+    std::swap(H0, H1);
+
+    D = -D;
+    T = 1 - T;
+  }
+
+  if (D <= 180) {
+    return H0 + T * (H1 - H0);
+  } else {
+    H0 = H0 + 360;
+    return std::fmod(H0 + T * (H1 - H0) + 720, 360);
+  }
+}
+
+// Interpolates between two HSV Colors both represented as a tuple of doubles
+// Returns an HSV Color represented as a tuple of doubles
+static std::tuple<double, double, double>
+interpolateHSV(const std::tuple<double, double, double> &C0,
+               const std::tuple<double, double, double> &C1, double T) {
+  double H = interpolateHue(std::get<0>(C0), std::get<0>(C1), T);
+  double S = std::get<1>(C0) + T * (std::get<1>(C1) - std::get<1>(C0));
+  double V = std::get<2>(C0) + T * (std::get<2>(C1) - std::get<2>(C0));
+  return std::make_tuple(H, S, V);
+}
+
+// Get the Color as a tuple of uint8_ts
+std::tuple<uint8_t, uint8_t, uint8_t>
+ColorHelper::getColorTuple(double Point) const {
+  assert(!ColorMap.empty() && "ColorMap must not be empty!");
+  size_t MaxIndex = ColorMap.size() - 1;
+  double IntervalWidth = MaxIn - MinIn;
+  double OffsetP = Point - MinIn;
+  double SectionWidth = IntervalWidth / static_cast<double>(MaxIndex);
+  size_t SectionNo = std::floor(OffsetP / SectionWidth);
+  double T = (OffsetP - SectionNo * SectionWidth) / SectionWidth;
+
+  auto &RGBColor0 = ColorMap[SectionNo];
+  auto &RGBColor1 = ColorMap[std::min(SectionNo + 1, MaxIndex)];
+
+  auto HSVColor0 = convertToHSV(RGBColor0);
+  auto HSVColor1 = convertToHSV(RGBColor1);
+
+  auto InterpolatedHSVColor = interpolateHSV(HSVColor0, HSVColor1, T);
+  return convertToRGB(InterpolatedHSVColor);
+}
+
+// A helper method to convert a color represented as tuple of uint8s to a hex
+// string.
+std::string
+ColorHelper::getColorString(std::tuple<uint8_t, uint8_t, uint8_t> t) {
+  return llvm::formatv("#{0:X-2}{1:X-2}{2:X-2}", std::get<0>(t), std::get<1>(t),
+                       std::get<2>(t));
+}
+
+// Gets a color in a gradient given a number in the interval [0,1], it does this
+// by evaluating a polynomial which maps [0, 1] -> [0, 1] for each of the R G
+// and B values in the color. It then converts this [0,1] colors to a 24 bit
+// color as a hex string.
+std::string ColorHelper::getColorString(double Point) const {
+  return getColorString(getColorTuple(Point));
+}