Add moodbar

src/moodbar/moodbarrenderer.cpp

@@ -0,0 +1,178 @@
+/* This file was part of Clementine.
+   Copyright 2012, David Sansome <me@davidsansome.com>
+
+   Strawberry is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Strawberry is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "moodbarrenderer.h"
+
+#include <QByteArray>
+#include <QString>
+#include <QImage>
+#include <QPainter>
+#include <QPalette>
+#include <QColor>
+
+#include "core/arraysize.h"
+
+const int MoodbarRenderer::kNumHues = 12;
+
+ColorVector MoodbarRenderer::Colors(const QByteArray& data, MoodbarStyle style, const QPalette& palette) {
+
+  const int samples = data.size() / 3;
+
+  // Set some parameters based on the moodbar style
+  StyleProperties properties;
+  switch (style) {
+    case Style_Angry:
+      properties = StyleProperties(samples / 360 * 9, 45, -45, 200, 100);
+      break;
+    case Style_Frozen:
+      properties = StyleProperties(samples / 360 * 1, 140, 160, 50, 100);
+      break;
+    case Style_Happy:
+      properties = StyleProperties(samples / 360 * 2, 0, 359, 150, 250);
+      break;
+    case Style_Normal:
+      properties = StyleProperties(samples / 360 * 3, 0, 359, 100, 100);
+      break;
+    case Style_SystemPalette:
+    default: {
+      const QColor highlight_color(palette.color(QPalette::Active, QPalette::Highlight));
+
+      properties.threshold_ = samples / 360 * 3;
+      properties.range_start_ = (highlight_color.hsvHue() - 20 + 360) % 360;
+      properties.range_delta_ = 20;
+      properties.sat_ = highlight_color.hsvSaturation();
+      properties.val_ = highlight_color.value() / 2;
+    }
+  }
+
+  const unsigned char* data_p = reinterpret_cast<const unsigned char*>(data.constData());
+
+  int hue_distribution[360];
+  int total = 0;
+
+  memset(hue_distribution, 0, sizeof(hue_distribution));
+
+  ColorVector colors;
+
+  // Read the colors, keeping track of some histograms
+  for (int i = 0; i < samples; ++i) {
+    QColor color;
+    color.setRed(int(*data_p++));
+    color.setGreen(int(*data_p++));
+    color.setBlue(int(*data_p++));
+
+    colors << color;
+
+    const int hue = qMax(0, color.hue());
+    if (hue_distribution[hue]++ == properties.threshold_) {
+      total++;
+    }
+  }
+
+  total = qMax(total, 1);
+
+  // Remap the hue values to be between rangeStart and
+  // rangeStart + rangeDelta.  Every time we see an input hue
+  // above the threshold, increment the output hue by
+  // (1/total) * rangeDelta.
+  for (int i = 0, n = 0; i < 360; i++) {
+    hue_distribution[i] = ((hue_distribution[i] > properties.threshold_ ? n++ : n) * properties.range_delta_ / total + properties.range_start_) % 360;
+  }
+
+  // Now huedist is a hue mapper: huedist[h] is the new hue value
+  // for a bar with hue h
+  for (ColorVector::iterator it = colors.begin(); it != colors.end(); ++it) {
+    const int hue = qMax(0, it->hue());
+
+    *it = QColor::fromHsv(qBound(0, hue_distribution[hue], 359), qBound(0, it->saturation() * properties.sat_ / 100, 255), qBound(0, it->value() * properties.val_ / 100, 255));
+  }
+
+  return colors;
+}
+
+void MoodbarRenderer::Render(const ColorVector& colors, QPainter* p, const QRect& rect) {
+
+  // Sample the colors and map them to screen pixels.
+  ColorVector screen_colors;
+  for (int x = 0; x < rect.width(); ++x) {
+    int r = 0;
+    int g = 0;
+    int b = 0;
+
+    int start = x * colors.size() / rect.width();
+    int end = (x + 1) * colors.size() / rect.width();
+
+    if (start == end) end = qMin(start + 1, colors.size() - 1);
+
+    for (int j = start; j < end; j++) {
+      r += colors[j].red();
+      g += colors[j].green();
+      b += colors[j].blue();
+    }
+
+    const int n = qMax(1, end - start);
+    screen_colors.append(QColor(r / n, g / n, b / n));
+  }
+
+  // Draw the actual moodbar.
+  for (int x = 0; x < rect.width(); x++) {
+    int h, s, v;
+    screen_colors[x].getHsv(&h, &s, &v);
+
+    for (int y = 0; y <= rect.height() / 2; y++) {
+      float coeff = float(y) / float(rect.height() / 2);
+      float coeff2 = 1.0f - ((1.0f - coeff) * (1.0f - coeff));
+      coeff = 1.0f - (1.0f - coeff) / 2.0f;
+      coeff2 = 1.f - (1.f - coeff2) / 2.0f;
+
+      p->setPen(QColor::fromHsv(h, qBound(0, int(float(s) * coeff), 255), qBound(0, int(255.f - (255.f - float(v)) * coeff2), 255)));
+
+      p->drawPoint(rect.left() + x, rect.top() + y);
+      p->drawPoint(rect.left() + x, rect.top() + rect.height() - 1 - y);
+    }
+  }
+}
+
+QImage MoodbarRenderer::RenderToImage(const ColorVector& colors, const QSize& size) {
+
+  QImage image(size, QImage::Format_ARGB32_Premultiplied);
+  QPainter p(&image);
+  Render(colors, &p, image.rect());
+  p.end();
+  return image;
+
+}
+
+QString MoodbarRenderer::StyleName(MoodbarStyle style) {
+
+  switch (style) {
+    case Style_Normal:
+      return QObject::tr("Normal");
+    case Style_Angry:
+      return QObject::tr("Angry");
+    case Style_Frozen:
+      return QObject::tr("Frozen");
+    case Style_Happy:
+      return QObject::tr("Happy");
+    case Style_SystemPalette:
+      return QObject::tr("System colors");
+
+    default:
+      return QString();
+  }
+
+}