Piano: Draw stereo waves

Draw two waves in different colors.

Applications/Piano/Music.h

@@ -112,7 +112,7 @@ constexpr KeyColor key_pattern[] = {
 const Color note_pressed_color(64, 64, 255);
 const Color column_playing_color(128, 128, 255);
 
-const Color wave_colors[] = {
+const Color left_wave_colors[] = {
  // Sine
  {
  255,
@@ -151,6 +151,45 @@ const Color wave_colors[] = {
  },
 };
 
+const Color right_wave_colors[] = {
+ // Sine
+ {
+ 255,
+ 223,
+ 0,
+ },
+ // Triangle
+ {
+ 35,
+ 171,
+ 90,
+ },
+ // Square
+ {
+ 139,
+ 128,
+ 255,
+ },
+ // Saw
+ {
+ 240,
+ 100,
+ 220,
+ },
+ // Noise
+ {
+ 197,
+ 223,
+ 225,
+ },
+ // RecordedSample
+ {
+ 227,
+ 105,
+ 39,
+ },
+};
+
 constexpr int notes_per_octave = 12;
 constexpr int white_keys_per_octave = 7;
 constexpr int black_keys_per_octave = 5;

Applications/Piano/SamplerWidget.cpp

@@ -69,18 +69,26 @@ void WaveEditor::paint_event(GUI::PaintEvent& event)
  painter.translate(frame_thickness(), frame_thickness());
 
  int prev_x = 0;
- int prev_y = sample_to_y(recorded_sample[0].left);
- painter.set_pixel({ prev_x, prev_y }, wave_colors[RecordedSample]);
+ int left_prev_y = sample_to_y(recorded_sample[0].left);
+ int right_prev_y = sample_to_y(recorded_sample[0].right);
+ painter.set_pixel({ prev_x, left_prev_y }, left_wave_colors[RecordedSample]);
+ painter.set_pixel({ prev_x, right_prev_y }, right_wave_colors[RecordedSample]);
 
  for (int x = 1; x < recorded_sample.size(); ++x) {
- int y = sample_to_y(recorded_sample[x].left);
+ int left_y = sample_to_y(recorded_sample[x].left);
+ int right_y = sample_to_y(recorded_sample[x].right);
 
- Gfx::Point point1(prev_x * width_scale, prev_y);
- Gfx::Point point2(x * width_scale, y);
- painter.draw_line(point1, point2, wave_colors[RecordedSample]);
+ Gfx::Point left_point1(prev_x * width_scale, left_prev_y);
+ Gfx::Point left_point2(x * width_scale, left_y);
+ painter.draw_line(left_point1, left_point2, left_wave_colors[RecordedSample]);
+
+ Gfx::Point right_point1(prev_x * width_scale, right_prev_y);
+ Gfx::Point right_point2(x * width_scale, right_y);
+ painter.draw_line(right_point1, right_point2, right_wave_colors[RecordedSample]);
 
  prev_x = x;
- prev_y = y;
+ left_prev_y = left_y;
+ right_prev_y = right_y;
  }
 }
 

Applications/Piano/WaveWidget.cpp

@@ -60,23 +60,32 @@ void WaveWidget::paint_event(GUI::PaintEvent& event)
  painter.fill_rect(frame_inner_rect(), Color::Black);
  painter.translate(frame_thickness(), frame_thickness());
 
- Color wave_color = wave_colors[m_audio_engine.wave()];
+ Color left_wave_color = left_wave_colors[m_audio_engine.wave()];
+ Color right_wave_color = right_wave_colors[m_audio_engine.wave()];
  auto buffer = m_audio_engine.buffer();
  double width_scale = static_cast<double>(frame_inner_rect().width()) / buffer.size();
 
  int prev_x = 0;
- int prev_y = sample_to_y(buffer[0].left);
- painter.set_pixel({ prev_x, prev_y }, wave_color);
+ int prev_y_left = sample_to_y(buffer[0].left);
+ int prev_y_right = sample_to_y(buffer[0].right);
+ painter.set_pixel({ prev_x, prev_y_left }, left_wave_color);
+ painter.set_pixel({ prev_x, prev_y_right }, right_wave_color);
 
  for (size_t x = 1; x < buffer.size(); ++x) {
- int y = sample_to_y(buffer[x].left);
+ int y_left = sample_to_y(buffer[x].left);
+ int y_right = sample_to_y(buffer[x].right);
 
- Gfx::Point point1(prev_x * width_scale, prev_y);
- Gfx::Point point2(x * width_scale, y);
- painter.draw_line(point1, point2, wave_color);
+ Gfx::Point point1_left(prev_x * width_scale, prev_y_left);
+ Gfx::Point point2_left(x * width_scale, y_left);
+ painter.draw_line(point1_left, point2_left, left_wave_color);
+
+ Gfx::Point point1_right(prev_x * width_scale, prev_y_right);
+ Gfx::Point point2_right(x * width_scale, y_right);
+ painter.draw_line(point1_right, point2_right, right_wave_color);
 
  prev_x = x;
- prev_y = y;
+ prev_y_left = y_left;
+ prev_y_right = y_right;
  }
 
  GUI::Frame::paint_event(event);