ladybird/Userland/Applications/Piano/WaveWidget.cpp
kleines Filmröllchen 4941cffdd0 Piano+LibDSP: Move Track to LibDSP
This is a tangly commit and it fixes all the bugs that a plain move
would have caused (i.e. we need to touch other logic which had wrong
assumptions).
2022-07-22 19:35:41 +01:00

67 lines
2.5 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2019-2020, William McPherson <willmcpherson2@gmail.com>
* Copyright (c) 2022, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include "WaveWidget.h"
#include "TrackManager.h"
#include <AK/NumericLimits.h>
#include <LibGUI/Painter.h>
WaveWidget::WaveWidget(TrackManager& track_manager)
: m_track_manager(track_manager)
{
}
int WaveWidget::sample_to_y(int sample) const
{
// Sample scaling that looks good, experimentally determined.
constexpr double nice_scale_factor = 1.0;
constexpr double sample_max = NumericLimits<i16>::max();
double percentage = sample / sample_max * nice_scale_factor;
double portion_of_half_height = percentage * ((frame_inner_rect().height() - 1) / 2.0);
double y = (frame_inner_rect().height() / 2.0) + portion_of_half_height;
return y;
}
void WaveWidget::paint_event(GUI::PaintEvent& event)
{
GUI::Painter painter(*this);
painter.fill_rect(frame_inner_rect(), Color::Black);
painter.translate(frame_thickness(), frame_thickness());
Color left_wave_color = left_wave_colors[m_track_manager.current_track()->synth()->wave()];
Color right_wave_color = right_wave_colors[m_track_manager.current_track()->synth()->wave()];
// FIXME: We can't get the last buffer from the track manager anymore
auto buffer = FixedArray<Music::Sample>::must_create_but_fixme_should_propagate_errors(sample_count);
double width_scale = static_cast<double>(frame_inner_rect().width()) / buffer.size();
int prev_x = 0;
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_left = sample_to_y(buffer[x].left);
int y_right = sample_to_y(buffer[x].right);
Gfx::IntPoint point1_left(prev_x * width_scale, prev_y_left);
Gfx::IntPoint point2_left(x * width_scale, y_left);
painter.draw_line(point1_left, point2_left, left_wave_color);
Gfx::IntPoint point1_right(prev_x * width_scale, prev_y_right);
Gfx::IntPoint point2_right(x * width_scale, y_right);
painter.draw_line(point1_right, point2_right, right_wave_color);
prev_x = x;
prev_y_left = y_left;
prev_y_right = y_right;
}
GUI::Frame::paint_event(event);
}