ladybird/Applications/Piano/WaveWidget.cpp
2020-04-15 16:58:46 +02:00

89 lines
3.4 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2019-2020, William McPherson <willmcpherson2@gmail.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "WaveWidget.h"
#include "AudioEngine.h"
#include <AK/NumericLimits.h>
#include <LibGUI/Painter.h>
WaveWidget::WaveWidget(AudioEngine& audio_engine)
: m_audio_engine(audio_engine)
{
}
WaveWidget::~WaveWidget()
{
}
int WaveWidget::sample_to_y(int sample) const
{
constexpr int nice_scale_factor = 4;
sample *= nice_scale_factor;
constexpr double sample_max = NumericLimits<i16>::max();
double percentage = sample / sample_max;
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_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_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::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_left = y_left;
prev_y_right = y_right;
}
GUI::Frame::paint_event(event);
}