ladybird/Userland/Applications/PixelPaint/Selection.cpp
Andreas Kling 4cecd79000 PixelPaint: Draw the current editor selection as marching ants
This patch moves the marching ants painting code to Selection and
unifies the timer mechanism so that all marching ants are synchronized
which looks neat. :^)
2021-06-14 18:25:17 +02:00

59 lines
1.5 KiB
C++

/*
* Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include "Selection.h"
#include "ImageEditor.h"
#include <LibGfx/Painter.h>
namespace PixelPaint {
constexpr int marching_ant_length = 4;
void Selection::paint(Gfx::Painter& painter, ImageEditor const& editor)
{
draw_marching_ants(painter, editor.image_rect_to_editor_rect(m_rect).to_type<int>());
}
Selection::Selection(ImageEditor& editor)
: m_editor(editor)
{
m_marching_ants_timer = Core::Timer::create_repeating(80, [this] {
++m_marching_ants_offset;
m_marching_ants_offset %= marching_ant_length;
if (!is_empty())
m_editor.update();
});
m_marching_ants_timer->start();
}
void Selection::draw_marching_ants(Gfx::Painter& painter, Gfx::IntRect const& rect) const
{
int offset = m_marching_ants_offset;
auto draw_pixel = [&](int x, int y) {
if ((offset % marching_ant_length) != 0)
painter.set_pixel(x, y, Color::Black);
offset++;
};
// Top line
for (int x = rect.left(); x <= rect.right(); ++x)
draw_pixel(x, rect.top());
// Right line
for (int y = rect.top() + 1; y <= rect.bottom(); ++y)
draw_pixel(rect.right(), y);
// Bottom line
for (int x = rect.right() - 1; x >= rect.left(); --x)
draw_pixel(x, rect.bottom());
// Left line
for (int y = rect.bottom() - 1; y > rect.top(); --y)
draw_pixel(rect.left(), y);
}
}