c6fafd3e90
Previously, in LibGFX's `Point` class, calculated distances were passed to the integer `abs` function, even if the stored type was a float. This caused the value to unexpectedly be truncated. Luckily, this API was not used with floating point types, but that can change in the future, so why not fix it now :^) Since we are in C++, we can use function overloading to make things easy, and to automatically use the right version. This is even better than the LibC/LibM functions, as using a bit of hackery, they are able to be constant-evaluated. They use compiler intrinsics, so they do not depend on external code and the compiler can emit the most optimized code by default. Since we aren't using the C++ standard library's trick of importing everything into the `AK` namespace, this `abs` function cannot be exported to the global namespace, as the names would clash.
118 lines
3.5 KiB
C++
118 lines
3.5 KiB
C++
/*
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* Copyright (c) 2020, Sergey Bugaev <bugaevc@serenityos.org>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#include "EyesWidget.h"
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#include <AK/StdLibExtraDetails.h>
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#include <LibGUI/Painter.h>
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#include <LibGUI/Window.h>
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#include <LibGUI/WindowServerConnection.h>
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#include <LibGfx/Palette.h>
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#include <math.h>
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EyesWidget::~EyesWidget()
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{
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}
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void EyesWidget::track_cursor_globally()
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{
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VERIFY(window());
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auto window_id = window()->window_id();
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VERIFY(window_id >= 0);
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set_global_cursor_tracking(true);
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GUI::WindowServerConnection::the().async_set_global_cursor_tracking(window_id, true);
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}
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void EyesWidget::mousemove_event(GUI::MouseEvent& event)
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{
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m_mouse_position = event.position();
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update();
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}
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void EyesWidget::paint_event(GUI::PaintEvent& event)
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{
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GUI::Painter painter(*this);
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painter.clear_rect(event.rect(), Gfx::Color());
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for (int i = 0; i < m_full_rows; i++) {
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for (int j = 0; j < m_eyes_in_row; j++)
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render_eyeball(i, j, painter);
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}
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for (int i = 0; i < m_extra_columns; ++i)
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render_eyeball(m_full_rows, i, painter);
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}
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void EyesWidget::render_eyeball(int row, int column, GUI::Painter& painter) const
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{
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auto eye_width = width() / m_eyes_in_row;
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auto eye_height = height() / m_num_rows;
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Gfx::IntRect bounds { column * eye_width, row * eye_height, eye_width, eye_height };
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auto width_thickness = max(int(eye_width / 5.5), 1);
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auto height_thickness = max(int(eye_height / 5.5), 1);
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bounds.shrink(int(eye_width / 12.5), 0);
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painter.fill_ellipse(bounds, palette().base_text());
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bounds.shrink(width_thickness, height_thickness);
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painter.fill_ellipse(bounds, palette().base());
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Gfx::IntPoint pupil_center = this->pupil_center(bounds);
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Gfx::IntSize pupil_size {
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bounds.width() / 5,
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bounds.height() / 5
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};
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Gfx::IntRect pupil {
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pupil_center.x() - pupil_size.width() / 2,
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pupil_center.y() - pupil_size.height() / 2,
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pupil_size.width(),
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pupil_size.height()
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};
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painter.fill_ellipse(pupil, palette().base_text());
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}
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Gfx::IntPoint EyesWidget::pupil_center(Gfx::IntRect& eyeball_bounds) const
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{
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auto mouse_vector = m_mouse_position - eyeball_bounds.center();
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double dx = mouse_vector.x();
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double dy = mouse_vector.y();
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double mouse_distance = sqrt(dx * dx + dy * dy);
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if (mouse_distance == 0.0)
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return eyeball_bounds.center();
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double width_squared = eyeball_bounds.width() * eyeball_bounds.width();
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double height_squared = eyeball_bounds.height() * eyeball_bounds.height();
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double max_distance_along_this_direction;
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// clang-format off
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if (dx != 0 && AK::abs(dx) >= AK::abs(dy)) {
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double slope = dy / dx;
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double slope_squared = slope * slope;
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max_distance_along_this_direction = 0.25 * sqrt(
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(slope_squared + 1) /
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(1 / width_squared + slope_squared / height_squared)
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);
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} else if (dy != 0 && AK::abs(dy) >= AK::abs(dx)) {
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double slope = dx / dy;
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double slope_squared = slope * slope;
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max_distance_along_this_direction = 0.25 * sqrt(
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(slope_squared + 1) /
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(slope_squared / width_squared + 1 / height_squared)
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);
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} else {
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VERIFY_NOT_REACHED();
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}
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// clang-format on
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double scale = min(1.0, max_distance_along_this_direction / mouse_distance);
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return {
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eyeball_bounds.center().x() + int(dx * scale),
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eyeball_bounds.center().y() + int(dy * scale)
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};
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}
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