754b8a643d
m_rotated_rectangle_path was unused and m_intersection_edge_path was cleared/free'd each time it was used. So sticking in the class just bloats the size.
795 lines
34 KiB
C++
795 lines
34 KiB
C++
/*
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* Copyright (c) 2021, Ali Mohammad Pur <mpfard@serenityos.org>
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* Copyright (c) 2022, Ben Maxwell <macdue@dueutil.tech>
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* Copyright (c) 2022, Torsten Engelmann <engelTorsten@gmx.de>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#if defined(AK_COMPILER_GCC)
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# pragma GCC optimize("O3")
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#endif
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#include "FillPathImplementation.h"
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#include <AK/Function.h>
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#include <AK/NumericLimits.h>
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#include <LibGfx/AntiAliasingPainter.h>
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#include <LibGfx/Line.h>
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namespace Gfx {
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template<AntiAliasingPainter::FixmeEnableHacksForBetterPathPainting path_hacks>
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void AntiAliasingPainter::draw_anti_aliased_line(FloatPoint actual_from, FloatPoint actual_to, Color color, float thickness, Painter::LineStyle style, Color)
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{
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// FIXME: Implement this :P
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VERIFY(style == Painter::LineStyle::Solid);
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if (color.alpha() == 0)
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return;
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// FIMXE:
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// This is not a proper line drawing algorithm.
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// It's hack-ish AA rotated rectangle painting.
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// There's probably more optimal ways to achieve this
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// (though this still runs faster than the previous AA-line code)
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//
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// If you, reading this comment, know a better way that:
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// 1. Does not overpaint (i.e. painting a line with transparency looks correct)
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// 2. Has square end points (i.e. the line is a rectangle)
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// 3. Has good anti-aliasing
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// 4. Is less hacky than this
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//
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// Please delete this code and implement it!
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int int_thickness = AK::ceil(thickness);
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auto mapped_from = m_transform.map(actual_from);
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auto mapped_to = m_transform.map(actual_to);
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auto length = mapped_to.distance_from(mapped_from);
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// Axis-aligned lines:
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if (mapped_from.y() == mapped_to.y()) {
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auto start_point = (mapped_from.x() < mapped_to.x() ? mapped_from : mapped_to).translated(0, -int_thickness / 2);
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if constexpr (path_hacks == FixmeEnableHacksForBetterPathPainting::Yes) {
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// FIXME: SVG fill_path() hack:
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// SVG asks for 1px scanlines at floating point y values, if they're not snapped to a pixel they look faint.
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start_point.set_y(floorf(start_point.y()));
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}
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return fill_rect(Gfx::FloatRect(start_point, { length, thickness }), color);
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}
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if (mapped_from.x() == mapped_to.x()) {
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auto start_point = (mapped_from.y() < mapped_to.y() ? mapped_from : mapped_to).translated(-int_thickness / 2, 0);
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return fill_rect(Gfx::FloatRect(start_point, { thickness, length }), color);
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}
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if constexpr (path_hacks == FixmeEnableHacksForBetterPathPainting::Yes) {
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// FIXME: SVG stoke_path() hack:
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// When painting stokes SVG asks for many thickness * < 1px lines.
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// It actually wants a thickness * thickness dot centered at that point.
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// (Technically this should be rotated or a circle, but that currently gives worse results)
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if (length < 1.0f)
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return fill_rect(Gfx::FloatRect::centered_at(mapped_from, { thickness, thickness }), color);
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}
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// The painting only works for the positive XY quadrant (because that is easier).
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// So flip things around until we're there:
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bool flip_x = false;
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bool flip_y = false;
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if (mapped_to.x() < mapped_from.x() && mapped_to.y() < mapped_from.y())
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swap(mapped_to, mapped_from);
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if ((flip_x = mapped_to.x() < mapped_from.x()))
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mapped_to.set_x(2 * mapped_from.x() - mapped_to.x());
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if ((flip_y = mapped_to.y() < mapped_from.y()))
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mapped_to.set_y(2 * mapped_from.y() - mapped_to.y());
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auto delta = mapped_to - mapped_from;
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auto line_angle_radians = AK::atan2(delta.y(), delta.x()) - 0.5f * AK::Pi<float>;
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float sin_inverse_angle;
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float cos_inverse_angle;
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AK::sincos(-line_angle_radians, sin_inverse_angle, cos_inverse_angle);
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auto inverse_rotate_point = [=](FloatPoint point) {
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return Gfx::FloatPoint(
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point.x() * cos_inverse_angle - point.y() * sin_inverse_angle,
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point.y() * cos_inverse_angle + point.x() * sin_inverse_angle);
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};
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Gfx::FloatRect line_rect({ -(thickness * 255) / 2.0f, 0 }, Gfx::FloatSize(thickness * 255, length * 255));
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auto gradient = delta.y() / delta.x();
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// Work out how long we need to scan along the X-axis to reach the other side of the line.
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// E.g. for a vertical line this would be `thickness', in general it is this:
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int scan_line_length = AK::ceil(AK::sqrt((gradient * gradient + 1) * thickness * thickness) / gradient);
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auto x_gradient = 1 / gradient;
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int x_step = floorf(x_gradient);
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float x_error = 0;
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float x_error_per_y = x_gradient - x_step;
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auto y_offset = int_thickness;
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auto x_offset = int(x_gradient * y_offset);
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int const line_start_x = mapped_from.x();
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int const line_start_y = mapped_from.y();
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int const line_end_x = mapped_to.x();
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int const line_end_y = mapped_to.y();
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auto set_pixel = [=, this](int x, int y, Gfx::Color color) {
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// FIXME: The lines seem slightly off (<= 1px) when flipped.
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if (flip_x)
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x = 2 * line_start_x - x;
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if (flip_y)
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y = 2 * line_start_y - y;
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m_underlying_painter.set_pixel(x, y, color, true);
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};
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// Scan a bit extra to avoid issues from the x_error:
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int const overscan = max(x_step, 1) * 2 + 1;
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int x = line_start_x - x_offset;
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int const center_offset = (scan_line_length + 1) / 2;
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for (int y = line_start_y - y_offset; y < line_end_y + y_offset; y += 1) {
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for (int i = -overscan; i < scan_line_length + overscan; i++) {
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int scan_x_pos = x + i - center_offset;
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// Avoid scanning over pixels definitely outside the line:
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int dx = (line_start_x - int_thickness) - (scan_x_pos + 1);
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if (dx > 0) {
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i += dx;
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continue;
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}
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if (line_end_x + int_thickness <= scan_x_pos - 1)
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break;
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auto sample = inverse_rotate_point(Gfx::FloatPoint(scan_x_pos - line_start_x, y - line_start_y));
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Gfx::FloatRect sample_px(sample * 255, Gfx::FloatSize(255, 255));
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sample_px.intersect(line_rect);
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auto alpha = (sample_px.width() * sample_px.height()) / 255.0f;
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alpha = (alpha * color.alpha()) / 255;
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set_pixel(scan_x_pos, y, color.with_alpha(alpha));
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}
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x += x_step;
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x_error += x_error_per_y;
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if (x_error > 1.0f) {
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x_error -= 1.0f;
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x += 1;
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}
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}
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}
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void AntiAliasingPainter::draw_line_for_path(FloatPoint const& actual_from, FloatPoint const& actual_to, Color color, float thickness, Painter::LineStyle style, Color alternate_color)
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{
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draw_anti_aliased_line<FixmeEnableHacksForBetterPathPainting::Yes>(actual_from, actual_to, color, thickness, style, alternate_color);
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}
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void AntiAliasingPainter::draw_dotted_line(IntPoint point1, IntPoint point2, Color color, int thickness)
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{
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// AA circles don't really work below a radius of 2px.
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if (thickness < 4)
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return m_underlying_painter.draw_line(point1, point2, color, thickness, Painter::LineStyle::Dotted);
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auto draw_spaced_dots = [&](int start, int end, auto to_point) {
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int step = thickness * 2;
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if (start > end)
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swap(start, end);
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int delta = end - start;
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int dots = delta / step;
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if (dots == 0)
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return;
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int fudge_per_dot = 0;
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int extra_fudge = 0;
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if (dots > 3) {
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// Fudge the numbers so the last dot is drawn at the `end' point (otherwise you can get lines cuts short).
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// You need at least a handful of dots to do this.
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int fudge = delta % step;
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fudge_per_dot = fudge / dots;
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extra_fudge = fudge % dots;
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}
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for (int dot = start; dot <= end; dot += (step + fudge_per_dot + (extra_fudge > 0))) {
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fill_circle(to_point(dot), thickness / 2, color);
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--extra_fudge;
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}
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};
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if (point1.y() == point2.y()) {
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draw_spaced_dots(point1.x(), point2.x(), [&](int dot_x) {
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return IntPoint { dot_x, point1.y() };
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});
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} else if (point1.x() == point2.x()) {
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draw_spaced_dots(point1.y(), point2.y(), [&](int dot_y) {
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return IntPoint { point1.x(), dot_y };
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});
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} else {
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TODO();
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}
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}
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void AntiAliasingPainter::draw_line(FloatPoint const& actual_from, FloatPoint const& actual_to, Color color, float thickness, Painter::LineStyle style, Color alternate_color)
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{
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if (style == Painter::LineStyle::Dotted)
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return draw_dotted_line(actual_from.to_rounded<int>(), actual_to.to_rounded<int>(), color, static_cast<int>(round(thickness)));
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draw_anti_aliased_line<FixmeEnableHacksForBetterPathPainting::No>(actual_from, actual_to, color, thickness, style, alternate_color);
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}
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void AntiAliasingPainter::fill_path(Path& path, Color color, Painter::WindingRule rule)
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{
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Detail::fill_path<Detail::FillPathMode::AllowFloatingPoints>(*this, path, color, rule);
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}
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void AntiAliasingPainter::stroke_path(Path const& path, Color color, float thickness)
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{
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FloatPoint cursor;
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bool previous_was_line = false;
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FloatLine last_line;
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Optional<FloatLine> first_line;
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for (auto& segment : path.segments()) {
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switch (segment.type()) {
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case Segment::Type::Invalid:
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VERIFY_NOT_REACHED();
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case Segment::Type::MoveTo:
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cursor = segment.point();
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break;
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case Segment::Type::LineTo:
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if (!first_line.has_value())
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first_line = FloatLine(cursor, segment.point());
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draw_line(cursor, segment.point(), color, thickness);
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if (previous_was_line) {
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stroke_segment_intersection(cursor, segment.point(), last_line, color, thickness);
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}
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last_line.set_a(cursor);
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last_line.set_b(segment.point());
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cursor = segment.point();
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break;
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case Segment::Type::QuadraticBezierCurveTo: {
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auto& through = static_cast<QuadraticBezierCurveSegment const&>(segment).through();
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draw_quadratic_bezier_curve(through, cursor, segment.point(), color, thickness);
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cursor = segment.point();
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break;
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}
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case Segment::Type::CubicBezierCurveTo: {
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auto& curve = static_cast<CubicBezierCurveSegment const&>(segment);
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auto& through_0 = curve.through_0();
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auto& through_1 = curve.through_1();
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draw_cubic_bezier_curve(through_0, through_1, cursor, segment.point(), color, thickness);
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cursor = segment.point();
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break;
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}
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case Segment::Type::EllipticalArcTo:
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auto& arc = static_cast<EllipticalArcSegment const&>(segment);
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draw_elliptical_arc(cursor, segment.point(), arc.center(), arc.radii(), arc.x_axis_rotation(), arc.theta_1(), arc.theta_delta(), color, thickness);
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cursor = segment.point();
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break;
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}
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previous_was_line = segment.type() == Segment::Type::LineTo;
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}
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// check if the figure was started and closed as line at the same position
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if (previous_was_line && path.segments().size() >= 2 && path.segments().first().point() == cursor && (path.segments().first().type() == Segment::Type::LineTo || (path.segments().first().type() == Segment::Type::MoveTo && path.segments()[1].type() == Segment::Type::LineTo)))
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stroke_segment_intersection(first_line.value().a(), first_line.value().b(), last_line, color, thickness);
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}
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void AntiAliasingPainter::draw_elliptical_arc(FloatPoint const& p1, FloatPoint const& p2, FloatPoint const& center, FloatPoint const& radii, float x_axis_rotation, float theta_1, float theta_delta, Color color, float thickness, Painter::LineStyle style)
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{
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Painter::for_each_line_segment_on_elliptical_arc(p1, p2, center, radii, x_axis_rotation, theta_1, theta_delta, [&](FloatPoint const& fp1, FloatPoint const& fp2) {
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draw_line_for_path(fp1, fp2, color, thickness, style);
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});
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}
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void AntiAliasingPainter::draw_quadratic_bezier_curve(FloatPoint const& control_point, FloatPoint const& p1, FloatPoint const& p2, Color color, float thickness, Painter::LineStyle style)
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{
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Painter::for_each_line_segment_on_bezier_curve(control_point, p1, p2, [&](FloatPoint const& fp1, FloatPoint const& fp2) {
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draw_line_for_path(fp1, fp2, color, thickness, style);
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});
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}
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void AntiAliasingPainter::draw_cubic_bezier_curve(FloatPoint const& control_point_0, FloatPoint const& control_point_1, FloatPoint const& p1, FloatPoint const& p2, Color color, float thickness, Painter::LineStyle style)
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{
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Painter::for_each_line_segment_on_cubic_bezier_curve(control_point_0, control_point_1, p1, p2, [&](FloatPoint const& fp1, FloatPoint const& fp2) {
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draw_line_for_path(fp1, fp2, color, thickness, style);
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});
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}
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void AntiAliasingPainter::fill_rect(FloatRect const& float_rect, Color color)
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{
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// Draw the integer part of the rectangle:
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float right_x = float_rect.x() + float_rect.width();
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float bottom_y = float_rect.y() + float_rect.height();
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int x1 = ceilf(float_rect.x());
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int y1 = ceilf(float_rect.y());
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int x2 = floorf(right_x);
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int y2 = floorf(bottom_y);
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auto solid_rect = Gfx::IntRect::from_two_points({ x1, y1 }, { x2, y2 });
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m_underlying_painter.fill_rect(solid_rect, color);
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if (float_rect == solid_rect)
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return;
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// Draw the rest:
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float left_subpixel = x1 - float_rect.x();
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float top_subpixel = y1 - float_rect.y();
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float right_subpixel = right_x - x2;
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float bottom_subpixel = bottom_y - y2;
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float top_left_subpixel = top_subpixel * left_subpixel;
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float top_right_subpixel = top_subpixel * right_subpixel;
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float bottom_left_subpixel = bottom_subpixel * left_subpixel;
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float bottom_right_subpixel = bottom_subpixel * right_subpixel;
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auto subpixel = [&](float alpha) {
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return color.with_alpha(color.alpha() * alpha);
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};
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auto set_pixel = [&](int x, int y, float alpha) {
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m_underlying_painter.set_pixel(x, y, subpixel(alpha), true);
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};
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auto line_to_rect = [&](int x1, int y1, int x2, int y2) {
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return IntRect::from_two_points({ x1, y1 }, { x2 + 1, y2 + 1 });
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};
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set_pixel(x1 - 1, y1 - 1, top_left_subpixel);
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set_pixel(x2, y1 - 1, top_right_subpixel);
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set_pixel(x2, y2, bottom_right_subpixel);
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set_pixel(x1 - 1, y2, bottom_left_subpixel);
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m_underlying_painter.fill_rect(line_to_rect(x1, y1 - 1, x2 - 1, y1 - 1), subpixel(top_subpixel));
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m_underlying_painter.fill_rect(line_to_rect(x1, y2, x2 - 1, y2), subpixel(bottom_subpixel));
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m_underlying_painter.fill_rect(line_to_rect(x1 - 1, y1, x1 - 1, y2 - 1), subpixel(left_subpixel));
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m_underlying_painter.fill_rect(line_to_rect(x2, y1, x2, y2 - 1), subpixel(right_subpixel));
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}
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void AntiAliasingPainter::draw_ellipse(IntRect const& a_rect, Color color, int thickness)
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{
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// FIXME: Come up with an allocation-free version of this!
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// Using draw_line() for segments of an ellipse was attempted but gave really poor results :^(
|
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// There probably is a way to adjust the fill of draw_ellipse_part() to do this, but getting it rendering correctly is tricky.
|
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// The outline of the steps required to paint it efficiently is:
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// - Paint the outer ellipse without the fill (from the fill() lambda in draw_ellipse_part())
|
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// - Paint the inner ellipse, but in the set_pixel() invert the alpha values
|
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// - Somehow fill in the gap between the two ellipses (the tricky part to get right)
|
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// - Have to avoid overlapping pixels and accidentally painting over some of the edge pixels
|
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|
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auto color_no_alpha = color;
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color_no_alpha.set_alpha(255);
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auto outline_ellipse_bitmap = ({
|
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auto bitmap = Bitmap::try_create(BitmapFormat::BGRA8888, a_rect.size());
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if (bitmap.is_error())
|
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return warnln("Failed to allocate temporary bitmap for antialiased outline ellipse!");
|
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bitmap.release_value();
|
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});
|
||
|
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auto outer_rect = a_rect;
|
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outer_rect.set_location({ 0, 0 });
|
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auto inner_rect = outer_rect.shrunken(thickness * 2, thickness * 2);
|
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Painter painter { outline_ellipse_bitmap };
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AntiAliasingPainter aa_painter { painter };
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aa_painter.fill_ellipse(outer_rect, color_no_alpha);
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aa_painter.fill_ellipse(inner_rect, color_no_alpha, BlendMode::AlphaSubtract);
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m_underlying_painter.blit(a_rect.location(), outline_ellipse_bitmap, outline_ellipse_bitmap->rect(), color.alpha() / 255.);
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}
|
||
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void AntiAliasingPainter::fill_circle(IntPoint const& center, int radius, Color color, BlendMode blend_mode)
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{
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if (radius <= 0)
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return;
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draw_ellipse_part(center, radius, radius, color, false, {}, blend_mode);
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}
|
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|
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void AntiAliasingPainter::fill_ellipse(IntRect const& a_rect, Color color, BlendMode blend_mode)
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||
{
|
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auto center = a_rect.center();
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auto radius_a = a_rect.width() / 2;
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auto radius_b = a_rect.height() / 2;
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if (radius_a <= 0 || radius_b <= 0)
|
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return;
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if (radius_a == radius_b)
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return fill_circle(center, radius_a, color, blend_mode);
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auto x_paint_range = draw_ellipse_part(center, radius_a, radius_b, color, false, {}, blend_mode);
|
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// FIXME: This paints some extra fill pixels that are clipped
|
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draw_ellipse_part(center, radius_b, radius_a, color, true, x_paint_range, blend_mode);
|
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}
|
||
|
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FLATTEN AntiAliasingPainter::Range AntiAliasingPainter::draw_ellipse_part(
|
||
IntPoint center, int radius_a, int radius_b, Color color, bool flip_x_and_y, Optional<Range> x_clip, BlendMode blend_mode)
|
||
{
|
||
/*
|
||
Algorithm from: https://cs.uwaterloo.ca/research/tr/1984/CS-84-38.pdf
|
||
|
||
This method can draw a whole circle with a whole circle in one call using
|
||
8-way symmetry, or an ellipse in two calls using 4-way symmetry.
|
||
*/
|
||
|
||
center *= m_underlying_painter.scale();
|
||
radius_a *= m_underlying_painter.scale();
|
||
radius_b *= m_underlying_painter.scale();
|
||
|
||
// If this is a ellipse everything can be drawn in one pass with 8 way symmetry
|
||
bool const is_circle = radius_a == radius_b;
|
||
|
||
// These happen to be the same here, but are treated separately in the paper:
|
||
// intensity is the fill alpha
|
||
int const intensity = 255;
|
||
// 0 to subpixel_resolution is the range of alpha values for the circle edges
|
||
int const subpixel_resolution = intensity;
|
||
|
||
// Current pixel address
|
||
int i = 0;
|
||
int q = radius_b;
|
||
|
||
// 1st and 2nd order differences of y
|
||
int delta_y = 0;
|
||
int delta2_y = 0;
|
||
|
||
int const a_squared = radius_a * radius_a;
|
||
int const b_squared = radius_b * radius_b;
|
||
|
||
// Exact and predicted values of f(i) -- the ellipse equation scaled by subpixel_resolution
|
||
int y = subpixel_resolution * radius_b;
|
||
int y_hat = 0;
|
||
|
||
// The value of f(i)*f(i)
|
||
int f_squared = y * y;
|
||
|
||
// 1st and 2nd order differences of f(i)*f(i)
|
||
int delta_f_squared = -(static_cast<int64_t>(b_squared) * subpixel_resolution * subpixel_resolution) / a_squared;
|
||
int delta2_f_squared = 2 * delta_f_squared;
|
||
|
||
// edge_intersection_area/subpixel_resolution = percentage of pixel intersected by circle
|
||
// (aka the alpha for the pixel)
|
||
int edge_intersection_area = 0;
|
||
int old_area = edge_intersection_area;
|
||
|
||
auto predict = [&] {
|
||
delta_y += delta2_y;
|
||
// y_hat is the predicted value of f(i)
|
||
y_hat = y + delta_y;
|
||
};
|
||
|
||
auto minimize = [&] {
|
||
// Initialize the minimization
|
||
delta_f_squared += delta2_f_squared;
|
||
f_squared += delta_f_squared;
|
||
|
||
int min_squared_error = y_hat * y_hat - f_squared;
|
||
int prediction_overshot = 1;
|
||
y = y_hat;
|
||
|
||
// Force error negative
|
||
if (min_squared_error > 0) {
|
||
min_squared_error = -min_squared_error;
|
||
prediction_overshot = -1;
|
||
}
|
||
|
||
// Minimize
|
||
int previous_error = min_squared_error;
|
||
while (min_squared_error < 0) {
|
||
y += prediction_overshot;
|
||
previous_error = min_squared_error;
|
||
min_squared_error += y + y - prediction_overshot;
|
||
}
|
||
|
||
if (min_squared_error + previous_error > 0)
|
||
y -= prediction_overshot;
|
||
};
|
||
|
||
auto correct = [&] {
|
||
int error = y - y_hat;
|
||
|
||
// FIXME: The alpha values seem too low, which makes things look
|
||
// overly pointy. This fixes that, though there's probably a better
|
||
// solution to be found. (This issue seems to exist in the base algorithm)
|
||
error /= 4;
|
||
|
||
delta2_y += error;
|
||
delta_y += error;
|
||
};
|
||
|
||
int min_paint_x = NumericLimits<int>::max();
|
||
int max_paint_x = NumericLimits<int>::min();
|
||
auto pixel = [&](int x, int y, int alpha) {
|
||
if (alpha <= 0 || alpha > 255)
|
||
return;
|
||
if (flip_x_and_y)
|
||
swap(x, y);
|
||
if (x_clip.has_value() && x_clip->contains_inclusive(x))
|
||
return;
|
||
min_paint_x = min(x, min_paint_x);
|
||
max_paint_x = max(x, max_paint_x);
|
||
alpha = (alpha * color.alpha()) / 255;
|
||
if (blend_mode == BlendMode::AlphaSubtract)
|
||
alpha = ~alpha;
|
||
auto pixel_color = color;
|
||
pixel_color.set_alpha(alpha);
|
||
m_underlying_painter.set_pixel(center + IntPoint { x, y }, pixel_color, blend_mode == BlendMode::Normal);
|
||
};
|
||
|
||
auto fill = [&](int x, int ymax, int ymin, int alpha) {
|
||
while (ymin <= ymax) {
|
||
pixel(x, ymin, alpha);
|
||
ymin += 1;
|
||
}
|
||
};
|
||
|
||
auto symmetric_pixel = [&](int x, int y, int alpha) {
|
||
pixel(x, y, alpha);
|
||
pixel(x, -y - 1, alpha);
|
||
pixel(-x - 1, -y - 1, alpha);
|
||
pixel(-x - 1, y, alpha);
|
||
if (is_circle) {
|
||
pixel(y, x, alpha);
|
||
pixel(y, -x - 1, alpha);
|
||
pixel(-y - 1, -x - 1, alpha);
|
||
pixel(-y - 1, x, alpha);
|
||
}
|
||
};
|
||
|
||
// These are calculated incrementally (as it is possibly a tiny bit faster)
|
||
int ib_squared = 0;
|
||
int qa_squared = q * a_squared;
|
||
|
||
auto in_symmetric_region = [&] {
|
||
// Main fix two stop cond here
|
||
return is_circle ? i < q : ib_squared < qa_squared;
|
||
};
|
||
|
||
// Draws a 8 octants for a circle or 4 quadrants for a (partial) ellipse
|
||
while (in_symmetric_region()) {
|
||
predict();
|
||
minimize();
|
||
correct();
|
||
old_area = edge_intersection_area;
|
||
edge_intersection_area += delta_y;
|
||
if (edge_intersection_area >= 0) {
|
||
// Single pixel on perimeter
|
||
symmetric_pixel(i, q, (edge_intersection_area + old_area) / 2);
|
||
fill(i, q - 1, -q, intensity);
|
||
fill(-i - 1, q - 1, -q, intensity);
|
||
} else {
|
||
// Two pixels on perimeter
|
||
edge_intersection_area += subpixel_resolution;
|
||
symmetric_pixel(i, q, old_area / 2);
|
||
q -= 1;
|
||
qa_squared -= a_squared;
|
||
fill(i, q - 1, -q, intensity);
|
||
fill(-i - 1, q - 1, -q, intensity);
|
||
if (!is_circle || in_symmetric_region()) {
|
||
symmetric_pixel(i, q, (edge_intersection_area + subpixel_resolution) / 2);
|
||
if (is_circle) {
|
||
fill(q, i - 1, -i, intensity);
|
||
fill(-q - 1, i - 1, -i, intensity);
|
||
}
|
||
} else {
|
||
edge_intersection_area += subpixel_resolution;
|
||
}
|
||
}
|
||
i += 1;
|
||
ib_squared += b_squared;
|
||
}
|
||
|
||
if (is_circle) {
|
||
int alpha = edge_intersection_area / 2;
|
||
pixel(q, q, alpha);
|
||
pixel(-q - 1, q, alpha);
|
||
pixel(-q - 1, -q - 1, alpha);
|
||
pixel(q, -q - 1, alpha);
|
||
}
|
||
|
||
return Range { min_paint_x, max_paint_x };
|
||
}
|
||
|
||
void AntiAliasingPainter::fill_rect_with_rounded_corners(IntRect const& a_rect, Color color, int radius)
|
||
{
|
||
fill_rect_with_rounded_corners(a_rect, color, radius, radius, radius, radius);
|
||
}
|
||
|
||
void AntiAliasingPainter::fill_rect_with_rounded_corners(IntRect const& a_rect, Color color, int top_left_radius, int top_right_radius, int bottom_right_radius, int bottom_left_radius)
|
||
{
|
||
fill_rect_with_rounded_corners(a_rect, color,
|
||
{ top_left_radius, top_left_radius },
|
||
{ top_right_radius, top_right_radius },
|
||
{ bottom_right_radius, bottom_right_radius },
|
||
{ bottom_left_radius, bottom_left_radius });
|
||
}
|
||
|
||
void AntiAliasingPainter::fill_rect_with_rounded_corners(IntRect const& a_rect, Color color, CornerRadius top_left, CornerRadius top_right, CornerRadius bottom_right, CornerRadius bottom_left, BlendMode blend_mode)
|
||
{
|
||
if (!top_left && !top_right && !bottom_right && !bottom_left) {
|
||
if (blend_mode == BlendMode::Normal)
|
||
return m_underlying_painter.fill_rect(a_rect, color);
|
||
else if (blend_mode == BlendMode::AlphaSubtract)
|
||
return m_underlying_painter.clear_rect(a_rect, Color());
|
||
}
|
||
|
||
if (color.alpha() == 0)
|
||
return;
|
||
|
||
IntPoint top_left_corner {
|
||
a_rect.x() + top_left.horizontal_radius,
|
||
a_rect.y() + top_left.vertical_radius,
|
||
};
|
||
IntPoint top_right_corner {
|
||
a_rect.x() + a_rect.width() - top_right.horizontal_radius,
|
||
a_rect.y() + top_right.vertical_radius,
|
||
};
|
||
IntPoint bottom_left_corner {
|
||
a_rect.x() + bottom_left.horizontal_radius,
|
||
a_rect.y() + a_rect.height() - bottom_left.vertical_radius
|
||
};
|
||
IntPoint bottom_right_corner {
|
||
a_rect.x() + a_rect.width() - bottom_right.horizontal_radius,
|
||
a_rect.y() + a_rect.height() - bottom_right.vertical_radius
|
||
};
|
||
|
||
// All corners are centered at the same point, so this can be painted as a single ellipse.
|
||
if (top_left_corner == top_right_corner && top_right_corner == bottom_left_corner && bottom_left_corner == bottom_right_corner)
|
||
return fill_ellipse(a_rect, color, blend_mode);
|
||
|
||
IntRect top_rect {
|
||
a_rect.x() + top_left.horizontal_radius,
|
||
a_rect.y(),
|
||
a_rect.width() - top_left.horizontal_radius - top_right.horizontal_radius,
|
||
top_left.vertical_radius
|
||
};
|
||
IntRect right_rect {
|
||
a_rect.x() + a_rect.width() - top_right.horizontal_radius,
|
||
a_rect.y() + top_right.vertical_radius,
|
||
top_right.horizontal_radius,
|
||
a_rect.height() - top_right.vertical_radius - bottom_right.vertical_radius
|
||
};
|
||
IntRect bottom_rect {
|
||
a_rect.x() + bottom_left.horizontal_radius,
|
||
a_rect.y() + a_rect.height() - bottom_right.vertical_radius,
|
||
a_rect.width() - bottom_left.horizontal_radius - bottom_right.horizontal_radius,
|
||
bottom_right.vertical_radius
|
||
};
|
||
IntRect left_rect {
|
||
a_rect.x(),
|
||
a_rect.y() + top_left.vertical_radius,
|
||
bottom_left.horizontal_radius,
|
||
a_rect.height() - top_left.vertical_radius - bottom_left.vertical_radius
|
||
};
|
||
|
||
IntRect inner = {
|
||
left_rect.x() + left_rect.width(),
|
||
left_rect.y(),
|
||
a_rect.width() - left_rect.width() - right_rect.width(),
|
||
a_rect.height() - top_rect.height() - bottom_rect.height()
|
||
};
|
||
|
||
if (blend_mode == BlendMode::Normal) {
|
||
m_underlying_painter.fill_rect(top_rect, color);
|
||
m_underlying_painter.fill_rect(right_rect, color);
|
||
m_underlying_painter.fill_rect(bottom_rect, color);
|
||
m_underlying_painter.fill_rect(left_rect, color);
|
||
m_underlying_painter.fill_rect(inner, color);
|
||
} else if (blend_mode == BlendMode::AlphaSubtract) {
|
||
m_underlying_painter.clear_rect(top_rect, Color());
|
||
m_underlying_painter.clear_rect(right_rect, Color());
|
||
m_underlying_painter.clear_rect(bottom_rect, Color());
|
||
m_underlying_painter.clear_rect(left_rect, Color());
|
||
m_underlying_painter.clear_rect(inner, Color());
|
||
}
|
||
|
||
auto fill_corner = [&](auto const& ellipse_center, auto const& corner_point, CornerRadius const& corner) {
|
||
PainterStateSaver save { m_underlying_painter };
|
||
m_underlying_painter.add_clip_rect(IntRect::from_two_points(ellipse_center, corner_point));
|
||
fill_ellipse(IntRect::centered_at(ellipse_center, { corner.horizontal_radius * 2, corner.vertical_radius * 2 }), color, blend_mode);
|
||
};
|
||
|
||
auto bounding_rect = a_rect.inflated(0, 1, 1, 0);
|
||
if (top_left)
|
||
fill_corner(top_left_corner, bounding_rect.top_left(), top_left);
|
||
if (top_right)
|
||
fill_corner(top_right_corner, bounding_rect.top_right(), top_right);
|
||
if (bottom_left)
|
||
fill_corner(bottom_left_corner, bounding_rect.bottom_left(), bottom_left);
|
||
if (bottom_right)
|
||
fill_corner(bottom_right_corner, bounding_rect.bottom_right(), bottom_right);
|
||
}
|
||
|
||
void AntiAliasingPainter::stroke_segment_intersection(FloatPoint const& current_line_a, FloatPoint const& current_line_b, FloatLine const& previous_line, Color color, float thickness)
|
||
{
|
||
// starting point of the current line is where the last line ended... this is an intersection
|
||
auto intersection = current_line_a;
|
||
auto previous_line_b = (previous_line.a());
|
||
|
||
// if both are straight lines we can simply draw a rectangle at the intersection
|
||
if ((current_line_a.x() == current_line_b.x() || current_line_a.y() == current_line_b.y()) && (previous_line.a().x() == previous_line.b().x() || previous_line.a().y() == previous_line.b().y())) {
|
||
intersection = m_transform.map(current_line_a);
|
||
|
||
// adjust coordinates to handle rounding offsets
|
||
auto intersection_rect = IntSize(thickness, thickness);
|
||
float drawing_edge_offset = fmodf(thickness, 2.0f) < 0.5f && thickness > 3 ? 1 : 0;
|
||
auto integer_part = [](float x) { return floorf(x); };
|
||
auto round = [&](float x) { return integer_part(x + 0.5f); };
|
||
|
||
if (thickness == 1)
|
||
drawing_edge_offset = -1;
|
||
if (current_line_a.x() == current_line_b.x() && previous_line.a().x() == previous_line.b().x()) {
|
||
intersection_rect.set_height(1);
|
||
}
|
||
if (current_line_a.y() == current_line_b.y() && previous_line.a().y() == previous_line.b().y()) {
|
||
intersection_rect.set_width(1);
|
||
drawing_edge_offset = thickness == 1 ? -1 : 0;
|
||
intersection.set_x(intersection.x() - 1 + (thickness == 1 ? 1 : 0));
|
||
intersection.set_y(intersection.y() + (thickness > 3 && fmodf(thickness, 2.0f) < 0.5f ? 1 : 0));
|
||
}
|
||
|
||
m_underlying_painter.fill_rect(IntRect::centered_on({ round(intersection.x()) + drawing_edge_offset, round(intersection.y()) + drawing_edge_offset }, intersection_rect), color);
|
||
return;
|
||
}
|
||
|
||
float scale_to_move_current = (thickness / 2) / intersection.distance_from(current_line_b);
|
||
float scale_to_move_previous = (thickness / 2) / intersection.distance_from(previous_line_b);
|
||
|
||
// move the point on the line by half of the thickness
|
||
double offset_current_edge_x = scale_to_move_current * (current_line_b.x() - intersection.x());
|
||
double offset_current_edge_y = scale_to_move_current * (current_line_b.y() - intersection.y());
|
||
double offset_prev_edge_x = scale_to_move_previous * (previous_line_b.x() - intersection.x());
|
||
double offset_prev_edge_y = scale_to_move_previous * (previous_line_b.y() - intersection.y());
|
||
|
||
// rotate the point by 90 and 270 degrees to get the points for both edges
|
||
double rad_90deg = 0.5 * M_PI;
|
||
FloatPoint current_rotated_90deg = { (offset_current_edge_x * cos(rad_90deg) - offset_current_edge_y * sin(rad_90deg)), (offset_current_edge_x * sin(rad_90deg) + offset_current_edge_y * cos(rad_90deg)) };
|
||
FloatPoint current_rotated_270deg = intersection - current_rotated_90deg;
|
||
FloatPoint previous_rotated_90deg = { (offset_prev_edge_x * cos(rad_90deg) - offset_prev_edge_y * sin(rad_90deg)), (offset_prev_edge_x * sin(rad_90deg) + offset_prev_edge_y * cos(rad_90deg)) };
|
||
FloatPoint previous_rotated_270deg = intersection - previous_rotated_90deg;
|
||
|
||
// translate coordinates to the intersection point
|
||
current_rotated_90deg += intersection;
|
||
previous_rotated_90deg += intersection;
|
||
|
||
FloatLine outer_line_current_90 = FloatLine({ current_rotated_90deg, current_line_b - static_cast<FloatPoint>(intersection - current_rotated_90deg) });
|
||
FloatLine outer_line_current_270 = FloatLine({ current_rotated_270deg, current_line_b - static_cast<FloatPoint>(intersection - current_rotated_270deg) });
|
||
FloatLine outer_line_prev_270 = FloatLine({ previous_rotated_270deg, previous_line_b - static_cast<FloatPoint>(intersection - previous_rotated_270deg) });
|
||
FloatLine outer_line_prev_90 = FloatLine({ previous_rotated_90deg, previous_line_b - static_cast<FloatPoint>(intersection - previous_rotated_90deg) });
|
||
|
||
Optional<FloatPoint> edge_spike_90 = outer_line_current_90.intersected(outer_line_prev_270);
|
||
Optional<FloatPoint> edge_spike_270;
|
||
|
||
if (edge_spike_90.has_value()) {
|
||
edge_spike_270 = intersection + (intersection - edge_spike_90.value());
|
||
} else {
|
||
edge_spike_270 = outer_line_current_270.intersected(outer_line_prev_90);
|
||
if (edge_spike_270.has_value()) {
|
||
edge_spike_90 = intersection + (intersection - edge_spike_270.value());
|
||
}
|
||
}
|
||
|
||
Path intersection_edge_path;
|
||
intersection_edge_path.move_to(current_rotated_90deg);
|
||
if (edge_spike_90.has_value())
|
||
intersection_edge_path.line_to(edge_spike_90.value());
|
||
intersection_edge_path.line_to(previous_rotated_270deg);
|
||
intersection_edge_path.line_to(current_rotated_270deg);
|
||
if (edge_spike_270.has_value())
|
||
intersection_edge_path.line_to(edge_spike_270.value());
|
||
intersection_edge_path.line_to(previous_rotated_90deg);
|
||
intersection_edge_path.close();
|
||
fill_path(intersection_edge_path, color);
|
||
}
|
||
|
||
// rotates a rectangle around 0,0
|
||
FloatQuad AntiAliasingPainter::build_rotated_rectangle(FloatPoint const& direction, float width)
|
||
{
|
||
double half_size = width / 2;
|
||
double radian = atan2(direction.y(), direction.x());
|
||
if (radian < 0) {
|
||
radian += (2 * M_PI);
|
||
}
|
||
// rotated by: (xcosθ−ysinθ ,xsinθ+ycosθ)
|
||
// p1 p2
|
||
//
|
||
// x,y
|
||
//
|
||
// p4 p3
|
||
double cos_radian = cos(radian);
|
||
double sin_radian = sin(radian);
|
||
|
||
// FIXME: Performing the rotation with AffineTransform::rotate_quad seems to generate more glitches at the edges than rotating manually
|
||
return FloatQuad(
|
||
{ ((-half_size * cos_radian) - (-half_size * sin_radian)), ((-half_size * sin_radian) + (-half_size * cos_radian)) },
|
||
{ ((half_size * cos_radian) - (-half_size * sin_radian)), ((half_size * sin_radian) + (-half_size * cos_radian)) },
|
||
{ ((half_size * cos_radian)) - (half_size * sin_radian), ((half_size * sin_radian) + (half_size * cos_radian)) },
|
||
{ ((-half_size * cos_radian) - (half_size * sin_radian)), ((-half_size * sin_radian) + (half_size * cos_radian)) });
|
||
}
|
||
|
||
}
|