92d9b6edb8
This adds CanvasPathClipper and ScopedCanvasPathClip. These allow clipping the canvas by some arbitrary path. This initial implementation is fairly naive, with a good few allocations, though this can probably be improved in future.
65 lines
1.7 KiB
C++
65 lines
1.7 KiB
C++
/*
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* Copyright (c) 2023, MacDue <macdue@dueutil.tech>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#pragma once
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#include <LibGfx/Painter.h>
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#include <LibGfx/Path.h>
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namespace Web::HTML {
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struct CanvasClip {
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Gfx::Path path;
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Gfx::Painter::WindingRule winding_rule;
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};
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class CanvasPathClipper {
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public:
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static ErrorOr<CanvasPathClipper> create(Gfx::Painter&, CanvasClip const& canvas_clip);
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ErrorOr<void> apply_clip(Gfx::Painter& painter);
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private:
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CanvasPathClipper(RefPtr<Gfx::Bitmap const> saved_clip_region, Gfx::IntRect bounding_box, CanvasClip const& canvas_clip)
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: m_saved_clip_region(saved_clip_region)
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, m_bounding_box(bounding_box)
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, m_canvas_clip(canvas_clip)
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{
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}
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RefPtr<Gfx::Bitmap const> m_saved_clip_region;
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Gfx::IntRect m_bounding_box;
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CanvasClip const& m_canvas_clip;
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};
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class ScopedCanvasPathClip {
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AK_MAKE_NONMOVABLE(ScopedCanvasPathClip);
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AK_MAKE_NONCOPYABLE(ScopedCanvasPathClip);
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public:
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ScopedCanvasPathClip(Gfx::Painter& painter, Optional<CanvasClip> const& canvas_clip)
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: m_painter(painter)
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{
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if (canvas_clip.has_value()) {
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auto clipper = CanvasPathClipper::create(painter, *canvas_clip);
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if (!clipper.is_error())
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m_canvas_clipper = clipper.release_value();
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else
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dbgln("CRC2D Error: Failed to apply canvas clip path: {}", clipper.error());
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}
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}
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~ScopedCanvasPathClip()
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{
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if (m_canvas_clipper.has_value())
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m_canvas_clipper->apply_clip(m_painter).release_value_but_fixme_should_propagate_errors();
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}
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private:
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Gfx::Painter& m_painter;
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Optional<CanvasPathClipper> m_canvas_clipper;
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};
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}
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