beenull/ladybird
1
0
Fork 0
mirror of https://github.com/LadybirdBrowser/ladybird.git synced 2024-11-22 15:40:19 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 6

LibWeb: Make canvas text preparation handle multi-code point glyphs

Browse source
This commit is contained in:
Timothy Flynn 2023-02-22 11:48:05 -05:00 committed by Linus Groh
parent cb04e4e9da
commit 3d7b13ac03
Notes: sideshowbarker 2024-07-17 03:03:37 +09:00 
Author: https://github.com/trflynn89
Commit: https://github.com/SerenityOS/serenity/commit/3d7b13ac03
Pull-request: https://github.com/SerenityOS/serenity/pull/17568
2 changed files with 18 additions and 9 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

24
Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.cpp
View file

@ -10,6 +10,7 @@
#include <LibGfx/Painter.h>
#include <LibGfx/Quad.h>
#include <LibGfx/Rect.h>
#include <LibUnicode/Segmentation.h>
#include <LibWeb/Bindings/Intrinsics.h>
#include <LibWeb/HTML/CanvasRenderingContext2D.h>
#include <LibWeb/HTML/HTMLCanvasElement.h>
@ -451,9 +452,10 @@ CanvasRenderingContext2D::PreparedText CanvasRenderingContext2D::prepare_text(De
auto& font = Platform::FontPlugin::the().default_font();
size_t width = 0;
size_t height = font.pixel_size();
for (auto c : Utf8View { replaced_text }) {
width += font.glyph_or_emoji_width(c);
}
Utf8View replaced_text_view { replaced_text };
for (auto it = replaced_text_view.begin(); it != replaced_text_view.end(); ++it)
width += font.glyph_or_emoji_width(it);
// 6. If maxWidth was provided and the hypothetical width of the inline box in the hypothetical line box is greater than maxWidth CSS pixels, then change font to have a more condensed font (if one is available or if a reasonably readable one can be synthesized by applying a horizontal scale factor to the font) or a smaller font, and return to the previous step.
// FIXME: Record the font size used for this piece of text, and actually retry with a smaller size if needed.
@ -478,11 +480,17 @@ CanvasRenderingContext2D::PreparedText CanvasRenderingContext2D::prepare_text(De
PreparedText prepared_text { {}, physical_alignment, { 0, 0, static_cast<int>(width), static_cast<int>(height) } };
prepared_text.glyphs.ensure_capacity(replaced_text.length());
size_t offset = 0;
for (auto c : Utf8View { replaced_text }) {
prepared_text.glyphs.append({ c, { static_cast<int>(offset), 0 } });
offset += font.glyph_or_emoji_width(c);
}
size_t previous_grapheme_boundary = 0;
Unicode::for_each_grapheme_segmentation_boundary(replaced_text_view, [&](auto boundary) {
if (boundary == 0)
return IterationDecision::Continue;
auto glyph_view = replaced_text_view.substring_view(previous_grapheme_boundary, boundary - previous_grapheme_boundary);
auto glyph = String::from_utf8(glyph_view.as_string()).release_value_but_fixme_should_propagate_errors();
prepared_text.glyphs.append({ move(glyph), { static_cast<int>(boundary), 0 } });
return IterationDecision::Continue;
});
// 9. Return result, physical alignment, and the inline box.
return prepared_text;

3
Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.h
View file

@ -7,6 +7,7 @@
#pragma once
#include <AK/String.h>
#include <AK/Variant.h>
#include <LibGfx/AffineTransform.h>
#include <LibGfx/AntiAliasingPainter.h>
@ -90,7 +91,7 @@ private:
virtual void visit_edges(Cell::Visitor&) override;
struct PreparedTextGlyph {
unsigned int c;
String glyph;
Gfx::IntPoint position;
};