mirror of
				https://github.com/RGBCube/serenity
				synced 2025-10-31 12:32:43 +00:00 
			
		
		
		
	 efdbd8238e
			
		
	
	
		efdbd8238e
		
	
	
	
	
		
			
			This change separates a part of the `draw_text_run()` function, which is responsible for calculating the positions for glyphs that need to be painted, into a separate function called `get_glyph_run()`. It is a part of the preparation for text run painting using OpenGL, where we can't immediately blit glyph bitmaps but instead need to prepare a sequence of quads for them in advance.
		
			
				
	
	
		
			134 lines
		
	
	
	
		
			4.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			134 lines
		
	
	
	
		
			4.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
 | |
|  * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
 | |
|  * Copyright (c) 2021, sin-ack <sin-ack@protonmail.com>
 | |
|  *
 | |
|  * SPDX-License-Identifier: BSD-2-Clause
 | |
|  */
 | |
| 
 | |
| #pragma once
 | |
| 
 | |
| #include <AK/CharacterTypes.h>
 | |
| #include <AK/DeprecatedString.h>
 | |
| #include <AK/Forward.h>
 | |
| #include <AK/Utf32View.h>
 | |
| #include <AK/Utf8View.h>
 | |
| #include <AK/Vector.h>
 | |
| #include <LibGfx/Font/Font.h>
 | |
| #include <LibGfx/Forward.h>
 | |
| #include <LibGfx/Rect.h>
 | |
| #include <LibGfx/TextElision.h>
 | |
| #include <LibGfx/TextWrapping.h>
 | |
| 
 | |
| namespace Gfx {
 | |
| 
 | |
| // FIXME: This currently isn't an ideal way of doing things; ideally, TextLayout
 | |
| // would be doing the rendering by painting individual glyphs. However, this
 | |
| // would regress our Unicode bidirectional text support. Therefore, fixing this
 | |
| // requires:
 | |
| // - Moving the bidirectional algorithm either here, or some place TextLayout
 | |
| //   can access;
 | |
| // - Making TextLayout render the given text into something like a Vector<Line>
 | |
| //   where:
 | |
| //   using Line = Vector<DirectionalRun>;
 | |
| //   struct DirectionalRun {
 | |
| //       Utf32View glyphs;
 | |
| //       Vector<int> advance;
 | |
| //       TextDirection direction;
 | |
| //   };
 | |
| // - Either;
 | |
| //   a) Making TextLayout output these Lines directly using a given Painter, or
 | |
| //   b) Taking the Lines from TextLayout and painting each glyph.
 | |
| class TextLayout {
 | |
| public:
 | |
|     TextLayout(Gfx::Font const& font, Utf8View const& text, FloatRect const& rect)
 | |
|         : m_font(font)
 | |
|         , m_font_metrics(font.pixel_metrics())
 | |
|         , m_text(text)
 | |
|         , m_rect(rect)
 | |
|     {
 | |
|     }
 | |
| 
 | |
|     Vector<DeprecatedString, 32> lines(TextElision elision, TextWrapping wrapping) const
 | |
|     {
 | |
|         return wrap_lines(elision, wrapping);
 | |
|     }
 | |
| 
 | |
|     FloatRect bounding_rect(TextWrapping) const;
 | |
| 
 | |
| private:
 | |
|     Vector<DeprecatedString, 32> wrap_lines(TextElision, TextWrapping) const;
 | |
|     DeprecatedString elide_text_from_right(Utf8View) const;
 | |
| 
 | |
|     Font const& m_font;
 | |
|     FontPixelMetrics m_font_metrics;
 | |
|     Utf8View m_text;
 | |
|     FloatRect m_rect;
 | |
| };
 | |
| 
 | |
| inline bool should_paint_as_space(u32 code_point)
 | |
| {
 | |
|     return is_ascii_space(code_point) || code_point == 0xa0;
 | |
| }
 | |
| 
 | |
| enum class IncludeLeftBearing {
 | |
|     Yes,
 | |
|     No
 | |
| };
 | |
| 
 | |
| struct DrawGlyph {
 | |
|     FloatPoint position;
 | |
|     u32 code_point;
 | |
|     Font const* font;
 | |
| };
 | |
| 
 | |
| struct DrawEmoji {
 | |
|     IntPoint position;
 | |
|     Gfx::Bitmap const* emoji;
 | |
|     Font const* font;
 | |
| };
 | |
| 
 | |
| using DrawGlyphOrEmoji = Variant<DrawGlyph, DrawEmoji>;
 | |
| 
 | |
| Variant<DrawGlyph, DrawEmoji> prepare_draw_glyph_or_emoji(FloatPoint point, Utf8CodePointIterator& it, Font const& font);
 | |
| 
 | |
| template<typename Callback>
 | |
| void for_each_glyph_position(FloatPoint baseline_start, Utf8View string, Font const& font, Callback callback, IncludeLeftBearing include_left_bearing = IncludeLeftBearing::No)
 | |
| {
 | |
|     float space_width = font.glyph_width(' ') + font.glyph_spacing();
 | |
| 
 | |
|     u32 last_code_point = 0;
 | |
| 
 | |
|     auto point = baseline_start;
 | |
|     point.translate_by(0, -font.pixel_metrics().ascent);
 | |
| 
 | |
|     for (auto code_point_iterator = string.begin(); code_point_iterator != string.end(); ++code_point_iterator) {
 | |
|         auto code_point = *code_point_iterator;
 | |
|         if (should_paint_as_space(code_point)) {
 | |
|             point.translate_by(space_width, 0);
 | |
|             last_code_point = code_point;
 | |
|             continue;
 | |
|         }
 | |
| 
 | |
|         auto kerning = font.glyphs_horizontal_kerning(last_code_point, code_point);
 | |
|         if (kerning != 0.0f)
 | |
|             point.translate_by(kerning, 0);
 | |
| 
 | |
|         auto it = code_point_iterator; // The callback function will advance the iterator, so create a copy for this lookup.
 | |
|         auto glyph_width = font.glyph_or_emoji_width(it) + font.glyph_spacing();
 | |
| 
 | |
|         auto glyph_or_emoji = prepare_draw_glyph_or_emoji(point, code_point_iterator, font);
 | |
|         if (include_left_bearing == IncludeLeftBearing::Yes) {
 | |
|             if (glyph_or_emoji.has<DrawGlyph>())
 | |
|                 glyph_or_emoji.get<DrawGlyph>().position += FloatPoint(font.glyph_left_bearing(code_point), 0);
 | |
|         }
 | |
| 
 | |
|         callback(glyph_or_emoji);
 | |
| 
 | |
|         point.translate_by(glyph_width, 0);
 | |
|         last_code_point = code_point;
 | |
|     }
 | |
| }
 | |
| 
 | |
| Vector<DrawGlyphOrEmoji> get_glyph_run(FloatPoint baseline_start, Utf8View const& string, Font const& font, IncludeLeftBearing include_left_bearing = IncludeLeftBearing::No);
 | |
| 
 | |
| }
 |