mirror of
				https://github.com/RGBCube/serenity
				synced 2025-10-31 16:42:44 +00:00 
			
		
		
		
	
		
			
				
	
	
		
			89 lines
		
	
	
	
		
			3 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			89 lines
		
	
	
	
		
			3 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
 | |
|  * Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>
 | |
|  * Copyright (c) 2022, Linus Groh <linusg@serenityos.org>
 | |
|  *
 | |
|  * SPDX-License-Identifier: BSD-2-Clause
 | |
|  */
 | |
| 
 | |
| #include <AK/HashMap.h>
 | |
| #include <AK/Span.h>
 | |
| #include <AK/String.h>
 | |
| #include <AK/Utf8View.h>
 | |
| #include <LibGfx/Bitmap.h>
 | |
| #include <LibGfx/Font/Emoji.h>
 | |
| 
 | |
| namespace Gfx {
 | |
| 
 | |
| // https://unicode.org/reports/tr51/
 | |
| // https://unicode.org/emoji/charts/emoji-list.html
 | |
| // https://unicode.org/emoji/charts/emoji-zwj-sequences.html
 | |
| 
 | |
| static HashMap<Span<u32>, RefPtr<Gfx::Bitmap>> s_emojis;
 | |
| 
 | |
| Bitmap const* Emoji::emoji_for_code_point(u32 code_point)
 | |
| {
 | |
|     return emoji_for_code_points(Array { code_point });
 | |
| }
 | |
| 
 | |
| Bitmap const* Emoji::emoji_for_code_points(Span<u32> const& code_points)
 | |
| {
 | |
|     auto it = s_emojis.find(code_points);
 | |
|     if (it != s_emojis.end())
 | |
|         return (*it).value.ptr();
 | |
| 
 | |
|     auto basename = String::join('_', code_points, "U+{:X}");
 | |
|     auto bitmap_or_error = Bitmap::try_load_from_file(String::formatted("/res/emoji/{}.png", basename));
 | |
|     if (bitmap_or_error.is_error()) {
 | |
|         s_emojis.set(code_points, nullptr);
 | |
|         return nullptr;
 | |
|     }
 | |
|     auto bitmap = bitmap_or_error.release_value();
 | |
|     s_emojis.set(code_points, bitmap);
 | |
|     return bitmap.ptr();
 | |
| }
 | |
| 
 | |
| Bitmap const* Emoji::emoji_for_code_point_iterator(Utf8CodePointIterator& it)
 | |
| {
 | |
|     // NOTE: I'm sure this could be more efficient, e.g. by checking if each code point falls
 | |
|     // into a certain range in the loop below (emojis, modifiers, variation selectors, ZWJ),
 | |
|     // and bailing out early if not. Current worst case is 10 file lookups for any sequence of
 | |
|     // code points (if the first glyph isn't part of the font in regular text rendering).
 | |
| 
 | |
|     constexpr size_t max_emoji_code_point_sequence_length = 10;
 | |
| 
 | |
|     Vector<u32, max_emoji_code_point_sequence_length> code_points;
 | |
| 
 | |
|     struct EmojiAndCodePoints {
 | |
|         Bitmap const* emoji;
 | |
|         Span<u32> code_points;
 | |
|     };
 | |
|     Vector<EmojiAndCodePoints, max_emoji_code_point_sequence_length> possible_emojis;
 | |
| 
 | |
|     // Determine all existing emojis for the longest possible ZWJ emoji sequence,
 | |
|     // or until we run out of code points in the iterator.
 | |
|     for (size_t i = 0; i < max_emoji_code_point_sequence_length; ++i) {
 | |
|         auto code_point = it.peek(i);
 | |
|         if (!code_point.has_value())
 | |
|             break;
 | |
|         code_points.append(*code_point);
 | |
|         if (auto const* emoji = emoji_for_code_points(code_points))
 | |
|             possible_emojis.empend(emoji, code_points);
 | |
|     }
 | |
| 
 | |
|     if (possible_emojis.is_empty())
 | |
|         return nullptr;
 | |
| 
 | |
|     // If we found one or more matches, return the longest, i.e. last. For example:
 | |
|     // U+1F3F3 - white flag
 | |
|     // U+1F3F3 U+FE0F U+200D U+1F308 - rainbow flag
 | |
|     auto& [emoji, emoji_code_points] = possible_emojis.last();
 | |
| 
 | |
|     // Advance the iterator, so it's on the last code point of our found emoji and
 | |
|     // whoever is iterating will advance to the next new code point.
 | |
|     for (size_t i = 0; i < emoji_code_points.size() - 1; ++i)
 | |
|         ++it;
 | |
| 
 | |
|     return emoji;
 | |
| }
 | |
| 
 | |
| }
 | 
