ada48a1daf
This adds the option to pass a subpixel offset when fetching a glyph from a font, this offset is currently snapped to thirds of a pixel (i.e. 0, 0.33, 0.66). This is then used when rasterizing the glyph, which is then cached like usual. Note that when using subpixel offsets you're trading a bit of space for accuracy. With the current third of a pixel offsets you can end up with up to 9 bitmaps per glyph.
29 lines
865 B
C++
29 lines
865 B
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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#include <LibGfx/Font/Font.h>
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namespace Gfx {
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GlyphRasterPosition GlyphRasterPosition::get_nearest_fit_for(FloatPoint position)
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{
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constexpr auto subpixel_divisions = GlyphSubpixelOffset::subpixel_divisions();
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auto fit = [](float pos, int& blit_pos, u8& subpixel_offset) {
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blit_pos = floorf(pos);
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subpixel_offset = round_to<u8>((pos - blit_pos) / (1.0f / subpixel_divisions));
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if (subpixel_offset >= subpixel_divisions) {
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blit_pos += 1;
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subpixel_offset = 0;
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}
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};
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int blit_x, blit_y;
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u8 subpixel_x, subpixel_y;
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fit(position.x(), blit_x, subpixel_x);
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fit(position.y(), blit_y, subpixel_y);
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return GlyphRasterPosition { { blit_x, blit_y }, { subpixel_x, subpixel_y } };
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}
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}
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