1/**
2 * Copyright (c) 2006-2023 LOVE Development Team
3 *
4 * This software is provided 'as-is', without any express or implied
5 * warranty. In no event will the authors be held liable for any damages
6 * arising from the use of this software.
7 *
8 * Permission is granted to anyone to use this software for any purpose,
9 * including commercial applications, and to alter it and redistribute it
10 * freely, subject to the following restrictions:
11 *
12 * 1. The origin of this software must not be misrepresented; you must not
13 * claim that you wrote the original software. If you use this software
14 * in a product, an acknowledgment in the product documentation would be
15 * appreciated but is not required.
16 * 2. Altered source versions must be plainly marked as such, and must not be
17 * misrepresented as being the original software.
18 * 3. This notice may not be removed or altered from any source distribution.
19 **/
20
21// LOVE
22#include "TrueTypeRasterizer.h"
23#include "common/Exception.h"
24
25// C
26#include <math.h>
27
28namespace love
29{
30namespace font
31{
32namespace freetype
33{
34
35TrueTypeRasterizer::TrueTypeRasterizer(FT_Library library, love::Data *data, int size, float dpiscale, Hinting hinting)
36 : data(data)
37 , hinting(hinting)
38{
39 this->dpiScale = dpiscale;
40 size = floorf(size * dpiscale + 0.5f);
41
42 if (size <= 0)
43 throw love::Exception("Invalid TrueType font size: %d", size);
44
45 FT_Error err = FT_Err_Ok;
46 err = FT_New_Memory_Face(library,
47 (const FT_Byte *)data->getData(), /* first byte in memory */
48 data->getSize(), /* size in bytes */
49 0, /* face_index */
50 &face);
51
52 if (err != FT_Err_Ok)
53 throw love::Exception("TrueType Font loading error: FT_New_Face failed: 0x%x (problem with font file?)", err);
54
55 err = FT_Set_Pixel_Sizes(face, size, size);
56
57 if (err != FT_Err_Ok)
58 throw love::Exception("TrueType Font loading error: FT_Set_Pixel_Sizes failed: 0x%x (invalid size?)", err);
59
60 // Set global metrics
61 FT_Size_Metrics s = face->size->metrics;
62 metrics.advance = (int) (s.max_advance >> 6);
63 metrics.ascent = (int) (s.ascender >> 6);
64 metrics.descent = (int) (s.descender >> 6);
65 metrics.height = (int) (s.height >> 6);
66}
67
68TrueTypeRasterizer::~TrueTypeRasterizer()
69{
70 FT_Done_Face(face);
71}
72
73int TrueTypeRasterizer::getLineHeight() const
74{
75 return (int)(getHeight() * 1.25);
76}
77
78GlyphData *TrueTypeRasterizer::getGlyphData(uint32 glyph) const
79{
80 love::font::GlyphMetrics glyphMetrics = {};
81 FT_Glyph ftglyph;
82
83 FT_Error err = FT_Err_Ok;
84 FT_UInt loadoption = hintingToLoadOption(hinting);
85
86 // Initialize
87 err = FT_Load_Glyph(face, FT_Get_Char_Index(face, glyph), FT_LOAD_DEFAULT | loadoption);
88
89 if (err != FT_Err_Ok)
90 throw love::Exception("TrueType Font glyph error: FT_Load_Glyph failed (0x%x)", err);
91
92 err = FT_Get_Glyph(face->glyph, &ftglyph);
93
94 if (err != FT_Err_Ok)
95 throw love::Exception("TrueType Font glyph error: FT_Get_Glyph failed (0x%x)", err);
96
97 FT_Render_Mode rendermode = FT_RENDER_MODE_NORMAL;
98 if (hinting == HINTING_MONO)
99 rendermode = FT_RENDER_MODE_MONO;
100
101 err = FT_Glyph_To_Bitmap(&ftglyph, rendermode, 0, 1);
102
103 if (err != FT_Err_Ok)
104 throw love::Exception("TrueType Font glyph error: FT_Glyph_To_Bitmap failed (0x%x)", err);
105
106 FT_BitmapGlyph bitmap_glyph = (FT_BitmapGlyph) ftglyph;
107 FT_Bitmap &bitmap = bitmap_glyph->bitmap; //just to make things easier
108
109 // Get metrics
110 glyphMetrics.bearingX = bitmap_glyph->left;
111 glyphMetrics.bearingY = bitmap_glyph->top;
112 glyphMetrics.height = bitmap.rows;
113 glyphMetrics.width = bitmap.width;
114 glyphMetrics.advance = (int) (ftglyph->advance.x >> 16);
115
116 GlyphData *glyphData = new GlyphData(glyph, glyphMetrics, PIXELFORMAT_LA8);
117
118 const uint8 *pixels = bitmap.buffer;
119 uint8 *dest = (uint8 *) glyphData->getData();
120
121 // We treat the luminance of the FreeType bitmap as alpha in the GlyphData.
122 if (bitmap.pixel_mode == FT_PIXEL_MODE_MONO)
123 {
124 for (int y = 0; y < (int) bitmap.rows; y++)
125 {
126 for (int x = 0; x < (int) bitmap.width; x++)
127 {
128 // Extract the 1-bit value and convert it to uint8.
129 uint8 v = ((pixels[x / 8]) & (1 << (7 - (x % 8)))) ? 255 : 0;
130 dest[2 * (y * bitmap.width + x) + 0] = 255;
131 dest[2 * (y * bitmap.width + x) + 1] = v;
132 }
133
134 pixels += bitmap.pitch;
135 }
136 }
137 else if (bitmap.pixel_mode == FT_PIXEL_MODE_GRAY)
138 {
139 for (int y = 0; y < (int) bitmap.rows; y++)
140 {
141 for (int x = 0; x < (int) bitmap.width; x++)
142 {
143 dest[2 * (y * bitmap.width + x) + 0] = 255;
144 dest[2 * (y * bitmap.width + x) + 1] = pixels[x];
145 }
146
147 pixels += bitmap.pitch;
148 }
149 }
150 else
151 {
152 delete glyphData;
153 FT_Done_Glyph(ftglyph);
154 throw love::Exception("Unknown TrueType glyph pixel mode.");
155 }
156
157 // Having copied the data over, we can destroy the glyph.
158 FT_Done_Glyph(ftglyph);
159
160 return glyphData;
161}
162
163int TrueTypeRasterizer::getGlyphCount() const
164{
165 return (int) face->num_glyphs;
166}
167
168bool TrueTypeRasterizer::hasGlyph(uint32 glyph) const
169{
170 return FT_Get_Char_Index(face, glyph) != 0;
171}
172
173float TrueTypeRasterizer::getKerning(uint32 leftglyph, uint32 rightglyph) const
174{
175 FT_Vector kerning = {};
176 FT_Get_Kerning(face,
177 FT_Get_Char_Index(face, leftglyph),
178 FT_Get_Char_Index(face, rightglyph),
179 FT_KERNING_DEFAULT,
180 &kerning);
181 return float(kerning.x >> 6);
182}
183
184Rasterizer::DataType TrueTypeRasterizer::getDataType() const
185{
186 return DATA_TRUETYPE;
187}
188
189bool TrueTypeRasterizer::accepts(FT_Library library, love::Data *data)
190{
191 const FT_Byte *fbase = (const FT_Byte *) data->getData();
192 FT_Long fsize = (FT_Long) data->getSize();
193
194 // Pasing in -1 for the face index lets us test if the data is valid.
195 return FT_New_Memory_Face(library, fbase, fsize, -1, nullptr) == 0;
196}
197
198FT_UInt TrueTypeRasterizer::hintingToLoadOption(Hinting hint)
199{
200 switch (hint)
201 {
202 case HINTING_NORMAL:
203 default:
204 return FT_LOAD_TARGET_NORMAL;
205 case HINTING_LIGHT:
206 return FT_LOAD_TARGET_LIGHT;
207 case HINTING_MONO:
208 return FT_LOAD_TARGET_MONO;
209 case HINTING_NONE:
210 return FT_LOAD_NO_HINTING;
211 }
212}
213
214} // freetype
215} // font
216} // love
217