Raph Levien | aaedde5 | 2012-10-30 15:55:33 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2012 Google Inc. All rights reserved. |
| 3 | * |
| 4 | * Redistribution and use in source and binary forms, with or without |
| 5 | * modification, are permitted provided that the following conditions are |
| 6 | * met: |
| 7 | * |
| 8 | * * Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * * Redistributions in binary form must reproduce the above |
| 11 | * copyright notice, this list of conditions and the following disclaimer |
| 12 | * in the documentation and/or other materials provided with the |
| 13 | * distribution. |
| 14 | * * Neither the name of Google Inc. nor the names of its |
| 15 | * contributors may be used to endorse or promote products derived from |
| 16 | * this software without specific prior written permission. |
| 17 | * |
| 18 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 19 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 20 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 21 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 22 | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 23 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 24 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 25 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 26 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 27 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 28 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 29 | */ |
| 30 | |
| 31 | #define LOG_TAG "TextLayoutCache" |
| 32 | |
| 33 | #include "HarfBuzzNGFaceSkia.h" |
| 34 | |
| 35 | #include <cutils/log.h> |
| 36 | #include <SkFontHost.h> |
| 37 | #include <SkPaint.h> |
| 38 | #include <SkPath.h> |
| 39 | #include <SkPoint.h> |
| 40 | #include <SkRect.h> |
| 41 | #include <SkUtils.h> |
| 42 | |
| 43 | #include <hb.h> |
| 44 | |
| 45 | namespace android { |
| 46 | |
| 47 | // Our implementation of the callbacks which Harfbuzz requires by using Skia |
| 48 | // calls. See the Harfbuzz source for references about what these callbacks do. |
| 49 | |
| 50 | struct HarfBuzzFontData { |
| 51 | HarfBuzzFontData(SkPaint* paint) : m_paint(paint) { } |
| 52 | SkPaint* m_paint; |
| 53 | }; |
| 54 | |
| 55 | static void SkiaGetGlyphWidthAndExtents(SkPaint* paint, hb_codepoint_t codepoint, hb_position_t* width, hb_glyph_extents_t* extents) |
| 56 | { |
| 57 | ALOG_ASSERT(codepoint <= 0xFFFF); |
| 58 | paint->setTextEncoding(SkPaint::kGlyphID_TextEncoding); |
| 59 | |
| 60 | SkScalar skWidth; |
| 61 | SkRect skBounds; |
| 62 | uint16_t glyph = codepoint; |
| 63 | |
| 64 | paint->getTextWidths(&glyph, sizeof(glyph), &skWidth, &skBounds); |
Jeff Sharkey | 3f32a31 | 2013-01-17 12:53:04 -0800 | [diff] [blame] | 65 | #if DEBUG_GLYPHS |
Raph Levien | aaedde5 | 2012-10-30 15:55:33 -0700 | [diff] [blame] | 66 | ALOGD("returned glyph for %i: width = %f", codepoint, skWidth); |
Jeff Sharkey | 3f32a31 | 2013-01-17 12:53:04 -0800 | [diff] [blame] | 67 | #endif |
Raph Levien | aaedde5 | 2012-10-30 15:55:33 -0700 | [diff] [blame] | 68 | if (width) |
| 69 | *width = SkScalarToHBFixed(skWidth); |
| 70 | if (extents) { |
| 71 | // Invert y-axis because Skia is y-grows-down but we set up harfbuzz to be y-grows-up. |
| 72 | extents->x_bearing = SkScalarToHBFixed(skBounds.fLeft); |
| 73 | extents->y_bearing = SkScalarToHBFixed(-skBounds.fTop); |
| 74 | extents->width = SkScalarToHBFixed(skBounds.width()); |
| 75 | extents->height = SkScalarToHBFixed(-skBounds.height()); |
| 76 | } |
| 77 | } |
| 78 | |
| 79 | static hb_bool_t harfbuzzGetGlyph(hb_font_t* hbFont, void* fontData, hb_codepoint_t unicode, hb_codepoint_t variationSelector, hb_codepoint_t* glyph, void* userData) |
| 80 | { |
| 81 | HarfBuzzFontData* hbFontData = reinterpret_cast<HarfBuzzFontData*>(fontData); |
| 82 | |
| 83 | if (unicode > 0x10ffff) { |
| 84 | unicode = 0xfffd; |
| 85 | } |
| 86 | SkPaint* paint = hbFontData->m_paint; |
| 87 | // It would be better to use kUTF32_TextEncoding directly |
| 88 | paint->setTextEncoding(SkPaint::kUTF16_TextEncoding); |
| 89 | uint16_t glyph16; |
| 90 | uint16_t unichar[2]; |
| 91 | size_t size = SkUTF16_FromUnichar(unicode, unichar); |
| 92 | paint->textToGlyphs(unichar, size * sizeof(*unichar), &glyph16); |
| 93 | *glyph = glyph16; |
| 94 | return !!*glyph; |
| 95 | } |
| 96 | |
| 97 | static hb_position_t harfbuzzGetGlyphHorizontalAdvance(hb_font_t* hbFont, void* fontData, hb_codepoint_t glyph, void* userData) |
| 98 | { |
| 99 | HarfBuzzFontData* hbFontData = reinterpret_cast<HarfBuzzFontData*>(fontData); |
| 100 | hb_position_t advance = 0; |
| 101 | |
| 102 | SkiaGetGlyphWidthAndExtents(hbFontData->m_paint, glyph, &advance, 0); |
| 103 | return advance; |
| 104 | } |
| 105 | |
| 106 | static hb_bool_t harfbuzzGetGlyphHorizontalOrigin(hb_font_t* hbFont, void* fontData, hb_codepoint_t glyph, hb_position_t* x, hb_position_t* y, void* userData) |
| 107 | { |
| 108 | // Just return true, following the way that Harfbuzz-FreeType |
| 109 | // implementation does. |
| 110 | return true; |
| 111 | } |
| 112 | |
| 113 | static hb_bool_t harfbuzzGetGlyphExtents(hb_font_t* hbFont, void* fontData, hb_codepoint_t glyph, hb_glyph_extents_t* extents, void* userData) |
| 114 | { |
| 115 | HarfBuzzFontData* hbFontData = reinterpret_cast<HarfBuzzFontData*>(fontData); |
| 116 | |
| 117 | SkiaGetGlyphWidthAndExtents(hbFontData->m_paint, glyph, 0, extents); |
| 118 | return true; |
| 119 | } |
| 120 | |
| 121 | static hb_font_funcs_t* harfbuzzSkiaGetFontFuncs() |
| 122 | { |
| 123 | static hb_font_funcs_t* harfbuzzSkiaFontFuncs = 0; |
| 124 | |
| 125 | // We don't set callback functions which we can't support. |
| 126 | // Harfbuzz will use the fallback implementation if they aren't set. |
| 127 | if (!harfbuzzSkiaFontFuncs) { |
| 128 | harfbuzzSkiaFontFuncs = hb_font_funcs_create(); |
| 129 | hb_font_funcs_set_glyph_func(harfbuzzSkiaFontFuncs, harfbuzzGetGlyph, 0, 0); |
| 130 | hb_font_funcs_set_glyph_h_advance_func(harfbuzzSkiaFontFuncs, harfbuzzGetGlyphHorizontalAdvance, 0, 0); |
| 131 | hb_font_funcs_set_glyph_h_origin_func(harfbuzzSkiaFontFuncs, harfbuzzGetGlyphHorizontalOrigin, 0, 0); |
| 132 | hb_font_funcs_set_glyph_extents_func(harfbuzzSkiaFontFuncs, harfbuzzGetGlyphExtents, 0, 0); |
| 133 | hb_font_funcs_make_immutable(harfbuzzSkiaFontFuncs); |
| 134 | } |
| 135 | return harfbuzzSkiaFontFuncs; |
| 136 | } |
| 137 | |
| 138 | hb_blob_t* harfbuzzSkiaReferenceTable(hb_face_t* face, hb_tag_t tag, void* userData) |
| 139 | { |
| 140 | SkTypeface* typeface = reinterpret_cast<SkTypeface*>(userData); |
| 141 | SkFontID uniqueID = typeface->uniqueID(); |
| 142 | |
| 143 | const size_t tableSize = SkFontHost::GetTableSize(uniqueID, tag); |
| 144 | if (!tableSize) |
| 145 | return 0; |
| 146 | |
| 147 | char* buffer = reinterpret_cast<char*>(malloc(tableSize)); |
| 148 | if (!buffer) |
| 149 | return 0; |
| 150 | size_t actualSize = SkFontHost::GetTableData(uniqueID, tag, 0, tableSize, buffer); |
| 151 | if (tableSize != actualSize) { |
| 152 | free(buffer); |
| 153 | return 0; |
| 154 | } |
| 155 | |
| 156 | return hb_blob_create(const_cast<char*>(buffer), tableSize, |
| 157 | HB_MEMORY_MODE_WRITABLE, buffer, free); |
| 158 | } |
| 159 | |
| 160 | static void destroyHarfBuzzFontData(void* data) { |
| 161 | delete (HarfBuzzFontData*)data; |
| 162 | } |
| 163 | |
| 164 | hb_font_t* createFont(hb_face_t* face, SkPaint* paint, float sizeX, float sizeY) { |
| 165 | hb_font_t* font = hb_font_create(face); |
| 166 | |
| 167 | // Note: this needs to be reworked when we do subpixels |
| 168 | int x_ppem = floor(sizeX + 0.5); |
| 169 | int y_ppem = floor(sizeY + 0.5); |
| 170 | hb_font_set_ppem(font, x_ppem, y_ppem); |
| 171 | hb_font_set_scale(font, HBFloatToFixed(sizeX), HBFloatToFixed(sizeY)); |
| 172 | |
| 173 | HarfBuzzFontData* data = new HarfBuzzFontData(paint); |
| 174 | hb_font_set_funcs(font, harfbuzzSkiaGetFontFuncs(), data, destroyHarfBuzzFontData); |
| 175 | |
| 176 | return font; |
| 177 | } |
| 178 | |
| 179 | } // namespace android |