1/*
2 * Copyright (c) 2008, 2009 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#include "config.h"
32#include "GlyphPageTreeNode.h"
33
34#include "Font.h"
35#include "HarfbuzzSkia.h"
36#include "SimpleFontData.h"
37
38#include "SkTemplates.h"
39#include "SkPaint.h"
40#include "SkUtils.h"
41
42namespace WebCore {
43
44static int substituteWithVerticalGlyphs(const SimpleFontData* fontData, uint16_t* glyphs, unsigned bufferLength)
45{
46    HB_FaceRec_* hbFace = fontData->platformData().harfbuzzFace();
47    if (!hbFace->gsub) {
48        // if there is no GSUB table, treat it as not covered
49        return 0Xffff;
50    }
51
52    HB_Buffer buffer;
53    hb_buffer_new(&buffer);
54    for (unsigned i = 0; i < bufferLength; ++i)
55        hb_buffer_add_glyph(buffer, glyphs[i], 0, i);
56
57    HB_UShort scriptIndex;
58    HB_UShort featureIndex;
59
60    HB_GSUB_Select_Script(hbFace->gsub, HB_MAKE_TAG('D', 'F', 'L', 'T'), &scriptIndex);
61    HB_GSUB_Select_Feature(hbFace->gsub, HB_MAKE_TAG('v', 'e', 'r', 't'), scriptIndex, 0xffff, &featureIndex);
62    HB_GSUB_Add_Feature(hbFace->gsub, featureIndex, 1);
63    HB_GSUB_Select_Feature(hbFace->gsub, HB_MAKE_TAG('v', 'r', 't', '2'), scriptIndex, 0xffff, &featureIndex);
64    HB_GSUB_Add_Feature(hbFace->gsub, featureIndex, 1);
65
66    int error = HB_GSUB_Apply_String(hbFace->gsub, buffer);
67    if (!error) {
68        for (unsigned i = 0; i < bufferLength; ++i)
69            glyphs[i] = static_cast<Glyph>(buffer->out_string[i].gindex);
70    }
71    return error;
72}
73
74bool GlyphPage::fill(unsigned offset, unsigned length, UChar* buffer, unsigned bufferLength, const SimpleFontData* fontData)
75{
76    if (SkUTF16_IsHighSurrogate(buffer[bufferLength-1])) {
77        SkDebugf("%s last char is high-surrogate", __FUNCTION__);
78        return false;
79    }
80
81    SkPaint paint;
82    fontData->platformData().setupPaint(&paint);
83    paint.setTextEncoding(SkPaint::kUTF16_TextEncoding);
84
85    SkAutoSTMalloc <GlyphPage::size, uint16_t> glyphStorage(length);
86    uint16_t* glyphs = glyphStorage.get();
87    // textToGlyphs takes a byte count, not a glyph count so we multiply by two.
88    unsigned count = paint.textToGlyphs(buffer, bufferLength * 2, glyphs);
89    if (count != length) {
90        SkDebugf("%s count != length\n", __FUNCTION__);
91        return false;
92    }
93
94    if (fontData->hasVerticalGlyphs()) {
95        bool lookVariants = false;
96        for (unsigned i = 0; i < bufferLength; ++i) {
97            if (!Font::isCJKIdeograph(buffer[i])) {
98                lookVariants = true;
99                continue;
100            }
101        }
102        if (lookVariants)
103            substituteWithVerticalGlyphs(fontData, glyphs, bufferLength);
104    }
105
106    unsigned allGlyphs = 0; // track if any of the glyphIDs are non-zero
107    for (unsigned i = 0; i < length; i++) {
108        setGlyphDataForIndex(offset + i, glyphs[i], glyphs[i] ? fontData : NULL);
109        allGlyphs |= glyphs[i];
110    }
111
112    return allGlyphs != 0;
113}
114
115}  // namespace WebCore
116