Update framework text layout to use Harfbuzz NG

These are the frameworks changes to use the new version of Harfbuzz.

Change-Id: Idbef325e8fc1c27a9f2296414ddb1f79b778a00e

1 files changed, 177 insertions, 0 deletions

diff --git a/core/jni/android/graphics/HarfBuzzNGFaceSkia.cpp b/core/jni/android/graphics/HarfBuzzNGFaceSkia.cpp
new file mode 100644
index 0000000..1752e5b
--- /dev/null
+++ b/core/jni/android/graphics/HarfBuzzNGFaceSkia.cpp
@@ -0,0 +1,177 @@
+/*
+ * Copyright (c) 2012 Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#define LOG_TAG "TextLayoutCache"
+
+#include "HarfBuzzNGFaceSkia.h"
+
+#include <cutils/log.h>
+#include <SkFontHost.h>
+#include <SkPaint.h>
+#include <SkPath.h>
+#include <SkPoint.h>
+#include <SkRect.h>
+#include <SkUtils.h>
+
+#include <hb.h>
+
+namespace android {
+
+// Our implementation of the callbacks which Harfbuzz requires by using Skia
+// calls. See the Harfbuzz source for references about what these callbacks do.
+
+struct HarfBuzzFontData {
+    HarfBuzzFontData(SkPaint* paint) : m_paint(paint) { }
+    SkPaint* m_paint;
+};
+
+static void SkiaGetGlyphWidthAndExtents(SkPaint* paint, hb_codepoint_t codepoint, hb_position_t* width, hb_glyph_extents_t* extents)
+{
+    ALOG_ASSERT(codepoint <= 0xFFFF);
+    paint->setTextEncoding(SkPaint::kGlyphID_TextEncoding);
+
+    SkScalar skWidth;
+    SkRect skBounds;
+    uint16_t glyph = codepoint;
+
+    paint->getTextWidths(&glyph, sizeof(glyph), &skWidth, &skBounds);
+    ALOGD("returned glyph for %i: width = %f", codepoint, skWidth);
+    if (width)
+        *width = SkScalarToHBFixed(skWidth);
+    if (extents) {
+        // Invert y-axis because Skia is y-grows-down but we set up harfbuzz to be y-grows-up.
+        extents->x_bearing = SkScalarToHBFixed(skBounds.fLeft);
+        extents->y_bearing = SkScalarToHBFixed(-skBounds.fTop);
+        extents->width = SkScalarToHBFixed(skBounds.width());
+        extents->height = SkScalarToHBFixed(-skBounds.height());
+    }
+}
+
+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)
+{
+    HarfBuzzFontData* hbFontData = reinterpret_cast<HarfBuzzFontData*>(fontData);
+
+    if (unicode > 0x10ffff) {
+        unicode = 0xfffd;
+    }
+    SkPaint* paint = hbFontData->m_paint;
+    // It would be better to use kUTF32_TextEncoding directly
+    paint->setTextEncoding(SkPaint::kUTF16_TextEncoding);
+    uint16_t glyph16;
+    uint16_t unichar[2];
+    size_t size = SkUTF16_FromUnichar(unicode, unichar);
+    paint->textToGlyphs(unichar, size * sizeof(*unichar), &glyph16);
+    *glyph = glyph16;
+    return !!*glyph;
+}
+
+static hb_position_t harfbuzzGetGlyphHorizontalAdvance(hb_font_t* hbFont, void* fontData, hb_codepoint_t glyph, void* userData)
+{
+    HarfBuzzFontData* hbFontData = reinterpret_cast<HarfBuzzFontData*>(fontData);
+    hb_position_t advance = 0;
+
+    SkiaGetGlyphWidthAndExtents(hbFontData->m_paint, glyph, &advance, 0);
+    return advance;
+}
+
+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)
+{
+    // Just return true, following the way that Harfbuzz-FreeType
+    // implementation does.
+    return true;
+}
+
+static hb_bool_t harfbuzzGetGlyphExtents(hb_font_t* hbFont, void* fontData, hb_codepoint_t glyph, hb_glyph_extents_t* extents, void* userData)
+{
+    HarfBuzzFontData* hbFontData = reinterpret_cast<HarfBuzzFontData*>(fontData);
+
+    SkiaGetGlyphWidthAndExtents(hbFontData->m_paint, glyph, 0, extents);
+    return true;
+}
+
+static hb_font_funcs_t* harfbuzzSkiaGetFontFuncs()
+{
+    static hb_font_funcs_t* harfbuzzSkiaFontFuncs = 0;
+
+    // We don't set callback functions which we can't support.
+    // Harfbuzz will use the fallback implementation if they aren't set.
+    if (!harfbuzzSkiaFontFuncs) {
+        harfbuzzSkiaFontFuncs = hb_font_funcs_create();
+        hb_font_funcs_set_glyph_func(harfbuzzSkiaFontFuncs, harfbuzzGetGlyph, 0, 0);
+        hb_font_funcs_set_glyph_h_advance_func(harfbuzzSkiaFontFuncs, harfbuzzGetGlyphHorizontalAdvance, 0, 0);
+        hb_font_funcs_set_glyph_h_origin_func(harfbuzzSkiaFontFuncs, harfbuzzGetGlyphHorizontalOrigin, 0, 0);
+        hb_font_funcs_set_glyph_extents_func(harfbuzzSkiaFontFuncs, harfbuzzGetGlyphExtents, 0, 0);
+        hb_font_funcs_make_immutable(harfbuzzSkiaFontFuncs);
+    }
+    return harfbuzzSkiaFontFuncs;
+}
+
+hb_blob_t* harfbuzzSkiaReferenceTable(hb_face_t* face, hb_tag_t tag, void* userData)
+{
+    SkTypeface* typeface = reinterpret_cast<SkTypeface*>(userData);
+    SkFontID uniqueID = typeface->uniqueID();
+
+    const size_t tableSize = SkFontHost::GetTableSize(uniqueID, tag);
+    if (!tableSize)
+        return 0;
+
+    char* buffer = reinterpret_cast<char*>(malloc(tableSize));
+    if (!buffer)
+        return 0;
+    size_t actualSize = SkFontHost::GetTableData(uniqueID, tag, 0, tableSize, buffer);
+    if (tableSize != actualSize) {
+        free(buffer);
+        return 0;
+    }
+
+    return hb_blob_create(const_cast<char*>(buffer), tableSize,
+                          HB_MEMORY_MODE_WRITABLE, buffer, free);
+}
+
+static void destroyHarfBuzzFontData(void* data) {
+    delete (HarfBuzzFontData*)data;
+}
+
+hb_font_t* createFont(hb_face_t* face, SkPaint* paint, float sizeX, float sizeY) {
+    hb_font_t* font = hb_font_create(face);
+    
+    // Note: this needs to be reworked when we do subpixels
+    int x_ppem = floor(sizeX + 0.5);
+    int y_ppem = floor(sizeY + 0.5);
+    hb_font_set_ppem(font, x_ppem, y_ppem); 
+    hb_font_set_scale(font, HBFloatToFixed(sizeX), HBFloatToFixed(sizeY));
+
+    HarfBuzzFontData* data = new HarfBuzzFontData(paint);
+    hb_font_set_funcs(font, harfbuzzSkiaGetFontFuncs(), data, destroyHarfBuzzFontData);
+
+    return font;
+}
+
+} // namespace android