Initial commit of Minikin library

This is the initial draft of Minikin, a library intended to perform text
layout functions. This version does basic weight selection and font runs
for scripts, and also has a simple renderer for drawing into bitmaps,
but is lacking measurement, line breaking, and a number of other
important features. It also lacks caching and other performance
refinements.

Change-Id: I789a2e47d11d71202dc84b4751b51a5e2cd9c451

1 files changed, 95 insertions, 0 deletions

diff --git a/libs/minikin/FontFamily.cpp b/libs/minikin/FontFamily.cpp
new file mode 100644
index 0000000..dc6e16c
--- /dev/null
+++ b/libs/minikin/FontFamily.cpp
@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "Minikin"
+
+#include <cutils/log.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <utils/UniquePtr.h>
+#include <ft2build.h>
+#include FT_FREETYPE_H
+#include FT_TRUETYPE_TABLES_H
+#include <minikin/AnalyzeStyle.h>
+#include <minikin/FontFamily.h>
+
+using std::vector;
+
+namespace android {
+
+bool FontFamily::addFont(FT_Face typeface) {
+    const uint32_t os2Tag = FT_MAKE_TAG('O', 'S', '/', '2');
+    FT_ULong os2Size = 0;
+    FT_Error error = FT_Load_Sfnt_Table(typeface, os2Tag, 0, NULL, &os2Size);
+    if (error != 0) return false;
+    UniquePtr<uint8_t[]> os2Data(new uint8_t[os2Size]);
+    error = FT_Load_Sfnt_Table(typeface, os2Tag, 0, os2Data.get(), &os2Size);
+    if (error != 0) return false;
+    int weight;
+    bool italic;
+    if (analyzeStyle(os2Data.get(), os2Size, &weight, &italic)) {
+        //ALOGD("analyzed weight = %d, italic = %s", weight, italic ? "true" : "false");
+        FontStyle style(weight, italic);
+        addFont(typeface, style);
+        return true;
+    } else {
+        ALOGD("failed to analyze style");
+    }
+    return false;
+}
+
+void FontFamily::addFont(FT_Face typeface, FontStyle style) {
+    mFonts.push_back(Font(typeface, style));
+    ALOGD("added font, mFonts.size() = %d", mFonts.size());
+}
+
+// Compute a matching metric between two styles - 0 is an exact match
+int computeMatch(FontStyle style1, FontStyle style2) {
+    if (style1 == style2) return 0;
+    int score = abs(style1.getWeight() - style2.getWeight());
+    if (style1.getItalic() != style2.getItalic()) {
+        score += 2;
+    }
+    return score;
+}
+
+FT_Face FontFamily::getClosestMatch(FontStyle style) const {
+    const Font* bestFont = NULL;
+    int bestMatch = 0;
+    for (size_t i = 0; i < mFonts.size(); i++) {
+        const Font& font = mFonts[i];
+        int match = computeMatch(font.style, style);
+        if (i == 0 || match < bestMatch) {
+            bestFont = &font;
+            bestMatch = match;
+        }
+    }
+    return bestFont == NULL ? NULL : bestFont->typeface;
+}
+
+size_t FontFamily::getNumFonts() const {
+    return mFonts.size();
+}
+
+FT_Face FontFamily::getFont(size_t index) const {
+    return mFonts[index].typeface;
+}
+
+FontStyle FontFamily::getStyle(size_t index) const {
+    return mFonts[index].style;
+}
+
+}  // namespace android