Initial implementation of local CJK glyph rendering on Android.

5 files changed, 137 insertions, 1 deletions

diff --git a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/text/LocalGlyphRasterizer.java b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/text/LocalGlyphRasterizer.java
new file mode 100644
index 0000000000..cb502c2725
--- /dev/null
+++ b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/text/LocalGlyphRasterizer.java
@@ -0,0 +1,24 @@
+package com.mapbox.mapboxsdk.text;
+
+import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.graphics.Bitmap;
+import android.graphics.Color;
+import android.graphics.Typeface;
+
+public class LocalGlyphRasterizer {
+
+    public static Bitmap drawGlyphBitmap(char glyphID) {
+        Bitmap bitmap = Bitmap.createBitmap(35, 35, Bitmap.Config.ARGB_8888);
+
+        Paint paint = new Paint();
+        paint.setTextSize(24);
+        paint.setTypeface(Typeface.create("Noto Sans", Typeface.NORMAL));
+
+        Canvas canvas = new Canvas();
+        canvas.setBitmap(bitmap);
+        canvas.drawText(String.valueOf(glyphID), 0, 20, paint);
+
+        return bitmap;
+    }
+}
diff --git a/platform/android/config.cmake b/platform/android/config.cmake
index a915f1d93d..3ef1b8f830 100644
--- a/platform/android/config.cmake
+++ b/platform/android/config.cmake
@@ -37,11 +37,12 @@ macro(mbgl_platform_core)
         PRIVATE platform/android/src/timer.cpp
 
         # Misc
+        PRIVATE platform/android/src/text/local_glyph_rasterizer_impl.hpp
+        PRIVATE platform/android/src/text/local_glyph_rasterizer.cpp
         PRIVATE platform/android/src/logging_android.cpp
         PRIVATE platform/android/src/thread.cpp
         PRIVATE platform/default/string_stdlib.cpp
         PRIVATE platform/default/bidi.cpp
-        PRIVATE platform/default/local_glyph_rasterizer.cpp
         PRIVATE platform/default/thread_local.cpp
         PRIVATE platform/default/utf.cpp
 
diff --git a/platform/android/src/jni.cpp b/platform/android/src/jni.cpp
index 63566e1772..354c7594c2 100755
--- a/platform/android/src/jni.cpp
+++ b/platform/android/src/jni.cpp
@@ -51,6 +51,7 @@
 #include "style/light.hpp"
 #include "snapshotter/map_snapshotter.hpp"
 #include "snapshotter/map_snapshot.hpp"
+#include "text/local_glyph_rasterizer_impl.hpp"
 
 namespace mbgl {
 namespace android {
@@ -188,6 +189,9 @@ void registerNatives(JavaVM *vm) {
     // Snapshotter
     MapSnapshotter::registerNative(env);
     MapSnapshot::registerNative(env);
+
+    // text
+    AndroidLocalGlyphRasterizer::registerNative(env);
 }
 
 } // namespace android
diff --git a/platform/android/src/text/local_glyph_rasterizer.cpp b/platform/android/src/text/local_glyph_rasterizer.cpp
new file mode 100644
index 0000000000..dd58ee2228
--- /dev/null
+++ b/platform/android/src/text/local_glyph_rasterizer.cpp
@@ -0,0 +1,84 @@
+#include <mbgl/text/local_glyph_rasterizer.hpp>
+#include <mbgl/util/i18n.hpp>
+
+#include <jni/jni.hpp>
+
+#include "../attach_env.hpp"
+#include "../bitmap.hpp"
+
+#include "local_glyph_rasterizer_impl.hpp" // Actually AndroidLocalGlyphRasterizer
+
+namespace mbgl {
+
+namespace android {
+
+PremultipliedImage AndroidLocalGlyphRasterizer::drawGlyphBitmap(const FontStack&, unsigned short glyphID, Size) {
+    UniqueEnv env { AttachEnv() }; // TODO: How should this be hooked up?
+
+    // TODO: Pass in font stack and size (and configuration)
+    // For now, just try to hard-wire any rendering at all
+    using Signature = jni::Object<Bitmap>(jni::jchar);
+    auto method = javaClass.GetStaticMethod<Signature>(*env, "drawGlyphBitmap");
+    auto result = javaClass.Call(*env, method, glyphID);
+
+    return Bitmap::GetImage(*env, result);
+}
+
+void AndroidLocalGlyphRasterizer::registerNative(jni::JNIEnv& env) {
+    javaClass = *jni::Class<AndroidLocalGlyphRasterizer>::Find(env).NewGlobalRef(env).release();
+}
+
+jni::Class<AndroidLocalGlyphRasterizer> AndroidLocalGlyphRasterizer::javaClass;
+
+} // namespace android
+
+class LocalGlyphRasterizer::Impl {
+public:
+    bool hasFont(const FontStack&) const {
+        return true;
+    }
+
+    PremultipliedImage drawGlyphBitmap(const FontStack& fontStack, GlyphID glyphID, Size size) {
+        return android::AndroidLocalGlyphRasterizer::drawGlyphBitmap(fontStack, (unsigned short)glyphID, size);
+    }
+};
+
+LocalGlyphRasterizer::LocalGlyphRasterizer(const optional<std::string>)
+    : impl(std::make_unique<Impl>())
+{}
+
+LocalGlyphRasterizer::~LocalGlyphRasterizer()
+{}
+
+bool LocalGlyphRasterizer::canRasterizeGlyph(const FontStack& fontStack, GlyphID glyphID) {
+     return util::i18n::allowsFixedWidthGlyphGeneration(glyphID) && impl->hasFont(fontStack);
+}
+
+Glyph LocalGlyphRasterizer::rasterizeGlyph(const FontStack& fontStack, GlyphID glyphID) {
+    Glyph fixedMetrics;
+    if (!impl->hasFont(fontStack)) {
+        return fixedMetrics;
+    }
+
+    fixedMetrics.id = glyphID;
+
+    Size size(35, 35);
+
+    fixedMetrics.metrics.width = size.width;
+    fixedMetrics.metrics.height = size.height;
+    fixedMetrics.metrics.left = 3;
+    fixedMetrics.metrics.top = -10;
+    fixedMetrics.metrics.advance = 24;
+
+    PremultipliedImage rgbaBitmap = impl->drawGlyphBitmap(fontStack, glyphID, size);
+
+    // Copy alpha values from RGBA bitmap into the AlphaImage output
+    fixedMetrics.bitmap = AlphaImage(size);
+    for (uint32_t i = 0; i < size.width * size.height; i++) {
+        fixedMetrics.bitmap.data[i] = rgbaBitmap.data[4 * i + 3];
+    }
+
+    return fixedMetrics;
+}
+
+} // namespace mbgl
diff --git a/platform/android/src/text/local_glyph_rasterizer_impl.hpp b/platform/android/src/text/local_glyph_rasterizer_impl.hpp
new file mode 100644
index 0000000000..2e14f87e34
--- /dev/null
+++ b/platform/android/src/text/local_glyph_rasterizer_impl.hpp
@@ -0,0 +1,23 @@
+#pragma once
+
+#include <mbgl/util/image.hpp>
+
+#include <jni/jni.hpp>
+
+namespace mbgl {
+namespace android {
+
+class AndroidLocalGlyphRasterizer {
+public:
+    static PremultipliedImage drawGlyphBitmap(const FontStack&, unsigned short glyphID, Size size);
+
+    static constexpr auto Name() { return "com/mapbox/mapboxsdk/text/LocalGlyphRasterizer"; };
+
+    static jni::Class<AndroidLocalGlyphRasterizer> javaClass;
+
+    static void registerNative(jni::JNIEnv&);
+
+};
+
+} // namespace android
+} // namespace mbgl