1 files changed, 132 insertions, 0 deletions
diff --git a/platform/android/src/bitmap.cpp b/platform/android/src/bitmap.cpp
new file mode 100644
index 0000000000..50088116f4
--- /dev/null
+++ b/platform/android/src/bitmap.cpp
@@ -0,0 +1,132 @@
+#include "bitmap.hpp"
+
+#include <android/bitmap.h>
+
+namespace mbgl {
+namespace android {
+
+class PixelGuard {
+public:
+    PixelGuard(jni::JNIEnv& env_, jni::Object<Bitmap> bitmap_) : env(env_), bitmap(bitmap_) {
+        const int result = AndroidBitmap_lockPixels(&env, jni::Unwrap(*bitmap),
+                                                    reinterpret_cast<void**>(&address));
+        if (result != ANDROID_BITMAP_RESULT_SUCCESS) {
+            throw std::runtime_error("bitmap decoding: could not lock pixels");
+        }
+    }
+    ~PixelGuard() {
+        const int result = AndroidBitmap_unlockPixels(&env, jni::Unwrap(*bitmap));
+        if (result != ANDROID_BITMAP_RESULT_SUCCESS) {
+            throw std::runtime_error("bitmap decoding: could not unlock pixels");
+        }
+    }
+
+    auto* get() {
+        return address;
+    }
+
+    const auto* get() const {
+        return address;
+    }
+
+private:
+    jni::JNIEnv& env;
+    jni::Object<Bitmap> bitmap;
+    uint8_t* address;
+};
+
+void Bitmap::Config::registerNative(jni::JNIEnv& env) {
+    _class = *jni::Class<Config>::Find(env).NewGlobalRef(env).release();
+}
+
+jni::Class<Bitmap::Config> Bitmap::Config::_class;
+
+jni::Object<Bitmap::Config> Bitmap::Config::Create(jni::JNIEnv& env, Value value) {
+    switch (value) {
+    case ALPHA_8:
+        return _class.Get(env,
+                          jni::StaticField<Config, jni::Object<Config>>(env, _class, "ALPHA_8"));
+    case ARGB_4444:
+        return _class.Get(env,
+                          jni::StaticField<Config, jni::Object<Config>>(env, _class, "ARGB_4444"));
+    case ARGB_8888:
+        return _class.Get(env,
+                          jni::StaticField<Config, jni::Object<Config>>(env, _class, "ARGB_8888"));
+    case RGB_565:
+        return _class.Get(env,
+                          jni::StaticField<Config, jni::Object<Config>>(env, _class, "RGB_565"));
+    default:
+        throw std::runtime_error("invalid enum value for Bitmap.Config");
+    }
+}
+
+void Bitmap::registerNative(jni::JNIEnv& env) {
+    _class = *jni::Class<Bitmap>::Find(env).NewGlobalRef(env).release();
+    Config::registerNative(env);
+}
+
+jni::Class<Bitmap> Bitmap::_class;
+
+jni::Object<Bitmap> Bitmap::CreateBitmap(jni::JNIEnv& env,
+                                         jni::jint width,
+                                         jni::jint height,
+                                         jni::Object<Config> config) {
+    using Signature = jni::Object<Bitmap>(jni::jint, jni::jint, jni::Object<Config>);
+    auto method = _class.GetStaticMethod<Signature>(env, "createBitmap");
+    return _class.Call(env, method, width, height, config);
+}
+
+jni::Object<Bitmap> Bitmap::CreateBitmap(jni::JNIEnv& env, const PremultipliedImage& image) {
+    auto bitmap = CreateBitmap(env, image.size.width, image.size.height, Config::ARGB_8888);
+
+    AndroidBitmapInfo info;
+    const int result = AndroidBitmap_getInfo(&env, jni::Unwrap(*bitmap), &info);
+    if (result != ANDROID_BITMAP_RESULT_SUCCESS) {
+        // TODO: more specific information
+        throw std::runtime_error("bitmap creation: couldn't get bitmap info");
+    }
+
+    assert(info.width == image.size.width);
+    assert(info.height == image.size.height);
+    assert(info.format == ANDROID_BITMAP_FORMAT_RGBA_8888);
+
+    PixelGuard guard(env, bitmap);
+
+    // Copy the PremultipliedImage into the Android Bitmap
+    for (uint32_t y = 0; y < image.size.height; y++) {
+        auto begin = image.data.get() + y * image.stride();
+        std::copy(begin, begin + image.stride(), guard.get() + y * info.stride);
+    }
+
+    return bitmap;
+}
+
+PremultipliedImage Bitmap::GetImage(jni::JNIEnv& env, jni::Object<Bitmap> bitmap) {
+    AndroidBitmapInfo info;
+    const int result = AndroidBitmap_getInfo(&env, jni::Unwrap(*bitmap), &info);
+    if (result != ANDROID_BITMAP_RESULT_SUCCESS) {
+        // TODO: more specific information
+        throw std::runtime_error("bitmap decoding: couldn't get bitmap info");
+    }
+
+    if (info.format != ANDROID_BITMAP_FORMAT_RGBA_8888) {
+        // TODO: convert
+        throw std::runtime_error("bitmap decoding: bitmap format invalid");
+    }
+
+    const PixelGuard guard(env, bitmap);
+
+    // Copy the Android Bitmap into the PremultipliedImage.
+    auto pixels =
+        std::make_unique<uint8_t[]>(info.width * info.height * PremultipliedImage::channels);
+    for (uint32_t y = 0; y < info.height; y++) {
+        auto begin = guard.get() + y * info.stride;
+        std::copy(begin, begin + info.width * PremultipliedImage::channels,
+                  pixels.get() + y * info.width * PremultipliedImage::channels);
+    }
+
+    return { Size{ info.width, info.height }, std::move(pixels) };
+}
+
+} // namespace android
+} // namespace mbgl