Re: How can copy SkBitmap draw to android.graphics.Bitmap?

[Derek Sollenberger]

I haven't looked into why the getPixels call is returning null, but in your case you shouldn't be allocating a separate native bitmap, but should instead wrap the existing pixels.

You can wrap the pixels by calling SkSurface::MakeRasterDirect which will return a surface that you can surface->getCanvas().  This will allow you to draw directly into the pixels allocated by the Java bitmap.

On Tue, Apr 25, 2017 at 12:09 AM Mingyue 郭 <gmybi...@gmail.com> wrote:

In Android Java:

public class SkiaDrawView extends View {
    public Bitmap fSkiaBitmap;

    public SkiaDrawView(Context ctx, AttributeSet attr) {
        super(ctx, attr);
    }

    @Override
    public void onSizeChanged(int w, int h, int oldw, int oldh)
    {
        fSkiaBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
    }

    @Override
    public void onDraw(Canvas canvas)
    {
        fun1(fSkiaBitmap);
        canvas.drawBitmap(fSkiaBitmap, 0, 0, null);

    }

    public native void fun1(Bitmap bitmap);

}

Jni:

JNIEXPORT void JNICALL Java_com_example_viewdraw_viewdrawinndkskiausestaticlib_SkiaDrawView_fun1(JNIEnv * env, jobject obj, jobject dstBitmap)
{
    AndroidBitmapInfo dstInfo;
    AndroidBitmap_getInfo(env, dstBitmap, &dstInfo);

    //draw SkBitmap;
    SkImageInfo imageInfo = SkImageInfo::MakeN32Premul(dstInfo.width, dstInfo.height);
    SkBitmap bitmap;
    bitmap.allocPixels(imageInfo);
//    if(!bitmap.tryAllocPixels(imageInfo))
//    {
//        __android_log_print(ANDROID_LOG_INFO, "YimaLib_ViewDraw", "bitmap.tryAllocPixels faild...");
//        return;
//    }
    SkCanvas canvas(bitmap);
    canvas.drawColor(SK_ColorRED);

    void *dstPixels;
    AndroidBitmap_lockPixels(env, dstBitmap, &dstPixels);
    //bitmap.lockPixels(); //when use this: build error:undefined reference to 'SkBitmap::lockPixels() const'
    memcpy(dstPixels, bitmap.getPixels(), dstInfo.width*dstInfo.height*4); //  the bitmap.getPixels() is null, I want copying bitmap to dstBitmap, what I should do ?
    AndroidBitmap_unlockPixels(env, dstBitmap);
}

I want draw something in SkBitmap in C++, and then show in Android View Use android.graphics.Bitmap.

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