graphics - How to scale path and photo together in android

Question

I'm working for draw on photo android app. I'm trying to add zoom photo and drawn path together.

    override fun onSizeChanged(w: Int, h: Int, oldw: Int, oldh: Int) {
        super.onSizeChanged(w, h, oldw, oldh)
        initialize()
        invalidate()
    }
    
    private fun initialize() {
        viewWidth = measuredWidth.toFloat()
        viewHeight = measuredHeight.toFloat()
        viewRect.set(0f, 0f, measuredWidth.toFloat(), measuredHeight.toFloat())
        initializeBitmapMatrix()
    }
    
    private fun initializeBitmapMatrix() {
        val scale = min(viewWidth / bitmapRect.width(), viewHeight / bitmapRect.height())
        bitmapMatrix.setScale(scale, scale)
    
        val translateX = (viewWidth - bitmapRect.width() * scale) / 2f
        val translateY = (viewHeight - bitmapRect.height() * scale) / 2f
        bitmapMatrix.postTranslate(translateX, translateY)
    }
    
    fun setBitmap(bitmap: Bitmap?) {
        this.bitmap = bitmap
    
        bitmapRect.set(
                0f,
                0f,
                this.bitmap?.width?.toFloat() ?: 0f,
                this.bitmap?.height?.toFloat() ?: 0f
        )
       
        initialize()
        invalidate()
    }

My gesture listener:

override fun onScale(scaleFactor: Float, focusX: Float, focusY: Float) {

        bitmapMatrix.preScale(
                scaleFactor,
                scaleFactor,
                bitmapRect.centerX(),
                bitmapRect.centerY()
        )


        val pathComputeBounds = RectF()
        path.computeBounds(pathComputeBounds, true)

        paint.strokeWidth = paint.strokeWidth * scaleFactor
        pathMatrix.setScale(scaleFactor, scaleFactor,
                pathComputeBounds.centerX(), pathComputeBounds.centerY()
        )
        path.transform(pathMatrix)

        invalidate()
    }

When I zoom photo and path It doesn't scale correctly. You see before zoom/after zoom on photo below. How can I fix this issue?

question from:https://stackoverflow.com/questions/65919029/how-to-scale-path-and-photo-together-in-android

Answer 1

Waitting for answers