How to draw a bitmap to another, but into a given quadrilateral (not necessary a rectangle)?

Question

Suppose I have 2 bitmaps. One is smallBitmap, and one is largeBitmap.

I want to draw the entire smallBitmap into largeBitmap, but only to a part of largeBitmap, and

Answer 1

to skew a bitmap,probably Matrix can be handy.

   /*use values accordingly*/
   Matrix matrix = new Matrix();
   matrix.postScale(curScale, curScale);  
   matrix.postRotate(curRotate);
   matrix.postSkew(curSkewX, curSkewY);

   Bitmap resizedBitmap = Bitmap.createBitmap(bitmap, 0, 0, bmpWidth, bmpHeight, matrix, true);
   myImageView.setImageBitmap(resizedBitmap);