Question

Im drawing a bitmap at a canvas. Im trying to have this bitmap rotate and change position.

For that im using this code:

 matrix.setTranslate(pos_x, 15);
 matrix.setRotate(30);
 canvas.drawBitmap(bitmap, matrix,paint);

And all this is in a loop so the variable “pos_x” will be increased.

But it seems like matrix wont accept both of these lines, setTranslate and setRotate.
The bitmap is rotated when i comment out the setTranslate. And the bitmap is moving when i comment out the rotate. But they won’t work together!

What should I do?

Thanks!

Answer 1

The problem most likely is in the meaning of the word ‘set’.

Instead of setting aka overwriting the matrix, one should incrementally adjust it:
either should one first setTranslate and then Rotate, or setRotate and then Translate.