How to find the current translate position in Canvas?

How do I get the current translate position from a Canvas? I am trying to draw stuff where my coordinates are a mix of relative (to each other) and absolute (to canvas).

Lets say I want to do

canvas.translate(x1, y1);
canvas.drawSomething(0, 0); // will show up at (x1, y1), all good
// now i want to draw a point at x2,y2
canvas.translate(x2, y2);
canvas.drawSomething(0, 0); // will show up at (x1+x2, y1+y2)
// i could do
canvas.drawSomething(-x1, -y1);
// but i don't always know those coords

This works but is dirty:

private static Point getCurrentTranslate(Canvas canvas) {
    float [] pos = new float [2];
    canvas.getMatrix().mapPoints(pos);
    return new Point((int)pos[0], (int)pos[1]);
}
...
Point p = getCurrentTranslate(canvas);
canvas.drawSomething(-p.x, -p.y);

The canv开发者_如何学Cas has a getMatrix method, it has a setTranslate but no getTranslate. I don't want to use canvas.save() and canvas.restore() because the way I'm drawing things it's a little tricky (and probably messy ...)

Is there a cleaner way to get these current coordinates?

You need to reset the transformation matrix first. I'm not an android developer, looking at the android canvas docs, there is no reset matrix, but there is a setMatrix(android.graphics.Matrix). It says if the given matrix is null it will set the current matrix to the identity matrix, which is what you want. So I think you can reset your position (and scale and skew) with:

canvas.setMatrix(null);

It would also be possible to get the current translation through getMatrix. There is a mapVectors() method you could use for matrices to see where the point [0,0] would be mapped to, this would be your translation. But in your case I think resetting the matrix is best.