Tag: matrix

Calculate the REAL scale factor and the angle of rotation from an Android Matrix

Apr 13, 2013

| android, another snippet | code

After performing transformations such as rotation of a bitmap about an arbitrary point, the scale is lost. Of course, this makes sense because the bitmap is rotated inside the same bounds. To get the real scale now, along with the most reliable degree of rotation, I had to follow this method. Hope it saves the…
Multi Touch in Android – Translate, Scale, and Rotate

Apr 9, 2013

| android

Here’s a quick and easy implementation of Android’s multi touch feature – one finger to move, two to zoom, and three to rotate the image. Assuming you have a basic understanding of 2D matrix transformations, the Matrix class in Android uses a 3×3 matrix to achieve all of the 2D transformations. The source code and…