How to draw with an "inverted" paint in Android Canvas?
I draw some stuff on a canvas, over I want to draw a circle in inverted color :
canvas.drawCircle(zx, zy, 8f, myPaint);
How to configure myPaint for circle pixel to be in the inverted color of the underlying pixels ?
Thanks
尝试这个
float mx [] = {
-1.0f, 0.0f, 0.0f, 1.0f, 0.0f,
0.0f, -1.0f, 0.0f, 1.0f, 0.0f,
0.0f, 0.0f, -1.0f, 1.0f, 0.0f,
1.0f, 1.0f, 1.0f, 1.0f, 0.0f
};
ColorMatrix cm = new ColorMatrix(mx);
p.setColorFilter(new ColorMatrixColorFilter(cm));
canvas.drawCircle(zx, zy, 8f, p);
I'd say a color matrix for inverting should look like this:
float mx [] = {
-1.0f, 0.0f, 0.0f, 0.0f, 255.0f,
0.0f, -1.0f, 0.0f, 0.0f, 255.0f,
0.0f, 0.0f, -1.0f, 0.0f, 255.0f,
0.0f, 0.0f, 0.0f, 1.0f, 0.0f
};
Here is more information for the matrix:
myPaint.setColor(Integer.MAX_VALUE - color);