Question

Why draw operation in android canvas are using float instead of int for (x,y)?
For example:
http://developer.android.com/reference/android/graphics/Canvas.html#drawCircle(float, float, float, android.graphics.Paint)

http://developer.android.com/reference/android/graphics/Canvas.html#drawRect(float, float, float, float, android.graphics.Paint)

If I have a lot of objects (say 200) to draw in my application and i have a class for each object, should I use ‘int’ or ‘float’ for the x, y attribute (the location of the object when drawn on screen)? i think ‘float’ use less memory than ‘int’.

class MyObject {
   public int x;
   public int y;
}

Thank you.

Answer 1

Float because anti-aliasing allows you to paint at sub-pixel level.
Also because there can be a transformation matrix active (e.g. A scale).

A float and int take both 32 bit (most likely)