Re: Hit detection for GWT canvas - which strategy for drawings?

All methods are viable. 

I know that the color based hit detection is widely used and supposed to be quite efficient. 

There are a couple of stackoverflow threads about that: 

http://stackoverflow.com/questions/31158/resources-of-techniques-use-for-collision-detection-in-2d

http://stackoverflow.com/questions/12618734/hit-detect-canvas-js

You can also think about using one of the canvas frameworks/libraries (like kinetic.js, etc). They have hit detection and also user interaction built in. 

On Thursday, December 20, 2012 12:14:43 PM UTC+1, membersound wrote:

I'm creating some kind of drawings/flowchart/UML-diagram like tool with GWT Canvas (Java).
For hit-detection of my drawings I could imagine 3 different strategies, but I do not know which would work best for my goal.

-  Just keep track of all Shape coordinates and iterate all objects on mouseclick
-  draw all objects on a ghost-canvas on mouseclick, and use isPointInPath() after every object drawing
- using a ghost-canvas and draw each object with its own color (like #000001, #000002), and keep reference of them in a Map<Color, Shape>. Then just detecting the mouseclick on the ghost-canvas and get the object belonging to the pixelcolor under mouse

What would you prefer, and why?

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