[JAVA][Beginning Java 8 Games Development]

Chapter 16 ■ Collision Detection: Creating SVG Polygons for the Game Actors and Writing Code to Detect Collision
To find out the data footprint optimization, simply divide these numbers into each other. If you divide 97 by 1605
(97/1605=0.0604) you find that 97 is 6% of 1605, giving you a 94% reduction in data footprint. If you divide 1605 by 97
(1605/97=16.546) it means you have reduced the file by 16.546 times, giving a 16.55X data footprint reduction. These
are the inverse (1/x) of each other on the calculator, so you can look at it from either direction. So 1605 bytes is 1,655%
more data than 97 bytes, or 97 bytes is 6% (or 94% less data) of 1605 bytes. Any way that you look at it, you have just
saved your game a whole lot of memory, processing, and JAR file data footprint, and that is only for one of the sprites!
Remember that optimizing your collision polygon to use more than 16 times less memory as well as 16 times less
CPU processing overhead can be very significant to the smoothness of your game play once you implement collision
detection in your game logic, which we are going to do after we take a look at CodeAndWeb’s PhysEd tool.
Creating and Optimizing Physics Data: Using PhysEd
I want to take a couple of pages to show you an alternative to GIMP that incorporates both physics and collision into a
unified game development tool offering that is extremely affordable relative to all that it does for game development.
PhysicsEditor, or PhysEd (or PE) is from CodeAndWeb GmbH, a company owned by another Apress author, Andreas
Loew, who writes about iOS Game Development. Let’s take a quick look at how we would define our sprite’s collision
polygon using this professional game development tool, and then we will be ready to get to collision detection coding.
Install and launch PE using the green cube PE icon, and use the Import Sprite button shown in Figure 16-21 to open
up your sprite1.png file, and use the zoom slider at the bottom of the screen to zoom in 600%, just like we did in GIMP.
Figure 16-21. Launch PhysicsEditor and use the Add Sprites button to open the sprite1.png file and zoom into it 600%
363