October 2009
Beginner
260 pages
7h 23m
English
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Tile Engine
The first step in constructing our game will be to focus on the foundation of the game world: the tile engine. The tile engine is responsible for loading the tiles that represent the level and drawing them to the screen. If the level is larger than the viewable area of the screen, we will keep track of a “camera offset” that will be used to draw the portion of the level we are interested in, as well as to draw the rest of the objects on top of the level with the same offset.
Unique Tiles
To begin, we will start with an image that represents our level (see Figure 4-1). This image was constructed out of tiles that are 32×32 pixels wide and high. The level is 15 tiles wide by 25 tiles high, or 375 tiles total. However, because it was created from a small set of tiles, we need to load only the unique tiles into memory; we need only 32 tiles (see Figure 4-2).
That’s more than 90% less memory! However, we’re also going to need to store some data that tells us which unique tile image to use when rendering the level. So, in addition to the unique tile image, we will also need an index array, such as:
1,0,0,0,0,0,0,0,0,0,0,0,0,0,2 1,0,0,0,0,11,12,13,14,15,0,0,0,0,2 1,0,10,0,0,16,17,18,19,20,0,0,0,0,2 1,0,0,0,0,21,22,23,24,25,0,0,4,0,2 1,0,0,0,0,0,0,0,0,0,0,0,0,0,2 1,0,0,0,0,0,0,0,0,0,0,0,0,0,2 1,0,0,0,0,0,0,0,0,0,0,0,0,0,2 1,0,0,0,0,10,0,0,0,4,0,0,0,0,2 1,0,4,5,0,0,0,0,0,0,0,0,0,0,2 1,0,0,10,0,0,0,0,0,0,0,0,7,0,2 1,0,0,0,0,0,0,0,0,0,0,0,0,0,2 1,0,0,0,0,0,0,0,0,0,0,0,0,0,2 1,0,0,0,0,0,0,0,0,0,0,0,0,0,2 ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.