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manual_v1:dynamic_textures [2013/03/05 10:19] (current)
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 +====== Dynamic Textures ======
 +Sparrow lets you create custom textures directly at run-time. However, we didn’t reinvent the wheel for that feature --- credit goes to the iPhone SDK, which already contains a powerful API called "Core Graphics"​.
 +You access the drawing API with a special init-method of SPTexture, which takes a "​block"​-parameter you can fill with your drawing code. If you haven'​t heard of blocks before, that's because they are a relatively new feature on iOS. They are, however, very simple to use. Just think of a block as a function you can define inline --- ActionScript developers are using them all the time.
 +Here's a sample of how to create a custom texture with Core Graphics in Sparrow:
 +<code objc>
 +SPTexture *customTexture = [[SPTexture alloc] initWithWidth:​200 height:100
 +    draw:​^(CGContextRef context)
 +    {
 +        // draw a string
 +        CGContextSetGrayFillColor(context,​ 1.0f, 1.0f);
 +        NSString *string = @"​Hello Core Graphics";​
 +        [string drawAtPoint:​CGPointMake(20.0f,​ 20.0f)
 +                 ​withFont:​[UIFont fontWithName:​@"​Arial"​ size:25]];
 +    }];
 +The thing starting with the caret (^) is the block. Place your drawing code in the block and it will appear on your texture later. ​
 +If you haven’t worked with Core Graphics before, there are numerous resources on the web that describe how to use them. [[http://​maniacdev.com/​2009/​09/​6-resources-for-learning-core-graphics/​|Here]] is a good starting point to find out more about them.
 +//Next section: [[Compiled Sprites]]//
  manual_v1/dynamic_textures.txt · Last modified: 2013/03/05 10:19 (external edit)
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