Apple II
Sample Code Notes
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                                                  Developer Technical Support


#3:    AnimDemo

Version:    1.0                                                September 1988

APW Components:    AnimDemo.Aii                   18 Aug 88
                   AnimDemo.Macros                18 Aug 88
                   AnimDemo                       18 Aug 88

MPW Components:    AnimDemo.Aii                   29 Jul 88
                   Makefile                       28 Jun 88

AnimDemo shows three different Apple IIGS animation techniques.  The source 
code also demonstrates the only supported way to access screen memory 
directly, bypassing QuickDraw II.
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The appearance of horizontally and vertically moving marquee lights is 
achieved by modifying color table entries using heartbeat (VBL) tasks.  
Horizontal scrolling of the text in the marquee box is handled via heartbeat 
tasks.  Pixel block transfers create the effect of a bouncing color object.

These three animation techniques are meant to give you an idea of what can be 
done to animate Apple IIGS graphics.  Other techniques will be illustrated in 
subsequent Sample Code releases.  We would like to hear about your methods 
too.

Use APW 1.0 and Apple IIGS System Disk 3.2 or later to execute the AnimDemo 
file included with the APW-compatible source code files.  To create a load 
file under APW, issue the following command:  ASML AnimDemo.Aii Keep=AnimDemo.

MPW IIGS users need MPW 2.02, MPW IIGS Tools 1.0, and any version of the MPW 
IIGS assembler.  The program name needed by the MPW Build menu's Build option 
is AnimDemo.


