Translated by OOPer in cooperation with shlab.jp, on 2015/1/5.
Based on https://developer.apple.com/library/content/samplecode/GLPaint/Introduction/Intro.html#//apple_ref/doc/uid/DTS40007328 2014-05-19.
As this is a line-by-line translation from the original sample code, "redistribute the Apple Software in its entirety and without modifications" would apply. See license terms in each file . Some faults caused by my translation may exist. Not all features tested. You should not contact to Apple or SHLab(jp) about any faults caused by my translation.
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Xcode 10.2, iOS SDK 12.2
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iOS 8.0 or later
=========================================================================== Some utility files are used to make line-by-line translation easier. They have another license terms. See license terms in each file.