CoreGraphics Render
I was intrigued by a challenge I came across: “Single drawRect function for a single 400x400 UIView that does something magical”. I believe constraints are powerful and added a few more (excerpt from code):
// Conditions:
// - no pixel graphic ressources
// - no external code besides SDK
…
// - finish under 4h
// Let's start: my goal is to approximate the Instagram iTunes Artwork.
700 lines of CoreGraphics code (a layer on top of OpenGL) later the program drew the Instagram logo. It features an implementation of multiplicative monochrome normal distributed saturated noise, usage of blending modes, detailed gradients and shading, smoothing radial gradients through clipping, and bezier paths with arcs for reflections. Isn’t it quite astonishing how a few thousand text instructions to a computer, carefully orchestrated, can create something that is instantly recognized by most people? The program ends with:
// Conclusions:
// - I reached the goal within the conditions and like the result, especially rendered on the device.
// - At some points I tried to use another technique than already used (e.g. transform an existing shape).
…
// - I like my quick implementation of multiplicative monochrome normal distributed saturated noise for this (formula from Wikipedia).
// - Edges of curves are rendered pretty choppy, a trick I found to smooth those is clipping the graphics context along the edge.
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