smallpt-swift
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Published
20 hours ago •
jackpal
jackpal
Smallpt: Global Illumination in Swift
Small Path Tracer in Swift
This is a straightforward translation of http://www.kevinbeason.com/smallpt/ to Swift.
Example Image
Setup
- Install Xcode 6.1
- Install a PPM image viewing program such as Toy Viewer
Build and run
xcrun swiftc -O -sdk `xcrun --show-sdk-path --sdk macosx` smallpt.swift
./smallpt
open image.ppm
You can also run the swift file directly. And in either case you can supply the number of samples per pixel. (Default = 4 samples per pixel.):
./smallpt.swift 512 && open image.ppm
Performance
On a MacBook Pro (Retina, 15-inch, Early 2013):
| Language | time (seconds) |
|---|---|
| C++ single threaded | 5.6 s |
| Swift single threaded | 13.8 s (of which 5.6 s is rendering, 8 s is file output) |
| Swift GCD | 9.8 s (of which 1 s is rendering, 8 s is file output) |
Discussion
- Swift file output seems to be very slow compared to C.
- partly because it is unbuffered
- partly because it is converting from Unicode to UTF8
jackpal