Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Multithreaded Drawing by Eric Lanz
Search
Triangle Cocoa
August 23, 2012
Programming
3
210
Multithreaded Drawing by Eric Lanz
Eric discusses multithreaded drawing with Core Graphics at CocoaHeads August in Raleigh
Triangle Cocoa
August 23, 2012
Tweet
Share
More Decks by Triangle Cocoa
See All by Triangle Cocoa
App Store Secrets by Lawrence Ingraham
trianglecocoa
1
280
iPhone 5 and You! by Ameir Al-Zoubi
trianglecocoa
0
180
Grand Central Dispatch by Jody Hagins
trianglecocoa
2
480
Instruments: Leaks by Trevor Brown
trianglecocoa
5
150
Foundation Collections by Kevin Conner
trianglecocoa
3
250
Unburdened ViewControllers by Jay Thrash
trianglecocoa
9
11k
Automated Acceptance Testing by Josh Johnson
trianglecocoa
4
180
Understanding UIResponder by Dirk Smith
trianglecocoa
5
310
Taming Xcode by Jay Thrash
trianglecocoa
3
140
Other Decks in Programming
See All in Programming
サーバーサイドのビルド時間87倍高速化
plaidtech
PRO
0
720
rage against annotate_predecessor
junk0612
0
160
AIを活用し、今後に備えるための技術知識 / Basic Knowledge to Utilize AI
kishida
20
5.2k
MCPとデザインシステムに立脚したデザインと実装の融合
yukukotani
4
1.4k
はじめてのMaterial3 Expressive
ym223
2
170
AIコーディングAgentとの向き合い方
eycjur
0
260
ソフトウェアテスト徹底指南書の紹介
goyoki
1
150
開発チーム・開発組織の設計改善スキルの向上
masuda220
PRO
19
10k
Putting The Genie in the Bottle - A Crash Course on running LLMs on Android
iurysza
0
130
Microsoft Orleans, Daprのアクターモデルを使い効率的に開発、デプロイを行うためのSekibanの試行錯誤 / Sekiban: Exploring Efficient Development and Deployment with Microsoft Orleans and Dapr Actor Models
tomohisa
0
240
Ruby×iOSアプリ開発 ~共に歩んだエコシステムの物語~
temoki
0
270
MCPで実現するAIエージェント駆動のNext.jsアプリデバッグ手法
nyatinte
7
1.1k
Featured
See All Featured
Optimising Largest Contentful Paint
csswizardry
37
3.4k
Practical Tips for Bootstrapping Information Extraction Pipelines
honnibal
PRO
23
1.4k
Being A Developer After 40
akosma
90
590k
Helping Users Find Their Own Way: Creating Modern Search Experiences
danielanewman
29
2.9k
The Invisible Side of Design
smashingmag
301
51k
Creating an realtime collaboration tool: Agile Flush - .NET Oxford
marcduiker
31
2.2k
ReactJS: Keep Simple. Everything can be a component!
pedronauck
667
120k
A Tale of Four Properties
chriscoyier
160
23k
Intergalactic Javascript Robots from Outer Space
tanoku
272
27k
Sharpening the Axe: The Primacy of Toolmaking
bcantrill
44
2.5k
How to train your dragon (web standard)
notwaldorf
96
6.2k
The World Runs on Bad Software
bkeepers
PRO
70
11k
Transcript
Multithreaded Drawing with core graphics Eric.Lanz @OrgBook.com
What you should do • Get an artist to make
all your graphics up front • Use tools like GraphicsMagick, OptiPng and PVRTC (OpenGL) • Use built in cache mechanisms • UIKit -> Core Animation -> OpenGL
What if you can’t • User defined image data at
run-time • Continuous animation responding to user interaction • Too much image data to pre-process and ship with the app
Know when to draw View Controllers Drawables Drawables Drawables Drawables
User Input • User triggers redraw • View controllers determine layout • Don’t directly call draw on a drawable
Synchronous Data API View Controllers Drawables Drawables Drawables Drawables Data
Controller User Input Core Data No Local Copy? Return a fake object while you wait for the API
Asynchronous Draw API View Controllers Drawables Drawables Drawables Drawables Data
Controller User Input Core Data Targeted NSNotifications: @”ObjectUpdate_XYZ”
Drawing Pipeline Render Controller Drawable • Drawable asks to be
drawn using some template • Entire operation contained in a block
Direct Draw Controller Drawable Direct Template Core Graphics Cache 1
Dispatch Serial Queue Draw Controller Drawable Dispatch_Serial Template Core Graphics
Cache 2 Create a serial dispatch queue, this will run one task at a time on a worker thread.
Dispatch Global Queue Draw Controller Drawable Dispatch_Global Template Core Graphics
Cache 3 Use the Global dispatch queue, this runs tasks concurrently on multiple worker threads.
All Together Now Draw Controller Drawable Dispatch_Global Template Core Graphics
Cache 3 Dispatch_Serial Template Core Graphics Cache 2 Direct Template Core Graphics Cache 1
Dispatch Serial Queue UIGraphicsPushContext(c); [[UIColor blackColor] setFill]; [@"Sample" drawInRect:CGRectMake(0, 4,
width, height) withFont:[UIFont fontWithName:@"Helvetica" size:fontSize] lineBreakMode:UILineBreakModeTailTruncation alignment:UITextAlignmentCenter]; UIGraphicsPopContext(); CGContextRelease(c); CGColorSpaceRelease(genericRGBColorspace); GLubyte *imageData = (GLubyte *) calloc(1, width * height * 4); CGColorSpaceRef genericRGBColorspace = CGColorSpaceCreateDeviceRGB(); CGContextRef c = CGBitmapContextCreate(imageData, width, height, 8, width * 4, genericRGBColorspace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst);
Dispatch Global CGContextScaleCTM(c, 1.0, -1.0); CGContextTranslateCTM(c, 0, -height); CGMutablePathRef circlePath
= CGPathCreateMutable(); CGPathAddEllipseInRect( circlePath , NULL , CGRectMake(1, 1, width-2, height-2) ); CGContextAddPath(c, circlePath); CGContextClip(c); UIImage * personImage = [UIImage imageWithContentsOfFile:path]; CGContextDrawImage(c, CGRectMake(0, 0, width, height), personImage.CGImage); CGContextRelease(c); CGColorSpaceRelease(genericRGBColorspace); GLubyte *imageData = (GLubyte *) calloc(1, width * height * 4); CGColorSpaceRef genericRGBColorspace = CGColorSpaceCreateDeviceRGB(); CGContextRef c = CGBitmapContextCreate(imageData, width, height, 8, width * 4, genericRGBColorspace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst);
Final Thoughts • No architecture is perfect • Maintain balance
• Make it easy to tweak • Don’t get lost in the details
Questions