问题
I am having a problem with a slight delay (lag) when transitioning from one SKScene to another. By commenting out various bit of code I have narrowed this down to SKLabelNode, my guess is thats its loading / caching the font when called which is resulting in a small delay/stutter when stating up the new SKScene.
Has anyone else noticed this, its less obvious when your just using a single SKScene (like the default template) as the slowdown just gets lost in the usual startup delay. Does anyone know a way round this, is there a way to pre-load the font? I guess I could load the font on the UIViewController at startup and see if I could access it from with the SKScene, anyone any ideas?
-(id)initWithSize:(CGSize)size {
if (self = [super initWithSize:size]) {
[self setScore:0];
[self setBackgroundColor:[SKColor blackColor]];
SKLabelNode *labelNode = [SKLabelNode labelNodeWithFontNamed:@"System"];
[labelNode setText:@"00000"];
[labelNode setFontSize:20.0];
[labelNode setPosition:CGPointMake(CGRectGetMidX(self.frame),500)];
[labelNode setName:@"SCORE"];
[labelNode setAlpha:1.0];
[self addChild:labelNode];
[self setScoreLabel:labelNode];
...
回答1:
The delay is based on the loading of your font. Best to preload fonts, sounds, and any other assets you intend to use, so that you don't have a delay when it's actually used the first time.
You can preload in your setup with :
SKLabelNode *preload = [SKLabelNode labelNodeWithFontNamed:@"System"];
[preload setText:@"anything"];
As noted in the comments, preloading is only needed when using a font that is not available via iOS.
回答2:
One thing I've noticed is that if you don't use a "real" font name when you create a SKLabelNode, you get the delay you mentioned. Since "System" is not an actual font name, you're experiencing the delay. Try choosing one of the actual fonts as listed by the system. (For example, try "HelveticaNeue" instead of "System".)
回答3:
The usual pre-load trick is to create a "dummy" version of the asset in your app delegate, which should effectively cache the custom font in your case at runtime. This will also help pinpoint if this is the real issue or not - there are many ways that stutters are introduced that are tough to efficiently track down in Sprite Kit.
回答4:
I had a delay in SKScene rendering because I was using multiple UIViewControllers to navigate through my app rather than having a single UIViewController whose view is an SKView; found the answer here. As soon as I refactored my code to use a single UIViewController transitioning between SKScenes became seamless.
If this is not your issue, maybe you could instantiate your SKScenes when your view loads and do any update to the scene's content just before you transition and present the scene.
回答5:
Be careful you aren't loading the entire font family. If I load "Chalkboard SE" it will take 4-6 seconds, and appear to work.
But if I load ChalkboardSE-Regular , it's virtually instantaneous ~100ms or less.
Here's a list of the actual font names you should use: AcademyEngravedLetPlain
AlNile-Bold
AlNile
AmericanTypewriter-Light
AmericanTypewriter-CondensedLight
AmericanTypewriter-CondensedBold
AmericanTypewriter
AmericanTypewriter-Condensed
AmericanTypewriter-Bold
AppleColorEmoji
AppleSDGothicNeo-Thin
AppleSDGothicNeo-UltraLight
AppleSDGothicNeo-SemiBold
AppleSDGothicNeo-Medium
AppleSDGothicNeo-Regular
AppleSDGothicNeo-Bold
AppleSDGothicNeo-Light
ArialMT
Arial-BoldItalicMT
Arial-ItalicMT
Arial-BoldMT
ArialHebrew-Bold
ArialHebrew-Light
ArialHebrew
ArialRoundedMTBold
Avenir-Heavy
Avenir-Oblique
Avenir-Black
Avenir-Book
Avenir-BlackOblique
Avenir-HeavyOblique
Avenir-Light
Avenir-MediumOblique
Avenir-Medium
Avenir-LightOblique
Avenir-Roman
Avenir-BookOblique
AvenirNext-MediumItalic
AvenirNext-Bold
AvenirNext-UltraLight
AvenirNext-DemiBold
AvenirNext-HeavyItalic
AvenirNext-Heavy
AvenirNext-Medium
AvenirNext-Italic
AvenirNext-UltraLightItalic
AvenirNext-BoldItalic
AvenirNext-Regular
AvenirNext-DemiBoldItalic
AvenirNextCondensed-Regular
AvenirNextCondensed-MediumItalic
AvenirNextCondensed-UltraLightItalic
AvenirNextCondensed-UltraLight
AvenirNextCondensed-BoldItalic
AvenirNextCondensed-Italic
AvenirNextCondensed-Medium
AvenirNextCondensed-HeavyItalic
AvenirNextCondensed-Heavy
AvenirNextCondensed-DemiBoldItalic
AvenirNextCondensed-DemiBold
AvenirNextCondensed-Bold
BanglaSangamMN
BanglaSangamMN-Bold
Baskerville-Bold
Baskerville-SemiBoldItalic
Baskerville-BoldItalic
Baskerville
Baskerville-SemiBold
Baskerville-Italic
BodoniSvtyTwoITCTT-Book
BodoniSvtyTwoITCTT-Bold
BodoniSvtyTwoITCTT-BookIta
BodoniSvtyTwoOSITCTT-BookIt
BodoniSvtyTwoOSITCTT-Bold
BodoniSvtyTwoOSITCTT-Book
BodoniSvtyTwoSCITCTT-Book
BodoniOrnamentsITCTT
BradleyHandITCTT-Bold
ChalkboardSE-Light
ChalkboardSE-Regular
ChalkboardSE-Bold
Chalkduster
Cochin-Bold
Cochin-BoldItalic
Cochin-Italic
Cochin
Copperplate
Copperplate-Light
Copperplate-Bold
Courier
Courier-Oblique
Courier-BoldOblique
Courier-Bold
CourierNewPSMT
CourierNewPS-BoldMT
CourierNewPS-ItalicMT
CourierNewPS-BoldItalicMT
DamascusBold
Damascus
DamascusLight
DamascusMedium
DamascusSemiBold
DevanagariSangamMN
DevanagariSangamMN-Bold
Didot-Bold
Didot-Italic
Didot
DINAlternate-Bold
DINCondensed-Bold
EuphemiaUCAS
EuphemiaUCAS-Bold
EuphemiaUCAS-Italic
Farah
Futura-Medium
Futura-CondensedMedium
Futura-MediumItalic
Futura-CondensedExtraBold
GeezaPro-Bold
GeezaPro
Georgia-BoldItalic
Georgia-Bold
Georgia-Italic
Georgia
GillSans
GillSans-Italic
GillSans-BoldItalic
GillSans-Light
GillSans-LightItalic
GillSans-Bold
GujaratiSangamMN-Bold
GujaratiSangamMN
GurmukhiMN-Bold
GurmukhiMN
STHeitiSC-Medium
STHeitiSC-Light
STHeitiTC-Medium
STHeitiTC-Light
Helvetica-Oblique
Helvetica-Light
Helvetica-Bold
Helvetica
Helvetica-BoldOblique
Helvetica-LightOblique
HelveticaNeue-BoldItalic
HelveticaNeue-Light
HelveticaNeue-Italic
HelveticaNeue-UltraLightItalic
HelveticaNeue-CondensedBold
HelveticaNeue-MediumItalic
HelveticaNeue-Thin
HelveticaNeue-Medium
HelveticaNeue-ThinItalic
HelveticaNeue-LightItalic
HelveticaNeue-UltraLight
HelveticaNeue-Bold
HelveticaNeue
HelveticaNeue-CondensedBlack
HiraKakuProN-W6
HiraKakuProN-W3
HiraMinProN-W6
HiraMinProN-W3
HoeflerText-Regular
HoeflerText-BlackItalic
HoeflerText-Italic
HoeflerText-Black
IowanOldStyle-Bold
IowanOldStyle-BoldItalic
IowanOldStyle-Italic
IowanOldStyle-Roman
Kailasa
Kailasa-Bold
KannadaSangamMN
KannadaSangamMN-Bold
KhmerSangamMN
KohinoorDevanagari-Light
KohinoorDevanagari-Book
KohinoorDevanagari-Medium
LaoSangamMN
MalayalamSangamMN
MalayalamSangamMN-Bold
Marion-Regular
Marion-Italic
Marion-Bold
MarkerFelt-Thin
MarkerFelt-Wide
Menlo-BoldItalic
Menlo-Regular
Menlo-Bold
Menlo-Italic
DiwanMishafi
Noteworthy-Bold
Noteworthy-Light
Optima-Regular
Optima-Italic
Optima-Bold
Optima-BoldItalic
Optima-ExtraBlack
OriyaSangamMN
OriyaSangamMN-Bold
Palatino-Roman
Palatino-Italic
Palatino-Bold
Palatino-BoldItalic
Papyrus-Condensed
Papyrus
PartyLetPlain
SavoyeLetPlain
SinhalaSangamMN
SinhalaSangamMN-Bold
SnellRoundhand-Black
SnellRoundhand-Bold
SnellRoundhand
Superclarendon-Regular
Superclarendon-BoldItalic
Superclarendon-Light
Superclarendon-BlackItalic
Superclarendon-Italic
Superclarendon-LightItalic
Superclarendon-Bold
Superclarendon-Black
Symbol
TamilSangamMN
TamilSangamMN-Bold
TeluguSangamMN
TeluguSangamMN-Bold
Thonburi-Bold
Thonburi
Thonburi-Light
TimesNewRomanPS-BoldItalicMT
TimesNewRomanPSMT
TimesNewRomanPS-BoldMT
TimesNewRomanPS-ItalicMT
Trebuchet-BoldItalic
TrebuchetMS
TrebuchetMS-Bold
TrebuchetMS-Italic
Verdana-BoldItalic
Verdana-Italic
Verdana
Verdana-Bold
ZapfDingbatsITC
Zapfino
See https://gilesey.wordpress.com/2015/01/14/ios-spritekit-font-loading-times-of-sklabelnodes/
回答6:
I added this method in my "AppDelegate.m":
- (void)setupFonts
{
SKLabelNode *preloadFontLabel = [SKLabelNode labelNodeWithFontNamed:@"cinnamonCake"];
[preloadFontLabel setText:@"Preload"];
}
and called it in:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
[self setupFonts];
return YES;
}
The app didn't load any slower and it worked in the whole app flawlessly. Found the answer here: SKLabelNode delays app start
来源：https://stackoverflow.com/questions/20380954/delay-when-calling-sklabelnode