QuartzComposerWithinScreenSaverView

Hi There…

I’m trying to create a ScreenSaver with the screensaver template in XCode. This is my first attempt at an app, so any help would be greatly appreciated.

I keep getting the error “invalid drawable” on the console when I run the saver. Any ideas?

Here’s the code I’ve got so far:

@implementation ScreenTest2View

(id)initWithFrame:(NSRect)frame isPreview:(BOOL)isPreview { self = [super initWithFrame:frame isPreview:isPreview]; if (self) {
```
   [self setAnimationTimeInterval:1/30.0];
```
NSOpenGLPixelFormatAttribute attributes[] = {
```
                                  NSOpenGLPFADoubleBuffer,
                                  NSOpenGLPFAAccelerated,
                                  NSOpenGLPFADepthSize, 24,
                                  (NSOpenGLPixelFormatAttribute) 0
                                  };
```
NSOpenGLPixelFormat* format = [[[NSOpenGLPixelFormat alloc] initWithAttributes:attributes] autorelease]; _openGLContext = [[NSOpenGLContext alloc] initWithFormat:format shareContext:nil];

if(_openGLContext == nil) { NSLog(@”Cannot create OpenGL context”); [NSApp terminate:nil]; }

self openGLContext] makeCurrentContext]; [_openGLContext setView: self];

_filePath = [[[[NSBundle mainBundle] pathForResource:@”particles” ofType:@”qtz”]; _renderer = [[QCRenderer alloc] initWithOpenGLContext:_openGLContext pixelFormat:format file:_filePath]; if(_renderer == nil) { NSLog(@”Cannot create QCRenderer”); [NSApp terminate:nil]; }

//Create a timer which will regularly call our rendering method _renderTimer = [[NSTimer scheduledTimerWithTimeInterval:(1.0 / (NSTimeInterval)kRendererFPS) target:self selector:@selector(_render:) userInfo:nil repeats:YES] retain]; if(_renderTimer == nil) { NSLog(@”Cannot create NSTimer”); [NSApp terminate:nil]; }

}

return self; }
(void) renderWithEvent:(NSEvent)event { NSTimeInterval time = [NSDate timeIntervalSinceReferenceDate]; NSPoint mouseLocation; NSMutableDictionary arguments;

//Let’s compute our local time if(_startTime == 0) { _startTime = time; time = 0; } else time -= _startTime;

_screenSize.width = CGDisplayPixelsWide(kCGDirectMainDisplay); _screenSize.height = CGDisplayPixelsHigh(kCGDirectMainDisplay);

//We setup the arguments to pass to the composition (normalized mouse coordinates and an optional event) mouseLocation = [NSEvent mouseLocation]; mouseLocation.x /= _screenSize.width; mouseLocation.y /= _screenSize.height; arguments = [NSMutableDictionary dictionaryWithObject:[NSValue valueWithPoint:mouseLocation] forKey:QCRendererMouseLocationKey]; if(event) [arguments setObject:event forKey:QCRendererEventKey];

//Render a frame if(![_renderer renderAtTime:time arguments:arguments]) NSLog(@”Rendering failed at time %.3fs”, time);

//Flush the OpenGL context to display the frame on screen [_openGLContext flushBuffer]; }
(void) _render:(NSTimer*)timer { //Simply call our rendering method, passing no event to the composition [self renderWithEvent:nil]; }
(void) sendEvent:(NSEvent*)event { [super sendEvent:event];

//If the renderer is active and we have a meaningful event, render immediately passing that event to the composition if(_renderer && (NSEventMaskFromType([event type]) & kRendererEventMask)) [self renderWithEvent:event];

}

Again, any help would be greatly appreciated. I know I’m missing something simple here, but I can’t seem to figure it out.

Thanks, Alexandre

Why not just add a QCView as a subview? ScreenSaverViews are NSViews and as such you have the full set of view machinery available to you.

Ok, I did what you suggested… however it can’t seem to load my composition. It’s in the resources folder and everything, so I don’t understand why it’s having a problem. Here’s the code… again, help is greatly appreciated.

#import “ScreenTest4View.h”

@implementation ScreenTest4View

(id)initWithFrame:(NSRect)frame isPreview:(BOOL)isPreview { self = [super initWithFrame:frame isPreview:isPreview]; if (self) {

  qcView = [[QCView alloc] init];
  
  if (!qcView) {
      NSLog(@"could not make qc view");
      }
		
    [qcView setAutostartsRendering:YES]; 
	
  // am i missing something here??
  if ([qcView loadCompositionFromFile:[[NSBundle mainBundle] pathForResource:@"particles" ofType:@"qtz"]] == NO) {
		
		
          NSLog(@"could not load");
          }
	
  // set values for all input keys
	
	
  // ...
  [qcView setFrame:[self bounds]];
  [self addSubview:qcView];
	
  [self setAnimationTimeInterval:1/30.0];
	
  if ([qcView isRendering] == YES) {
  NSLog(@"no rendering");
  }

} return self; }

(void)startAnimation { [super startAnimation]; }
(void)stopAnimation { [super stopAnimation]; }
(void)drawRect:(NSRect)rect { [super drawRect:rect]; }
(void)animateOneFrame {

return; }
(BOOL)hasConfigureSheet { return NO; }
(NSWindow*)configureSheet { return nil; }

@end

When you’re a screensaver, you’re a plugin. As such, [NSBundle mainBundle] is not you, it is whatever app loaded you.

A bit of quality time spent with the debugger and NSLog would answer your question.

Thanks so much. I figured it out..

CocoaDev