SampleCIView.m

/*
     File: SampleCIView.m
 Abstract: Simple OpenGL based CoreImage view
  Version: 2.1
 
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 */
 
#import "SampleCIView.h"
 
#import <OpenGL/OpenGL.h>
#import <OpenGL/gl.h>
 
@interface SampleCIView (internalCalls)
 
- (BOOL)displaysWhenScreenProfileChanges;
- (void)viewWillMoveToWindow:(NSWindow*)newWindow;
- (void)displayProfileChanged:(NSNotification*)notification;
 
@end
 
 
@implementation SampleCIView
 
+ (NSOpenGLPixelFormat *)defaultPixelFormat
{
    static NSOpenGLPixelFormat *pf;
    
    if (pf == nil)
    {
        /* Making sure the context's pixel format doesn't have a recovery
         * renderer is important - otherwise CoreImage may not be able to
         * create deeper context's that share textures with this one. */
        
        static const NSOpenGLPixelFormatAttribute attr[] = {
            NSOpenGLPFAAccelerated,
            NSOpenGLPFANoRecovery,
            NSOpenGLPFAColorSize, 32,
#if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5
            NSOpenGLPFAAllowOfflineRenderers,  /* allow use of offline renderers               */
#endif
            0
        };
        
        pf = [[NSOpenGLPixelFormat alloc] initWithAttributes:(void *)&attr];
    }
    
    return pf;
}
 
- (void)dealloc
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];
    [_image release];
    [_contextOptions release];
    [_context release];
    
    [super dealloc];
}
 
- (void)setContextOptions:(NSMutableDictionary *)dict
{
    [_contextOptions release];
    _contextOptions = [dict retain];
    
    [_context release];
    _context = nil;
}
 
- (CIImage *)image
{
    return [[_image retain] autorelease];
}
 
- (void)setImage:(CIImage *)image dirtyRect:(CGRect)r
{
    if (_image != image)
    {
        [_image release];
        _image = [image retain];
        
        if (CGRectIsInfinite (r))
            [self setNeedsDisplay:YES];
        else
            [self setNeedsDisplayInRect:*(NSRect *)&r];
    }
}
 
- (void)setImage:(CIImage *)image
{
    [self setImage:image dirtyRect:CGRectInfinite];
}
 
- (void)prepareOpenGL
{
    GLint parm = 1;
    
    /* Enable beam-synced updates. */
    
    [[self openGLContext] setValues:&parm forParameter:NSOpenGLCPSwapInterval];
    
    /* Make sure that everything we don't need is disabled. Some of these
     * are enabled by default and can slow down rendering. */
    
    glDisable (GL_ALPHA_TEST);
    glDisable (GL_DEPTH_TEST);
    glDisable (GL_SCISSOR_TEST);
    glDisable (GL_BLEND);
    glDisable (GL_DITHER);
    glDisable (GL_CULL_FACE);
    glColorMask (GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
    glDepthMask (GL_FALSE);
    glStencilMask (0);
    glClearColor (0.0f, 0.0f, 0.0f, 0.0f);
    glHint (GL_TRANSFORM_HINT_APPLE, GL_FASTEST);
}
 
- (void)viewBoundsDidChange:(NSRect)bounds
{
    /* For subclasses. */
}
 
- (void)updateMatrices
{
    NSRect r = [self bounds];
    
    if (!NSEqualRects (r, _lastBounds))
    {
        [[self openGLContext] update];
        
        /* Install an orthographic projection matrix (no perspective)
         * with the origin in the bottom left and one unit equal to one
         * device pixel. */
        
        glViewport (0, 0, r.size.width, r.size.height);
        
        glMatrixMode (GL_PROJECTION);
        glLoadIdentity ();
        glOrtho (0, r.size.width, 0, r.size.height, -1, 1);
        
        glMatrixMode (GL_MODELVIEW);
        glLoadIdentity ();
        
        _lastBounds = r;
        
        [self viewBoundsDidChange:r];
    }
}
 
- (BOOL)displaysWhenScreenProfileChanges
{
    return YES;
}
 
- (void)viewWillMoveToWindow:(NSWindow*)newWindow
{
    NSNotificationCenter* center = [NSNotificationCenter defaultCenter];
    [center removeObserver:self name:NSWindowDidChangeScreenProfileNotification object:nil];
    [center addObserver:self selector:@selector(displayProfileChanged:) name:NSWindowDidChangeScreenProfileNotification object:newWindow];
    [center addObserver:self selector:@selector(displayProfileChanged:) name:NSWindowDidMoveNotification object:newWindow];
    
    // When using OpenGL, we should disable the window's "one-shot" feature
    [newWindow setOneShot:NO];
}
 
- (void)displayProfileChanged:(NSNotification*)notification
{
    CGDirectDisplayID oldDid = _did;
    _did = (CGDirectDisplayID)[[[[[self window] screen] deviceDescription] objectForKey:@"NSScreenNumber"] pointerValue];
    if(_did == oldDid)
        return;
    
    _cglContext = [[self openGLContext] CGLContextObj];
    
    if(_pf == nil)
    {
        _pf = [self pixelFormat];
        if (_pf == nil)
            _pf = [[self class] defaultPixelFormat];
        
    }
    CGLLockContext(_cglContext);
    {
        
        // Create a new CIContext using the new output color space      
        [_context release];
        
#if MAC_OS_X_VERSION_MAX_ALLOWED <= MAC_OS_X_VERSION_10_5
        CMProfileRef displayProfile = NULL;
        CGColorSpaceRef displayColorSpace = NULL;
        // Ask ColorSync for our current display's profile
        CMGetProfileByAVID((CMDisplayIDType)_did, &displayProfile);
        displayColorSpace = CGColorSpaceCreateWithPlatformColorSpace(displayProfile);
        CMCloseProfile(displayProfile);
 
        if(_contextOptions)
        {
            [_contextOptions setObject:(id)displayColorSpace forKey:kCIContextOutputColorSpace];
        } else {
            _contextOptions = [[NSMutableDictionary dictionaryWithObject:(id)displayColorSpace forKey:kCIContextOutputColorSpace] retain];
        }
        [_contextOptions setObject:[[NSUserDefaults standardUserDefaults] objectForKey:@"useSoftwareRenderer"] forKey:kCIContextUseSoftwareRenderer];
        
        _context = [[CIContext contextWithCGLContext:_cglContext pixelFormat:[_pf CGLPixelFormatObj] options:_contextOptions] retain];
        CGColorSpaceRelease(displayColorSpace);
#else       
        if(_contextOptions)
        {
            [_contextOptions setObject:[[NSUserDefaults standardUserDefaults] objectForKey:@"useSoftwareRenderer"] forKey:kCIContextUseSoftwareRenderer];
        } else {
            _contextOptions = [[NSMutableDictionary dictionaryWithObject:[[NSUserDefaults standardUserDefaults] objectForKey:@"useSoftwareRenderer"] forKey:kCIContextUseSoftwareRenderer] retain];
        }
        // For 10.6 onwards we use the new API but do not pass in a colorspace as. 
        // Since the cgl context will be rendered to the display, it is valid to rely on CI to get the colorspace from the context.
        _context = [[CIContext contextWithCGLContext:_cglContext pixelFormat:[_pf CGLPixelFormatObj] colorSpace:nil options:_contextOptions] retain];    
#endif
    }
    CGLUnlockContext(_cglContext);
    
}
 
 
- (void)drawRect:(NSRect)r
{
    CGRect ir, rr;
    CGImageRef cgImage;
    
    [[self openGLContext] makeCurrentContext];
    
    /* Allocate a CoreImage rendering context using the view's OpenGL
     * context as its destination if none already exists. */
    
    if (_context == nil)
        [self displayProfileChanged:nil];
    
    ir = CGRectIntegral (*(CGRect *)&r);
    
    if ([NSGraphicsContext currentContextDrawingToScreen])
    {
        [self updateMatrices];
        
        /* Clear the specified subrect of the OpenGL surface then
         * render the image into the view. Use the GL scissor test to
         * clip to * the subrect. Ask CoreImage to generate an extra
         * pixel in case * it has to interpolate (allow for hardware
         * inaccuracies) */
        
        rr = CGRectIntersection (CGRectInset (ir, -1.0f, -1.0f),
                                 *(CGRect *)&_lastBounds);
        
        glScissor (ir.origin.x, ir.origin.y, ir.size.width, ir.size.height);
        glEnable (GL_SCISSOR_TEST);
        
        glClear (GL_COLOR_BUFFER_BIT);
        
        if ([self respondsToSelector:@selector (drawRect:inCIContext:)])  // for subclasses to provide their own drawing method
        {
            [self drawRect:*(NSRect *)&rr inCIContext:_context];
        }
        else if (_image != nil)
        {
            [_context drawImage:_image inRect:rr fromRect:rr];
        }
        
        glDisable (GL_SCISSOR_TEST);
        
        /* Flush the OpenGL command stream. If the view is double
         * buffered this should be replaced by [[self openGLContext]
         * flushBuffer]. */
        
        glFlush ();
    }
    else
    {
        /* Printing the view contents. Render using CG, not OpenGL. */
        
        if ([self respondsToSelector:@selector (drawRect:inCIContext:)])
        {
            [self drawRect:*(NSRect *)&ir inCIContext:_context];
        }
        else if (_image != nil)
        {
            cgImage = [_context createCGImage:_image fromRect:ir format:kCIFormatRGBA16 colorSpace:nil];
            
            if (cgImage != NULL)
            {
                CGContextDrawImage ([[NSGraphicsContext currentContext]
                                     graphicsPort], ir, cgImage);
                CGImageRelease (cgImage);
            }
        }
    }
}
 
@end