/* SampleCIView.m - simple OpenGL based CoreImage view 
 
 Version: 1.1
 
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 original Apple software (the "Apple Software"), 
 to use, reproduce, modify and redistribute the 
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 The Apple Software is provided by Apple on an "AS 
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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:(NSDictionary *)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 atPoint:rr.origin 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
