/*

File: QuartzUtils.m

Abstract: Assorted CoreGraphics / Core Animation utility functions.

Version: 1.0

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*/

#import "QuartzUtils.h"

CGColorRef kBlackColor, kWhiteColor, 

           kTranslucentGrayColor, kTranslucentLightGrayColor,

           kAlmostInvisibleWhiteColor,

           kHighlightColor;

__attribute__((constructor))        // Makes this function run when the app loads

static void InitQuartzUtils()

{

    kBlackColor = CGColorCreateGenericGray(0.0, 1.0);

    kWhiteColor = CGColorCreateGenericGray(1.0, 1.0);

    kTranslucentGrayColor = CGColorCreateGenericGray(0.0, 0.5);

    kTranslucentLightGrayColor = CGColorCreateGenericGray(0.0, 0.25);

    kAlmostInvisibleWhiteColor = CGColorCreateGenericGray(1, 0.05);

    kHighlightColor = CGColorCreateGenericRGB(1, 1, 0, 0.5);

}

void ChangeSuperlayer( CALayer *layer, CALayer *newSuperlayer, int index )

{

    // Disable actions, else the layer will move to the wrong place and then back!

    [CATransaction flush];

    [CATransaction begin];

    [CATransaction setValue:(id)kCFBooleanTrue

                     forKey:kCATransactionDisableActions];

    CGPoint pos = [newSuperlayer convertPoint: layer.position 

                      fromLayer: layer.superlayer];

    [layer removeFromSuperlayer];

    if( index >= 0 )

        [newSuperlayer insertSublayer: layer atIndex: index];

    else

        [newSuperlayer addSublayer: layer];

    layer.position = pos;

    [CATransaction commit];

}

void RemoveImmediately( CALayer *layer )

{

    [CATransaction flush];

    [CATransaction begin];

    [CATransaction setValue:(id)kCFBooleanTrue

                     forKey:kCATransactionDisableActions];

    [layer removeFromSuperlayer];

    [CATransaction commit];

}    

CATextLayer* AddTextLayer( CALayer *superlayer,

                           NSString *text, NSFont* font,

                           enum CAAutoresizingMask align )

{

    CATextLayer *label = [[CATextLayer alloc] init];

    label.string = text;

    label.font = font;

    label.fontSize = font.pointSize;

    label.foregroundColor = kBlackColor;

    NSString *mode;

    if( align & kCALayerWidthSizable )

        mode = @"center";

    else if( align & kCALayerMinXMargin )

        mode = @"right";

    else

        mode = @"left";

    align |= kCALayerWidthSizable;

    label.alignmentMode = mode;

    CGFloat inset = superlayer.borderWidth + 3;

    CGRect bounds = CGRectInset(superlayer.bounds, inset, inset);

    CGFloat height = font.ascender;

    CGFloat y = bounds.origin.y;

    if( align & kCALayerHeightSizable )

        y += (bounds.size.height-height)/2.0;

    else if( align & kCALayerMinYMargin )

        y += bounds.size.height - height;

    align &= ~kCALayerHeightSizable;

    label.bounds = CGRectMake(0, font.descender,

                              bounds.size.width, height - font.descender);

    label.position = CGPointMake(bounds.origin.x,y+font.descender);

    label.anchorPoint = CGPointMake(0,0);

    label.autoresizingMask = align;

    [superlayer addSublayer: label];

    return label;

}

CGImageRef CreateCGImageFromFile( NSString *path )

{

    CGImageRef image = NULL;

    CFURLRef url = (CFURLRef) [NSURL fileURLWithPath: path];

    CGImageSourceRef src = CGImageSourceCreateWithURL(url, NULL);

    if( src ) {

        image = CGImageSourceCreateImageAtIndex(src, 0, NULL);

        CFRelease(src);

        if(!image) NSLog(@"Warning: CGImageSourceCreateImageAtIndex failed on file %@ (ptr size=%u)",path,sizeof(void*));

    }

    return image;

}

CGImageRef GetCGImageNamed( NSString *name )

{

    // For efficiency, loaded images are cached in a dictionary by name.

    static NSMutableDictionary *sMap;

    if( ! sMap )

        sMap = [[NSMutableDictionary alloc] init];

    CGImageRef image = (CGImageRef) [sMap objectForKey: name];

    if( ! image ) {

        // Hasn't been cached yet, so load it:

        NSString *path;

        if( [name hasPrefix: @"/"] )

            path = name;

        else {

            path = [[NSBundle mainBundle] pathForResource: name ofType: nil];

            NSCAssert1(path,@"Couldn't find bundle image resource '%@'",name);

        }

        image = CreateCGImageFromFile(path);

        NSCAssert1(image,@"Failed to load image from %@",path);

        [sMap setObject: (id)image forKey: name];

    }

    return image;

}

CGColorRef GetCGPatternNamed( NSString *name )         // can be resource name or abs. path

{

    // For efficiency, loaded patterns are cached in a dictionary by name.

    static NSMutableDictionary *sMap;

    if( ! sMap )

        sMap = [[NSMutableDictionary alloc] init];

    CGColorRef pattern = (CGColorRef) [sMap objectForKey: name];

    if( ! pattern ) {

        pattern = CreatePatternColor( GetCGImageNamed(name) );

        [sMap setObject: (id)pattern forKey: name];

    }

    return pattern;

}

CGImageRef GetCGImageFromPasteboard( NSPasteboard *pb )

{

    CGImageSourceRef src = NULL;

    NSArray *paths = [pb propertyListForType: NSFilenamesPboardType];

    if( paths.count==1 ) {

        // If a file is being dragged, read it:

        CFURLRef url = (CFURLRef) [NSURL fileURLWithPath: [paths objectAtIndex: 0]];

        src = CGImageSourceCreateWithURL(url, NULL);

    } else {

        // Else look for an image type:

        NSString *type = [pb availableTypeFromArray: [NSImage imageUnfilteredPasteboardTypes]];

        if( type ) {

            NSData *data = [pb dataForType: type];

            src = CGImageSourceCreateWithData((CFDataRef)data, NULL);

        }

    }

    if(src) {

        CGImageRef image = CGImageSourceCreateImageAtIndex(src, 0, NULL);

        CFRelease(src);

        return image;

    } else

        return NULL;

}    

float GetPixelAlpha( CGImageRef image, CGSize imageSize, CGPoint pt )

{

    // Trivial reject:

    if( pt.x<0 || pt.x>=imageSize.width || pt.y<0 || pt.y>=imageSize.height )

        return 0.0;

    // sTinyContext is a 1x1 CGBitmapContext whose pixmap stores only alpha.

    static UInt8 sPixel[1];

    static CGContextRef sTinyContext;

    if( ! sTinyContext ) {

        sTinyContext = CGBitmapContextCreate(sPixel, 1, 1, 

                                             8, 1,     // bpp, rowBytes

                                             NULL,

                                             kCGImageAlphaOnly);

        CGContextSetBlendMode(sTinyContext, kCGBlendModeCopy);

    }

    // Draw the image into sTinyContext, positioned so the desired point is at

    // (0,0), then examine the alpha value in the pixmap:

    CGContextDrawImage(sTinyContext, 

                       CGRectMake(-pt.x,-pt.y, imageSize.width,imageSize.height),

                       image);

    return sPixel[0] / 255.0;

}

#pragma mark -

#pragma mark PATTERNS:

// callback for CreateImagePattern.

static void drawPatternImage (void *info, CGContextRef ctx)

{

    CGImageRef image = (CGImageRef) info;

    CGContextDrawImage(ctx, 

                       CGRectMake(0,0, CGImageGetWidth(image),CGImageGetHeight(image)),

                       image);

}

// callback for CreateImagePattern.

static void releasePatternImage( void *info )

{

    CGImageRelease( (CGImageRef)info );

}

CGPatternRef CreateImagePattern( CGImageRef image )

{

    NSCParameterAssert(image);

    int width = CGImageGetWidth(image);

    int height = CGImageGetHeight(image);

    static const CGPatternCallbacks callbacks = {0, &drawPatternImage, &releasePatternImage};

    return CGPatternCreate (image,

                            CGRectMake (0, 0, width, height),

                            CGAffineTransformMake (1, 0, 0, 1, 0, 0),

                            width,

                            height,

                            kCGPatternTilingConstantSpacing,

                            true,

                            &callbacks);

}

CGColorRef CreatePatternColor( CGImageRef image )

{

    CGPatternRef pattern = CreateImagePattern(image);

    CGColorSpaceRef space = CGColorSpaceCreatePattern(NULL);

    CGFloat components[1] = {1.0};

    CGColorRef color = CGColorCreateWithPattern(space, pattern, components);

    CGColorSpaceRelease(space);

    CGPatternRelease(pattern);

    return color;

}