/*

File: Piece.m

Abstract: A playing piece. A concrete subclass of Bit that displays an image..

Version: 1.0

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*/

#import "Piece.h"

#import "QuartzUtils.h"

/**  WARNING: THIS CODE REQUIRES GARBAGE COLLECTION!

 **  This sample application uses Objective-C 2.0 garbage collection.

 **  Therefore, the source code in this file does NOT perform manual object memory management.

 **  If you reuse any of this code in a process that isn't garbage collected, you will need to

 **  add all necessary retain/release/autorelease calls, and implement -dealloc methods,

 **  otherwise unpleasant leakage will occur!

 **/

@implementation Piece

- (id) initWithImageNamed: (NSString*)imageName

                    scale: (CGFloat)scale

{

    self = [super init];

    if (self != nil) {

        _imageName = imageName;

        [self setImage: GetCGImageNamed(imageName) scale: scale];

        self.zPosition = kPieceZ;

    }

    return self;

}

- (id) initWithCoder: (NSCoder*)decoder

{

    self = [super initWithCoder: decoder];

    if( self ) {

        _imageName = [decoder decodeObjectForKey: @"imageName"];

        // (actual image (self.contents) was already restord by superclass)

    }

    return self;

}

- (void) encodeWithCoder: (NSCoder*)coder

{

    [super encodeWithCoder: coder];

    [coder encodeObject: _imageName forKey: @"imageName"];

}

- (NSString*) description

{

    return [NSString stringWithFormat: @"%@[%@]", 

            [self class],

            _imageName.lastPathComponent.stringByDeletingPathExtension];

}

@synthesize imageName=_imageName;

- (void) setImage: (CGImageRef)image scale: (CGFloat)scale

{

    self.contents = (id) image;

    self.contentsGravity = @"resize";

    self.minificationFilter = kCAFilterLinear;

    int width = CGImageGetWidth(image), height = CGImageGetHeight(image);

    if( scale > 0 ) {

        if( scale >= 4.0 )

            scale /= MAX(width,height);             // interpret scale as target dimensions

        width = ceil( width * scale);

        height= ceil( height* scale);

    }

    self.bounds = CGRectMake(0,0,width,height);

    _imageName = nil;

}

- (void) setImage: (CGImageRef)image

{

    CGSize size = self.bounds.size;

    [self setImage: image scale: MAX(size.width,size.height)];

}

- (void) setImageNamed: (NSString*)name

{

    [self setImage: GetCGImageNamed(name)];

    _imageName = name;

}

- (BOOL)containsPoint:(CGPoint)p

{

    // Overrides CGLayer's implementation,

    // returning YES only for pixels at which this layer's alpha is at least 0.5.

    // This takes into account the opacity, bg color, and background image's alpha channel.

    if( ! [super containsPoint: p] )

        return NO;

    float opacity = self.opacity;

    if( opacity < 0.5 )

        return NO;

    float thresholdAlpha = 0.5 / self.opacity;

    CGColorRef bg = self.backgroundColor;

    float alpha = bg ?CGColorGetAlpha(bg) :0.0;

    if( alpha < thresholdAlpha ) {

        CGImageRef image = (CGImageRef)self.contents;

        if( image ) {

            // Note: This makes the convenient assumption that the image entirely fills the bounds.

            alpha = MAX(alpha, GetPixelAlpha(image, self.bounds.size, p));

        }

    }

    return alpha >= thresholdAlpha;

}

@end