IJSVG/source/IJSVGTransform.m

//
//  IJSVGTransform.m
//  IconJar
//
//  Created by Curtis Hard on 01/09/2014.
//  Copyright (c) 2014 Curtis Hard. All rights reserved.
//

#import "IJSVGTransform.h"

@implementation IJSVGTransform

@synthesize command;
@synthesize parameters;
@synthesize parameterCount;
@synthesize sort;

- (void)dealloc
{
    free(parameters);
    [super dealloc];
}

- (id)copyWithZone:(NSZone *)zone
{
    IJSVGTransform * trans = [[[self class] alloc] init];
    trans.command = self.command;
    trans.parameters = (CGFloat*)malloc(sizeof(CGFloat)*self.parameterCount);
    trans.sort = sort;
    trans.parameterCount = self.parameterCount;
    memcpy( trans.parameters, self.parameters, sizeof(CGFloat)*self.parameterCount);
    return trans;
}

- (void)recalculateWithBounds:(CGRect)bounds
{
    CGFloat max = bounds.size.width>bounds.size.height?bounds.size.width:bounds.size.height;
    switch (self.command) {
        case IJSVGTransformCommandRotate: {
            if( self.parameterCount == 1 )
                return;
            self.parameters[1] = self.parameters[1]*max;
            self.parameters[2] = self.parameters[2]*max;
        }
        default:
            return;
    }
}

+ (IJSVGTransformCommand)commandForCommandString:(NSString *)str
{
    if( [str isEqualToString:@"matrix"] )
        return IJSVGTransformCommandMatrix;
    if( [str isEqualToString:@"translate"] )
        return IJSVGTransformCommandTranslate;
    if( [str isEqualToString:@"scale"] )
        return IJSVGTransformCommandScale;
    if( [str isEqualToString:@"rotate"] )
        return IJSVGTransformCommandRotate;
    return IJSVGTransformCommandNotImplemented;
}

+ (NSInteger)sortForTransformCommand:(IJSVGTransformCommand)command
{
    switch (command) {
        case IJSVGTransformCommandScale:
            return 0;
        case IJSVGTransformCommandRotate:
            return 1;
        case IJSVGTransformCommandMatrix:
            return 2;
        case IJSVGTransformCommandTranslate:
            return -1;
        default:
            return 10;
    }
    return 10;
}

+ (NSArray *)transformsForString:(NSString *)string
{
    static NSRegularExpression * _reg = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        _reg = [[NSRegularExpression alloc] initWithPattern:@"([a-zA-Z]+)\\((.*?)\\)"
                                                    options:0
                                                      error:nil];
    });
    NSMutableArray * transforms = [[[NSMutableArray alloc] init] autorelease];
    @autoreleasepool {
        [_reg enumerateMatchesInString:string
                               options:0
                                 range:NSMakeRange( 0, string.length )
                            usingBlock:^(NSTextCheckingResult *result, NSMatchingFlags flags, BOOL *stop)
        {
            NSString * command = [string substringWithRange:[result rangeAtIndex:1]];
            IJSVGTransformCommand commandType = [[self class] commandForCommandString:command];
            if( commandType == IJSVGTransformCommandNotImplemented )
                return;
            
            // create the transform
            NSString * params = [string substringWithRange:[result rangeAtIndex:2]];
            IJSVGTransform * transform = [[[[self class] alloc] init] autorelease];
            NSInteger count = 0;
            transform.command = commandType;
            transform.parameters = [IJSVGUtils commandParameters:params
                                                           count:&count];
            transform.parameterCount = count;
            transform.sort = [[self class] sortForTransformCommand:commandType];
            [transforms addObject:transform];
        }];
    }
    return transforms;
}

+ (NSBezierPath *)transformedPath:(IJSVGPath *)path
{
    if( path.transforms.count == 0 )
        return path.path;
    NSBezierPath * cop = [[path.path copy] autorelease];
    for( IJSVGTransform * transform in path.transforms )
    {
        NSAffineTransform * at = [NSAffineTransform transform];
        switch( transform.command )
        {
            // matrix
            case IJSVGTransformCommandMatrix: {
                at.transformStruct = (NSAffineTransformStruct) {
                    .m11 = transform.parameters[0],
                    .m12 = transform.parameters[1],
                    .m21 = transform.parameters[2],
                    .m22 = transform.parameters[3],
                    .tX = transform.parameters[4],
                    .tY = transform.parameters[5],
                };
                break;
            }
                
            // translate
            case IJSVGTransformCommandTranslate: {
                if( transform.parameterCount == 1 )
                    [at translateXBy:transform.parameters[0]
                                 yBy:0];
                else
                    [at translateXBy:transform.parameters[0]
                                 yBy:transform.parameters[1]];
                break;
            }
            
            // scale
            case IJSVGTransformCommandScale: {
                if( transform.parameterCount == 1 )
                    [at scaleBy:transform.parameters[0]];
                else
                    [at scaleXBy:transform.parameters[0]
                             yBy:transform.parameters[1]];
                break;
            }
                
            // rotate
            case IJSVGTransformCommandRotate: {
                if( transform.parameterCount == 1 )
                    [at rotateByDegrees:transform.parameters[0]];
                else {
                    CGFloat centerX = transform.parameters[1];
                    CGFloat centerY = transform.parameters[2];
                    CGFloat angle = transform.parameters[0]*(M_PI/180.f);
                    [at translateXBy:centerX
                                 yBy:centerY];
                    [at rotateByRadians:angle];
                    [at translateXBy:-1.f*centerX
                                 yBy:-1.f*centerY];
                }
                break;
            }
                
            // do nothing
            case IJSVGTransformCommandNotImplemented: {
                
            }
            
        }
        [cop transformUsingAffineTransform:at];
    }
    return cop;
}

+ (void)performTransform:(IJSVGTransform *)transform
               inContext:(CGContextRef)context
{
    switch( transform.command )
    {
        // matrix
        case IJSVGTransformCommandMatrix: {
            CGContextConcatCTM( context, CGAffineTransformMake( transform.parameters[0],
                                                               transform.parameters[1],
                                                               transform.parameters[2],
                                                               transform.parameters[3],
                                                               transform.parameters[4],
                                                               transform.parameters[5]));
            break;
        }
        
        // translate
        case IJSVGTransformCommandTranslate: {
            if( transform.parameterCount == 1 )
                CGContextTranslateCTM( context, transform.parameters[0], 0 );
            else
                CGContextTranslateCTM( context, transform.parameters[0], transform.parameters[1]);
            break;
        }
            
        // scale
        case IJSVGTransformCommandScale: {
            if( transform.parameterCount == 1 )
                CGContextScaleCTM( context, transform.parameters[0], transform.parameters[0] );
            else
                CGContextScaleCTM( context, transform.parameters[0], transform.parameters[1] );
            break;
        }
            
        // rotate
        case IJSVGTransformCommandRotate: {
            // these are in radians, not degrees
            if( transform.parameterCount == 1 )
            {
                CGContextRotateCTM( context, (transform.parameters[0] / 180) * M_PI);
            } else {
                // need support for rotate around a point
                CGFloat centerX = transform.parameters[1];
                CGFloat centerY = transform.parameters[2];
                CGFloat angle = transform.parameters[0]*(M_PI/180.f);
                CGContextTranslateCTM(context, centerX, centerY);
                CGContextRotateCTM(context, angle);
                CGContextTranslateCTM(context, -1.f*centerX, -1.f*centerY);
            }
        }
            
        // do nothing
        case IJSVGTransformCommandNotImplemented: {
            
        }
    }
    
}

- (CGAffineTransform)CGAffineTransform
{
    return [self CGAffineTransformWithModifier:nil];
}

- (CGAffineTransform)CGAffineTransformWithModifier:(IJSVGTransformParameterModifier)modifier
{
    switch(self.command)
    {
        // matrix
        case IJSVGTransformCommandMatrix: {
            CGFloat p0 = self.parameters[0];
            CGFloat p1 = self.parameters[1];
            CGFloat p2 = self.parameters[2];
            CGFloat p3 = self.parameters[3];
            CGFloat p4 = self.parameters[4];
            CGFloat p5 = self.parameters[5];
            if(modifier != nil)
            {
                p0 = modifier(0,p0);
                p1 = modifier(1,p1);
                p2 = modifier(2,p2);
                p3 = modifier(2,p3);
                p4 = modifier(2,p4);
                p5 = modifier(2,p5);
            }
            return CGAffineTransformMake(p0, p1, p2, p3, p4, p5);
        }
            
        // translate
        case IJSVGTransformCommandTranslate: {
            CGFloat p0 = self.parameters[0];
            CGFloat p1 = self.parameters[1];
            if(modifier != nil)
            {
                p0 = modifier(0,p0);
                p1 = modifier(1,p1);
            }
            if(self.parameterCount == 1)
                return CGAffineTransformMakeTranslation( p0, 0 );
            return CGAffineTransformMakeTranslation(p0, p1);
        }
            
        // scale
        case IJSVGTransformCommandScale: {
            CGFloat p0 = self.parameters[0];
            CGFloat p1 = self.parameters[1];
            if(modifier != nil)
            {
                p0 = modifier(0,p0);
                p1 = modifier(1,p1);
            }
            if(self.parameterCount == 1)
                return CGAffineTransformMakeScale( p0, p0);
            return CGAffineTransformMakeScale( p0, p1);
        }
        
        // rotate
        case IJSVGTransformCommandRotate: {
            if(self.parameterCount == 1)
                return CGAffineTransformMakeRotation((self.parameters[0]/180) * M_PI);
            else {
                CGFloat p0 = self.parameters[0];
                CGFloat p1 = self.parameters[1];
                CGFloat p2 = self.parameters[2];
                if(modifier != nil)
                {
                    p0 = modifier(0,p0);
                    p1 = modifier(1,p1);
                    p2 = modifier(2,p2);
                }
                CGFloat angle = p0*(M_PI/180.f);
                CGAffineTransform def = CGAffineTransformIdentity;
                def = CGAffineTransformTranslate(def, p1, p2);
                def = CGAffineTransformRotate(def, angle);
                def = CGAffineTransformTranslate(def, -1.f*p1, -1.f*p2);
                return def;
            }
            break;
        }
            
        // do nothing
        case IJSVGTransformCommandNotImplemented: {
            return CGAffineTransformIdentity;
        }
    }
    return CGAffineTransformIdentity;
}

@end