IJSVG/source/IJSVGUtils.m

//
//  IJSVGUtils.m
//  IconJar
//
//  Created by Curtis Hard on 30/08/2014.
//  Copyright (c) 2014 Curtis Hard. All rights reserved.
//

#import "IJSVGUtils.h"

@implementation IJSVGUtils

CGFloat angle( CGPoint a, CGPoint b ) {
    return [IJSVGUtils angleBetweenPointA:a
                                   pointb:b];
}

CGFloat ratio( CGPoint a, CGPoint b ) {
    return (a.x * b.x + a.y * b.y) / (magnitude(a) * magnitude(b));
}

CGFloat magnitude(CGPoint point)
{
    return sqrtf(powf(point.x, 2) + powf(point.y, 2));
}

CGFloat radians_to_degrees(CGFloat radians)
{
    return ((radians) * (180.0 / M_PI));
}

CGFloat degrees_to_radians( CGFloat degrees )
{
    return ( ( degrees ) / 180.0 * M_PI );
}

+ (IJSVGCommandType)typeForCommandString:(NSString *)string
{
    return [string isEqualToString:[string uppercaseString]] ? IJSVGCommandTypeAbsolute : IJSVGCommandTypeRelative;
}

+ (NSString *)defURL:(NSString *)string
{
    static NSRegularExpression * _reg = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        _reg = [[NSRegularExpression alloc] initWithPattern:@"url\\s?\\(\\s?#(.*?)\\)\\;?"
                                                    options:0
                                                      error:nil];
    });
    __block NSString * foundID = nil;
    [_reg enumerateMatchesInString:string
                           options:0
                             range:NSMakeRange( 0, string.length )
                        usingBlock:^(NSTextCheckingResult *result, NSMatchingFlags flags, BOOL *stop)
     {
         if( ( foundID = [string substringWithRange:[result rangeAtIndex:1]] ) != nil )
             *stop = YES;
     }];
    return foundID;
}

+ (IJSVGWindingRule)windingRuleForString:(NSString *)string
{
    if( [string isEqualToString:@"evenodd"] )
        return IJSVGWindingRuleEvenOdd;
    if( [string isEqualToString:@"inherit"] )
        return IJSVGWindingRuleInherit;
    return IJSVGWindingRuleNonZero;
}

+ (IJSVGLineJoinStyle)lineJoinStyleForString:(NSString *)string
{
    if( [string isEqualToString:@"mitre"] )
        return IJSVGLineJoinStyleMiter;
    if( [string isEqualToString:@"round"] )
        return IJSVGLineJoinStyleRound;
    if( [string isEqualToString:@"bevel"] )
        return IJSVGLineJoinStyleBevel;
    if( [string isEqualToString:@"inherit"] )
        return IJSVGLineJoinStyleInherit;
    return IJSVGLineJoinStyleMiter;
}

+ (IJSVGLineCapStyle)lineCapStyleForString:(NSString *)string
{
    if( [string isEqualToString:@"butt"] )
        return IJSVGLineCapStyleButt;
    if( [string isEqualToString:@"square"] )
        return IJSVGLineCapStyleSquare;
    if( [string isEqualToString:@"round"] )
        return IJSVGLineCapStyleRound;
    if( [string isEqualToString:@"inherit"] )
        return IJSVGLineCapStyleInherit;
    return IJSVGLineCapStyleButt;
}

+ (CGFloat *)commandParameters:(NSString *)command
                         count:(NSInteger *)count
{
    if( [command isKindOfClass:[NSNumber class]] )
    {
        CGFloat * ret = (CGFloat *)malloc(1*sizeof(CGFloat));
        ret[0] = [(NSNumber *)command floatValue];
        *count = 1;
        return ret;
    }
    return [[self class] scanFloatsFromString:command
                                         size:count];
}

+ (CGFloat *)scanFloatsFromString:(NSString *)string
                             size:(NSInteger *)length
{
    // default sizes and memory
    // sizes for the string buffer
    NSInteger defSize = 50;
    NSInteger size = defSize;
    NSInteger sLength = string.length;
    
    // default memory size for the floats
    NSInteger defFloatSize = 100;
    NSInteger floatSize = defFloatSize;
    
    NSInteger i = 0;
    NSInteger counter = 0;
    
    const char * cString = [string cStringUsingEncoding:NSUTF8StringEncoding];
    const char * validChars = "0123456789eE+-.";
    
    // buffer for the returned floats
    CGFloat * floats = (CGFloat *)malloc(sizeof(CGFloat)*defFloatSize);
    
    char * buffer = NULL;
    bool isDecimal = false;
    int bufferCount = 0;
    
    while(i < sLength) {
        char currentChar = cString[i];
        
        // work out next char
        char nextChar = (char)0;
        if(i < (sLength-1)) {
            nextChar = cString[i+1];
        }
        
        bool isValid = strchr(validChars, currentChar);
        
        // in order to work out the split, its either because the next char is
        // a  hyphen or a plus, or next char is a decimal and the current number is a decimal
        bool wantsEnd = nextChar == '-' || nextChar == '+' || (nextChar == '.' && isDecimal);
        
        // make sure its a valid string
        if(isValid) {
            // alloc the buffer if needed
            if(buffer == NULL) {
                buffer = (char *)calloc(sizeof(char),size);
            } else if((bufferCount+1) == size) {
                // realloc the buffer, incase the string is overflowing the
                // allocated memory
                size += defSize;
                buffer = (char *)realloc(buffer, sizeof(char)*size);
            }
            // set the actual char against it
            if(currentChar == '.') {
                isDecimal = true;
            }
            buffer[bufferCount++] = currentChar;
        } else {
            // if its an invalid char, just stop it
            wantsEnd = true;
        }
        
        // is at end of string, or wants to be stopped
        // buffer has to actually exist or its completly
        // useless and will cause a crash
        if(buffer != NULL && (wantsEnd || i == sLength-1)) {
            // make sure there is enough room in the float pool
            if((counter+1) == floatSize) {
                floatSize += defFloatSize;
                floats = (CGFloat *)realloc(floats, sizeof(CGFloat)*floatSize);
            }
            
            // add the float
            floats[counter++] = atof(buffer);
            
            // memory clean and counter resets
            free(buffer);
            size = defSize;
            isDecimal = false;
            bufferCount = 0;
            buffer = NULL;
        }
        i++;
    }
    *length = counter;
    return floats;
}

+ (CGFloat *)parseViewBox:(NSString *)string
{
    NSInteger size = 0;
    return [[self class] scanFloatsFromString:string
                                         size:&size];
}

+ (CGFloat)floatValue:(NSString *)string
   fallBackForPercent:(CGFloat)fallBack
{
    CGFloat val = [string floatValue];
    if( [string rangeOfString:@"%"].location != NSNotFound )
        val = (fallBack * val)/100;
    return val;
}

+ (void)logParameters:(CGFloat *)param
                count:(NSInteger)count
{
    NSMutableString * str = [[[NSMutableString alloc] init] autorelease];
    for( NSInteger i = 0; i < count; i++ )
    {
        [str appendFormat:@"%f ",param[i]];
    }
    NSLog(@"%@",str);
}

+ (CGFloat)floatValue:(NSString *)string
{
    if( [string isEqualToString:@"inherit"] )
        return IJSVGInheritedFloatValue;
    return [string floatValue];
}

+ (CGFloat)angleBetweenPointA:(NSPoint)point1
                       pointb:(NSPoint)point2
{
    return (point1.x * point2.y < point1.y * point2.x ? -1 : 1) * acosf(ratio(point1, point2));
}

@end