fix(ios): optimize extractPathData, clear PathMeasure when no textPath

Return early if calling extractPathData with same CGPath as previously

Author: msand

ios/Text/RNSVGTSpan.m

@@ -1032,18 +1032,22 @@ - (void)setupTextPath:(CGContextRef)context
 {
     textPath = nil;
     RNSVGText *parent = (RNSVGText*)[self superview];
+    CGPathRef path;
     while (parent) {
         if ([parent class] == [RNSVGTextPath class]) {
             textPath = (RNSVGTextPath*) parent;
             RNSVGNode *template = [self.svgView getDefinedTemplate:textPath.href];
-            CGPathRef path = [template getPath:nil];
+            path = [template getPath:context];
             [measure extractPathData:path];
             break;
         } else if (![parent isKindOfClass:[RNSVGText class]]) {
             break;
         }
         parent = (RNSVGText*)[parent superview];
     }
+    if (!path) {
+        [measure reset];
+    }
 }
 
 @end

ios/Utils/RNSVGPathMeasure.h

@@ -11,12 +11,13 @@
 @interface RNSVGPathMeasure : NSObject
 
 @property CGFloat pathLength;
-@property CGPathRef textPath;
+@property CGPathRef path;
 @property NSMutableArray *lengths;
 @property NSMutableArray *lines;
 @property NSUInteger lineCount;
 @property BOOL isClosed;
 
+- (void)reset;
 - (void)extractPathData:(CGPathRef)path;
 - (void)getPosAndTan:(CGFloat *)angle midPoint:(CGFloat)midPoint px:(CGFloat *)px py:(CGFloat *)py;
 

ios/Utils/RNSVGPathMeasure.m

@@ -94,7 +94,20 @@ - (void)addLine:(CGPoint *)last next:(const CGPoint *)next {
     *last = *next;
 }
 
+- (void)reset {
+    _lengths = nil;
+    _lines = nil;
+    _isClosed = NO;
+    _lineCount = 0;
+    _pathLength = 0;
+    _path = nil;
+}
+
 - (void)extractPathData:(CGPathRef)path {
+    if (path == _path) {
+        return;
+    }
+    _path = path;
     CGPoint origin = CGPointMake (0.0, 0.0);
     CGPoint last = CGPointMake (0.0, 0.0);
     _lengths = [NSMutableArray array];