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Moved to ARC, removed forced sorting #2

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16 changes: 5 additions & 11 deletions ShapeReducer/ShapeReducer.h
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Original file line number Diff line number Diff line change
@@ -1,27 +1,21 @@
#import <Foundation/Foundation.h>

@interface ShapePoint : NSObject {
double latitude;
double longitude;
unsigned int sequence;
}

@property (nonatomic, assign) double latitude;
@property (nonatomic, assign) double longitude;
@property unsigned int sequence;
@property (nonatomic, readonly) double latitude;
@property (nonatomic, readonly) double longitude;

- (id)initWithLatitude:(double)aLatitude longitude:(double)aLongitude sequence:(unsigned int)aSequence;
- (id)initWithLatitude:(double)aLatitude longitude:(double)aLongitude;

@end

@interface Shape : NSObject {
@private
NSMutableArray *_points;
BOOL _needs_sort;
}

@property (nonatomic, retain) NSMutableArray *_points;
@property BOOL _needs_sort;
@property (nonatomic, strong) NSMutableArray *_points;

- (void)addPoint:(ShapePoint *)point;
- (NSArray *)points;
Expand All @@ -31,6 +25,6 @@
@interface ShapeReducer : NSObject

- (Shape*)reduce:(Shape*)aShape tolerance:(double)tolerance;
- (void) douglasPeuckerReductionWithTolerance:(double)tolerance shape:(Shape*)shape outputShape:(Shape*)outputShape firstIndex:(int)first lastIndex:(int)last;
- (void) douglasPeuckerReductionWithTolerance:(double)tolerance shape:(Shape*)shape outputShape:(Shape*)outputShape firstIndex:(NSUInteger)first lastIndex:(NSUInteger)last;
+ (double)orthogonalDistanceWithPoint:(ShapePoint *)point lineStart:(ShapePoint *)lineStart lineEnd:(ShapePoint *)lineEnd;
@end
69 changes: 17 additions & 52 deletions ShapeReducer/ShapeReducer.m
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Original file line number Diff line number Diff line change
Expand Up @@ -2,109 +2,76 @@

@implementation ShapePoint

@synthesize latitude, longitude, sequence;

- (id)initWithLatitude:(double)aLatitude longitude:(double)aLongitude sequence:(unsigned int)aSequence {
- (id)initWithLatitude:(double)aLatitude longitude:(double)aLongitude {
if ((self = [super init])) {
self.latitude = aLatitude;
self.longitude = aLongitude;
self.sequence = aSequence;
}
return self;
}

- (id)init
{
self = [super init];
return self;
_latitude = aLatitude;
_longitude = aLongitude;
}
return self;
}

@end

@implementation Shape

@synthesize _points, _needs_sort;
@synthesize _points;

- (id)init
{
if ((self = [super init])) {
_points = [[NSMutableArray alloc] init];
_needs_sort = NO;
}
}
return self;
}

- (void)addPoint:(ShapePoint *)point {
[_points addObject:point];
_needs_sort = YES;
}

- (NSArray *)points {
if (_needs_sort) {
NSComparisonResult (^sortBlock)(id, id) = ^(id obj1, id obj2) {
if ([obj1 sequence] > [obj2 sequence]) {
return (NSComparisonResult)NSOrderedDescending;
}
if ([obj1 sequence] < [obj2 sequence]) {
return (NSComparisonResult)NSOrderedAscending;
}
return (NSComparisonResult)NSOrderedSame;
};
NSArray *sortedPoints = [_points sortedArrayUsingComparator:sortBlock];
return sortedPoints;
}
return _points;
}

- (void)dealloc {
[_points release];
[super dealloc];
_points = nil;
}

@end


@implementation ShapeReducer

- (id)init
{
self = [super init];

return self;
}

- (Shape*)reduce:(Shape*)aShape tolerance:(double)tolerance {
if (tolerance <= 0 || [aShape.points count] < 3) {
return aShape;
}

NSArray *points = [aShape points];
Shape *newShape = [[[Shape alloc] init] autorelease];
NSArray *points = aShape.points;
Shape *newShape = [[Shape alloc] init];

[newShape addPoint:[points objectAtIndex:0]];
[newShape addPoint:[points lastObject]];
[newShape addPoint:points.firstObject];

[self douglasPeuckerReductionWithTolerance:tolerance shape:aShape
outputShape:newShape firstIndex:0 lastIndex:[points count]-1];

return newShape;
[newShape addPoint:points.lastObject];

return newShape;
}

- (void) douglasPeuckerReductionWithTolerance:(double)tolerance shape:(Shape*)shape outputShape:(Shape*)outputShape firstIndex:(int)first lastIndex:(int)last {
- (void) douglasPeuckerReductionWithTolerance:(double)tolerance shape:(Shape*)shape outputShape:(Shape*)outputShape firstIndex:(NSUInteger)first lastIndex:(NSUInteger)last {
if (last <= first + 1) {
return;
}

NSArray *points = [shape points];

double distance, maxDistance = 0.0;
int indexFarthest = 0;
NSUInteger indexFarthest = 0;

ShapePoint *firstPoint = [points objectAtIndex:first];
ShapePoint *lastPoint = [points objectAtIndex:last];

for (int idx=first+1; idx<last; idx++) {
for (NSUInteger idx=first+1; idx<last; idx++) {
ShapePoint *point = [points objectAtIndex:idx];

distance = [ShapeReducer orthogonalDistanceWithPoint:point lineStart:firstPoint lineEnd:lastPoint];
Expand All @@ -118,11 +85,9 @@ - (void) douglasPeuckerReductionWithTolerance:(double)tolerance shape:(Shape*)sh

if (maxDistance>tolerance && indexFarthest!=0) {
//add index of Point to list of Points to keep
[outputShape addPoint:[points objectAtIndex:indexFarthest]];

[self douglasPeuckerReductionWithTolerance:tolerance shape:shape
outputShape:outputShape firstIndex:first lastIndex:indexFarthest];

[outputShape addPoint:[points objectAtIndex:indexFarthest]];
[self douglasPeuckerReductionWithTolerance:tolerance shape:shape outputShape:outputShape firstIndex:indexFarthest lastIndex:last];
}
}
Expand Down