Using sprite sheets in xcode

Question

I\'m trying to animate my game using a sprite sheet. How would I go about cutting out each sprite from the sprite sheet and using the sprite in xcode? I\'m currently using o

Answer 1

Since the original question was tagged as Objective-C, here's a rough version of this SpriteSheet class in that language. Hope this is helpful:

#import "SpriteSheet.h"

@interface SpriteSheet ()
@property (nonatomic, strong) SKTexture *texture;
@property (nonatomic)         NSInteger rows;
@property (nonatomic)         NSInteger cols;
@property (nonatomic)         CGFloat   margin;
@property (nonatomic)         CGFloat   spacing;
@property (nonatomic, getter=frameSize)         CGSize    frameSize;
@end


@implementation SpriteSheet

- (instancetype)initWithTextureName:(NSString *)name rows:(NSInteger)rows cols:(NSInteger)cols margin:(CGFloat)margin spacing:(CGFloat)spacing {
  SKTexture *texture = [SKTexture textureWithImageNamed:name];
  return [self initWithTexture:texture rows:rows cols:cols margin:margin spacing:spacing];
}

- (instancetype)initWithTexture:(SKTexture *)texture rows:(NSInteger)rows cols:(NSInteger)cols {
  return [self initWithTexture:texture rows:rows cols:cols margin:0 spacing:0];
}

- (instancetype)initWithTexture:(SKTexture *)texture rows:(NSInteger)rows cols:(NSInteger)cols margin:(CGFloat)margin spacing:(CGFloat)spacing {
  if (self == [super init]) {
    _texture = texture;
    _rows = rows;
    _cols = cols;
    _margin = margin;
    _spacing = spacing;
    _frameSize = [self frameSize];

  }
  return self;
}

- (CGSize)frameSize {

  CGSize newSize = CGSizeMake((self.texture.size.width - (self.margin * 2.0 + self.spacing * ((CGFloat)self.cols - 1.0))) / ((CGFloat)self.cols),
                    (self.texture.size.height - ((self.margin * 2.0) + (self.spacing * ((CGFloat)self.rows - 1.0))) / ((CGFloat)self.rows)));

  return newSize;
}

- (SKTexture *)textureForColumn:(NSInteger)column andRow:(NSInteger)row {

  if (column >= (self.cols) || row >= (self.rows)) {
    NSLog(@"Asking for row or col greater than spritesheet");
    return nil;
  }

  CGRect textureRect = CGRectMake(self.margin + (column * self.frameSize.width + self.spacing) - self.spacing,
                                  self.margin + (row * self.frameSize.width + self.spacing) - self.spacing, // note using width here
                                  self.frameSize.width,
                                  self.frameSize.height);

  textureRect = CGRectMake(textureRect.origin.x / self.texture.size.width, textureRect.origin.y / self.texture.size.height, textureRect.size.width / self.texture.size.width, textureRect.size.height/self.texture.size.height);

  return [SKTexture textureWithRect:textureRect inTexture:self.texture];
}