Using sprites in xcode

Question

I am trying to revive my game using a sprite sheet. How could I cut every sprite from a sprite sheet and use a sprite in xcode? I am currently using obj -c. I read somewhere that I need to use the frame work, cocoa2d to do this?

Answer 1

In the sprite set, you can cut out part of the texture using SKTexture(rect: inTexture:). This is a helper class that manages a sprite sheet that is evenly spaced and can cut out the texture in a given row and column. Used like that

let sheet=SpriteSheet(texture: SKTexture(imageNamed: "spritesheet"), rows: 1, columns: 11, spacing: 1, margin: 1)
let sprite=SKSpriteNode(texture: sheet.textureForColumn(0, row: 0))

Here is the complete code

//
//  SpriteSheet.swift
//

import SpriteKit

class SpriteSheet {
    let texture: SKTexture
    let rows: Int
    let columns: Int
    var margin: CGFloat=0
    var spacing: CGFloat=0
    var frameSize: CGSize {
        return CGSize(width: (self.texture.size().width-(self.margin*2+self.spacing*CGFloat(self.columns-1)))/CGFloat(self.columns),
            height: (self.texture.size().height-(self.margin*2+self.spacing*CGFloat(self.rows-1)))/CGFloat(self.rows))
    }

    init(texture: SKTexture, rows: Int, columns: Int, spacing: CGFloat, margin: CGFloat) {
        self.texture=texture
        self.rows=rows
        self.columns=columns
        self.spacing=spacing
        self.margin=margin

    }

    convenience init(texture: SKTexture, rows: Int, columns: Int) {
        self.init(texture: texture, rows: rows, columns: columns, spacing: 0, margin: 0)
    }

    func textureForColumn(column: Int, row: Int)->SKTexture? {
        if !(0...self.rows ~= row && 0...self.columns ~= column) {
            //location is out of bounds
            return nil
        }

        var textureRect=CGRect(x: self.margin+CGFloat(column)*(self.frameSize.width+self.spacing)-self.spacing,
                               y: self.margin+CGFloat(row)*(self.frameSize.height+self.spacing)-self.spacing,
                               width: self.frameSize.width,
                               height: self.frameSize.height)

        textureRect=CGRect(x: textureRect.origin.x/self.texture.size().width, y: textureRect.origin.y/self.texture.size().height,
            width: textureRect.size.width/self.texture.size().width, height: textureRect.size.height/self.texture.size().height)
        return SKTexture(rect: textureRect, inTexture: self.texture)
    }

}

margin - . - . FameSize - . :

Answer 2

, , :

:

var textureRect=CGRect(x: self.margin+CGFloat(column)*(self.frameSize.width+self.spacing)-self.spacing,
                       y: self.margin+CGFloat(row)*(self.frameSize.width+self.spacing)-self.spacing,
                       width: self.frameSize.width,
                       height: self.frameSize.height)

Swift Objective-C . self.frameSize.width , . .

: SKTexture (0,0) , .

, :

var anim = [SKTexture]()
for row in (0..<self.rows).reversed() {
  for column in 0..<self.columns {
    if let frame = textureForColumn(column: column, row: row) {
        anim.append(frame)
    }
  }
}

PS. SpriteKit, , - , , .

Answer 3

Since the original question was tagged Objective-C, a rough version of this SpriteSheet class in this language is presented here. Hope this helps:

#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];
}