(function() {(function() {A Spritesheet is used to easily divide an image in rectangular blocks (sprites) Their most important use is animations (see Luv.Graphics.Animation for details)
Luv.Graphics.SpriteSheet = Luv.Class('Luv.Graphics.SpriteSheet', {init has the following parameters:
image is the image from which the spriteSheet takes its sprites. It's mandatory.width and height are the dimensions (in pixels) of all the sprites that the
spriteSheet will generate. They are mandatory.left and top are the coordinates where the spritesheet starts inside the image;
an "offset" (they default to 0,0)border is the distance in pixels between each sprite and its neighbors. Defaults to 0. init: function(image, width, height, left, top, border) {
this.image = image;
this.width = width;
this.height = height;
this.left = left || 0;
this.top = top || 0;
this.border = border || 0;
},getSprites accepts a variable number of parameters and returns an array of sprites (instances of
Luv.Graphics.Sprite). The parameters can be either integers or strings of the form 'A-B', where A and
B are integers, too. It's parsed as follows:
sheet.getSprites(1,1) will return the sprite on the
second row and second column of the spritesheet in one array. sheet.getSprites(0,0, 0,1) will return
the first two sprites of the first column of the spritesheet.sheet.getSprites('0-9', 0) will return the first 9 sprites of the first row of the sheet (y remains fixed
at 0, and x iterates from 0 to 9). You can also iterate over columns: sheet.getSprites(0, '0-9'). If you
want to iterate backwards (from right to left or from bottom to top) just switch the numbers of the string:
sheet.getSprites('9-0', 0).sheet.getSprites('5-10', '2-3') will return the sprites in [5,2], [5,3], [6,2], [6,3] ... [10,2], [10,3].Finally, take into accont that you can get as many rows/columns as you want
in a single call, and even add individual spritesheets. For example, this call will get the 10 first sprites
of the first two rows, and then the sprite in 10,10: sheet.getSprites('0-9',0, '0-9',1, 10,10).
getSprites: function() {
var result = [], xCoords, yCoords;
for(var i=0; i<arguments.length; i+=2) {
xCoords = parseRange(arguments[i]);
yCoords = parseRange(arguments[i+1]);
for(var iy=0; iy < yCoords.length; iy++) {
for(var ix=0; ix < xCoords.length; ix++) {
result.push(this.Sprite(xCoords[ix], yCoords[iy]));
}
}
}
return result;
},Sprite returns the instance of Luv.Graphics.Sprite which is on column x, row y of the SpriteSheet.
Sprite: function(x,y) {
return Luv.Graphics.Sprite(
this.image,
this.left + this.width * x + this.border * (x+1),
this.top + this.height * y + this.border * (y+1),
this.width,
this.height
);
},Animation returns an instance of Luv.Graphics.Animation.
spriteInfo is an array of indexes for sprites, following the same rules as the parameters of getSprites.durations follows the same rules as it does in Luv.Graphics.Animation.init. See Luv.Graphics.Animation.init
for details Animation: function(spriteInfo, durations) {
var sprites = this.getSprites.apply(this, spriteInfo);
return Luv.Graphics.Animation(sprites, durations);
}
});Transform a string of type '2-5' in an array of type [2,3,4,5].
var parseRange = function(r) {
if(typeof r == "number") { return [r]; }
if(typeof r == "string") {
var split = r.split("-");
if(split.length != 2) {
throw new Error("Could not parse from '" + r + "'. Must be of the form 'start-end'");
}
var result = [],
start = Number(split[0]),
end = Number(split[1]),
i;
if(start < end) {
for(i=start; i<=end; i++) { result.push(i); }
} else {
for(i=start; i>=end; i--) { result.push(i); }
}
return result;
}
throw new Error("Ranges must be integers or strings of the form 'start-end'. Got " + r);
};
}());