piskel/js/drawingtools/BaseTool.js

53 lines
1.2 KiB
JavaScript

/*
* @provide pskl.drawingtools.BaseTool
*
* @require pskl.utils
*/
(function() {
var ns = $.namespace("pskl.drawingtools");
ns.BaseTool = function() {};
ns.BaseTool.prototype.applyToolAt = function(col, row, frame) {};
ns.BaseTool.prototype.moveToolAt = function(col, row, frame) {};
ns.BaseTool.prototype.releaseToolAt = function(col, row, frame) {};
/**
* Bresenham line algorihtm: Get an array of pixels from
* start and end coordinates.
*
* http://en.wikipedia.org/wiki/Bresenham's_line_algorithm
* http://stackoverflow.com/questions/4672279/bresenham-algorithm-in-javascript
*
* @private
*/
ns.BaseTool.prototype.getLinePixels_ = function(x0, x1, y0, y1) {
var pixels = [];
var dx = Math.abs(x1-x0);
var dy = Math.abs(y1-y0);
var sx = (x0 < x1) ? 1 : -1;
var sy = (y0 < y1) ? 1 : -1;
var err = dx-dy;
while(true){
// Do what you need to for this
pixels.push({"col": x0, "row": y0});
if ((x0==x1) && (y0==y1)) break;
var e2 = 2*err;
if (e2>-dy){
err -= dy;
x0 += sx;
}
if (e2 < dx) {
err += dx;
y0 += sy;
}
}
return pixels;
};
})();