1 files changed, 80 insertions, 0 deletions
diff --git a/public/js/brush.js b/public/js/brush.js
new file mode 100644
index 0000000..8d3eaf8
--- /dev/null
+++ b/public/js/brush.js
@@ -0,0 +1,80 @@
+function Brush (b) {
+  this.opt = b;
+  var canvas = this.canvas = document.createElement("canvas");
+  var ctx = this.ctx = canvas.getContext('2d');
+  canvas.width = b.width;
+  canvas.height = b.height || b.width;
+  canvas.className = "brush";
+  this.width = b.width;
+  this.height = b.height || b.width;
+  this.color = b.color;
+
+  if (b.style == "soft") {
+    var hw = Math.floor(b.width / 2);
+    var r = clamp(b.width-1, 1, 1000);
+    ctx.beginPath();
+    var rad = ctx.createRadialGradient(hw, hw, 1, hw, hw, r);
+    rad.addColorStop(0, b.color.alpha(b.color.a).toString());
+    rad.addColorStop(0.5, b.color.alpha(0).toString());
+    ctx.fillStyle = rad;
+    ctx.arc(hw, hw, r, 0, Math.PI*2, false);
+    ctx.fill();
+  }
+  else if (b.style == "hard") {
+    var hw = Math.floor(b.width / 2);
+    var r = clamp(b.width-1, 1, 1000);
+    ctx.beginPath();
+    var rad = ctx.createRadialGradient(hw, hw, 1, hw, hw, r);
+    rad.addColorStop(0.5, b.color.toString() );
+    rad.addColorStop(0.5, b.color.toString() );
+    ctx.fillStyle = rad;
+    ctx.arc(hw, hw, r, 0, Math.PI*2, false);
+    ctx.fill();
+  }
+  else if (b.style == "pencil") {
+    var hw = canvas.width / 2, hh = canvas.height / 2;
+    var id = ctx.getImageData( 0, 0, canvas.width, canvas.height );
+    var data = id.data;
+    for (var i = -hw; i <= hw; i++) {
+      for (var j = -hh; j <= hh; j++) {
+        var xx = Math.floor( i + hw );
+        var yy = Math.floor( j + hh );
+        var mag = Trig.magnitude({ x: i, y: j });
+        var offset = (yy * canvas.width + xx) * 4;
+        data[ offset ]     = color.r;
+        data[ offset + 1 ] = color.g;
+        data[ offset + 2 ] = color.b;
+        data[ offset + 3 ] = mag < r ? 1.0 : 0.0;
+      }
+    }
+  }
+}
+Brush.prototype.copy = function(opt){
+  return new Brush ( extend(opt, this.opt) )
+}
+
+function extend (h,a) {
+  h = h || {};
+  for (var i in a) {
+    if (a.hasOwnProperty(i) && ! h.hasOwnProperty(i)) {
+      h[i] = a[i];
+    }
+  }
+  return h;
+}
+
+var brush;
+function makeBrushes () {
+  document.getElementById('brushes').innerHTML = '';
+  fib(function(n){
+    var b = new Brush({ style: 'pencil', color: color, width: n })
+    b.canvas.onclick = function(){
+      brush = b;
+    }
+    document.getElementById('brushes').appendChild( b.canvas );
+    if (! brush) brush = b;
+  });
+}
+
+makeBrushes();
+