Fixed up erase and added scratch draw highlighting

js-lib/common.js

@@ -92,6 +92,11 @@ ascii.Cell.prototype.isSpecial = function() {
   return this.getRawValue() == SPECIAL_VALUE;
 };
 
+/** @return {boolean} */
+ascii.Cell.prototype.hasScratch = function() {
+  return this.scratchValue != null;
+};
+
 /**
  * The context for a cell, i.e. the status of the cells around it.
  *

js-lib/controller.js

@@ -174,10 +174,10 @@ ascii.Controller.prototype.updateButtons = function(id) {
     this.drawFunction = new ascii.DrawLine(this.state);
   }
   if (id == 'freeform-button') {
-    this.drawFunction = new ascii.DrawFreeform(this.state, '+');
+    this.drawFunction = new ascii.DrawFreeform(this.state, SPECIAL_VALUE);
   }
   if (id == 'erase-button') {
-    this.drawFunction = new ascii.DrawFreeform(this.state, null);
+    this.drawFunction = new ascii.DrawErase(this.state);
   }
   if (id == 'move-button') {
     this.drawFunction = new ascii.DrawMove(this.state);

js-lib/draw.js

@@ -14,23 +14,23 @@
 function drawLine(state, startPosition, endPosition, clockwise, opt_value) {
   var value = opt_value || SPECIAL_VALUE;
 
-  var hX1 = Math.min(startPosition.x, endPosition.x);
+  var startX = Math.min(startPosition.x, endPosition.x);
-  var vY1 = Math.min(startPosition.y, endPosition.y);
+  var startY = Math.min(startPosition.y, endPosition.y);
-  var hX2 = Math.max(startPosition.x, endPosition.x);
+  var endX = Math.max(startPosition.x, endPosition.x);
-  var vY2 = Math.max(startPosition.y, endPosition.y);
+  var endY = Math.max(startPosition.y, endPosition.y);
 
-  var hY = clockwise ? startPosition.y : endPosition.y;
+  var midX = clockwise ? endPosition.x : startPosition.x;
-  var vX = clockwise ? endPosition.x : startPosition.x;
+  var midY = clockwise ? startPosition.y : endPosition.y;
 
-  while (hX1++ < hX2) {
+  while (startX++ < endX) {
-    state.drawValue(new ascii.Vector(hX1, hY), value);
+    state.drawValue(new ascii.Vector(startX, midY), value);
   }
-  while (vY1++ < vY2) {
+  while (startY++ < endY) {
-    state.drawValue(new ascii.Vector(vX, vY1), value);
+    state.drawValue(new ascii.Vector(midX, startY), value);
   }
   state.drawValue(startPosition, value);
   state.drawValue(endPosition, value);
-  state.drawValue(new ascii.Vector(vX, hY), value);
+  state.drawValue(new ascii.Vector(midX, midY), value);
 }
 
 /**
@@ -120,17 +120,55 @@ ascii.DrawFreeform = function(state, value) {
 };
 
 ascii.DrawFreeform.prototype.start = function(position) {
-  this.state.setValue(position, this.value);
+  this.state.drawValue(position, this.value);
 };
 ascii.DrawFreeform.prototype.move = function(position) {
-  this.state.setValue(position, this.value);
+  this.state.drawValue(position, this.value);
 };
 ascii.DrawFreeform.prototype.end = function(position) {
+  this.state.commitDraw();
 };
 ascii.DrawFreeform.prototype.getCursor = function(position) {
   return 'crosshair';
 };
 
+/**
+ * @constructor
+ * @implements {ascii.DrawFunction}
+ * @param {ascii.State} state
+ */
+ascii.DrawErase = function(state) {
+  this.state = state;
+  this.startPosition = null;
+  this.endPosition = null;
+};
+
+ascii.DrawErase.prototype.start = function(position) {
+  this.startPosition = position;
+  this.move(position);
+};
+ascii.DrawErase.prototype.move = function(position) {
+  this.state.clearDraw();
+  this.endPosition = position;
+
+  var startX = Math.min(this.startPosition.x, this.endPosition.x);
+  var startY = Math.min(this.startPosition.y, this.endPosition.y);
+  var endX = Math.max(this.startPosition.x, this.endPosition.x);
+  var endY = Math.max(this.startPosition.y, this.endPosition.y);
+
+  for (var i = startX; i < endX; i++) {
+    for (var j = startY; j < endY; j++) {
+      this.state.drawValue(new ascii.Vector(i, j), ' ');
+    }
+  }
+};
+ascii.DrawErase.prototype.end = function(position) {
+  this.state.commitDraw();
+};
+ascii.DrawErase.prototype.getCursor = function(position) {
+  return 'crosshair';
+};
+
 /**
  * @constructor
  * @implements {ascii.DrawFunction}

js-lib/state.js

@@ -106,8 +106,13 @@ ascii.State.prototype.getContext = function(position) {
  */
 ascii.State.prototype.commitDraw = function() {
   for (var i in this.scratchCells) {
-    this.scratchCells[i].value = this.scratchCells[i].getRawValue();
+    var newValue = this.scratchCells[i].getRawValue();
+    // Cheeky little hack for making erase play nicely.
+    if (newValue == ' ') {
+      newValue = null;
+    }
     this.scratchCells[i].scratchValue = null;
+    this.scratchCells[i].value = newValue;
   }
 };
 

js-lib/view.js

@@ -89,8 +89,9 @@ ascii.View.prototype.render = function() {
   this.context.font = '15px Courier New';
   for (var i = startOffset.x; i < endOffset.x; i++) {
     for (var j = startOffset.y; j < endOffset.y; j++) {
-      if (this.state.getCell(new ascii.Vector(i, j)).isSpecial()) {
+      var cell = this.state.getCell(new ascii.Vector(i, j));
-        this.context.fillStyle = '#F5F5F5';
+      if (cell.hasScratch() || cell.isSpecial()) {
+        this.context.fillStyle = cell.hasScratch() ? '#DEF' : '#F5F5F5';
         context.fillRect(
             i * CHARACTER_PIXELS - this.offset.x,
             (j - 1) * CHARACTER_PIXELS - this.offset.y,