add 'nearby' predicate

model/scripts/engine/Actions.js

@@ -65,25 +65,7 @@ Actions.if_neighbor = {
 		// First, get num of actual neighbors that are STATE
 		var count = Grid.countNeighbors(agent, config.stateID);
 
-		// Did condition pass?
-		var pass;
-		switch(config.sign){
-			case "<":
-				pass = (count<config.num);
-				break;
-			case "<=":
-				pass = (count<=config.num);
-				break;
-			case ">":
-				pass = (count>config.num);
-				break
-			case ">=":
-				pass = (count>=config.num);
-				break;
-			case "=":
-				pass = (count==config.num);
-				break;
-		}
+		var pass = compare(config.sign, config.num, count);
 
 		// If so, perform the following actions.
 		if(pass){
@@ -118,6 +100,73 @@ Actions.if_neighbor = {
 
 };
 
+// IF_NEAR: If we're near a thing, do a thing!
+Actions.if_near = {
+
+	name: "If near to a certain number of...",
+
+	props: {
+		countSign: ">=",
+		num: 3,
+		distance: 3,
+		stateID: 0,
+		actions: []
+	},
+
+	step: function(agent,config){
+
+		var pass = Grid.nearby(agent, config.stateID, config.num, config.countSign, config.distance);
+
+		if(pass) {
+			PerformActions(agent, config.actions);
+		}
+
+	},
+
+	ui: function(config){
+
+		return EditorHelper()
+				.label("If ")
+				.selector([
+					{ name:"fewer than (<)", value:"<" },
+					{ name:"at least (>=)", value:">=" },
+				],config,"countSign")
+				.label(" ")
+				.number(config, "num", {
+					integer:true,
+					min:0, max:8,
+					step:1
+				})
+				.stateSelector(config, "stateID")
+				.label(" are within")
+				.number(config, "distance", {
+					integer: true,
+					min:1, max:8,
+					step: 1
+				})
+				.actionsUI(config.actions)
+				.dom;
+	}
+
+};
+
+function compare(sign, constraint, value) {
+		switch(sign){
+			case "<":
+				return value<constraint;
+			case "<=":
+				return value<=constraint;
+			case ">":
+				return value>constraint;
+			case ">=":
+				return value>=constraint;
+			case "=":
+				return value==constraint;
+		}
+}
+
+
+
 // IF_RANDOM: With a X% chance, do a thing
 Actions.if_random = {
 

model/scripts/engine/Grid.js

@@ -227,15 +227,7 @@ Grid.getNeighbors = function(agent){
 	}
 
 	// Then, filter out ones that can't work
-	coords = coords.filter(function(coord){
-		var x = coord[0];
-		var y = coord[1];
-		if(x<0) return false;
-		if(x>=Grid.array[0].length) return false;
-		if(y<0) return false;
-		if(y>=Grid.array.length) return false;
-		return true;
-	});
+	coords = coords.filter(validCoordinate);
 
 	// Then, get all neighbors at those coords
 	var neighbors = [];
@@ -250,6 +242,27 @@ Grid.getNeighbors = function(agent){
 
 };
 
+function validCoordinate(coord) {
+  var x = coord[0];
+  var y = coord[1];
+  return legalX(x) && legalY(y);
+}
+
+function legalX(x) {
+  return x>=0 && x < gridWidth();
+}
+function legalY(y) {
+  return y>=0 && y < gridHeight();
+}
+
+function gridWidth() {
+  return  Grid.array[0].length;
+}
+
+function gridHeight() {
+  return  Grid.array.length;
+}
+
 // Get ALL agents (just collapses to a single array)
 Grid.getAllAgents = function(){
 
@@ -276,6 +289,45 @@ Grid.countNeighbors = function(agent,stateID){
 	return count;
 };
 
+// Count items nearby of a certain state
+Grid.nearby = function(agent,stateID, target, moreOrLess, within){
+
+  var isAtLeast = moreOrLess === ">=";
+
+  // no neighbours, so can't be at least, and definitely less than
+  if(within < 1) {
+    return !isAtLeast;
+  }
+
+  // calculate the maximum valid neighbourhood considering
+  // grid constraints
+  var coords = {
+    x: Math.max(0, agent.x - within),
+    mx: Math.min(agent.x + within, gridWidth()),
+    y: Math.max(0, agent.y - within),
+    my: Math.min(agent.y + within, gridHeight()),
+  };
+
+  var count = 0;
+
+  for(var y = coords.y, maxY = coords.my; y < maxY; y++) {
+    for(var x = coords.x, maxX = coords.mx; x < maxX; x++) {
+      if(Grid.array[y][x].stateID==stateID) {
+        count += 1;
+        // if we're at target for at least, we've done enough to know we've passed
+        // if at target for less than, we know we've failed
+        if(count >= target) {
+          return isAtLeast;
+        }
+      }
+    }
+  }
+
+  // if we're here we haven't found the target count. that is
+  // a fail for more than, a pass for less than
+  return !isAtLeast;
+};
+
 // Reset world, update the view, and resize to fit
 Grid.reinitialize = function(){
 	Grid.initialize();