RAYCASTING ISSUES

[Raul Rivera Arroyo]

Hello again fellow coders. I've been having some issues with this class while I follow along this tutorial : http://haxeflixel.com/documentation/part-viii-enemies-and-basic-ai/. I've spent a good amount of time between yesterday and today trying to get to the bottom of it, but I fear that my little knowledge of Haxe, although increasing, limits me somewhat. Thankfully, I've a workaround in place that suits me well. But if I want to know how to use this class correctly, I need to know what's wrong with my code. Or if it's perhaps not my code but Ogmo Editor trolling me somehow. First, here is my issue, a stacktrace:

Invalid field access : allowCollisions

Called from flixel/tile/FlxTilemap.hx line 1357

Called from PlayState.hx line 115

Called from flixel/group/FlxTypedGroup.hx line 651

Called from PlayState.hx line 92

Called from flixel/FlxState.hx line 155

Called from flixel/FlxGame.hx line 700

Called from flixel/FlxGame.hx line 648

Called from flixel/FlxGame.hx line 493

Called from openfl/_legacy/events/EventDispatcher.hx line 98

Called from openfl/_legacy/display/DisplayObject.hx line 182

Called from openfl/_legacy/display/DisplayObject.hx line 161

Called from openfl/_legacy/display/DisplayObjectContainer.hx line 280

Called from openfl/_legacy/display/Stage.hx line 1098

Called from openfl/_legacy/display/Stage.hx line 351

Called from openfl/_legacy/display/Stage.hx line 1079

Called from openfl/_legacy/display/Stage.hx line 430

Playstate.hx line 115 is:

if (_mWalls.ray(e.getMidpoint(), _player.getMidpoint()))

Playstate.hx line 92 is:

_grpEnemies.forEachAlive(checkEnemyVision);

The context of what's happening is, once I test the project out it either A) Crashes immediately, or B) Crashes just a few seconds in. If I eliminate a few enemy entities from the level using Ogmo, and just place one entity, the project does not crash immediately. Im able to move around, if the enemy has line of sight, he will head towards me. If I escape, he stops following and just goes back to moping around. After a while though, the game crashes again and gives me that invalid field access. Im not sure if the checkEnemyVision function is crashing my game as the raycast hits a wall, if its Ogmo and it's entities or if it's something else. I've attached my playstate.hx code. Followed along the tutorial.

[Brian Flyte]

I don't see anything wrong with the PlayState. Maybe it's something in the Enemy class?

[Jimmy JimJim]

Invalid field access means it tried to access a property which does not exist. Throw some breakpoints in at line 115 and see if perhaps the raycast is firing before HaxeFlixel has properly setup all the entities. 

[Bl4ckb0ne]

Check if the field you're trying to acces is not out of bounds or null.

[Junjo]

Given that the error is thrown from FlxTilemap.hx, I would check if you are using a correct version set of the libraries.

[Raul Rivera Arroyo]

Hey guys, thanks for the comments. I was able to fix the problem with some help from the IRC chat channel. The problem I was having is that OGMO was setting some tilemap values to -1 in the .oel file. This is what was causing the ruckus. However, adding:

var tiles = _mWalls.getData(); for (i in 0...tiles.length) if (tiles[i] < 0) tiles[i] = 0;

to the create() function in the PlayState resolved the issue, though the .oel file still has the values outside of the map as -1.