Understanding the tile co-ordinates

[robaldred]

I'm having some trouble understanding the tile co-ordinates. Specifically the overTiles() method, it seems to return points that are confusing me.
I want to be able to find out where my entities are and how many tiles away they are from other entities.

1st test:
Dog at x:0,y:0 overTiles() reports x:0,y:0, happy days.
Distance returns 0.

Screen Shot 2013-09-12 at 11.21.51.png

2nd test:
I've moved the dog to tile x:2,y:0, however overTiles() reports it's on x:1,y:-1
Distance returns 1.4142135623730951

Screen Shot 2013-09-12 at 11.21.17.png

3rd test:
I've moved the dog to tile x:0,y:2, however overTiles() reports it's on x:2,y:2
Distance returns 2.8284271247461903

Screen Shot 2013-09-12 at 11.21.31.png

4th test:
I've moved the dog to tile x:9,y:9 however overTiles() reports it's on x:14,y:5
Distance returns 14.866068747318506

[coolbloke1324]

Hey answering from my phone so will be short at moment but points are 2d unless told otherwise. Check iso example quests in character container class to see how to get iso coordinates from 2d point. It is very easy has built in method in igepoint.

Rob

[robaldred]

Ahh magic!

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entity._parent.pointToTile(entity._translate.toIso())

Thanks, I thought I was going crazy

[robaldred]

Hi again, so the tile positions are good!
However the distance method that's added to Math seems to get less accurate the further the distance.

eg.
Sheep is on 0,0

.1
I've moved the dog so it's on tile x:5 y:5
with diagonal pathing, the dog is 5 tiles away from the sheep.
However, distance calculation says 7

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Math.distance(0,0,5,5) # => 7.0710678118654755

.2
Moving dog to 9,9 distance returns 12

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Math.distance(0,0,9,9) # => 12.727922061357855

It's good enough for what I need, I need to check for entities on neighbouring tiles.

[coolbloke1324]

Distance is calculated via pythagorean theorem and your results are correct. Remember the values are 2d coordinates not projected to isometric. The distance still works though. It is the hypotenuse line from point to point.

[robaldred]

Do you know what maths would be to reliably calculate the distance in tiles between two iso tile points?

[coolbloke1324]

Do you know what maths would be to reliably calculate the distance in tiles between two iso tile points?

X distance = startx - endx
Y distance = starty - endy

Now you know how many tiles in each vector the start position is away from the end position.

[robaldred]

Thanks for your help Rob

[zaquanishak]

Hi,
im having the same problem about the overTiles() method. Currently im using the overTiles method in my characterContainer class update method to compare which tile the character is step on. The code as below.

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 var tiles = this.overTiles(), playerReachDoor = false;

                if((tiles[0].x === 1) && (tiles[0].y === 1)){
                playerReachDoor = true;
                if(playerReachDoor === true){
                    ige.network.send('goToDoor' , {id: this.id() , map:2});
                    playerReachDoor = false;
                }

                this.break;
            }

but the location of the tiles is not the same similar problem as robaldred. So i would like to as how to i use

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entity._parent.pointToTile(entity._translate.toIso())

to convert the overTiles method to be isometric?

Please advise.

Regards,
Zachz

[coolbloke1324]

Hey ya,

I believe this has now been answered in a different question thread you made.