CollisionMap

Defined in Module impact.collision-map, inherits from ig.Map

Synopsis

// Create CollisionMap
var data = [
	[1,2,6],
	[0,3,5],
	[2,8,1],
];
var collision = new ig.CollisionMap( 16, data );

// Do a trace
var res = collision.trace( x, y, vx, vy, objectWidth, objectHeight );

if( res.collision.x || res.collision.y ) {
	// The trace collided with the map at
	// (res.pos.x, res.pos.y)
}

Description

An ig.Collision takes a 2D tilemap and allows tracing against it for collisions.

The ig.Game class' .loadLevel() method takes the save data from Weltmeister and creates a CollisonMap if present.

By default, all entities trace against the ig.game.collisionMap as part of their update cycle.

Constructor

new ig.CollisionMap( tilesize, data, [tiledef] )

tilesize Width and height of a single tile in pixels
data A 2D Array (Array of Arrays) indicating where to draw which tile from the Tileset.

New in 1.19

The optional tiledef parameter specifies the tile definition to use. This defines which tiles are slopes etc. The default is ig.CollisionMap.defaultTileDef. Pass an empty object ({}) to only have solid/non-solid tiles.

Properties

.firstSolidTile

Removed in 1.19

First tile number that is considered solid. Default 1.

.lastSolidTile

Removed in 1.19

Last tile number that is considered solid. Default 255.

.lastSlope

New in 1.20

The last tile number that is used for slopes. All tiles above this number can be used for custom tiles. .lastSlope is automatically determined by the constructor through the tiledef property.

Methods

.trace( x, y, sx, sy, objectWidth, objectHeight )

Does a trace from (x, y) to (x + sx, y + sy) for an object with the specified objectWidth and objectHeight. This method returns a "trace result" in the following form:

{
	collision: { x: false, y: false, slope: false },
	pos: { x: 0, y: 0 }, // Resulting object position
	tile: { x: 0, y: 0 } // Tile for the collision
}