45° Slopes in a Tile based 2D platformer
- by xNidhogg
I want to have simple 45° slopes in my tile based platformer, however I just cant seem to get the algorithm down. Please take a look at the code and video, maybe I'm missing the obvious?
//collisionRectangle is the collision rectangle of the player with
//origin at the top left and width and height
//wantedPosition is the new position the player will be set to.
//this is determined elsewhere by checking the bottom center point of the players rect
if(_leftSlope || _rightSlope)
{
//Test bottom center point
var calculationPoint = new Vector2(collisionRectangle.Center.X, collisionRectangle.Bottom);
//Get the collision rectangle of the tile, origin is top-left
Rectangle cellRect =
_tileMap.CellWorldRectangle(
_tileMap.GetCellByPixel(calculationPoint));
//Calculate the new Y coordinate depending on if its a left or right slope
//CellSize = 8
float newY = _leftSlope
? (calculationPoint.X % CellSize) + cellRect.Y
: (-1 * (calculationPoint.X % CellSize) - CellSize) + cellRect.Y;
//reset variables so we dont jump in here next frame
_leftSlope = false;
_rightSlope = false;
//now change the players Y according to the difference of our calculation
wantedPosition.Y += newY - calculationPoint.Y;
}
Video of what it looks like:
http://youtu.be/EKOWgD2muoc
