public void BindEntityToTiles(GameEntity entity, bool bind)
{
for (int i = getTileIndexFromLeftEdgeX(entity.getLeftEdgeX()); i <= getTileIndexFromRightEdgeX(entity.getRightEdgeX()); i++)
{
for (int j = getTileIndexFromTopEdgeY(entity.getTopEdgeY()); j <= getTileIndexFromBottomEdgeY(entity.getBottomEdgeY()); j++)
{
Tile currTile = currLevel.getTile(i, j);
if (currTile != null) //if within bounds of level
{
currLevel.getTile(i, j).BindEntity(entity, bind);
}
}
}
}
public void moveGameEntity(GameEntity entity, int dx, int dy)
{
BindEntityToTiles(entity, false);
if (!entity.isCollidable()) //skip collision detection
{
moveGameEntityWithoutCollision(entity, entity.x + dx, entity.y + dy);
BindEntityToTiles(entity, true);
return;
}
bool wallCollision = false;
//calculate number of tiles distance covers
int tilesX = (int)Math.Floor((float)Math.Abs(dx) / Static.TILE_WIDTH) + 1;
int tilesY = (int)Math.Floor((float)Math.Abs(dy) / Static.TILE_HEIGHT) + 1;
//get entity bounds
int leftEdgeTile = getTileIndexFromLeftEdgeX(entity.getLeftEdgeX());
int rightEdgeTile = getTileIndexFromRightEdgeX(entity.getRightEdgeX());
int topEdgeTile = getTileIndexFromTopEdgeY(entity.getTopEdgeY());
int bottomEdgeTile = getTileIndexFromBottomEdgeY(entity.getBottomEdgeY());
int distanceToTravelX = dx;
int distanceToTravelY = dy;
//find distance to level boundary in movement direction and see if it is less move amount
//figure out how many tiles your movement translates to in each direction
//scan tiles in front of you to find closest obstacle in that direction
//final movement is min of original movement and distance to obstacle
if (dx > 0)
{
//right
int distanceToBoundary = currLevel.GetTilesHorizontal() * Static.TILE_WIDTH - entity.getRightEdgeX();
if (distanceToBoundary < distanceToTravelX)
{
distanceToTravelX = distanceToBoundary;
//wallCollision = true;
}
int tilesToScanX = tilesX;
if (rightEdgeTile + tilesToScanX > currLevel.GetTilesHorizontal() - 1)
{
tilesToScanX = currLevel.GetTilesHorizontal() - 1 - rightEdgeTile;
}
for (int i = 1; i <= tilesToScanX; i++)
{
for (int j = topEdgeTile; j <= bottomEdgeTile; j++)
{
Tile currTile = currLevel.getTile(rightEdgeTile + i, j);
if (currTile.isObstacle())
{
int distanceToTile = currTile.x - entity.getRightEdgeX();
if (distanceToTile < distanceToTravelX)
{
distanceToTravelX = distanceToTile;
wallCollision = true;
break;
}
}
GameEntity closest = null;
foreach (GameEntity tileEntity in currTile.getEntities())
{
if (tileEntity.getLeftEdgeX() - entity.getRightEdgeX() < distanceToTravelX)
{
if (tileEntity.OverlapsY(entity))
{
distanceToTravelX = tileEntity.getLeftEdgeX() - entity.getRightEdgeX();
closest = tileEntity;
}
}
}
if (closest != null)
{
collisions.Add(new Collision(entity, closest));
}
}
}
}
else if (dx < 0)
{
//left
int distanceToBoundary = -1 * entity.getLeftEdgeX();
if (distanceToBoundary > distanceToTravelX)
{
distanceToTravelX = distanceToBoundary;
//wallCollision = true;
}
int tilesToScanX = tilesX;
if (leftEdgeTile - tilesToScanX < 0)
{
tilesToScanX = leftEdgeTile;
}
for (int i = 1; i <= tilesToScanX; i++)
{
for (int j = topEdgeTile; j <= bottomEdgeTile; j++)
{
Tile currTile = currLevel.getTile(leftEdgeTile - i, j);
if (currTile.isObstacle())
{
int distanceToTile = (currTile.x + Static.TILE_WIDTH) - entity.getLeftEdgeX();
if (distanceToTile > distanceToTravelX)
{
distanceToTravelX = distanceToTile;
wallCollision = true;
break;
}
}
GameEntity closest = null;
foreach (GameEntity tileEntity in currTile.getEntities())
{
if (tileEntity.getRightEdgeX() - entity.getLeftEdgeX() > distanceToTravelX)
{
if (tileEntity.OverlapsY(entity))
{
distanceToTravelX = tileEntity.getRightEdgeX() - entity.getLeftEdgeX();
closest = tileEntity;
}
}
}
if (closest != null)
{
collisions.Add(new Collision(entity, closest));
}
}
}
}
entity.x = entity.x + distanceToTravelX;
entity.hitbox.Offset(distanceToTravelX, 0);
leftEdgeTile = getTileIndexFromLeftEdgeX(entity.getLeftEdgeX());
rightEdgeTile = getTileIndexFromRightEdgeX(entity.getRightEdgeX());
if (dy > 0)
{ //down
int distanceToBoundary = currLevel.GetTilesVertical() * Static.TILE_HEIGHT - entity.getBottomEdgeY();
if (distanceToBoundary < distanceToTravelY)
{
distanceToTravelY = distanceToBoundary;
//wallCollision = true;
}
int tilesToScanY = tilesY;
if (bottomEdgeTile + tilesToScanY > currLevel.GetTilesVertical() - 1)
{
tilesToScanY = currLevel.GetTilesVertical() - 1 - bottomEdgeTile;
}
for (int i = 1; i <= tilesToScanY; i++)
{
for (int j = leftEdgeTile; j <= rightEdgeTile; j++)
{
Tile currTile = currLevel.getTile(j, bottomEdgeTile + i);
if (currTile.isObstacle())
{
int distanceToTile = currTile.y - entity.getBottomEdgeY();
if (distanceToTile < distanceToTravelY)
{
distanceToTravelY = distanceToTile;
wallCollision = true;
break;
}
}
GameEntity closest = null;
foreach (GameEntity tileEntity in currTile.getEntities())
{
if (tileEntity.getTopEdgeY() - entity.getBottomEdgeY() < distanceToTravelY)
{
if (tileEntity.OverlapsX(entity))
{
distanceToTravelY = tileEntity.getTopEdgeY() - entity.getBottomEdgeY();
closest = tileEntity;
}
}
}
if (closest != null)
{
collisions.Add(new Collision(entity, closest));
}
}
}
}
else if (dy < 0)
{ //up
int distanceToBoundary = -1 * entity.getTopEdgeY();
if (distanceToBoundary > distanceToTravelY)
{
distanceToTravelY = distanceToBoundary;
//wallCollision = true;
}
int tilesToScanY = tilesY;
if (topEdgeTile - tilesToScanY < 0)
{
tilesToScanY = topEdgeTile;
}
for (int i = 1; i <= tilesToScanY; i++)
{
for (int j = leftEdgeTile; j <= rightEdgeTile; j++)
{
Tile currTile = currLevel.getTile(j, topEdgeTile - i);
if (currTile.isObstacle())
{
int distanceToTile = (currTile.y + Static.TILE_HEIGHT) - entity.getTopEdgeY();
if (distanceToTile > distanceToTravelY)
{
distanceToTravelY = distanceToTile;
wallCollision = true;
break;
}
}
GameEntity closest = null;
foreach (GameEntity tileEntity in currTile.getEntities())
{
if (tileEntity.getBottomEdgeY() - entity.getTopEdgeY() > distanceToTravelY)
{
if (tileEntity.OverlapsX(entity))
{
distanceToTravelY = tileEntity.getBottomEdgeY() - entity.getTopEdgeY();
closest = tileEntity;
}
}
}
if (closest != null)
{
collisions.Add(new Collision(entity, closest));
}
}
}
}
entity.y = entity.y + distanceToTravelY;
entity.hitbox.Offset(0, distanceToTravelY);
if (wallCollision)
{
entity.collideWithWall();
}
BindEntityToTiles(entity, true);
}
public bool OverlapsX(GameEntity entity)
{
return ((this.getRightEdgeX() > entity.getLeftEdgeX() && this.getRightEdgeX() < entity.getRightEdgeX())
|| (this.getLeftEdgeX() < entity.getRightEdgeX() && this.getLeftEdgeX() > entity.getLeftEdgeX())
|| (this.getLeftEdgeX() >= entity.getLeftEdgeX() && this.getRightEdgeX() <= entity.getRightEdgeX())
|| (this.getLeftEdgeX() <= entity.getLeftEdgeX() && this.getRightEdgeX() >= entity.getRightEdgeX()));
}