/// <summary>
/// Detects and resolves collisions between the Player and the glidingPlatform nearest him.
/// </summary>
public void HandleGlidingPlatformCollisions()
{
// Did I just collide with a gliding platform?
foreach (GlidingPlatform platform in Level.playerPlatforms)
// To know this we have to check the list of platforms in
// the camera's visible range
// which we collected from the level calss
{
// We check if the player's feet intersect with the platform's surface.
if (platform.Surface.Intersects(Feet))
{
OnPlatform(platform); // If so, then this is the platform we want to save.
}
}
// If I own a platform
if (isOnPlatform == true)
{
// reset isOnPlatform for the purposes of evaluating it again.
isOnPlatform = false;
// Do they intersect?
if (Feet.Intersects(platform.Surface))
{
isOnPlatform = true;
//Yes they intersect. By how deep?
Vector2 depth = RectangleExtensions.GetIntersectionDepth(Feet, platform.Surface);
// Is it more than zero?
if (depth != Vector2.Zero)
{
// Yes they intersect and it is more than zero depth!
// Find out by how much.
float absDepthX = Math.Abs(depth.X);
float absDepthY = Math.Abs(depth.Y);
// Act as if we are on the ground if we were previously on the a platform.
if (previousBottom >= platform.Surface.Top)
{
isOnGround = true;
}
if (isOnPlatform)
{
// Resolve the collision along the Y axis.
Position = new Vector2(Position.X /*+ platform.Position.X*/, Position.Y - Math.Abs(depth.Y));
}
}
}
}
// Check if the player's Y has moved through a platform's surface.
foreach (GlidingPlatform platform in level.playerPlatforms)
{
if ((position.Y > platform.Surface.Top - 12) && (position.Y < platform.Surface.Top + 12) &&
(position.X > platform.Surface.Left - BoundingRectangle.Width / 2) &&
(position.X < platform.Surface.Right + BoundingRectangle.Width / 2) &&
(velocity.Y > 0)) // if the velocity is negative the player is jumping up.
// If the player is jumping up, we don't want him to stick, only when moving down.
// The speed the player moves with a MaxFallSpeed of 600.0f is 12 pixels per second.
// If we don't check this condition, the player can jump right past the surface of the platform,
// and the game will never know to make the player stick!
{
OnPlatform(platform);
position.Y = platform.Surface.Top;
}
}
previousBottom = BoundingRectangle.Bottom;
}
/// <summary>
/// Moves the platform along a path, waiting at either end.
/// </summary>
public void Update(GameTime gameTime)
{
bool mustmove = true;
// Get the bounding rectangle and find neighboring tiles.
Rectangle bounds = BoundingRectangle;
int leftTile = (int)Math.Floor((float)bounds.Left / Tile.Width);
int rightTile = (int)Math.Ceiling(((float)bounds.Right / Tile.Width)) - 1;
int topTile = (int)Math.Floor((float)bounds.Top / Tile.Height);
int bottomTile = (int)Math.Ceiling(((float)bounds.Bottom / Tile.Height)) - 1;
// For each potentially colliding tile,
for (int y = topTile; y <= bottomTile; ++y)
{
for (int x = leftTile; x <= rightTile; ++x)
{
// If this tile is collidable,
TileCollision collision = Level.GetCollision(x, y);
if (collision != TileCollision.Passable)
{
// Determine collision depth (with direction) and magnitude.
Rectangle tileBounds = Level.GetBounds(x, y);
Vector2 depth = RectangleExtensions.GetIntersectionDepth(bounds, tileBounds);
if (depth != Vector2.Zero)
{
float elapsed = (float)gameTime.ElapsedGameTime.TotalSeconds;
direction = (FaceDirection)(-(int)direction);
if (glidermovement == TileMovement.Vertical)
{
Position = new Vector2(Position.X, Position.Y + depth.Y);
}
else if (glidermovement == TileMovement.Horizontal)
{
Position = new Vector2(Position.X + depth.X, Position.Y);
}
mustmove = false;
break;
}
}
}
if (!mustmove)
{
break;
}
}
if (mustmove)
{
float elapsed = (float)gameTime.ElapsedGameTime.TotalSeconds;
if (position.Y < 0.0f - bounds.Height)
{
position = new Vector2(position.X, (level.Height * Tile.Height) + bounds.Height);
}
else if (position.Y > (level.Height * Tile.Height) + bounds.Height)
{
position = new Vector2(position.X, 0.0f);
}
else
{
if (glidermovement == TileMovement.Vertical)
{
Vector2 velocity = new Vector2(0.0f, (int)direction * moveSpeed * elapsed);
position = position + velocity;
}
else if (glidermovement == TileMovement.Horizontal)
{
Vector2 velocity = new Vector2((int)direction * moveSpeed * elapsed, 0.0f);
position = position + velocity;
}
}
}
}
/// <summary>
/// Detects and resolves all collisions between the player and his neighboring
/// tiles. When a collision is detected, the player is pushed away along one
/// axis to prevent overlapping. There is some special logic for the Y axis to
/// handle platforms which behave differently depending on direction of movement.
/// </summary>
private void HandleCollisions()
{
// Get the player's bounding rectangle and find neighboring tiles.
Rectangle bounds = BoundingRectangle;
int leftTile = (int)Math.Floor((float)bounds.Left / Tile.Width);
int rightTile = (int)Math.Ceiling(((float)bounds.Right / Tile.Width)) - 1;
int topTile = (int)Math.Floor((float)bounds.Top / Tile.Height);
int bottomTile = (int)Math.Ceiling(((float)bounds.Bottom / Tile.Height)) - 1;
// Reset flag to search for ground collision.
isOnGround = false;
// For each potentially colliding tile,
for (int y = topTile; y <= bottomTile; ++y)
{
for (int x = leftTile; x <= rightTile; ++x)
{
// If this tile is collidable,
TileCollision collision = Level.GetCollision(x, y);
if (collision != TileCollision.Passable)
{
// Determine collision depth (with direction) and magnitude.
Rectangle tileBounds = Level.GetBounds(x, y);
Vector2 depth = RectangleExtensions.GetIntersectionDepth(bounds, tileBounds);
if (depth != Vector2.Zero)
{
float absDepthX = Math.Abs(depth.X);
float absDepthY = Math.Abs(depth.Y);
// Resolve the collision along the shallow axis.
if (absDepthY < absDepthX || collision == TileCollision.Platform)
{
// If we crossed the top of a tile, we are on the ground.
if (previousBottom <= tileBounds.Top)
{
isOnGround = true;
}
// Ignore platforms, unless we are on the ground.
if (collision == TileCollision.Impassable || IsOnGround)
{
// Resolve the collision along the Y axis.
Position = new Vector2(Position.X, Position.Y + depth.Y);
// Perform further collisions with the new bounds.
bounds = BoundingRectangle;
}
}
else if (collision == TileCollision.Impassable) // Ignore platforms.
{
// Resolve the collision along the X axis.
Position = new Vector2(Position.X + depth.X, Position.Y);
// Perform further collisions with the new bounds.
bounds = BoundingRectangle;
}
}
}
}
}
// Save the new bounds bottom.
// previousBottom = bounds.Bottom;
}