/// <summary>
/// Will check if the given character has collided with a tile
/// in the level and then handle the position correction.
/// ENSURE: the given character will not be colliding with any tiles.
/// </summary>
private void checkTileCollision(Character.Character character)
{
//for every tile in the level
foreach (Tile tile in this.level_tiles)
{
//save the character's bounding box
Rectangle character_bounds = character.BoundingBox();
//now get the character's current velocity
Vector2 character_velocity = character.currentSpeed();
//compute the future position of the character
Rectangle future_bounds = new Rectangle(
character_bounds.X + (int)character_velocity.X,
character_bounds.Y + (int)character_velocity.Y,
character_bounds.Width, character_bounds.Height);
//check if the character WILL collide with this tile
if (tile.collidesWith(future_bounds)){
//find how much overlap is occuring
Rectangle intersection = Rectangle.Intersect(tile.destinationRectangle, future_bounds);
//alter the characters velocity to take the collision into account
Vector2 offset = new Vector2();
//if the character has horizontal velocity
//and isn't jumping or falling
if ((character.isJumping() == false && character.isFalling() == false)
&& character_velocity.X != 0)
{
//compute the horizontal offset
offset.X = (character_velocity.X > 0) ?
(intersection.X - intersection.Right) : //negative offset if positive velocity
(intersection.Right - intersection.X); //positive offset if negative velocity
//add the offset to the velocity value
//character_velocity.X = character_velocity.X + offset.X;
}
//if the character has vertical velocity
if (character_velocity.Y != 0)
{
//they are jumping or falling into this object
//first fix their vertical forces
//if the character has a positive vertical velocity
if (character_velocity.Y > 0)
{
//then the offset needs to be negative
offset.Y = (intersection.Y - intersection.Bottom) -1;
//this also means the character has hit ground
//character.ground();
}
//otherwise, the velocity is negative
else
{
//so the offset needs to be positive
offset.Y = (intersection.Bottom - intersection.Y);
//the character hit the bottom of something, fall
character.fall();
}
//now they might have horizontal forces,
//before we fix them, see if the character is no longer colliding
//compute the future position of the character
Rectangle new_future_bounds = new Rectangle(
future_bounds.X + (int)offset.X,
future_bounds.Y + (int)offset.Y,
future_bounds.Width, future_bounds.Height);
if (tile.collidesWith(new_future_bounds))
{
//then fix the horizontal forces
Rectangle new_intersection = Rectangle.Intersect(tile.destinationRectangle, new_future_bounds);
//compute the horizontal offset
offset.X = (character_velocity.X > 0) ?
(intersection.X - intersection.Right) : //negative offset if positive velocity
(intersection.Right - intersection.X); //positive offset if negative velocity
}
}
character_velocity.X = character_velocity.X + offset.X;
character_velocity.Y = character_velocity.Y + offset.Y;
//give the player it's new position
character.setVelocity(character_velocity);
}
}
}
/// <summary>
/// Returns whether or not the tile is under the given character.
/// ENSURE: if the tile is immidiately below the character,
/// return true
/// otherwise,
/// return false
/// </summary>
internal bool isUnder(Character.Character character)
{
bool result = false;
Rectangle box = character.BoundingBox();
//if the box is within the correct horizontal scope
if ((box.Left <= this.destinationRectangle.Right &&
box.Left >= this.destinationRectangle.Left) ||
(box.Right <= this.destinationRectangle.Right &&
box.Right >= this.destinationRectangle.Left))
{
//if this tile is immidiate below the character
if (box.Bottom < this.destinationRectangle.Top &&
box.Bottom > (this.destinationRectangle.Top - 5))
{
result = true;
}
}
return result;
}
/// <summary>
/// Will check if the given character has collided with another character.
/// If so, the opposing character will be removed from play.
/// </summary>
private void checkCharacterCollision(Character.Character character)
{
//for every enemy alive
foreach (Character.Enemy enemy in this.character_manager.enemyList())
{
//if the enemy is alive
if (enemy.isAlive() == true)
{
//check if it is overlapping with the given character
if (enemy.BoundingBox().Intersects(character.BoundingBox()))
{
//then remove the enemy from play
enemy.kill();
}
}
}
}
