public void CollideAxis(PhysicalObject obj, Vector2 startpos, Vector2 move, Axis axis)
{
float xcol = 0.05f;
bool touch_u = false;
bool touch_r = false;
bool touch_d = false;
bool touch_l = false;
obj.on_ladder[(int)axis] = false;
Vector2 feet = new Vector2(startpos.X, startpos.Y + obj.hitbox.Y);
if (axis == Axis.X)
{
move = new Vector2(move.X, 0);
//if the ground is a slope, include the Y-movement
if (obj.surface_k != 0)
if (move.X * -obj.surface_k < 0)
move.Y = move.X * -obj.surface_k;
}
else
move = new Vector2(0, move.Y);
obj.pos += move;
int index_x = (int)obj.pos.X;
int index_y = (int)obj.pos.Y;
//how many tiles can the object potentially collide with
int width = (int)Math.Ceiling(obj.hitbox.X) + 1;
int height = (int)Math.Ceiling(obj.hitbox.Y) + 1;
//get a list of all those
int[][] check = new int[width * height][];
int c = 0;
for (int w = 0; w < width; w++)
for (int h = 0; h < height; h++)
{
check[c] = new int[] { w + index_x, h + index_y };
c++;
}
for (int i = 0; i < check.Length; i++)
{
Vector4 playerHitBox = new Vector4(obj.pos.X, obj.pos.Y, obj.hitbox.X, obj.hitbox.Y);
//todo: other blocktypes
//upper left corner of the tile
int x = check[i][0];
int y = check[i][1];
if (x >= 0 && x < map[0].Length && y >= 0 && y < map.Length)
{
//get the tile from map
Tile tile = map[y][x];
//reusable variables
Vector4 tileHitBox;
switch (tile.tileType)
{
case Tile.TileType.scenery:
break;
case Tile.TileType.solid:
if (tile.GetType() == typeof(Slope))
{
//SLABS / HALF-BLOCKS
Slope slope = tile as Slope;
if (slope.side == Slope.Side.floor)
tileHitBox = new Vector4(x, y + (1f - slope.leftY), 1, slope.leftY);
else
tileHitBox = new Vector4(x, y, 1, slope.leftY);
}
else
tileHitBox = new Vector4(x, y, 1, 1);//Regular square
//Does it collide?
if (VectorIntersect(playerHitBox, tileHitBox))
{
if (axis == Axis.X)
{
if (move.X > 0)
{
obj.pos.X = x - obj.hitbox.X;
touch_r = true;
//reset velocity
obj.velocity.X = xcol;
}
else
{
obj.pos.X = x + 1;
touch_l = true;
obj.velocity.X = -xcol;
}
}
else
{
if (playerHitBox.Y < tileHitBox.Y)
{
obj.pos.Y = tileHitBox.Y - obj.hitbox.Y;//tile y pos - player height
touch_d = true;
}
else
{
obj.pos.Y = tileHitBox.Y + tileHitBox.W;//tile y pos + tile height
touch_u = true;
}
//reset velocity
obj.velocity.Y = 0;
obj.surface_k = 0;
}
}
break;
case Tile.TileType.platform:
if (axis == Axis.Y)
{
tileHitBox = new Vector4(x, y, 1, 1);//Regular square
float slope_m;
float slope_k = 0;
float slope_x;
bool was_above = false;
Slope slope = new Slope(Tile.TileType.platform, Slope.Side.floor, 0f, 0f);
if (tile.GetType() == typeof(Slope))
{
//SLOPES
//y = kx + m
//m -> plat.Y
//k -> plat.right - plat.left
//x -> player.x - plat.x
slope = tile as Slope;
if (slope.leftY == slope.rightY)//slab
{
if (slope.side == Slope.Side.roof)//roof slab
tileHitBox = new Vector4(x, y, 1, slope.leftY);
else//floor slab
tileHitBox = new Vector4(x, (float)y + (1f - slope.leftY), 1, slope.leftY);
}
else
{
if (slope.side == Slope.Side.floor)
{
slope_m = slope.leftY;
slope_k = slope.rightY - slope.leftY;
slope_x = playerHitBox.X + playerHitBox.Z / 2f - (float)x;
float slopeheight = get_slopeheight(slope_k, x, slope_m, slope, obj.pos.X, obj.pos.X + obj.hitbox.X);
float old_slopeheight = get_slopeheight(slope_k, x, slope_m, slope, feet.X, feet.X + obj.hitbox.X);
tileHitBox = new Vector4(x, (float)y + (1f - slopeheight), 1, slopeheight);
was_above = feet.Y <= (float)y + (1f - old_slopeheight) + 0.0001f;
}
}
}
if (VectorIntersect(playerHitBox, tileHitBox) && (feet.Y <= tileHitBox.Y || was_above))
{
//do collision
if (slope.side == Slope.Side.floor)
{
obj.pos.Y = tileHitBox.Y - obj.hitbox.Y;//tile y pos - player height
touch_d = true;
}
else
{
obj.pos.Y = tileHitBox.Y + tileHitBox.W;//tile y pos + tile height
touch_u = true;
}
obj.velocity.Y = 0;
obj.surface_k = slope_k;
}
}
break;
case Tile.TileType.ladder:
tileHitBox = new Vector4(x + 1f/3, y - 1f/3, 1f/2, 4f/3); //The hitbox is "squeezed" along the x-axis to avoid the ladder being grabbed with minimal overlap.
if (VectorIntersect(tileHitBox, playerHitBox))
{
obj.on_ladder[(int)axis] = true;
}
break;
case Tile.TileType.death:
break;
case Tile.TileType.win:
break;
}
}
}
//update the objects intel
if (axis == Axis.X)
{
obj.touch_left.Update(touch_l);
obj.touch_right.Update(touch_r);
}
else
{
obj.touch_down.Update(touch_d);
obj.touch_up.Update(touch_u);
}
}
public bool Collides(PhysicalObject obj)
{
Vector4 rec1 = new Vector4(pos.X, pos.Y, hitbox.X, hitbox.Y);
Vector4 rec2 = new Vector4(obj.pos.X, obj.pos.Y, obj.hitbox.X, obj.hitbox.Y);
Vector2 pos1 = new Vector2(rec1.X + rec1.Z / 2f, rec1.Y + rec1.W / 2f);
Vector2 pos2 = new Vector2(rec2.X + rec2.Z / 2f, rec2.Y + rec2.W / 2f);
return (Math.Abs(pos1.X - pos2.X) < (rec1.Z + rec2.Z) / 2 //if ΔX < medelvärdet av width
&&
Math.Abs(pos1.Y - pos2.Y) < (rec1.W + rec2.W) / 2); //if ΔY < medelvärdet av height
}
public void UpdatePhysicalObject(PhysicalObject obj)
{
//store start position and velocity
Vector2 pos = obj.pos;
Vector2 vel = obj.velocity;
//move on the X-axis
CollideAxis(obj, pos, obj.velocity, Axis.X);
//since the slope-movement (int the Y axis) is already included in the X-step if the ground is sloped,
//remove the slopes' Y movement
float correction = 0f;
if (obj.surface_k != 0)
if (vel.X * -obj.surface_k < 0)
correction = vel.X * obj.surface_k;
else
correction += 0.1f;//make sure the character gets pushed down to the ground
//reset surface
obj.surface_k = 0;
//move on the Y-axis
CollideAxis(obj, pos, obj.velocity + new Vector2(0, correction), Axis.Y);
}
