Player.Update() now uses Bresenham's line algorithm.

This works, but is still a bit hacky. Cleanups to follow soon.

GitOrigin-RevId: 597a857a200584fee2c06237d7d7dd10403bdfeb
This commit is contained in:
Colin McMillen 2020-01-29 15:43:00 -05:00
parent 4410ff137a
commit 946497160b

View File

@ -1,5 +1,6 @@
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using System;
using System.Collections.Generic;
namespace SemiColinGames {
@ -17,10 +18,12 @@ namespace SemiColinGames {
private const int gravity = 2400;
private const int spriteSize = 48;
// TODO: rename to spriteHalfWidth / spriteHalfHeight.
private const int spriteWidth = 7;
private const int spriteHeight = 13;
private readonly Texture2D texture;
private Point position = new Point(64, 16 * 14);
private Point position = new Point(64, 16 * 10);
private int jumps = 0;
private Facing facing = Facing.Right;
private Pose pose = Pose.Jumping;
@ -43,65 +46,89 @@ namespace SemiColinGames {
}
private Aabb Box(Point position, int yOffset) {
return new Aabb(new Vector2(position.X, position.Y - 7 + 13 + yOffset),
new Vector2(spriteWidth, 13));
return new Aabb(new Vector2(position.X, position.Y - 7 + spriteHeight + yOffset),
new Vector2(spriteWidth, spriteHeight));
}
public void Update(float modelTime, History<Input> input, Rectangle[] collisionTargets) {
Point oldPosition = position;
Vector2 movement = HandleInput(modelTime, input);
position = new Point((int) (oldPosition.X + movement.X), (int) (oldPosition.Y + movement.Y));
Rectangle oldBbox = Bbox(oldPosition);
Rectangle playerBbox = Bbox(position);
bool standingOnGround = false;
// TODO: we shouldn't hardcode the tile sizes here.
Vector2 halfBoxSize = new Vector2(World.TileSize / 2, World.TileSize / 2);
foreach (var rect in collisionTargets) {
Aabb rectBox = new Aabb(
// Broad test: remove all collision targets nowhere near the player.
List<Rectangle> candidates = new List<Rectangle>();
// TODO: This is strictly larger than it needs to be. We could expand only in the actual
// direction of movement.
Aabb largeBox = new Aabb(
new Vector2(position.X, position.Y - 7 + spriteHeight), // current player position
new Vector2(spriteWidth + Math.Abs(movement.X), spriteHeight + Math.Abs(movement.Y)));
for (int i = 0; i < collisionTargets.Length; i++) {
Rectangle rect = collisionTargets[i];
Aabb box = new Aabb(
new Vector2(rect.X + World.TileSize / 2, rect.Y + World.TileSize / 2), halfBoxSize);
Aabb playerBox = Box(position);
playerBbox = Bbox(position);
// first we check for left-right collisions...
if (playerBox.Intersect(rectBox) != null) {
if (oldBbox.Right <= rect.Left && playerBbox.Right > rect.Left) {
position.X = rect.Left - spriteWidth;
}
if (oldBbox.Left >= rect.Right && playerBbox.Left < rect.Right) {
position.X = rect.Right + spriteWidth;
}
playerBox = Box(position);
if (box.Intersect(largeBox) != null) {
Debug.AddRect(box, Color.Green);
candidates.Add(rect);
}
// after fixing that, we check for hitting our head or hitting the ground.
if (playerBox.Intersect(rectBox) != null) {
if (oldPosition.Y > position.Y) {
int diff = playerBbox.Top - rect.Bottom;
position.Y -= diff;
// TODO: set ySpeed = 0 here so that bonking our head actually reduces hangtime?
} else {
standingOnGround = true;
int diff = playerBbox.Bottom - rect.Top;
position.Y -= diff;
}
Point[] movePoints = Line.Rasterize(0, 0, (int) movement.X, (int) movement.Y);
for (int i = 1; i < movePoints.Length; i++) {
int dx = movePoints[i].X - movePoints[i - 1].X;
int dy = movePoints[i].Y - movePoints[i - 1].Y;
if (dy != 0) {
Point newPosition = new Point(position.X, position.Y + dy);
Aabb player = Box(newPosition);
bool reject = false;
foreach (var rect in candidates) {
Aabb box = new Aabb(
new Vector2(rect.X + World.TileSize / 2, rect.Y + World.TileSize / 2), halfBoxSize);
if (box.Intersect(player) != null) {
reject = true;
break;
}
}
} else {
playerBox = Box(position, 1);
if (playerBox.Intersect(rectBox) != null) {
standingOnGround = true;
Debug.AddRect(rect, Color.Cyan);
} else {
Debug.AddRect(rect, Color.Green);
if (!reject) {
position = newPosition;
}
}
if (dx != 0) {
Point newPosition = new Point(position.X + dx, position.Y);
Aabb player = Box(newPosition);
bool reject = false;
foreach (var rect in candidates) {
Aabb box = new Aabb(
new Vector2(rect.X + World.TileSize / 2, rect.Y + World.TileSize / 2), halfBoxSize);
if (box.Intersect(player) != null) {
reject = true;
break;
}
}
if (!reject) {
position = newPosition;
}
}
}
bool standingOnGround = false;
Aabb groundIntersect = Box(position, 1);
foreach (var rect in candidates) {
Aabb box = new Aabb(
new Vector2(rect.X + World.TileSize / 2, rect.Y + World.TileSize / 2), halfBoxSize);
if (groundIntersect.Intersect(box) != null) {
standingOnGround = true;
Debug.AddRect(rect, Color.Cyan);
// break;
}
}
if (standingOnGround) {
jumps = 1;
ySpeed = 0;
Debug.AddRect(playerBbox, Color.Red);
ySpeed = -0.0001f;
// Debug.AddRect(playerBbox, Color.Red);
} else {
jumps = 0;
Debug.AddRect(playerBbox, Color.Orange);
// Debug.AddRect(playerBbox, Color.Orange);
}
if (movement.X > 0) {