using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Graphics; using Microsoft.Xna.Framework.Input; using System; using System.Collections.Generic; namespace Jumpy { class Player { enum Facing { Left, Right }; enum Pose { Walking, Standing, Crouching, Stretching, SwordSwing, Jumping }; enum AirState { Jumping, Ground, Falling }; private Texture2D texture; private const int spriteSize = 48; private const int spriteWidth = 7; private const int moveSpeed = 180; private const int jumpSpeed = 600; private const int gravity = 2400; private Point position = new Point(64, 16); private Facing facing = Facing.Right; private Pose pose = Pose.Standing; private AirState airState = AirState.Ground; private double swordSwingTime = 0; private double jumpTime = 0; private double ySpeed = 0; public Player(Texture2D texture) { this.texture = texture; } public Point Position { get { return position; } } private Rectangle Bbox(Point position) { return new Rectangle(position.X - spriteWidth, position.Y - 7, spriteWidth * 2, 26); } public void Update( GameTime time, History gamePad, History keyboard, List collisionTargets) { Point oldPosition = position; AirState oldAirState = airState; UpdateFromInput(time, gamePad, keyboard); Rectangle oldBbox = Bbox(oldPosition); Rectangle playerBbox = Bbox(position); bool standingOnGround = false; // TODO: implement https://en.wikipedia.org/wiki/Bresenham%27s_line_algorithm // e.g. http://members.chello.at/~easyfilter/bresenham.html // TODO: currently player doesn't fall through a gap one tile wide; presumably this will // be fixed by switching to a line-rasterization approach. foreach (var rect in collisionTargets) { playerBbox = Bbox(position); // first we check for left-right collisions... if (playerBbox.Intersects(rect)) { 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; } playerBbox = Bbox(position); } // after fixing that, we check for hitting our head or hitting the ground. if (playerBbox.Intersects(rect)) { if (oldPosition.Y > position.Y) { int diff = playerBbox.Top - rect.Bottom; position.Y -= diff; } else { airState = AirState.Ground; int diff = playerBbox.Bottom - rect.Top; position.Y -= diff; } } else { playerBbox.Height += 1; if (playerBbox.Intersects(rect)) { standingOnGround = true; Debug.AddRect(rect, Color.Cyan); } else { Debug.AddRect(rect, Color.Green); } } } if (oldAirState != AirState.Ground && standingOnGround) { airState = AirState.Ground; ySpeed = 0.0; } if (airState == AirState.Ground && !standingOnGround) { airState = AirState.Falling; ySpeed = 0.0; } if (airState == AirState.Ground) { Debug.AddRect(playerBbox, Color.Red); } else if (airState == AirState.Jumping) { Debug.AddRect(playerBbox, Color.Orange); } else { Debug.AddRect(playerBbox, Color.Yellow); } } // TODO: refactor input to have a virtual "which directions & buttons were being pressed" // instead of complicated if-statements in this function. // TODO: refactor to use a state-machine. void UpdateFromInput( GameTime time, History gamePad, History keyboard) { if ((gamePad[0].IsButtonDown(Buttons.A) && gamePad[1].IsButtonUp(Buttons.A) || keyboard[0].IsKeyDown(Keys.J) && keyboard[1].IsKeyUp(Keys.J)) && airState == AirState.Ground) { pose = Pose.Jumping; airState = AirState.Jumping; jumpTime = 0.5; ySpeed = -jumpSpeed; return; } if ((gamePad[0].IsButtonDown(Buttons.X) && gamePad[1].IsButtonUp(Buttons.X) || keyboard[0].IsKeyDown(Keys.K) && keyboard[1].IsKeyUp(Keys.K)) && swordSwingTime <= 0) { pose = Pose.SwordSwing; swordSwingTime = 0.3; return; } Vector2 leftStick = gamePad[0].ThumbSticks.Left; // TODO: have keyboard directions cancel each other out if mutually-incompatible keys are // held down? if (gamePad[0].IsButtonDown(Buttons.DPadLeft) || leftStick.X < -0.5 || keyboard[0].IsKeyDown(Keys.A)) { facing = Facing.Left; pose = Pose.Walking; position.X -= (int) (moveSpeed * time.ElapsedGameTime.TotalSeconds); } else if (gamePad[0].IsButtonDown(Buttons.DPadRight) || leftStick.X > 0.5 || keyboard[0].IsKeyDown(Keys.D)) { facing = Facing.Right; pose = Pose.Walking; position.X += (int) (moveSpeed * time.ElapsedGameTime.TotalSeconds); } else if (gamePad[0].IsButtonDown(Buttons.DPadDown) || leftStick.Y < -0.5 || keyboard[0].IsKeyDown(Keys.S)) { pose = Pose.Crouching; } else if (gamePad[0].IsButtonDown(Buttons.DPadUp) || leftStick.Y > 0.5 || keyboard[0].IsKeyDown(Keys.W)) { pose = Pose.Stretching; } else { pose = Pose.Standing; } if (jumpTime > 0) { jumpTime -= time.ElapsedGameTime.TotalSeconds; } if (swordSwingTime > 0) { swordSwingTime -= time.ElapsedGameTime.TotalSeconds; pose = Pose.SwordSwing; } if (airState == AirState.Jumping || airState == AirState.Falling) { position.Y += (int) (ySpeed * time.ElapsedGameTime.TotalSeconds); ySpeed += gravity * (float) time.ElapsedGameTime.TotalSeconds; } if (airState == AirState.Jumping && pose != Pose.SwordSwing) { pose = Pose.Jumping; } // TODO: also bound player position by the right edge of the World? position.X = Math.Max(position.X, 0 + spriteWidth); } private int spritePosition(Pose pose, GameTime time) { int frameNum = (time.TotalGameTime.Milliseconds / 125) % 4; if (frameNum == 3) { frameNum = 1; } switch (pose) { case Pose.Walking: return 6 + frameNum; case Pose.Stretching: return 18 + frameNum; case Pose.Jumping: if (jumpTime > 0.25) { return 15; } else if (jumpTime > 0) { return 16; } else { return 17; } case Pose.SwordSwing: if (swordSwingTime > 0.2) { return 30; } else if (swordSwingTime > 0.1) { return 31; } else { return 32; } case Pose.Crouching: return 25; case Pose.Standing: default: return 7; } } public void Draw(SpriteBatch spriteBatch, Camera camera, GameTime time) { // TODO: don't create so many "new" things that could be cached / precomputed. int index = spritePosition(pose, time); Rectangle textureSource = new Rectangle(index * spriteSize, 0, spriteSize, spriteSize); Vector2 spriteCenter = new Vector2(spriteSize / 2, spriteSize / 2); SpriteEffects effect = facing == Facing.Right ? SpriteEffects.FlipHorizontally : SpriteEffects.None; Vector2 drawPos = new Vector2(position.X - camera.Left, position.Y); spriteBatch.Draw(texture, drawPos, textureSource, Color.White, 0f, spriteCenter, Vector2.One, effect, 0f); } } }