Sprint 1 Main Character Movement and Animation - UQdeco2800/2021-ext-studio-2 GitHub Wiki
Contents
Movement
The main player character can be controlled using the WASD keys or the arrow keys. Below is a table including descriptions and controls of how to manipulate the main character.
Key Map:
| Action | Key Control | Comment |
|---|---|---|
| Jump | W / UP | Implemented |
| Walk | Default movement | Implemented |
| Run Right | D / RIGHT | Implemented |
| Deprecated | ||
| Crouch | To be determined | Future Sprints |
| Attack | To be determined | Future Sprints |
| Item Pick Up | To be determined | Future Sprints |
| Use Item | To be determined | Future Sprints |
| Switch Item | To be determined | Future Sprints |
Movement Implementation
The movement and action controls are implemented by using the KeyboardPlayerInputComponent class, while using functions to detect key presses and releases. Each key press triggers a certain event and is handled using trigger/listener pairs.
Implementation in KeyboardPlayerInputComponent.java:
/**
* Triggers player events on specific keycodes.
*
* @return whether the input was processed
* @see InputProcessor#keyDown(int)
*/
@Override
public boolean keyDown(int keycode) {
switch (keycode) {
case Keys.S:
case Keys.DOWN:
walkDirection.add(Vector2Utils.DOWN);
triggerWalkEvent();
return true;
case Keys.D:
case Keys.RIGHT:
walkDirection.add(Vector2Utils.RIGHT);
triggerWalkEvent();
entity.getEvents().trigger(("walkRight"));
return true;
case Keys.SPACE:
entity.getEvents().trigger("attack");
return true;
case Keys.W:
case Keys.UP:
entity.getEvents().trigger("jump");
return true;
default:
return false;
}
}
/**
* Triggers player events on specific keycodes.
*
* @return whether the input was processed
* @see InputProcessor#keyUp(int)
*/
@Override
public boolean keyUp(int keycode) {
switch (keycode) {
case Keys.S:
case Keys.DOWN:
walkDirection.sub(Vector2Utils.DOWN);
triggerWalkEvent();
return true;
case Keys.D:
case Keys.RIGHT:
walkDirection.sub(Vector2Utils.RIGHT);
entity.getEvents().trigger(("stopWalkRight"));
triggerWalkEvent();
return true;
case Keys.W:
case Keys.UP:
entity.getEvents().trigger("stopJump");
default:
return false;
}
}
Implementation of Jump
A vertical vector impulse is applied directly to the body of the main player entity to simulate jumping in the game environment.
Implementation in PlayerActions.java:
/**
* Makes the player jump
*/
void jump() {
Sound jumpSound = ServiceLocator.getResourceService().getAsset("sounds/jump.ogg", Sound.class);
jumpSound.play();
Body body = physicsComponent.getBody();
body.applyForceToCenter(0, 400f, true);
Relevant Files
KeyboardPlayerInputComponent.java
Animations
The main player character starts off as a static texture until the user presses the key for the right movement. Once the movement is triggered, the texture is removed from the game area and replaced with an AnimationRenderComponent. As movement is triggered, the default movement animation is walking. Once the move right key is pressed, the animation switches to running and all the previous animations are stopped for the entity player.
Animation Implementation
An AnimationRenderComponent is used to define the animation of the character, itโs movement and the FPS:
AnimationRenderComponent animator =
new AnimationRenderComponent(
ServiceLocator.getResourceService()
.getAsset("images/mpcMovement.atlas",
TextureAtlas.class));
animator.addAnimation("main_player_run", 0.1f, Animation.PlayMode.LOOP);
animator.addAnimation("main_player_walk", 0.5f, Animation.PlayMode.LOOP);
animator.addAnimation("mpc_front", 1f, Animation.PlayMode.LOOP);
The listeners implemented here lookout for trigger events and run the corresponding functions in PlayerActions.java:
public void create() {
animator = this.entity.getComponent(AnimationRenderComponent.class);
physicsComponent = entity.getComponent(PhysicsComponent.class);
entity.getEvents().addListener("walk", this::walk);
entity.getEvents().addListener("walkStop", this::stopWalking);
entity.getEvents().addListener("walkRight", this::walkRight);
entity.getEvents().addListener("stopWalkRight", this::stopWalkRight);
entity.getEvents().addListener("walkLeft", this::walkLeft);
entity.getEvents().addListener("attack", this::attack);
entity.getEvents().addListener("jump", this::jump);
}
The below functions are triggered on key press events and are responsible for switching between the running and walking animation - PlayerActions.java:
/**
* Updates the player sprite to run right
*/
void walkRight() {
animator.getEntity().setRemoveTexture();
animator.stopAnimation();
animator.startAnimation("main_player_run");
Sound turnSound = ServiceLocator.getResourceService().getAsset("sounds/turnDirection.ogg", Sound.class);
turnSound.play();
}
void stopWalkRight() {
animator.stopAnimation();
animator.startAnimation("main_player_walk");
}
Relevant Files
In-game Animations Demonstration
Walking
Running
Texture atlas
The atlas that was used for creating the animations was generated using a texture packer. The atlas has player representation in three states:
- Standing (facing right, static)
- Walking (facing right, animated)
- Running (facing right, animated)
- Standing (facing forward, static)
Generated Texture pack
Generated Texture atlas
mpcMovement.png
size: 4096, 1024
format: RGBA8888
filter: Nearest, Nearest
repeat: none
main_player_right
rotate: false
xy: 2717, 2
size: 541, 541
orig: 541, 541
offset: 0, 0
index: -1
main_player_run
rotate: false
xy: 545, 2
size: 541, 541
orig: 541, 541
offset: 0, 0
index: 2
main_player_run
rotate: false
xy: 2174, 2
size: 541, 541
orig: 541, 541
offset: 0, 0
index: 1
main_player_walk
rotate: false
xy: 2, 2
size: 541, 541
orig: 541, 541
offset: 0, 0
index: 2
main_player_walk
rotate: false
xy: 1088, 2
size: 541, 541
orig: 541, 541
offset: 0, 0
index: 1
mpc_front
rotate: false
xy: 1631, 2
size: 541, 541
orig: 541, 541
offset: 0, 0
index: -1
Relevant Files
UML Diagrams
Class Diagrams
PlayerActions
PlayerAnimationController
Sequence Diagrams
animateJump
animateAttack
animateCrouch
stopAnimateAll
preAnimationCleanUp
PlayerAnimationController
