carotidartillery/creep.go

package main

import (
	"math/rand"
	"sync"

	"github.com/hajimehoshi/ebiten/v2"
)

type gameCreep struct {
	x, y   float64
	sprite *ebiten.Image

	moveX, moveY float64

	tick       int
	nextAction int

	level *Level

	health int

	sync.Mutex
}

func NewCreep(sprite *ebiten.Image, level *Level) *gameCreep {
	return &gameCreep{
		x:      float64(1 + rand.Intn(108)),
		y:      float64(1 + rand.Intn(108)),
		sprite: sprite,
		level:  level,
		health: 1,
	}
}

func (c *gameCreep) doNextAction() {
	c.moveX = (rand.Float64() - 0.5) / 7
	c.moveY = (rand.Float64() - 0.5) / 7

	if c.x <= 2 && c.moveX < 0 {
		c.moveX *= 1
	} else if c.x >= float64(c.level.w-3) && c.moveX > 0 {
		c.moveX *= 1
	}
	if c.y <= 2 && c.moveY > 0 {
		c.moveY *= 1
	} else if c.y >= float64(c.level.h-3) && c.moveY < 0 {
		c.moveY *= 1
	}

	c.nextAction = 400 + rand.Intn(400)
}

func (c *gameCreep) Update() {
	c.Lock()
	defer c.Unlock()

	if c.health == 0 {
		return
	}

	c.tick++
	if c.tick >= c.nextAction {
		c.doNextAction()
		c.tick = 0
	}

	x, y := c.x+c.moveX, c.y+c.moveY
	clampX, clampY := c.level.Clamp(x, y)
	c.x, c.y = clampX, clampY
	if clampX != x || clampY != y {
		c.nextAction = 0
	}
}

func (c *gameCreep) Position() (float64, float64) {
	c.Lock()
	defer c.Unlock()
	return c.x, c.y
}