实现2D相机的视角控制

脚本编写

该示例场景比较简单，主要就是脚本对于相机视角的控制，具体代码如下

extends Node2D

onready var camera = $Camera2D
var scaleNum = 2
var isDrag = fasle
var startPos = Vector2.ZERO
var startCamPos = Vector2.ZERO

func _ready():
    camera.zoom = Vector2(scaleNum, scaleNum)

func _input(event):
    if event is InputEventMouseButton:
        # 缩放操作
        if event.button_index == 4:
            startPos = Vector2.ZERO
            if scaleNum <= 0.1:
                return
            elif scaleNum >= 2:
                scaleNum -= 0.3
            else:
                scaleNum -= 0.1
        elif event.button_index == 5:
            startPos = Vector2.ZERO
            if scaleNum >= 10:
                return
            if scaleNum <= 0.3:
                scaleNum += 0.03
            elif scaleNum >= 8:
                scaleNum += 0.6
            else:
                scaleNum += 0.1
        
        # 移动操作
        if event.button_index == 2 or event.button_index == 3:
            if event.is_pressed():
                isDrag = true
                startPos = event.position
                startCamPos = camera.position
            else:
                isDrag = false
                startPos = Vector2.ZERO
    
    if isDrag:
        # 只有当在非缩放才会进行移动，避免边平移边缩放导致的图片跳动
        if startPos != Vector2.ZERO:
            var offset = startPos - event.position
            camera.position = startCamPos + offset * scaleNum

func _process(delta):
    camera.zoom = lerp(camera.zoom, Vector2(scaleNum, scaleNum), 8 * delta)