游戏demo -星星池

该例使用物理引擎+重力加速器事件完成，代码如下：

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-- Author: Your Name
-- Date: 2019-11-19 13:47:00
-- 星星玻璃瓶

local GlassBottle = class("glass_bottle")

local STAR_WH = 50;
local STAR_RADIUS = 25;

function GlassBottle:onCreate()
    --设置物理场景
    local physics_scene = self:create_physics_scene()
    physics_scene:getPhysicsWorld():setGravity(cc.p(0, 0))
    
    --设置物理边界
    local edge_size = cc.size(1000, 100)
    self.edge_layer = cc.LayerColor:create(cc.c4f(0,0,0,0))
    
    --启用加速计事件  加速计：用于检测设备是否在运动。有x,y,z三个运动方向
    self.edge_layer:setAccelerometerEnabled(true)
    self.edge_layer:setContentSize(edge_size)
    self:add_child_to_physics(self.edge_layer)

    local csb_path = "scenes/common/glasstube/pic_practice_glasstube.csb"
    local view = utils:load_csb(csb_path, self, {
        
    })
    self:addChildToPhysics(view)
    view:setPosition(display.cx,display.cy)
    local half_layer_width = self.edge_layer:getContentSize().width * 0.5
    local half_layer_height = self.edge_layer:getContentSize().height * 0.5
    self.edge_layer:setPosition(view:getPositionX() - half_layer_width, view:getPositionY() - half_layer_height)

    --创建多边形刚体
    local points = {
        cc.p(STAR_RADIUS - half_layer_width, -half_layer_height),
        cc.p(-half_layer_width, -half_layer_height + STAR_RADIUS),
        cc.p(-half_layer_width, half_layer_height - STAR_RADIUS),
        cc.p(STAR_RADIUS - half_layer_width, half_layer_height),
        cc.p(half_layer_width - STAR_RADIUS, half_layer_height),
        cc.p(half_layer_width, half_layer_height - STAR_RADIUS),
        cc.p(half_layer_width, -half_layer_height + STAR_RADIUS),
        cc.p(half_layer_width - STAR_RADIUS, -half_layer_height)
    }
    --cc.PhysicsMaterial类型，表示物理材质的属性，即密度设为1，弹性系数设为1，摩擦系数设为1.
    local edge_body = cc.PhysicsBody:createEdgePolygon(points,cc.PhysicsMaterial(1,1,0))
    self.edge_layer:setPhysicsBody(edge_body)

    --注册加速度事件监听器,与其他事件监听器不同的是，它没有事件响应属性，事件响应是通过静态create指定的
    local listener = cc.EventListenerAcceleration:create(handler(self, self.accelerometerListener))
    self.edge_layer:getEventDispatcher():addEventListenerWithSceneGraphPriority(listener, self.edge_layer)

    self:create_star_with_count(20)
end

function GlassBottle:accelerometerListener(event,x,y,z,timestamp)
    local vNowX = x * 9.81 * 240
    local vNowY = y * 9.81 * 240
    self.physic_scene:getPhysicsWorld():setGravity(cc.p(vNowX, vNowY))
end

function GlassBottle:create_physics_scene()
    if self.physic_scene == nil then
        --创建有物理空间的场景
        local physic_scene = cc.Scene:createWithPhysics()
        physic_scene:setRotation(0)
        self:addChild(physic_scene)
        physic_scene:setName("physic_scene")

        --设置Debug模式，你会看到物体的表面被线条包围，主要为了在调试中更容易地观察
        --physic_scene:getPhysicsWorld():setDebugDrawMask(debug and cc.PhysicsWorld.DEBUGDRAW_ALL or cc.PhysicsWorld.DEBUGDRAW_NONE)
        self.physic_scene = physic_scene

        self:begin_timer()
    end
    return self.physic_scene
end

function GlassBottle:add_child_to_physics( VIEW )
    if self.physic_scene then
        self.physic_scene:addChild(VIEW)
    else
        self:addChild(VIEW)
    end
end

function GlassBottle:begin_timer( ... )
    self.update_hander = self.update_hander or 0
    if self.update_hander == 0 then
        local scheduler = cc.Director:getInstance():getScheduler()
        self.update_hander = scheduler:scheduleScriptFunc(handler(self,self.update),1/60.0,false)
    end 
end

function GlassBottle:update( dt )
    if self.physic_scene and not tolua.isnull(self.physic_scene) and self.physic_scene.stepPhysicsAndNavigation then 
        self.physic_scene:stepPhysicsAndNavigation(dt)
    end
end

function GlassBottle:stop_timer()
    self.update_hander = self.update_hander or 0
    if self.update_hander > 0 then
        local scheduler = cc.Director:getInstance():getScheduler()
        scheduler:unschedulerSciptEntry(self.update_hander)
        self.update_hander = 0
    end
end

function GlassBottle:dealloc()
    self:stop_timer()
    self.edge_layer:setAccelerometerEnabled(false)
end

function GlassBottle:create_star_with_count( count )
    for i=1,count do
        self:create_physic_star( i * 10)
    end
end

function GlassBottle:create_physic_star( deltaX )
    local star = cc.Sprite:create("pic_practice_glassstar.png")
    if deltaX then
        star:setPosition(self.edge_layer:getContentSize().width * 0.5 + deltaX, self.edge_layer:getContentSize().height - STAR_RADIUS - 5)
    else 
        star:setPosition(self.edge_layer:getContentSize().width * 0.5, self.edge_layer:getContentSize().height - STAR_RADIUS - 5)
    end

    local points = {
            cc.p(0, 25),
            cc.p(24, 7.5),
            cc.p(15, -20),
            cc.p(-15, -20),
            cc.p(-24, 7.5)
        }
    local star_body = cc.PhysicsBody:createPolygon(points, cc.PhysicsMaterial(1,0.2,0))
    star:setPhysicsBody(star_body)
    self.edge_layer:addChild(star)

end

return GlassBottle

效果图：

星星池.gif