1-- Urho2D particle example.
2-- This sample demonstrates:
3--     - Creating a 2D scene with particle
4--     - Displaying the scene using the Renderer subsystem
5--     - Handling mouse move to move particle
6
7require "LuaScripts/Utilities/Sample"
8
9local particleNode = nil
10
11function Start()
12    -- Execute the common startup for samples
13    SampleStart()
14
15    -- Set mouse visible
16    input.mouseVisible = true
17
18    -- Create the scene content
19    CreateScene()
20
21    -- Create the UI content
22    CreateInstructions()
23
24    -- Setup the viewport for displaying the scene
25    SetupViewport()
26
27    -- Set the mouse mode to use in the sample
28    SampleInitMouseMode(MM_FREE)
29
30    -- Hook up to the frame update events
31    SubscribeToEvents()
32end
33
34function CreateScene()
35    scene_ = Scene()
36    -- Create the Octree component to the scene. This is required before adding any drawable components, or else nothing will
37    -- show up. The default octree volume will be from (-1000, -1000, -1000) to (1000, 1000, 1000) in world coordinates it
38    -- is also legal to place objects outside the volume but their visibility can then not be checked in a hierarchically
39    -- optimizing manner
40    scene_:CreateComponent("Octree")
41
42    -- Create a scene node for the camera, which we will move around
43    -- The camera will use default settings (1000 far clip distance, 45 degrees FOV, set aspect ratio automatically)
44    cameraNode = scene_:CreateChild("Camera")
45    -- Set an initial position for the camera scene node above the plane
46    cameraNode.position = Vector3(0.0, 0.0, -10.0)
47    local camera = cameraNode:CreateComponent("Camera")
48    camera.orthographic = true
49    camera.orthoSize = graphics.height * PIXEL_SIZE
50    camera.zoom = 1.2 * Min(graphics.width / 1280, graphics.height / 800) -- Set zoom according to user's resolution to ensure full visibility (initial zoom (1.2) is set for full visibility at 1280x800 resolution)
51
52    local particleEffect = cache:GetResource("ParticleEffect2D", "Urho2D/sun.pex")
53    if particleEffect == nil then
54        return
55    end
56
57    particleNode = scene_:CreateChild("ParticleEmitter2D")
58    local particleEmitter = particleNode:CreateComponent("ParticleEmitter2D")
59    particleEmitter.effect = particleEffect
60
61    local greenSpiralEffect = cache:GetResource("ParticleEffect2D", "Urho2D/greenspiral.pex")
62    if greenSpiralEffect == nil then
63        return
64    end
65
66    greenSpiralNode = scene_:CreateChild("GreenSpiral")
67    local greenSpiralEmitter = greenSpiralNode:CreateComponent("ParticleEmitter2D")
68    greenSpiralEmitter.effect = greenSpiralEffect
69end
70
71function CreateInstructions()
72    -- Construct new Text object, set string to display and font to use
73    local instructionText = ui.root:CreateChild("Text")
74    instructionText:SetText("Use mouse to move the particle.")
75    instructionText:SetFont(cache:GetResource("Font", "Fonts/Anonymous Pro.ttf"), 15)
76
77    -- Position the text relative to the screen center
78    instructionText.horizontalAlignment = HA_CENTER
79    instructionText.verticalAlignment = VA_CENTER
80    instructionText:SetPosition(0, ui.root.height / 4)
81end
82
83function SetupViewport()
84    -- Set up a viewport to the Renderer subsystem so that the 3D scene can be seen. We need to define the scene and the camera
85    -- at minimum. Additionally we could configure the viewport screen size and the rendering path (eg. forward / deferred) to
86    -- use, but now we just use full screen and default render path configured in the engine command line options
87    local viewport = Viewport:new(scene_, cameraNode:GetComponent("Camera"))
88    renderer:SetViewport(0, viewport)
89end
90
91function SubscribeToEvents()
92    -- Subscribe HandleMouseMove() function for tracking mouse/touch move events
93    SubscribeToEvent("MouseMove", "HandleMouseMove")
94    if touchEnabled then SubscribeToEvent("TouchMove", "HandleMouseMove") end
95
96    -- Unsubscribe the SceneUpdate event from base class to prevent camera pitch and yaw in 2D sample
97    UnsubscribeFromEvent("SceneUpdate")
98end
99
100function HandleMouseMove(eventType, eventData)
101    if particleNode ~= nil then
102        local x = eventData["x"]:GetInt()
103        local y = eventData["y"]:GetInt()
104        local camera = cameraNode:GetComponent("Camera")
105        particleNode.position = camera:ScreenToWorldPoint(Vector3(x / graphics.width, y / graphics.height, 10.0))
106    end
107end
108
109-- Create XML patch instructions for screen joystick layout specific to this sample app
110function GetScreenJoystickPatchString()
111    return
112        "<patch>" ..
113        "    <add sel=\"/element/element[./attribute[@name='Name' and @value='Hat0']]\">" ..
114        "        <attribute name=\"Is Visible\" value=\"false\" />" ..
115        "    </add>" ..
116        "</patch>"
117end
118