Jump to content

Say Hello to Leadwerks 5 Shared Objects

Josh

1,243 views

All classes in Leadwerks are derived from a base Object class.  In Leadwerks 5 we separate simple and complex objects with the new SharedObject class.

Simple objects like a Vec3 ( a three-dimensional vector), an AABB (axis-aligned bounding box), and other items are all derived from the Object class.  Simple objects are created with constructors.  When we make one object equal to another the value is copied from one variable to another, but the two variables are still separate objects.  Below, A and B have the same value but are separate objects:

Vec3 a = Vec3(1,2,3);
Vec3 b = a;

Shared objects are things you don't want to copy, because they involve more than just some numbers.  These always use C++11 shared pointers and use a Create function.  Below, A and B refer to the same object:

shared_ptr<World> a = CreateWorld();
shared_ptr<World> b = a;

The SharedObject class has a couple of functions to make life easier.  Instead of casting pointers with some funny syntax we can use the Cast() method.  Here's an example of casting in Leadwerks 4:

Entity* entity = Model::Load("car.mdl");
Model* model = (Model*)entity;

And here's how it works in Leadwerks 5:

shared_ptr<Entity> entity = LoadModel("car.mdl");
shared_ptr<Model> model = entity->Cast<Model>();

Instead of using "this" inside a class method you can use Self() to get a shared pointer to the object itself:

class MyActor : public Actor
{
	void MyFunction()
	{
		//MyActor* me = this;
		shared_ptr<SharedObject> me = Self();
	}
}

Self() will always return a shared_ptr<SharedObject> value, so you can use Cast() if you need a specific type of object (and match the behavior of "this"):

class MyActor : public Actor
{
	void MyFunction()
	{
		//MyActor* me = this;
		shared_ptr<MyActor> me = Cast<MyActor>();
	}
}

Instead of calling delete or Release to destroy a shared object, all you have to do is set its variable to NULL:

shared_ptr<Model> model = LoadModel("car.mdl");
model = NULL;// poof!

And of course we can always use the auto keyword to make things really simple:

auto model = LoadModel("car.mdl");

Shared objects use automatic reference counting to give you the ease of use of a garbage-collected language, together with the blazing performance of modern C++.  These features are set to make Leadwerks Game Engine 5 the easiest and most cutting-edge development system in the history of game programming.



6 Comments


Recommended Comments

On 9/16/2017 at 3:30 PM, jen said:

I would imagine LUA is now being maintained only for backwards compatibility. It would still be advantageous to have LUA, obviously. I just don't think it should be the primary language for the engine's creative environment. Then again marketing the engine with LUA as its primary language bids well to the newbies.

I'm really happy to see the upgrades though, this engine will be super accessible and flexible to use in the near future.

Lua will continue to be important because it is super convenient for entity scripts, and it's great for beginners.  Our implementation in Leadwerks 5 will work with shared pointers which will make everything a lot easier to manage.  With C++ in Leadwerks you have automatic reference counting that does everything except catch circular references.  Lua garbage collection is slower so I don't recommend it for VR or intensive code routines, but it does catch circular references.

Share this comment


Link to comment

Plus I believe you said some time ago that the vast majority of your customers are using Lua, not C++ (it was some high number like 90%).  I imagine that hasn't changed much since.

Share this comment


Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Add a comment...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Blog Entries

    • By Josh in Josh's Dev Blog 2
      The Leadwerks 5 beta will soon be updated with particle emitters and an example particle system plugin. Previously, I showed some impressive results with physically interactive particles that collide with and exert forces on the environment. I decided to use the plugin system for controlling particle behavior, as this offers the best performance and can be run on the physics thread. 
      A particle system plugin uses some predefined structures and functions to modify the behavior of particles when they are emitted or as they are updated. This allows for unlimited features to be added to the particle system, because anything you want can be added with a plugin. A system for sending settings to the plugin will be implemented in the future so you can adjust the plugin settings and see the results. The default particle settings and features will probably stay pretty barebones and I will just use the plugin system to add any advanced functionality since it is so flexible.
      void EmitParticle(ParticleModifier* mod, ParticleSystem* particlesystem, Particle* particle) { if (mod->emissionshape == EMISSION_SHAPE_BOX) { particle->position[0] = Random(-mod->area[0], mod->area[0]); particle->position[1] = Random(-mod->area[1], mod->area[1]); particle->position[2] = Random(-mod->area[2], mod->area[2]); } else if (mod->emissionshape == EMISSION_SHAPE_CYLINDER) { particle->position[0] = Random(-mod->area[0], mod->area[0]); particle->position[1] = Random(-mod->area[1], mod->area[1]); particle->position[2] = Random(-mod->area[2], mod->area[2]); auto l = sqrt(particle->position[0] * particle->position[0] + particle->position[1] * particle->position[1] + particle->position[2] * particle->position[2]); if (l > 0.0f) { particle->position[0] /= l; particle->position[1] /= l; particle->position[2] /= l; } } particle->position[0] += particlesystem->matrix[12]; particle->position[1] += particlesystem->matrix[13]; particle->position[2] += particlesystem->matrix[14]; } There are three other new Lua examples included. Coroutines.lua shows how a sequence of actions can be added to an entity before the game starts, and the actions will be executed in order:
      --Create model local model = CreateBox(world) --Add some behaviors to be executed in order model:AddCoroutine(MoveToPoint, Vec3(3,0,0), 2) model:AddCoroutine(MoveToPoint, Vec3(-3,0,0), 2) model:AddCoroutine(MoveToPoint, Vec3(0,0,0), 2) --Main loop while window:Closed() == false do world:Update() world:Render(framebuffer) end This is great for setting up cut scenes or other sequences of events.
      An example showing how to enable tessellation is also included. Tessellation is now a per-camera setting.
      camera:SetTessellation(10) The number you input is the size in pixels of the tessellated primitives. Use zero to disable tessellation. Tessellation is disabled by default on all cameras.
      Finally, an example showing how to use a texture loader plugin is included. All you have to do is load the plugin and after that textures can be loaded in VTF format:
      local vtfloader = LoadPlugin("Plugins/VTF.dll") local tex = LoadTexture("Materials/wall01.vtf")  
    • By Josh in Josh's Dev Blog 4
      I made some changes to the design of the particle system. I am less concerned with the exact behavior of particles as they move around and move interested right now in building a system with good performance and deep physics interactions. Although I want particle behavior to be customizable, I don't think scripts are the right tool for the job. C++ plugins are better suited for this for two reasons.
      C++ is much faster, and particles are a system that will make heavy use of that. Lua scripts can't be run on separate threads. In Leadwerks Engine 4 we have basic particle collisions, but I wanted something more interactive in the new system. I move the particle update code into the physics thread. I implemented collision as well as the ability for particles to exert forces on other objects. Here's what happens when some slow-moving smoke particles interact with a scene: The lower platform rotates freely while the upper platform is motorized.
      When the particle velocity is increase they start to behave like a stream of water:
      Best of all, the speed is surprisingly fast. 4000 particles with collision update in just 2 milliseconds. The code scales well across cores so if you have a lot of CPU cores simulations with 100,000 particles are possible.
      Right now particles are processed in the physics thread, and get sent to the rendering thread for display, but right now the main thread actually never sees the individual particles.
      This is fast enough I think particles will default to full physics. Instead of just being a dumb visual effect we are going to have fully interactive fluids and gases. Flamethrowers can fill a room with fire and it will creep around corners to fill a space.
    • By Josh in Josh's Dev Blog 7
      For finer control over what 2D elements appear on what camera, I have implemented a system of "Sprite Layers". Here's how it works:
      A sprite layer is created in a world. Sprites are created in a layer. Layers are attached to a camera (in the same world). The reason the sprite layer is linked to the world is because the render tweening operates on a per-world basis, and it works with the sprite system just like the entity system. In fact, the rendering thread uses the same RenderNode class for both.
      I have basic GUI functionality working now. A GUI can be created directly on a window and use the OS drawing commands, or it can be created on a sprite layer and rendered with 3D graphics. The first method is how I plan to make the new editor user interface, while the second is quite flexible. The most common usage will be to create a sprite layer, attach it to the main camera, and add a GUI to appear in-game. However, you can just as easily attach a sprite layer to a camera that has a texture render target, and make the GUI appear in-game on a panel in 3D. Because of these different usages, you must manually insert events like mouse movements into the GUI in order for it to process them:
      while true do local event = GetEvent() if event.id == EVENT_NONE then break end if event.id == EVENT_MOUSE_DOWN or event.id == EVENT_MOUSE_MOVE or event.id == EVENT_MOUSE_UP or event.id == EVENT_KEY_DOWN or event.id == EVENT_KEY_UP then gui:ProcessEvent(event) end end You could also input your own events from the mouse position to create interactive surfaces, like in games like DOOM and Soma. Or you can render the GUI to a texture and interact with it by feeding in input from VR controllers.

      Because the new 2D drawing system uses persistent objects instead of drawing commands the code to display elements has changed quite a lot. Here is my current button script. I implemented a system of abstract GUI "rectangles" the script can create and modify. If the GUI is attached to a sprite layer these get translated into sprites, and if it is attached directly to a window they get translated into system drawing commands. Note that the AddTextRect doesn't even allow you to access the widget text directly because the widget text is stored in a wstring, which supports Unicode characters but is not supported by Lua.
      --Default values widget.pushed=false widget.hovered=false widget.textindent=4 widget.checkboxsize=14 widget.checkboxindent=5 widget.radius=3 widget.textcolor = Vec4(1,1,1,1) widget.bordercolor = Vec4(0,0,0,0) widget.hoverbordercolor = Vec4(51/255,151/255,1) widget.backgroundcolor = Vec4(0.2,0.2,0.2,1) function widget:MouseEnter(x,y) self.hovered = true self:Redraw() end function widget:MouseLeave(x,y) self.hovered = false self:Redraw() end function widget:MouseDown(button,x,y) if button == MOUSE_LEFT then self.pushed=true self:Redraw() end end function widget:MouseUp(button,x,y) if button == MOUSE_LEFT then self.pushed = false if self.hovered then EmitEvent(EVENT_WIDGET_ACTION,self) end self:Redraw() end end function widget:OK() EmitEvent(EVENT_WIDGET_ACTION,self) end function widget:KeyDown(keycode) if keycode == KEY_ENTER then EmitEvent(EVENT_WIDGET_ACTION,self) self:Redraw() end end function widget:Start() --Background self:AddRect(self.position, self.size, self.backgroundcolor, false, self.radius) --Border if self.hovered == true then self:AddRect(self.position, self.size, self.hoverbordercolor, true, self.radius) else self:AddRect(self.position, self.size, self.bordercolor, true, self.radius) end --Text if self.pushed == true then self:AddTextRect(self.position + iVec2(1,1), self.size, self.textcolor, TEXT_CENTER + TEXT_MIDDLE) else self:AddTextRect(self.position, self.size, self.textcolor, TEXT_CENTER + TEXT_MIDDLE) end end function widget:Draw() --Update position and size self.primitives[1].position = self.position self.primitives[1].size = self.size self.primitives[2].position = self.position self.primitives[2].size = self.size self.primitives[3].size = self.size --Update the border color based on the current hover state if self.hovered == true then self.primitives[2].color = self.hoverbordercolor else self.primitives[2].color = self.bordercolor end --Offset the text when button is pressed if self.pushed == true then self.primitives[3].position = self.position + iVec2(1,1) else self.primitives[3].position = self.position end end This is arguably harder to use than the Leadwerks 4 system, but it gives you advanced capabilities and better performance that the previous design did not allow.
×
×
  • Create New...