Leadwerks Game Engine

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ForEachVisibleEntityDo

This command calls the specified function for all entities in the world that are visible to the specified camera. The optional extra parameter will be passed to the callback function each time it is called.

Syntax

ForEachVisibleEntityDo(Camera camera, callback(Camera camera, Entity entity, Object extra), Object extra = NULL)
ForEachVisibleEntityDo(Camera camera, string functionname, Object extra = NULL)

Parameters

camera: the camera to test visibility with.
callback: the function to call for each top-level entity found within the specified camera frustum.
funcname: the name of the script function to call for each top-level entity found within the specified camera frustum.
extra: an optional object that will be passed in the second parameter of the callback function.

Remarks

The callback function will only be called for the top-level entities who's recursive bounding boxes intersect the specified camera's frustum volume. Your callback function should be written so that it is called recursively with the top-level entity's children.

Example

function Callback(camera,entity, extra)
        --We only want to execute this on models.
        if (entity:GetClass()==Object.ModelClass) then
                local name = entity:GetKeyValue("name") 
                if (name ~= "") then
                        local context = extra
                        local position = entity:GetPosition() 
                        position = camera:Project(position) 
                        local font = context:GetFont() 
                        context:DrawText(name,position.x - font:GetTextWidth(name)/2, position.y - font:GetHeight()/2)
                end
        end
end

--Create a window
window = Window:Create()
context = Context:Create(window)
world = World:Create()
camera = Camera:Create()
camera:Move(0,0,-6)
local light = DirectionalLight:Create()
light:SetRotation(35,35,0)

--Create some entities
local model = Model:Box() 
model:SetKeyValue("name","Box1")
model:SetColor(0.0,0.0,1.0) 
model:SetPosition(-5,0,0) 

model = Model:Box() 
model:SetKeyValue("name","Box2")
model:SetColor(0.0,0.0,1.0) 
model:SetPosition(-2,1,0) 

model = Model:Box() 
model:SetKeyValue("name","Box3")
model:SetColor(0.0,0.0,1.0) 
model:SetPosition(5,0,0) 

while true do
        
        if window:Closed() or window:KeyHit(Key.Escape) then return false end
        
        Time:Update()
        world:Update()
        world:Render()
        
        context:SetBlendMode(Blend.Alpha) 
        
        --Execute the callback for all entities that intersect the bounding box.  
        world:ForEachVisibleEntityDo(camera,"Callback",context) 
        
        context:SetBlendMode(Blend.Solid) 
        
        context:Sync(false)
        
end