feat(actor3D): cast shadow below the actor.

CHANGELOG.md

@@ -27,7 +27,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - **camera:** Add two new camera types: "middle" and "zoom".
 
-- **world:** Add a fake 3D world, à la Zelda or BeatThemAll
+- **world:** Add a fake 3D world, à la Zelda or BeatThemAll, complete with shadow support
 
 ### Changed
 

gamecore/modules/world/actors/actor3D.lua

@@ -37,9 +37,14 @@ function Actor3D:new(world, type, x, y, z, w, h, d, isSolid)
   self:initHitboxes()
   self.world:registerShape(self)
   self.boxes = Boxes
+  self.doCastShadows = true
 end
 
 function Actor3D:destroy()
+  self:removeOldShadowTargets()
+  if self.box ~= nil then
+    self.world:removeTerrain(self)
+  end
   self.world:removeActor(self)
   self.mainHitbox:destroy()
   self.world:removeShape(self)
@@ -87,11 +92,19 @@ end
 
 function Actor3D:move(dx, dy, dz)
   local cols, colNumber = {}, 0
+  local oldx, oldy, oldz = self.x, self.y, self.z
   if (self.isDestroyed == false) then
     self.x, self.y, self.z, cols, colNumber = self.mainHitbox:checkCollision(dx, dy, dz, self.filter)
     self.mainHitbox:updatePosition()
     self.world:updateShape(self)
   end
+
+  if (oldx ~= self.x) or (oldy ~= self.y) or (oldz ~= self.z) or (self.shadowTargetsPrevious == nil) then
+    if (self.doCastShadows) then
+      self:castShadow()
+    end
+  end
+
   return self.x, self.y, self.z, cols, colNumber
 end
 
@@ -201,9 +214,71 @@ function Actor3D:checkHitboxCollisionsAtPoint(name, dx, dy, dz, filter)
     return x, y, z, cols, colNumber
 end
 
+-- SHADOW FUNCTIONS
+-- Handle everything related to shadow
+
+function Actor3D:castShadow()
+  local shadowTargets = self.world:getTerrainInRect(self.x, self.y, self.w, self.d)
+  -- initialize the shadowTargetsPrevious variable if it doesn't exist
+  if (self.shadowTargetsPrevious == nil) then
+    self.shadowTargetsPrevious = {}
+  end
+
+  for i, target in ipairs(shadowTargets) do
+    -- We test if the actor is below the current actor
+    if (target ~= self) and (target.box ~= nil) then
+
+      if (target.z + target.d <= self.z + self.d) then
+        -- Remove the target of the list of item targeted last update,
+        -- in order to only have object no longer shadowed after the
+        -- end of the loop
+        for j, oldtarget in ipairs(self.shadowTargetsPrevious) do
+          if (target == oldtarget) then
+            table.remove(self.shadowTargetsPrevious, j)
+          end
+        end
+
+        -- We update the shadow source
+        local x, y = math.floor(self.x - target.x), math.floor(self.y - target.y)
+        target.box:setShadowSource(self, x, y)
+      end
+
+    end
+
+  end
+
+  -- At this point, if a target is still in the shadowTargetsPrevious list,
+  -- it mean that it's not shadowed. So we can simply remove the shadow.
+  self:removeOldShadowTargets()
+
+  self.shadowTargetsPrevious = shadowTargets
+end
+
+function Actor3D:removeOldShadowTargets()
+  if (self.shadowTargetsPrevious ~= nil) then
+    for i, target in ipairs(self.shadowTargetsPrevious) do
+      if (target.box ~= nil) then
+        target.box:removeShadowSource(self)
+      end
+    end
+  end
+end
+
+function Actor3D:redrawShadowCanvas()
+  if (self.box ~= nil) then
+    self.box:redrawShadowCanvas()
+  end
+end
+
 -- DRAW FUNCTIONS
 -- Draw the actors.
 
+function Actor3D:drawShadow(x, y)
+  love.graphics.setColor(0, 0, 0, 1)
+  love.graphics.rectangle("fill", x, y, self.w, self.h)
+  utils.graphics.resetColor()
+end
+
 function Actor3D:getShape()
   return (self.x), (self.y - self.z - self.d), self.w, (self.h + self.d)
 end

gamecore/modules/world/actors/utils/boxes/parent.lua

@@ -25,6 +25,8 @@ local Box3D = Object:extend()
 
 function Box3D:new(owner, w, h, d)
   self.owner    = owner
+  self.world    = owner.world
+  self.cameras  = self.world.cameras
 
   self.w = w
   self.h = h
@@ -32,15 +34,20 @@ function Box3D:new(owner, w, h, d)
 
   self.haveLine = true
 
+  self.shadowSources = {}
+  self.needRedraw = false
+
   self.texture = {}
   self:setTopTexture()
   self:setBottomTexture()
+  self.texture.shadows = nil
 
   self:register()
 end
 
 function Box3D:register()
   self.owner.box = self
+  self.world:registerTerrain(self.owner)
 end
 
 function Box3D:setSizeFromOwner()
@@ -80,6 +87,60 @@ function Box3D:setBottomTexture()
   canvas:release()
 end
 
+function Box3D:setShadowSource(actor, x, y)
+  local foundShadow = false
+
+  for i,v in ipairs(self.shadowSources) do
+    if (v.actor == actor) then
+      if (v.x ~= x) or (v.y ~= y) then
+        v.x = x
+        v.y = y
+        self.needRedraw = true
+      end
+      foundShadow = true
+    end
+  end
+
+  if (foundShadow == false) then
+    local shadow = {}
+    shadow.actor = actor
+    shadow.x = x
+    shadow.y = y
+    self.needRedraw   = true
+
+    table.insert(self.shadowSources, shadow)
+  end
+end
+
+function Box3D:removeShadowSource(actor)
+  for i,v in ipairs(self.shadowSources) do
+    if (v.actor == actor) then
+      table.remove(self.shadowSources, i)
+      self.needRedraw = true
+    end
+  end
+end
+
+function Box3D:redrawShadowCanvas()
+  if (self.needRedraw) then
+    print("DEBUG: Generating " .. #self.shadowSources .. " shadows")
+    local canvas = love.graphics.newCanvas(self.w, self.h)
+    love.graphics.setCanvas( canvas )
+    for i,v in ipairs(self.shadowSources) do
+      v.actor:drawShadow(v.x, v.y)
+    end
+
+    love.graphics.setCanvas( )
+
+    local imagedata = canvas:newImageData()
+    self.texture.shadows = love.graphics.newImage( imagedata )
+    imagedata:release()
+    canvas:release()
+
+    self.needRedraw = false
+  end
+end
+
 function Box3D:draw(x, y, z)
   love.graphics.setColor(0, 0, 0, 1)
   if (self.haveLine) then
@@ -88,6 +149,10 @@ function Box3D:draw(x, y, z)
   utils.graphics.resetColor()
   love.graphics.draw(self.texture.top, x, (y-z) - (self.d))
   love.graphics.draw(self.texture.bottom, x, (y-z) - (self.d) + (self.h))
+  if (self.texture.shadows ~= nil) and (#self.shadowSources > 0) then
+    print("DEBUG: Drawing " .. #self.shadowSources .. " shadow textures")
+    love.graphics.draw(self.texture.shadows, x, (y-z) - (self.d))
+  end
 end
 
 return Box3D

gamecore/modules/world/world3D.lua

@@ -46,6 +46,7 @@ function World3D:initActors()
   self.actors = {}
   self.bodies = Bump3D.newWorld(50)
   self:initShapes()
+  self:initTerrain()
 end
 
 function World3D:newActor(name, x, y, z)
@@ -161,6 +162,17 @@ function World3D:getBodiesInRect(x, y, w, h)
   return {} --self.bodies:queryRect(x, y, w, h)
 end
 
+-- UPDATE
+-- Update everything in the world
+
+function World3D:updateActors(dt)
+  World3D.super.updateActors(self, dt)
+  local actors = self:getActors()
+  for i,v in ipairs(actors) do
+    v:redrawShadowCanvas()
+  end
+end
+
 -- SHAPE SYSTEM
 -- Handle onscreen shapes
 
@@ -190,6 +202,29 @@ function World3D:getShapeInRect(x, y, w, h)
   return self.shapes:queryRect(x, y, w, h)
 end
 
+-- TERRAIN SYSTEM
+-- Handle onscreen shapes
+
+function World3D:initTerrain()
+  self.terrains = Bump.newWorld(50)
+end
+
+function World3D:registerTerrain(actor)
+  return self.terrains:add(actor, actor.x, actor.y, actor.w, actor.h)
+end
+
+function World3D:updateTerrain(actor)
+  return self.terrains:update(actor, actor.x, actor.y, actor.w, actor.h)
+end
+
+function World3D:removeTerrain(actor)
+  return self.terrains:remove(actor)
+end
+
+function World3D:getTerrainInRect(x, y, w, h)
+  return self.terrains:queryRect(x, y, w, h)
+end
+
 -- DRAW FUNCTIONS
 -- Functions to draw the world