From 0f882da30093233cb88c9977aafc5cefb64ba3af Mon Sep 17 00:00:00 2001
From: Tim Anema <timanema@gmail.com>
Date: Tue, 21 Oct 2014 22:48:19 -0400
Subject: [PATCH] finally coming up with a proper strategy to handle
 translation and zooming of canvases

---
 examples/short.lua  |  24 +++++-----
 lib/body.lua        |  17 +++++--
 lib/light.lua       |  89 +++++++++++++++++-----------------
 lib/light_world.lua | 114 +++++++++++++++++---------------------------
 lib/postshader.lua  |   3 +-
 lib/stencils.lua    |  29 ++++-------
 lib/util.lua        |  40 ++++++++++++++++
 main.lua            |   2 +-
 8 files changed, 164 insertions(+), 154 deletions(-)
 create mode 100644 lib/util.lua

diff --git a/examples/short.lua b/examples/short.lua
index b9577e1..7b4fc27 100644
--- a/examples/short.lua
+++ b/examples/short.lua
@@ -1,11 +1,11 @@
 -- Example: Short Example
-local gamera     = require "vendor/gamera"
 local LightWorld = require "lib/light_world"
 
 function love.load()
   testShader = 0
+  x = 0
+  y = 0
   scale = 1
-  camera = gamera.new(0,0,2000,2000)
 	-- load images
 	image = love.graphics.newImage("gfx/machine2.png")
 	image_normal = love.graphics.newImage("gfx/cone_normal.png")
@@ -62,7 +62,6 @@ end
 function love.update(dt)
 	love.window.setTitle("Light vs. Shadow Engine (FPS:" .. love.timer.getFPS() .. ")")
 
-  local x, y = camera:getPosition()
 	if love.keyboard.isDown("up") then
 		y = y - dt * 200
 	elseif love.keyboard.isDown("down") then
@@ -81,20 +80,23 @@ function love.update(dt)
 		scale = scale + 0.01
 	end
 
-  camera:setPosition(x, y)
-  camera:setScale(scale)
-	lightMouse:setPosition(camera:toWorld(love.mouse.getX(), love.mouse.getY()))
+	lightMouse:setPosition(love.mouse.getX(), love.mouse.getY())
 end
 
 function love.draw()
-  camera:draw(function(l,t,w,h)
-    lightWorld:draw(l,t,w,h,scale)
-  end)
+  love.graphics.push()
+    love.graphics.translate(x, y)
+    love.graphics.scale(scale)
+    lightWorld:draw(x,y,scale)
+  love.graphics.pop()
 end
 
 function drawBackground(l,t,w,h)
-  love.graphics.setColor(255, 255, 255)
-  love.graphics.rectangle("fill", 0, 0, 2000, 2000)
+  love.graphics.push()
+    love.graphics.origin()
+    love.graphics.setColor(255, 255, 255)
+    love.graphics.rectangle("fill", 0, 0, w, h)
+  love.graphics.pop()
 end
 
 function drawForground(l,t,w,h)
diff --git a/lib/body.lua b/lib/body.lua
index dda4e26..60f57ba 100644
--- a/lib/body.lua
+++ b/lib/body.lua
@@ -363,7 +363,6 @@ function body:setShadowType(type, ...)
     self:refresh()
   elseif self.shadowType == "polygon" then
     self.data = args or {0, 0, 0, 0, 0, 0}
-    print(self.data)
   elseif self.shadowType == "image" then
     if self.img then
       self.width = self.imgWidth
@@ -388,7 +387,19 @@ function body:setShadowType(type, ...)
   end
 end
 
-function body:drawShadow(light, l,t,w,h)
+function body:shadowStencil()
+  if self.shadowType == "circle" then
+    love.graphics.circle("fill", self.x - self.ox, self.y - self.oy, self.radius)
+  elseif self.shadowType == "rectangle" then
+    love.graphics.rectangle("fill", self.x - self.ox, self.y - self.oy, self.width, self.height)
+  elseif self.shadowType == "polygon" then
+    love.graphics.polygon("fill", unpack(self.data))
+  elseif self.shadowType == "image" then
+  --love.graphics.rectangle("fill", self.x - self.ox, self.y - self.oy, self.width, self.height)
+  end
+end
+
+function body:drawShadow(light, l,t,w,h,s)
   if self.alpha < 1.0 then
     love.graphics.setBlendMode("multiplicative")
     love.graphics.setColor(self.red, self.green, self.blue)
@@ -446,7 +457,7 @@ function body:drawShadow(light, l,t,w,h)
     }
 
     self.shadowMesh:setVertices(self.shadowVert)
-    love.graphics.draw(self.shadowMesh, self.x - self.ox + l, self.y - self.oy + t)
+    love.graphics.draw(self.shadowMesh, self.x - self.ox + l, self.y - self.oy + t, 0, s, s)
   end
 end
 
diff --git a/lib/light.lua b/lib/light.lua
index 4279ed4..59fa3ab 100644
--- a/lib/light.lua
+++ b/lib/light.lua
@@ -1,6 +1,7 @@
 local _PACKAGE = (...):match("^(.+)[%./][^%./]+") or ""
 local class = require(_PACKAGE.."/class")
 local stencils = require(_PACKAGE..'/stencils')
+local util = require(_PACKAGE..'/util')
 
 local light = class()
 
@@ -127,20 +128,8 @@ function light:inRange(l,t,w,h)
   return self.x + self.range > l and self.x - self.range < (l+w) and self.y + self.range > t and self.y - self.range < (t+h)
 end
 
-function light:updateShadow(l,t,w,h, bodies)
-  love.graphics.setShader(self.shader)
+function light:drawShadow(l,t,w,h,s,bodies, canvas)
   if self.visible and self:inRange(l,t,w,h) then
-
-    self.shader:send("lightPosition", {self.x - l, h - (self.y - t), self.z})
-    self.shader:send("lightRange", self.range)
-    self.shader:send("lightColor", {self.red / 255.0, self.green / 255.0, self.blue / 255.0})
-    self.shader:send("lightSmooth", self.smooth)
-    self.shader:send("lightGlow", {1.0 - self.glowSize, self.glowStrength})
-    self.shader:send("lightAngle", math.pi - self.angle / 2.0)
-    self.shader:send("lightDirection", self.direction)
-    self.shadow:clear()
-    love.graphics.setCanvas(self.shadow)
-
     -- calculate shadows
     local shadow_geometry = {}
     for i = 1, #bodies do
@@ -150,46 +139,54 @@ function light:updateShadow(l,t,w,h, bodies)
       end
     end
 
+    self.shadow:clear()
+    self.shader:send("lightPosition", {self.x - l, h - (self.y - t), self.z})
+    self.shader:send("lightRange", self.range)
+    self.shader:send("lightColor", {self.red / 255.0, self.green / 255.0, self.blue / 255.0})
+    self.shader:send("lightSmooth", self.smooth)
+    self.shader:send("lightGlow", {1.0 - self.glowSize, self.glowStrength})
+    self.shader:send("lightAngle", math.pi - self.angle / 2.0)
+    self.shader:send("lightDirection", self.direction)
+
     -- draw shadow
-    love.graphics.setInvertedStencil(stencils.shadow(shadow_geometry, bodies))
-    love.graphics.setBlendMode("additive")
-    love.graphics.rectangle("fill", l,t,w,h)
+    util.drawto(self.shadow, l, t, s, function()
+      love.graphics.setShader(self.shader)
+      love.graphics.setInvertedStencil(stencils.shadow(shadow_geometry, bodies))
+      love.graphics.setBlendMode("additive")
+      love.graphics.rectangle("fill", l,t,w,h)
 
-    -- draw color shadows
-    love.graphics.setBlendMode("multiplicative")
-    love.graphics.setShader()
-    for k = 1,#shadow_geometry do
-      if shadow_geometry[k].alpha < 1.0 then
-        love.graphics.setColor(
-          shadow_geometry[k].red * (1.0 - shadow_geometry[k].alpha),
-          shadow_geometry[k].green * (1.0 - shadow_geometry[k].alpha),
-          shadow_geometry[k].blue * (1.0 - shadow_geometry[k].alpha)
-        )
-        love.graphics.polygon("fill", unpack(shadow_geometry[k]))
+      -- draw color shadows
+      love.graphics.setBlendMode("multiplicative")
+      love.graphics.setShader()
+      for k = 1,#shadow_geometry do
+        if shadow_geometry[k].alpha < 1.0 then
+          love.graphics.setColor(
+            shadow_geometry[k].red * (1.0 - shadow_geometry[k].alpha),
+            shadow_geometry[k].green * (1.0 - shadow_geometry[k].alpha),
+            shadow_geometry[k].blue * (1.0 - shadow_geometry[k].alpha)
+          )
+          love.graphics.polygon("fill", unpack(shadow_geometry[k]))
+        end
       end
-    end
 
-    for k = 1, #bodies do
-      bodies[k]:drawShadow(self, l,t,w,h)
-    end
+      for k = 1, #bodies do
+        bodies[k]:drawShadow(self,l,t,w,h,s)
+      end
+    end)
 
     -- draw shine
-    love.graphics.setShader(self.shader)
-    love.graphics.setCanvas(self.shine)
-    self.shine:clear(255, 255, 255)
-    love.graphics.setBlendMode("alpha")
-    love.graphics.setStencil(stencils.poly(bodies))
-    love.graphics.rectangle("fill", l,t,w,h)
-    love.graphics.setStencil()
-  end
-  love.graphics.setShader()
-end
+    util.drawto(self.shine, l, t, s, function()
+      love.graphics.setShader(self.shader)
+      self.shine:clear(255, 255, 255)
+      love.graphics.setBlendMode("alpha")
+      love.graphics.setStencil(stencils.colorShadow(bodies))
+      love.graphics.rectangle("fill", 0,0,w,h)
+    end)
 
-function light:drawShadow(l,t,w,h)
-  if self.visible then
-    love.graphics.setColor(255, 255, 255)
-    love.graphics.setBlendMode("additive")
-    love.graphics.draw(self.shadow, l, t)
+    love.graphics.setStencil()
+    love.graphics.setShader()
+
+    util.drawCanvasToCanvas(self.shadow, canvas, {blendmode = "additive"})
   end
 end
 
diff --git a/lib/light_world.lua b/lib/light_world.lua
index dd700f7..0bacea1 100644
--- a/lib/light_world.lua
+++ b/lib/light_world.lua
@@ -25,6 +25,7 @@ local _PACKAGE = (...):match("^(.+)[%./][^%./]+") or ""
 local class = require(_PACKAGE..'/class')
 local Light = require(_PACKAGE..'/light')
 local Body = require(_PACKAGE..'/body')
+local util = require(_PACKAGE..'/util')
 local normal_map = require(_PACKAGE..'/normal_map')
 local PostShader = require(_PACKAGE..'/postshader')
 require(_PACKAGE..'/postshader')
@@ -62,44 +63,19 @@ function light_world:init(options)
   self:refreshScreenSize()
 end
 
-function light_world:drawBlur(blendmode, blur, canvas, canvas2, l, t, w, h)
+function light_world:drawBlur(blendmode, blur, canvas, canvas2, l, t, w, h, s)
   if blur <= 0 then
     return
   end
 
-  love.graphics.setColor(255, 255, 255)
+  canvas2:clear()
   self.blurv:send("steps", blur)
   self.blurh:send("steps", blur)
-  love.graphics.setBlendMode(blendmode)
-  canvas2:clear()
-  love.graphics.setCanvas(canvas2)
-  love.graphics.setShader(self.blurv)
-  love.graphics.draw(canvas, l, t)
-  love.graphics.setCanvas(canvas)
-  love.graphics.setShader(self.blurh)
-  love.graphics.draw(canvas2, l, t)
+  util.drawCanvasToCanvas(canvas, canvas2, {shader = self.blurv, blendmode = blendmode})
+  util.drawCanvasToCanvas(canvas2, canvas, {shader = self.blurh, blendmode = blendmode})
 end
 
-function light_world:updateShadows(l,t,w,h)
-  for i = 1, #self.lights do
-    self.lights[i]:updateShadow(l,t,w,h, self.body)
-  end
-
-  -- update shadow
-  love.graphics.setCanvas(self.shadow)
-  love.graphics.setColor(unpack(self.ambient))
-  love.graphics.setBlendMode("alpha")
-  love.graphics.rectangle("fill", l, t, w, h)
-
-  for i = 1, #self.lights do
-    self.lights[i]:drawShadow(l,t,w,h)
-  end
-
-  light_world:drawBlur("alpha", self.blur, self.shadow, self.shadow2, l, t, w, h)
-  love.graphics.setCanvas(self.render_buffer)
-end
-
-function light_world:updateShine(l,t,w,h)
+function light_world:updateShine(l,t,w,h,s)
   -- update shine
   love.graphics.setCanvas(self.shine)
   love.graphics.setColor(unpack(self.ambient))
@@ -112,8 +88,7 @@ function light_world:updateShine(l,t,w,h)
     self.lights[i]:drawShine(l,t,w,h)
   end
 
-  --light_world:drawBlur("additive", self.blur, self.shine, self.shine2, l, t, w, h)
-  love.graphics.setCanvas(self.render_buffer)
+  --light_world:drawBlur("additive", self.blur, self.shine, self.shine2, l, t, w, h, s)
 end
 
 function light_world:updatePixelShadows(l,t,w,h)
@@ -148,11 +123,9 @@ function light_world:updatePixelShadows(l,t,w,h)
   love.graphics.setBlendMode("additive")
   love.graphics.setColor({self.ambient[1], self.ambient[2], self.ambient[3]})
   love.graphics.rectangle("fill", l,t,w,h)
-  love.graphics.setBlendMode("alpha")
-  love.graphics.setCanvas(self.render_buffer)
 end
 
-function light_world:updateGlow(l,t,w,h)
+function light_world:updateGlow(l,t,w,h,s)
   -- create glow map
   self.glowMap:clear(0, 0, 0)
   love.graphics.setCanvas(self.glowMap)
@@ -173,8 +146,7 @@ function light_world:updateGlow(l,t,w,h)
     self.body[i]:drawGlow(l,t,w,h)
   end
 
-  light_world:drawBlur("alpha", self.glowBlur, self.glowMap, self.glowMap2, l, t, w, h)
-  love.graphics.setCanvas(self.render_buffer)
+  light_world:drawBlur("alpha", self.glowBlur, self.glowMap, self.glowMap2, l, t, w, h, s)
 end
 
 function light_world:updateRefraction(l,t,w,h)
@@ -189,8 +161,6 @@ function light_world:updateRefraction(l,t,w,h)
   love.graphics.setBlendMode("alpha")
   love.graphics.setCanvas(self.refractionMap2)
   love.graphics.draw(self.render_buffer, l, t)
-  love.graphics.setShader()
-  love.graphics.setCanvas(self.render_buffer)
 end
 
 function light_world:updateRelfection(l,t,w,h)
@@ -205,8 +175,6 @@ function light_world:updateRelfection(l,t,w,h)
   love.graphics.setBlendMode("alpha")
   love.graphics.setCanvas(self.reflectionMap2)
   love.graphics.draw(self.render_buffer, l, t)
-  love.graphics.setShader()
-  love.graphics.setCanvas(self.render_buffer)
 end
 
 function light_world:refreshScreenSize(w, h)
@@ -239,32 +207,24 @@ function light_world:refreshScreenSize(w, h)
   self.post_shader:refreshScreenSize(w, h)
 end
 
-function light_world:draw(l,t,w,h,s)
-  l,t,w,h,s = (l or 0), (t or 0), (w or love.graphics.getWidth()), (h or love.graphics.getHeight()), s or 1 
+function light_world:draw(l,t,s)
+  l,t,s = (l or 0), (t or 0), s or 1 
+  local w, h = (love.graphics.getWidth() / s), (love.graphics.getHeight() / s)
 
-  if s ~= self.scale then
-    --self:refreshScreenSize(w, h)
-    self.scale = scale
-  end
+  util.drawto(self.render_buffer, l, t, s, function()
+    self.drawBackground( l,t,w,h,s)
+    self:drawShadow(     l,t,w,h,s)
+    self.drawForground(  l,t,w,h,s)
+		--self:drawMaterial(   l,t,w,h,s)
+    --self:drawShine(      l,t,w,h,s)
+    --self:drawPixelShadow(l,t,w,h,s)
+    --self:drawGlow(       l,t,w,h,s)
+    --self:drawRefraction( l,t,w,h,s)
+    --self:drawReflection( l,t,w,h,s)
+  end)
 
-  local last_buffer = love.graphics.getCanvas()
-	love.graphics.setCanvas(self.render_buffer)
-
-  love.graphics.push()
-    love.graphics.scale(1/s)
-    local sl, st, sw, sh = (l*s), (t*s), (w*s), (h*s)
-    self.drawBackground(  sl,st,sw,sh,s)
-    self:drawShadow(      sl,st,sw,sh,s)
-    self.drawForground(   sl,st,sw,sh,s)
-		self:drawMaterial(    sl,st,sw,sh,s)
-    self:drawShine(       sl,st,sw,sh,s)
-    self:drawPixelShadow( sl,st,sw,sh,s)
-    self:drawGlow(        sl,st,sw,sh,s)
-    self:drawRefraction(  sl,st,sw,sh,s)
-    self:drawReflection(  sl,st,sw,sh,s)
-  love.graphics.pop()
- 
-  self.post_shader:drawWith(self.render_buffer, l, t, s)
+  util.drawCanvasToCanvas(self.render_buffer)
+  --self.post_shader:drawWith(self.render_buffer, l, t, s)
 end
 
 -- draw shadow
@@ -272,12 +232,19 @@ function light_world:drawShadow(l,t,w,h,s)
   if not self.isShadows and not self.isLight then
     return
   end
-  self:updateShadows(l,t,w,h)
-  love.graphics.setColor(255, 255, 255)
-  love.graphics.setBlendMode("multiplicative")
-  love.graphics.setShader()
-  love.graphics.draw(self.shadow, l, t)
-  love.graphics.setBlendMode("alpha")
+
+  -- draw ambient
+  util.drawto(self.shadow, l, t, s, function()
+    love.graphics.setColor(unpack(self.ambient))
+    love.graphics.setBlendMode("alpha")
+    love.graphics.rectangle("fill", l, t, w, h)
+    for i = 1, #self.lights do
+      self.lights[i]:drawShadow(l,t,w,h,s,self.body, self.shadow)
+    end
+  end)
+
+  light_world:drawBlur("alpha", self.blur, self.shadow, self.shadow2, l, t, w, h, s)
+  util.drawCanvasToCanvas(self.shadow, self.render_buffer, {blendmode = "multiplicative"})
 end
 
 -- draw shine
@@ -286,6 +253,7 @@ function light_world:drawShine(l,t,w,h,s)
     return
   end
   self:updateShine(l,t,w,h)
+  love.graphics.setCanvas(self.render_buffer)
   love.graphics.setColor(255, 255, 255)
   love.graphics.setBlendMode("multiplicative")
   love.graphics.setShader()
@@ -299,6 +267,7 @@ function light_world:drawPixelShadow(l,t,w,h,s)
     return 
   end
   self:updatePixelShadows(l,t,w,h)
+  love.graphics.setCanvas(self.render_buffer)
   love.graphics.setColor(255, 255, 255)
   love.graphics.setBlendMode("multiplicative")
   love.graphics.setShader()
@@ -319,6 +288,7 @@ function light_world:drawGlow(l,t,w,h,s)
     return
   end
   self:updateGlow(l,t,w,h)
+  love.graphics.setCanvas(self.render_buffer)
   love.graphics.setColor(255, 255, 255)
   love.graphics.setBlendMode("additive")
   love.graphics.setShader()
@@ -331,6 +301,7 @@ function light_world:drawRefraction(l,t,w,h,s)
     return
   end
   self:updateRefraction(l,t,w,h)
+  love.graphics.setCanvas(self.render_buffer)
   self.refractionShader:send("backBuffer", self.refractionMap2)
   self.refractionShader:send("refractionStrength", self.refractionStrength)
   love.graphics.setShader(self.refractionShader)
@@ -344,6 +315,7 @@ function light_world:drawReflection(l,t,w,h,s)
     return
   end
   self:updateRelfection(l,t,w,h)
+  love.graphics.setCanvas(self.render_buffer)
   self.reflectionShader:send("backBuffer", self.reflectionMap2)
   self.reflectionShader:send("reflectionStrength", self.reflectionStrength)
   self.reflectionShader:send("reflectionVisibility", self.reflectionVisibility)
diff --git a/lib/postshader.lua b/lib/postshader.lua
index 2352429..94091ec 100644
--- a/lib/postshader.lua
+++ b/lib/postshader.lua
@@ -69,7 +69,7 @@ function post_shader:toggleEffect(shaderName, ...)
   end
 end
 
-function post_shader:drawWith(canvas, l, t)
+function post_shader:drawWith(canvas, l, t, scale)
   for shader, args in pairs(self.effects) do 
     if shader == "bloom" then
       self:drawBloom(canvas, args)
@@ -274,7 +274,6 @@ function post_shader:drawTest(canvas, args)
       effect[1]:send(def, defaults[def])
     end
   end
-  print(effect[3])
   love.graphics.setShader(effect[1])
   love.graphics.draw(canvas)
 
diff --git a/lib/stencils.lua b/lib/stencils.lua
index 073fb15..c5561cb 100644
--- a/lib/stencils.lua
+++ b/lib/stencils.lua
@@ -2,40 +2,29 @@ local stencils = {}
 
 function stencils.shadow(geometry, bodies)
   return function()
+    --cast shadows
     for i = 1,#geometry do
       if geometry[i].alpha == 1.0 then
         love.graphics.polygon("fill", unpack(geometry[i]))
       end
     end
+    -- underneath shadows
     for i = 1, #bodies do
       if not bodies[i].castsNoShadow then
-        if bodies[i].shadowType == "circle" then
-          love.graphics.circle("fill", bodies[i].x - bodies[i].ox, bodies[i].y - bodies[i].oy, bodies[i].radius)
-        elseif bodies[i].shadowType == "rectangle" then
-          love.graphics.rectangle("fill", bodies[i].x - bodies[i].ox, bodies[i].y - bodies[i].oy, bodies[i].width, bodies[i].height)
-        elseif bodies[i].shadowType == "polygon" then
-          love.graphics.polygon("fill", unpack(bodies[i].data))
-        elseif bodies[i].shadowType == "image" then
-        --love.graphics.rectangle("fill", bodies[i].x - bodies[i].ox, bodies[i].y - bodies[i].oy, bodies[i].width, bodies[i].height)
-        end
+        bodies[i]:shadowStencil()
       end
     end
   end
 end
 
-function stencils.poly(bodies)
+function stencils.colorShadow(bodies)
   return function()
     for i = 1, #bodies do
-      if bodies[i].shine and (bodies[i].glowStrength == 0.0 or (bodies[i].type == "image" and not bodies[i].normal)) then
-        if bodies[i].shadowType == "circle" then
-          love.graphics.circle("fill", bodies[i].x - bodies[i].ox, bodies[i].y - bodies[i].oy, bodies[i].radius)
-        elseif bodies[i].shadowType == "rectangle" then
-          love.graphics.rectangle("fill", bodies[i].x - bodies[i].ox, bodies[i].y - bodies[i].oy, bodies[i].width, bodies[i].height)
-        elseif bodies[i].shadowType == "polygon" then
-          love.graphics.polygon("fill", unpack(bodies[i].data))
-        elseif bodies[i].shadowType == "image" then
-        --love.graphics.rectangle("fill", bodies[i].x - bodies[i].ox, bodies[i].y - bodies[i].oy, bodies[i].width, bodies[i].height)
-        end
+      if bodies[i].shine and 
+        (bodies[i].glowStrength == 0.0 or 
+        (bodies[i].type == "image" and not bodies[i].normal)) 
+      then
+        bodies[i]:shadowStencil()
       end
     end
   end
diff --git a/lib/util.lua b/lib/util.lua
new file mode 100644
index 0000000..f8a62b6
--- /dev/null
+++ b/lib/util.lua
@@ -0,0 +1,40 @@
+local util = {}
+
+function util.drawCanvasToCanvas(canvas, other_canvas, options)
+  options = options or {}
+
+  local last_buffer = love.graphics.getCanvas()
+  love.graphics.push()
+    love.graphics.origin()
+    love.graphics.setCanvas(other_canvas)
+      if options["blendmode"] then
+        love.graphics.setBlendMode(options["blendmode"])
+      end
+      if options["shader"] then
+        love.graphics.setShader(options["shader"])
+      end
+      love.graphics.setColor(255,255,255)
+      love.graphics.draw(canvas,0,0)
+    love.graphics.setCanvas(last_buffer)
+    if options["blendmode"] then
+      love.graphics.setBlendMode("alpha")
+    end
+    if options["shader"] then
+      love.graphics.setShader()
+    end
+  love.graphics.pop()
+end
+
+function util.drawto(canvas, x, y, scale, cb)
+  local last_buffer = love.graphics.getCanvas()
+  love.graphics.push()
+    love.graphics.origin()
+    love.graphics.setCanvas(canvas)
+      love.graphics.translate(x, y)
+      love.graphics.scale(scale)
+      cb()
+    love.graphics.setCanvas(last_buffer)
+  love.graphics.pop()
+end
+
+return util
diff --git a/main.lua b/main.lua
index 651d50d..50e1420 100644
--- a/main.lua
+++ b/main.lua
@@ -58,7 +58,7 @@ function exf.update(dt)
 end
 
 function exf.draw()
-	lightWorld:draw(0, 0, love.window.getWidth(), love.window.getHeight(), 1)
+	lightWorld:draw()
 end
 
 function exf.drawBackground()