just some light screen presence checking

lib/init.lua

@@ -89,6 +89,10 @@ function light_world:update(dt)
       self.bodies[i]:update(dt)
     end
   end
+
+  for i = 1, #self.lights do
+    self.lights[i].is_on_screen = self.lights[i]:inRange(self.l,self.t,self.w,self.h,self.s)
+  end
 end
 
 function light_world:draw(cb)
@@ -129,7 +133,7 @@ function light_world:drawNormalShading(l,t,w,h,s)
   self.normal2:clear()
   for i = 1, #self.lights do
     local light = self.lights[i]
-    if light:inRange(l,t,w,h,s) then
+    if light:isVisible() then
       -- create shadow map for this light
       self.shadowMap:clear()
       util.drawto(self.shadowMap, l, t, s, function()
@@ -146,7 +150,7 @@ function light_world:drawNormalShading(l,t,w,h,s)
       self.shadowShader:send('shadowMap', self.shadowMap)
       self.shadowShader:send('lightColor', {light.red / 255.0, light.green / 255.0, light.blue / 255.0})
       self.shadowShader:send("lightPosition", {(light.x + l/s) * s, (h/s - (light.y + t/s)) * s, (light.z * 10) / 255.0})
-      self.shadowShader:send('lightRange',{light.range * s})
+      self.shadowShader:send('lightRange',  light.range * s)
       self.shadowShader:send("lightSmooth", light.smooth)
       self.shadowShader:send("lightGlow", {1.0 - light.glowSize, light.glowStrength})
       self.shadowShader:send("invert_normal", self.normalInvert)

lib/light.lua

@@ -17,6 +17,7 @@ function light:init(x, y, r, g, b, range)
 	self.glowSize = 0.1
 	self.glowStrength = 0.0
 	self.visible = true
+  self.is_on_screen = true
 end
 
 -- set position
@@ -112,4 +113,8 @@ function light:setVisible(visible)
   self.visible = visible
 end
 
+function light:isVisible()
+  return self.visible and self.is_on_screen
+end
+
 return light

lib/shaders/shadow.glsl

@@ -8,7 +8,7 @@ extern vec3  lightColor;       //the rgb color of the light
 extern float lightRange;                     //the range of the light
 extern float lightSmooth;                    //smoothing of the lights attenuation
 extern vec2  lightGlow     = vec2(0.5, 0.5); //how brightly the light bulb part glows
-extern bool  invert_normal;   //if the light should invert normals
+extern bool  invert_normal = false;          //if the light should invert normals
 
 vec4 effect(vec4 color, Image texture, vec2 texture_coords, vec2 pixel_coords) {
   vec4 pixelColor = Texel(texture, texture_coords);