From 3cafa726845e84f10b152b133ff344ec7ccd53b5 Mon Sep 17 00:00:00 2001
From: Tim Anema <timanema@gmail.com>
Date: Sat, 20 Dec 2014 00:21:00 -0500
Subject: [PATCH] just a bit of a refactor that should be a bit of an
 optimizations because I wont be sending a buffer several time for no reason

---
 lib/init.lua            |  7 ++++---
 lib/shaders/shadow.glsl | 14 +++++++-------
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/lib/init.lua b/lib/init.lua
index c20de2e..52349fb 100644
--- a/lib/init.lua
+++ b/lib/init.lua
@@ -109,6 +109,9 @@ function light_world:drawNormalShading(l,t,w,h,s)
     end
   end)
 
+  self.shadowShader:send('normalMap', self.normalMap)
+  self.shadowShader:send("invert_normal", self.normalInvert == true)
+
   self.shadow_buffer:clear()
   for i = 1, #self.lights do
     local light = self.lights[i]
@@ -131,14 +134,12 @@ function light_world:drawNormalShading(l,t,w,h,s)
         end
       end)
       -- draw scene for this light using normals and shadowmap
-      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("lightSmooth", light.smooth)
       self.shadowShader:send("lightGlow", {1.0 - light.glowSize, light.glowStrength})
-      self.shadowShader:send("invert_normal", self.normalInvert == true)
-      util.drawCanvasToCanvas(self.normalMap, self.shadow_buffer, {
+      util.drawCanvasToCanvas(self.shadowMap, self.shadow_buffer, {
         blendmode = 'additive',
         shader = self.shadowShader,
         stencil = function()
diff --git a/lib/shaders/shadow.glsl b/lib/shaders/shadow.glsl
index 312a887..a4351f0 100644
--- a/lib/shaders/shadow.glsl
+++ b/lib/shaders/shadow.glsl
@@ -4,7 +4,7 @@
 */
 #define PI 3.1415926535897932384626433832795
 
-extern Image shadowMap;       //a canvas containing shadow data only
+extern Image normalMap;       //a canvas containing shadow data only
 extern vec3 lightPosition;    //the light position on the screen(not global)
 extern vec3 lightColor;       //the rgb color of the light
 extern float lightRange;      //the range of the light
@@ -13,8 +13,7 @@ extern vec2 lightGlow;        //how brightly the light bulb part glows
 extern bool  invert_normal;   //if the light should invert normals
 
 vec4 effect(vec4 color, Image texture, vec2 texture_coords, vec2 pixel_coords) {
-  vec4 pixelColor = Texel(texture, texture_coords);
-  vec4 shadowColor = Texel(shadowMap, texture_coords);
+  vec4 normalColor = Texel(normalMap, texture_coords);
 
   float dist = distance(lightPosition, vec3(pixel_coords, 1.0));
   //if the pixel is within this lights range
@@ -23,13 +22,13 @@ vec4 effect(vec4 color, Image texture, vec2 texture_coords, vec2 pixel_coords) {
     return vec4(0.0, 0.0, 0.0, 1.0);
   }else{
     vec3 normal;
-    if(pixelColor.a > 0.0) {
+    if(normalColor.a > 0.0) {
       //if on the normal map ie there is normal map data
       //so get the normal data
       if(invert_normal) {
-        normal = normalize(vec3(pixelColor.r, 1 - pixelColor.g, pixelColor.b) * 2.0 - 1.0); 
+        normal = normalize(vec3(normalColor.r, 1 - normalColor.g, normalColor.b) * 2.0 - 1.0); 
       } else {
-        normal = normalize(pixelColor.rgb * 2.0 - 1.0);
+        normal = normalize(normalColor.rgb * 2.0 - 1.0);
       }
     } else {
       // not on the normal map so it is the floor with a normal point strait up
@@ -38,7 +37,7 @@ vec4 effect(vec4 color, Image texture, vec2 texture_coords, vec2 pixel_coords) {
     //calculater attenuation of light based on the distance
     float att = clamp((1.0 - dist / lightRange) / lightSmooth, 0.0, 1.0);
     // if not on the normal map draw attenuated shadows
-    if(pixelColor.a == 0.0) {
+    if(normalColor.a == 0.0) {
       //start with a dark color and add in the light color and shadow color
       vec4 pixel = vec4(0.0, 0.0, 0.0, 1.0);
       if (lightGlow.x < 1.0 && lightGlow.y > 0.0) {
@@ -47,6 +46,7 @@ vec4 effect(vec4 color, Image texture, vec2 texture_coords, vec2 pixel_coords) {
         pixel.rgb = lightColor * pow(att, lightSmooth);
       }
       //If on the shadow map add the shadow color
+      vec4 shadowColor = Texel(texture, texture_coords);
       if(shadowColor.a > 0.0) {
         pixel.rgb = pixel.rgb * shadowColor.rgb;
       }