From 02d6f00b8e7954a9b238242c4042bcdc33f3e692 Mon Sep 17 00:00:00 2001
From: AryanKoundal <aryankoundal474@gmail.com>
Date: Sat, 14 Oct 2023 10:05:57 +0530
Subject: [PATCH] added code for specular light

---
 src/webgl/p5.RendererGL.js                    | 33 ++++++++++++++++++-
 ...mageLight.frag => imageLightDiffused.frag} |  0
 src/webgl/shaders/lighting.glsl               | 17 ++++++++--
 3 files changed, 47 insertions(+), 3 deletions(-)
 rename src/webgl/shaders/{imageLight.frag => imageLightDiffused.frag} (100%)

diff --git a/src/webgl/p5.RendererGL.js b/src/webgl/p5.RendererGL.js
index 317e679d25..91d72d0f33 100644
--- a/src/webgl/p5.RendererGL.js
+++ b/src/webgl/p5.RendererGL.js
@@ -76,7 +76,7 @@ const defaultShaders = {
   pointVert: readFileSync(join(__dirname, '/shaders/point.vert'), 'utf-8'),
   pointFrag: readFileSync(join(__dirname, '/shaders/point.frag'), 'utf-8'),
   imageLightVert : readFileSync(join(__dirname, '/shaders/imageLight.vert'), 'utf-8'),
-  imageLightFrag : readFileSync(join(__dirname, '/shaders/imageLight.frag'), 'utf-8'),
+  imageLightFrag : readFileSync(join(__dirname, '/shaders/imageLightDiffused.frag'), 'utf-8'),
   imageLightSpecularFrag : readFileSync(join(__dirname, '/shaders/imageLightSpecular.frag'), 'utf-8')
 };
 for (const key in defaultShaders) {
@@ -1926,7 +1926,30 @@ p5.RendererGL = class RendererGL extends p5.Renderer {
     return newGraphic;
   }
 
+  getSpecularTexture(){
+    // check if already exits (there are tex of diff resolution so which one to check)
+    // currently doing the whole array
+    if(this.specularTextures.length !== 0){
+      return this.specularTextures;
+    }
 
+    const graphic = createGraphics(size, size, WEBGL);
+    let count = Math.log(size)/Math.log(2);
+    graphic.pixelDensity(1);
+    for (let w = size; w >= 1; w /= 2) {
+      graphic.resizeCanvas(w, w);
+      let currCount = Math.log(w)/Math.log(2);
+      let roughness = 1-currCount/count;
+      console.log(roughness);
+      graphic.shader(myShader);
+      graphic.clear();
+      myShader.setUniform('environmentMap', img);
+      myShader.setUniform('roughness', roughness);
+      graphic.noStroke();
+      graphic.plane(w, w);
+      levels.push(graphic.get().drawingContext.getImageData(0, 0, w, w));
+    }
+  }
 
   /**
    * @method activeFramebuffer
@@ -2037,8 +2060,16 @@ p5.RendererGL = class RendererGL extends p5.Renderer {
     if (this.activeImageLight) {
       // this.activeImageLight has image as a key
       // look up the texture from the blurryTexture map
+      // change the name of shader of diffused to prevent confusion
       let diffusedLight = this.getBlurryTexture(this.activeImageLight);
+      // change the name of this uniform as diff for diffused and specular
       shader.setUniform('environmentMap', diffusedLight);
+      let specularLight = this.getSpecularTexture();
+      // shine >= 1 so
+      let roughness = 1/this._useShininess;
+      // 0 - 1
+      shader.setUniform('lod', roughness*8);
+      shader.setUniform('environmentMapSpecular', specularLight);
     }
   }
 
diff --git a/src/webgl/shaders/imageLight.frag b/src/webgl/shaders/imageLightDiffused.frag
similarity index 100%
rename from src/webgl/shaders/imageLight.frag
rename to src/webgl/shaders/imageLightDiffused.frag
diff --git a/src/webgl/shaders/lighting.glsl b/src/webgl/shaders/lighting.glsl
index 6925c1bc68..c5f78a8e92 100644
--- a/src/webgl/shaders/lighting.glsl
+++ b/src/webgl/shaders/lighting.glsl
@@ -40,6 +40,9 @@ uniform float uQuadraticAttenuation;
 uniform bool uUseImageLight;
 // storing the texture
 uniform sampler2D environmentMap;
+// make a diffused texture and specular texture differently
+uniform sampler2D environmentMapSpecular;
+uniform float lod;
 
 const float specularFactor = 2.0;
 const float diffuseFactor = 0.73;
@@ -105,18 +108,28 @@ vec2 mapTextureToNormal( vec3 normal ){
 vec3 calculateImageDiffuse( vec3 vNormal, vec3 vViewPosition ){
   // put the code from the sketch frag here
   // hardcoded world camera position
+  // make 2 seperate builds 
   vec3 worldCameraPosition =  vec3(0.0, 0.0, 0.0);
   vec3 worldNormal = normalize(vNormal);
   vec3 lightDirection = normalize( vViewPosition - worldCameraPosition );
   vec3 R = reflect(lightDirection, worldNormal);
+  // use worldNormal instead of R
   vec2 newTexCoor = mapTextureToNormal( R );
   vec4 texture = texture2D( environmentMap, newTexCoor );
   return texture.xyz;
 }
 
 // TODO
-vec3 calculateImageSpecular(){
+vec3 calculateImageSpecular( vec3 vNormal, vec3 vViewPosition ){
   // not sure what to do here
+  vec3 worldCameraPosition =  vec3(0.0, 0.0, 0.0);
+  vec3 worldNormal = normalize(vNormal);
+  vec3 lightDirection = normalize( vViewPosition - worldCameraPosition );
+  vec3 R = reflect(lightDirection, worldNormal);
+  vec2 newTexCoor = mapTextureToNormal( R );
+  
+  vec4 outColor = textureLod(environmentMapSpecular, newTexCoor, lod);
+  return outColor.xyz;
 }
 
 void totalLight(
@@ -193,7 +206,7 @@ void totalLight(
   if( uUseImageLight ){
     totalDiffuse += calculateImageDiffuse(normal, modelPosition);
     // TODO
-    totalSpecular += calculateImageSpecular();
+    totalSpecular += calculateImageSpecular(normal, modelPosition);
   }
 
   totalDiffuse *= diffuseFactor;