lights() support on framebuffer block

Author: perminder-17

src/webgl/p5.Geometry.js

@@ -103,7 +103,7 @@ p5.Geometry = class Geometry {
    * let points = [];
    *
    * function setup() {
-   *   createCanvas(600, 600, WEBGL);
+   *   createCanvas(100, 100, WEBGL);
    *   points.push(new p5.Vector(-1, -1, 0), new p5.Vector(-1, 1, 0),
    *     new p5.Vector(1, -1, 0), new p5.Vector(-1, -1, 0));
    *   buildShape01();

src/webgl/p5.RendererGL.js

@@ -1095,6 +1095,7 @@ p5.RendererGL = class RendererGL extends p5.Renderer {
         this.filterShader.setUniform('tex0', target);
         this._pInst.clear();
         this._pInst.shader(this.filterShader);
+        this._pInst.noLights();
         this._pInst.rect(-target.width / 2,
           -target.height / 2, target.width, target.height);
       });
@@ -1105,6 +1106,7 @@ p5.RendererGL = class RendererGL extends p5.Renderer {
         this.filterShader.setUniform('tex0', tmp);
         this._pInst.clear();
         this._pInst.shader(this.filterShader);
+        this._pInst.noLights();
         this._pInst.rect(-target.width / 2,
           -target.height / 2, target.width, target.height);
       });
@@ -1122,6 +1124,7 @@ p5.RendererGL = class RendererGL extends p5.Renderer {
         // filterParameter uniform only used for POSTERIZE, and THRESHOLD
         // but shouldn't hurt to always set
         this.filterShader.setUniform('filterParameter', filterParameter);
+        this._pInst.noLights();
         this._pInst.rect(-target.width / 2, -target.height / 2,
           target.width, target.height);
       });