typo

Author: greggman

threejs/lessons/threejs-post-processing.md

@@ -260,7 +260,7 @@ const colorShader = {
       vec4 previousPassColor = texture2D(tDiffuse, vUv);
       gl_FragColor = vec4(
           previousPassColor.rgb * color,
-          previousPassColor.w);
+          previousPassColor.a);
     }
   `,
 };
@@ -275,7 +275,7 @@ is pretty much standard and rarely needs to be changed. Without going into too
 many details (see articles linked above) the variables `uv`, `projectionMatrix`,
 `modelViewMatrix` and `position` are all magically added by THREE.js.
 
-Finally we create a fragment shader. In it we get get pixel color from the
+Finally we create a fragment shader. In it we get a pixel color from the
 previous pass with this line
 
 ```glsl