Dynamic fix as fun (#207)

getNeighborPixel(x, y) method for Dynamic module

src/modules/Dynamic/Module.js

@@ -35,6 +35,10 @@ module.exports = function Dynamic(options,UI) {
     });
     
     function changePixel(r, g, b, a) {
+
+      /* neighbourpixels can be calculated by
+       this.getNeighbourPixel.fun(x,y)  or this.getNeighborPixel.fun(x,y)
+       */
       var combined = (r + g + b) / 3.000;
       return [
         options.red_function(r, g, b, a),
@@ -44,6 +48,17 @@ module.exports = function Dynamic(options,UI) {
       ];
     }
     
+    /* Functions to get the neighbouring pixel by position (x,y) */
+    function getNeighbourPixel(pixels,curX,curY,distX,distY){
+      return [
+         pixels.get(curX+distX,curY+distY,0)
+        ,pixels.get(curX+distX,curY+distY,1)
+        ,pixels.get(curX+distX,curY+distY,2)
+        ,pixels.get(curX+distX,curY+distY,3)
+      ]
+    }
+    
+    
     function output(image,datauri,mimetype){
       
       // This output is accessible by Image Sequencer
@@ -59,6 +74,8 @@ module.exports = function Dynamic(options,UI) {
     return require('../_nomodule/PixelManipulation.js')(input, {
       output: output,
       changePixel: changePixel,
+      getNeighbourPixel: getNeighbourPixel,
+      getNeighborPixel: getNeighbourPixel,
       format: input.format,
       image: options.image,
       inBrowser: options.inBrowser,

src/modules/_nomodule/PixelManipulation.js

@@ -22,6 +22,12 @@ module.exports = function PixelManipulation(image, options) {
       return;
     }
 
+    if(options.getNeighbourPixel){
+      options.getNeighbourPixel.fun = function (distX,distY) { 
+        return options.getNeighbourPixel(pixels,x,y,distX,distY);
+      };
+    }
+    
     // iterate through pixels;
     // this could possibly be more efficient; see
     // https://github.com/p-v-o-s/infragram-js/blob/master/public/infragram.js#L173-L181