1 files changed, 39 insertions, 0 deletions
diff --git a/public/js/mp/dye.js b/public/js/mp/dye.js
index 530b6c4..7cf8da5 100644
--- a/public/js/mp/dye.js
+++ b/public/js/mp/dye.js
@@ -28,11 +28,50 @@ var mp = function(mp) {
 
         return { channel: channel[idx], intensity: max };
     }
+    /*
+     * Return a dye specification from a dye string.
+     */
     function parseDyeString(dyeString) {
         /* TODO */
     }
+    /*
+     * Dye the internal image data based on the specification provided by dyeData.
+     * The specification can be generated from a dyeString by parseDyeString.
+     * The array passed in will be modified.
+     */
     function dyeImage(imageData, dyeData) {
+        for (var p = 0; p < imageData.length; p += 4) {
+            var pixel = [imageData[p], imageData[p + 1], imageData[p + 2]];
+            var alpha = imageData[p + 3];
+            if (!alpha) {
+                continue;
+            }
+
+            var channel = getChannel(pixel);
+            var channelId = channel.channel;
+
+            if (!channelId || !(channelId in dyeData) || !dyeData[channelId].length) {
+                continue;
+            }
+
+            var intensity = channel.intensity;
+            var val = intensity * dyeData[channelId].length
+            var i = Math.floor(val / 255);
+            var t = val - i * 255;
+            if (!t) {
+                --i;
+                imageData[p    ] = dyeData[channelId][i][0];
+                imageData[p + 1] = dyeData[channelId][i][1];
+                imageData[p + 2] = dyeData[channelId][i][2];
+                continue;
+            }
+
+            imageData[p    ] = ((255 - t) * (i && dyeData[channelId][i - 1][0]) + t * dyeData[channelId][i][0]) / 255;
+            imageData[p + 1] = ((255 - t) * (i && dyeData[channelId][i - 1][1]) + t * dyeData[channelId][i][1]) / 255;
+            imageData[p + 2] = ((255 - t) * (i && dyeData[channelId][i - 1][2]) + t * dyeData[channelId][i][2]) / 255;
+        }
         /* TODO */
+        return imageData;
     }
     return mp;
 }(mp || {});