First commit, containing the basic system.

- TODO: Add/Remove item system (so it's not fixed to two).

dist/js/beautify.js

@@ -0,0 +1,21 @@
+function syntaxHighlight(json) {
+    if (typeof json != 'string') {
+        json = JSON.stringify(json, undefined, 4);
+    }
+    json = json.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;');
+    return json.replace(/("(\\u[a-zA-Z0-9]{4}|\\[^u]|[^\\"])*"(\s*:)?|\b(true|false|null)\b|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?)/g, function (match) {
+        let cls = 'number';
+        if (/^"/.test(match)) {
+            if (/:$/.test(match)) {
+                cls = 'key';
+            } else {
+                cls = 'string';
+            }
+        } else if (/true|false/.test(match)) {
+            cls = 'boolean';
+        } else if (/null/.test(match)) {
+            cls = 'null';
+        }
+        return '<span class="' + cls + '">' + match + '</span>';
+    });
+}

dist/js/calculator.js

@@ -0,0 +1,59 @@
+//TODO Support more items
+const itemDamages = {
+    'leather_boots': 65
+};
+
+/**
+ * Map an in-game Damage to an texturepack Damage.
+ *
+ * @param value The input value.
+ * @param oldMax The old max value, from the itemDamages array.
+ */
+function getMappedDamage(value, oldMax) {
+    return value / oldMax;
+}
+
+/**
+ * Generate the JSON file.
+ *
+ * @param item The item to generate it for.
+ * @param models An array of models to insert.
+ * @returns {String} The JSON for the texturepack.
+ */
+function toJSON(item, models) {
+    const json = {};
+
+    //Default values
+    json['parent'] = 'item/handheld';
+    json['textures'] = {
+        'layer0': 'item/leather_boots',
+        'layer1': 'items/leather_boots_overlay'
+    };
+
+    //Insert models
+    json['overrides'] = [];
+
+    for (let i = 0; i < models.length; i++) {
+        const model = models[i];
+        const damage = getMappedDamage(i+1, itemDamages[item]);
+
+        json['overrides'][i] = {
+            'predicate': {
+                'damaged': 0,
+                'damage': damage,
+                'model': 'item/' + model
+            }
+        };
+    }
+
+    //Insert damaged model
+    json['overrides'][models.length] = {
+        'predicate': {
+            'damaged': 1,
+            'damage': 0,
+            'model': 'item/' + item
+        }
+    };
+
+    return JSON.stringify(json, null, 2);
+}