aboutsummaryrefslogtreecommitdiff
path: root/node_modules/color-convert/route.js
diff options
context:
space:
mode:
Diffstat (limited to 'node_modules/color-convert/route.js')
-rw-r--r--node_modules/color-convert/route.js97
1 files changed, 97 insertions, 0 deletions
diff --git a/node_modules/color-convert/route.js b/node_modules/color-convert/route.js
new file mode 100644
index 0000000..0a1fdea
--- /dev/null
+++ b/node_modules/color-convert/route.js
@@ -0,0 +1,97 @@
+var conversions = require('./conversions');
+
+/*
+ this function routes a model to all other models.
+
+ all functions that are routed have a property `.conversion` attached
+ to the returned synthetic function. This property is an array
+ of strings, each with the steps in between the 'from' and 'to'
+ color models (inclusive).
+
+ conversions that are not possible simply are not included.
+*/
+
+function buildGraph() {
+ var graph = {};
+ // https://jsperf.com/object-keys-vs-for-in-with-closure/3
+ var models = Object.keys(conversions);
+
+ for (var len = models.length, i = 0; i < len; i++) {
+ graph[models[i]] = {
+ // http://jsperf.com/1-vs-infinity
+ // micro-opt, but this is simple.
+ distance: -1,
+ parent: null
+ };
+ }
+
+ return graph;
+}
+
+// https://en.wikipedia.org/wiki/Breadth-first_search
+function deriveBFS(fromModel) {
+ var graph = buildGraph();
+ var queue = [fromModel]; // unshift -> queue -> pop
+
+ graph[fromModel].distance = 0;
+
+ while (queue.length) {
+ var current = queue.pop();
+ var adjacents = Object.keys(conversions[current]);
+
+ for (var len = adjacents.length, i = 0; i < len; i++) {
+ var adjacent = adjacents[i];
+ var node = graph[adjacent];
+
+ if (node.distance === -1) {
+ node.distance = graph[current].distance + 1;
+ node.parent = current;
+ queue.unshift(adjacent);
+ }
+ }
+ }
+
+ return graph;
+}
+
+function link(from, to) {
+ return function (args) {
+ return to(from(args));
+ };
+}
+
+function wrapConversion(toModel, graph) {
+ var path = [graph[toModel].parent, toModel];
+ var fn = conversions[graph[toModel].parent][toModel];
+
+ var cur = graph[toModel].parent;
+ while (graph[cur].parent) {
+ path.unshift(graph[cur].parent);
+ fn = link(conversions[graph[cur].parent][cur], fn);
+ cur = graph[cur].parent;
+ }
+
+ fn.conversion = path;
+ return fn;
+}
+
+module.exports = function (fromModel) {
+ var graph = deriveBFS(fromModel);
+ var conversion = {};
+
+ var models = Object.keys(graph);
+ for (var len = models.length, i = 0; i < len; i++) {
+ var toModel = models[i];
+ var node = graph[toModel];
+
+ if (node.parent === null) {
+ // no possible conversion, or this node is the source model.
+ continue;
+ }
+
+ conversion[toModel] = wrapConversion(toModel, graph);
+ }
+
+ return conversion;
+};
+