From 1d2651c4ef780076fb7b1e9692c8ed7740f4a06a Mon Sep 17 00:00:00 2001
From: Ivan Danyliuk <ivan.daniluk@gmail.com>
Date: Tue, 23 Oct 2018 08:28:14 +0200
Subject: [PATCH] Fix WebGL initialization order issue

---
 graph.go                    |  3 +++
 page.go                     |  8 +++++++-
 scene.go                    | 10 ++++++++--
 widgets/network_selector.go |  8 ++++----
 4 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/graph.go b/graph.go
index d995eca..3ff87c6 100644
--- a/graph.go
+++ b/graph.go
@@ -29,6 +29,9 @@ func (p *Page) UpdateGraph() {
 // and creates all new objects based on current data and positions.
 // It doesn't do any calculations of changes to the layout or graph data.
 func (p *Page) RecreateObjects() {
+	p.loaded = true
+	p.loader.Reset()
+
 	p.webgl.RemoveObjects()
 	p.webgl.CreateObjects(p.layout.Positions(), p.layout.Links())
 
diff --git a/page.go b/page.go
index d963d71..1cf0574 100644
--- a/page.go
+++ b/page.go
@@ -39,7 +39,7 @@ func NewPage() *Page {
 	}
 	page.forceEditor = widgets.NewForceEditor(page.onForcesApply)
 	page.network = widgets.NewNetworkSelector(page.onNetworkChange)
-	page.webgl = NewWebGLScene()
+	page.webgl = NewWebGLScene(page.onWebGLReady)
 	page.simulationWidget = widgets.NewSimulation("http://localhost:8084", page.startSimulation, page.replaySimulation)
 	page.statsWidget = widgets.NewStats()
 	return page
@@ -128,6 +128,7 @@ func (p *Page) onNetworkChange(network *network.Network) {
 
 	// set forced positions if found in network
 	if network.Positions != nil {
+		fmt.Println("Using precalculated positions")
 		p.layout.SetPositions(network.Positions)
 		go p.RecreateObjects()
 		return
@@ -194,3 +195,8 @@ func (p *Page) header() *vecty.HTML {
 		),
 	)
 }
+
+// onWebGLReady is executed when WebGL context is up and ready to render scene.
+func (p *Page) onWebGLReady() {
+	p.onNetworkChange(p.network.Current())
+}
diff --git a/scene.go b/scene.go
index 18c41ee..be6b2f4 100644
--- a/scene.go
+++ b/scene.go
@@ -33,12 +33,15 @@ type WebGLScene struct {
 	lines []*Line
 
 	rt *RenderThrottler // used as a helper to reduce rendering calls when animation is not needed (experimental)
+
+	initFn func() // function to run on initialization
 }
 
 // NewWebGLScene inits and returns new WebGL scene and canvas.
-func NewWebGLScene() *WebGLScene {
+func NewWebGLScene(initFn func()) *WebGLScene {
 	w := &WebGLScene{
-		rt: NewRenderThrottler(),
+		rt:     NewRenderThrottler(),
+		initFn: initFn,
 	}
 	w.WebGLRenderer = vthree.NewWebGLRenderer(vthree.WebGLOptions{
 		Init:      w.init,
@@ -61,6 +64,9 @@ func (w *WebGLScene) init(renderer *three.WebGLRenderer) {
 
 	w.InitScene(windowWidth, windowHeight)
 
+	if w.initFn != nil {
+		w.initFn()
+	}
 	w.animate()
 }
 
diff --git a/widgets/network_selector.go b/widgets/network_selector.go
index de4a012..fa202ed 100644
--- a/widgets/network_selector.go
+++ b/widgets/network_selector.go
@@ -139,6 +139,10 @@ func (n *NetworkSelector) onUpload(json []byte) {
 	n.networks[net.Name] = net
 	n.setCurrentNetwork(net)
 
+	if n.handler != nil {
+		go n.handler(n.current)
+	}
+
 	vecty.Rerender(n)
 }
 
@@ -150,8 +154,4 @@ func (n *NetworkSelector) Current() *network.Network {
 // setCurrentNetwork changes current network and runs needed update handlers.
 func (n *NetworkSelector) setCurrentNetwork(net *network.Network) {
 	n.current = net
-
-	if n.handler != nil {
-		go n.handler(n.current)
-	}
 }