From 2c9d55a1aa5fb7d65a1c7dd7c00db6a27802dc3a Mon Sep 17 00:00:00 2001
From: kgv <kgv@opencascade.com>
Date: Sun, 16 Feb 2020 21:53:08 +0300
Subject: [PATCH] 0031373: Samples - provide sample combining OCCT and 3 viewer

---
 samples/webgl/WasmOcctView.cpp       | 14 ++++++++++
 samples/webgl/occt-webgl-sample.html | 40 ++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+)

diff --git a/samples/webgl/WasmOcctView.cpp b/samples/webgl/WasmOcctView.cpp
index 68a8b86bba..7f78ee6b9d 100644
--- a/samples/webgl/WasmOcctView.cpp
+++ b/samples/webgl/WasmOcctView.cpp
@@ -52,6 +52,14 @@ namespace
     return aDevicePixelRatio;
   });
 
+  /*EM_JS(void, jsSetOcctCamera, (float theFOV, float theAspect, float theNear, float theFar), {
+    setOcctCamera();
+  });*/
+
+  EM_JS(void, jsPostFrameRender, (), {
+    postFrameRender();
+  });
+
   //! Return cavas size in pixels.
   static Graphic3d_Vec2i jsCanvasSize()
   {
@@ -336,7 +344,13 @@ void WasmOcctView::handleViewRedraw (const Handle(AIS_InteractiveContext)& theCt
                                      const Handle(V3d_View)& theView)
 {
   myUpdateRequests = 0;
+
+  theView->Invalidate(); /// Three.js cannot be rendered properly without full redraw
+  glEnable (GL_POLYGON_OFFSET_FILL); /// reset defaults Graphic3d_PolygonOffset after Three.js
+  glPolygonOffset (1.0f, 1.0f);
+
   AIS_ViewController::handleViewRedraw (theCtx, theView);
+  jsPostFrameRender();
   if (myToAskNextFrame)
   {
     // ask more frames
diff --git a/samples/webgl/occt-webgl-sample.html b/samples/webgl/occt-webgl-sample.html
index 80f7e6f4d8..fc417b2e8f 100644
--- a/samples/webgl/occt-webgl-sample.html
+++ b/samples/webgl/occt-webgl-sample.html
@@ -16,6 +16,7 @@
 <div><label for="fileInput">Choose BREP file to upload: </label><input type="file" id="fileInput" accept=".brep"></div>
 <h4>Console output:</h4>
 <p id="output"></p>
+<script src="three.min.js"></script>
 <script>
 //! Resize canvas to fit into window.
 function updateCanvasSize()
@@ -57,6 +58,7 @@ if (!isWasmSupported())
 {
   var anElement = document.getElementById('output');
   anElement.innerHTML += "Browser is too old - WebAssembly support is missing!<br>Please check updates or install a modern browser.<br>";
+  throw new Error();
 }
 
 //! Define OCCT WebGL Viewer module.
@@ -76,6 +78,44 @@ var Module =
   })()
 };
 
+var aCanvas = document.getElementById ('canvas');
+var aGlCtx  = aCanvas.getContext ('webgl2', { alpha: false, depth: true, antialias: false, preserveDrawingBuffer: true } );
+if (aGlCtx == null)
+{
+  aGlCtx    = aCanvas.getContext ('webgl',  { alpha: false, depth: true, antialias: false, preserveDrawingBuffer: true } );
+}
+var aScene  = new THREE.Scene();
+var aCamera = new THREE.PerspectiveCamera (75, window.innerWidth / window.innerHeight);
+//var aRenderer = new THREE.WebGLRenderer ({antialias: true});
+var aRenderer = new THREE.WebGLRenderer ({antialias: false, canvas: aCanvas, context: aGlCtx});
+aRenderer.autoClear = false;
+aRenderer.autoClearColor = false;
+aRenderer.autoClearDepth = false;
+aRenderer.autoClearStencil = false;
+aRenderer.setSize (window.innerWidth,window.innerHeight);
+//document.body.appendChild (aRenderer.domElement);
+var aGeom = new THREE.BoxGeometry (1,1,1);
+var aMat  = new THREE.MeshBasicMaterial ({color: 0xff0000});
+var aCube = new THREE.Mesh (aGeom, aMat);
+aScene.add (aCube);
+aCube.position.z = -5; aCube.rotation.x = 10; aCube.rotation.y = 5;
+/*aRenderer.render (aScene, aCamera);
+var anAnimate = function(){
+  aCube.rotation.x += 0.01;
+  aRenderer.state.reset();
+  aRenderer.render (aScene, aCamera);
+  requestAnimationFrame (anAnimate);
+}
+anAnimate();*/
+
+function postFrameRender()
+{
+  //console.log("postFrameRender()"); ///
+  //aCamera.
+  aRenderer.state.reset();
+  aRenderer.render (aScene, aCamera)
+}
+
 //! Handle file uploading.
 fileInput.onchange = function()
 {
-- 
2.39.5