NaCl SDK: Demonstrate use of pp::View::GetDeviceScale for 3D

native_client_sdk/src/examples/api/graphics_3d/graphics_3d.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <GLES2/gl2.h>
 #include <math.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <string.h>
@@ skipping 229 matching lines @@
         mvp_loc_(0),
         x_angle_(0),
         y_angle_(0),
         animating_(true) {}
 
   virtual bool Init(uint32_t argc, const char* argn[], const char* argv[]) {
     return true;
   }
 
   virtual void DidChangeView(const pp::View& view) {
-    int32_t new_width = view.GetRect().width();
-    int32_t new_height = view.GetRect().height();
+    // Pepper specifies dimensions in DIPs (device-independent pixels). To
+    // generate a context that is at device-pixel resolution on HiDPI devices,
+    // scale the dimensions by view.GetDeviceScale().
+    int32_t new_width = view.GetRect().width() * view.GetDeviceScale();
+    int32_t new_height = view.GetRect().height() * view.GetDeviceScale();
 
     if (context_.is_null()) {
       if (!InitGL(new_width, new_height)) {
         // failed.
         return;
       }
 
       InitShaders();
       InitBuffers();
       InitTexture();
@@ skipping 235 matching lines @@
   virtual ~Graphics3DModule() {}
 
   virtual pp::Instance* CreateInstance(PP_Instance instance) {
     return new Graphics3DInstance(instance);
   }
 };
 
 namespace pp {
 Module* CreateModule() { return new Graphics3DModule(); }
 }  // namespace pp