Add OpenGL support to Linux viewer

tools/viewer/sk_app/unix/VulkanWindowContext_unix.cpp

 
 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "../VulkanWindowContext.h"
 #include "Window_unix.h"
@@ skipping 21 matching lines @@
 
 
     VkSurfaceKHR surface;
 
     VkXcbSurfaceCreateInfoKHR surfaceCreateInfo;
     memset(&surfaceCreateInfo, 0, sizeof(VkXcbSurfaceCreateInfoKHR));
     surfaceCreateInfo.sType = VK_STRUCTURE_TYPE_XCB_SURFACE_CREATE_INFO_KHR;
     surfaceCreateInfo.pNext = nullptr;
     surfaceCreateInfo.flags = 0;
     surfaceCreateInfo.connection = XGetXCBConnection(unixPlatformData->fDisplay);
-    surfaceCreateInfo.window = unixPlatformData->fHWnd;
+    surfaceCreateInfo.window = unixPlatformData->fWindow;
 
     VkResult res = createXcbSurfaceKHR(instance, &surfaceCreateInfo, nullptr, &surface);
     if (VK_SUCCESS != res) {
         return VK_NULL_HANDLE;
     }
 
     return surface;
 }
 
 // Platform dependant call
 bool VulkanWindowContext::canPresent(VkInstance instance, VkPhysicalDevice physDev,
                                      uint32_t queueFamilyIndex, void* platformData) {
     static PFN_vkGetPhysicalDeviceXcbPresentationSupportKHR
                                             getPhysicalDeviceXcbPresentationSupportKHR = nullptr;
     if (!getPhysicalDeviceXcbPresentationSupportKHR) {
         getPhysicalDeviceXcbPresentationSupportKHR =
             (PFN_vkGetPhysicalDeviceXcbPresentationSupportKHR) vkGetInstanceProcAddr(instance,
                                                  "vkGetPhysicalDeviceXcbPresentationSupportKHR");
     }
 
     ContextPlatformData_unix* unixPlatformData =
                                           reinterpret_cast<ContextPlatformData_unix*>(platformData);
 
     Display* display = unixPlatformData->fDisplay;
+    VisualID visualID = unixPlatformData->fVisualInfo->visualid;
     VkBool32 check = getPhysicalDeviceXcbPresentationSupportKHR(physDev, 
                                                                 queueFamilyIndex, 
                                                                 XGetXCBConnection(display),
-                                                                unixPlatformData->fVisualID);
+                                                                visualID);
     return (VK_FALSE != check);
 }
 
 }   // namespace sk_app