First pass at VulkanViewer

tools/vulkan/VulkanTestContext.h

Index: tools/vulkan/VulkanTestContext.h
diff --git a/tools/vulkan/VulkanTestContext.h b/tools/vulkan/VulkanTestContext.h
new file mode 100644
index 0000000000000000000000000000000000000000..735b5dcdf6626d4712d9a8b7bdb79eb8a1f00f46
--- /dev/null
+++ b/tools/vulkan/VulkanTestContext.h
@@ -0,0 +1,91 @@
+
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#ifndef VULKANTESTCONTEXT_DEFINED

[egdaniel, 2016/04/05 16:50:28]

we don't usually capitalize every letter in the class name here

[jvanverth1, 2016/04/05 18:16:49]

Done.

+#define VULKANTESTCONTEXT_DEFINED
+
+#ifdef SK_VULKAN
+
+#include "GrTypes.h"
+#include "vk/GrVkBackendContext.h"
+
+class SkSurface;
+class GrContext;
+
+class VulkanTestContext {

[bsalomon, 2016/04/05 14:24:43]

Is this class specifically handling the window-backed case? Seems centered
around having a real back buffer, presenting, etc. Wondering if it should be
VulkanWindowContext or something. Or do you imagine using it for offscreen
contexts as well?

[jvanverth1, 2016/04/05 18:16:49]

I was thinking it would be -- don't we create a window and do swapping in
nanobench?

+public:
+    ~VulkanTestContext();
+
+    // each platform will have to implement these in its CPP file
+    VkSurfaceKHR createVkSurface(void* platformData);
+    bool canPresent(uint32_t queueFamilyIndex);
+
+    static VulkanTestContext* Create(void* platformData, int msaaSampleCount) {
+        VulkanTestContext* ctx = new VulkanTestContext(platformData, msaaSampleCount);
+        if (!ctx->isValid()) {
+            delete ctx;
+            return nullptr;
+        }
+        return ctx;
+    }
+
+    SkSurface* getBackbufferSurface();
+    void swapBuffers();
+
+    bool makeCurrent() { return true; }
+    int getStencilBits() { return 0;  }
+    int getSampleCount() { return 0; }
+
+    bool isValid() { return SkToBool(fBackendContext.get()); }
+
+    void resize() { 
+        this->createSwapchain(0, 0); 
+    }
+
+    GrBackendContext getBackendContext() { return (GrBackendContext)fBackendContext.get(); }
+
+private:
+    VulkanTestContext();
+    VulkanTestContext(void*, int msaaSampleCount);
+    void initializeContext(void*);
+    void destroyContext();
+
+    struct BackbufferInfo {
+        uint32_t        fImageIndex;          // image this is associated with
+        VkSemaphore     fAcquireSemaphore;    // we signal on this for acquisition of image
+        VkSemaphore     fRenderSemaphore;     // we wait on this for rendering to be done
+        VkCommandBuffer fTransitionCmdBuffers[2]; // to transition layout between present and render
+        VkFence         fUsageFences[2];      // used to ensure this data is no longer used on GPU
+    };
+
+    BackbufferInfo* getAvailableBackbuffer();
+    bool createSwapchain(uint32_t width, uint32_t height);
+    void createBuffers();
+    void destroyBuffers();
+
+    GrContext*  fContext;
+    SkAutoTUnref<const GrVkBackendContext> fBackendContext;

[egdaniel, 2016/04/05 16:50:28]

use sk_sp?

[jvanverth1, 2016/04/05 18:16:49]

I agree, but I'd like to do that as a separate change -- it looks like changing
this might cause other changes to propagate outside of this patch.

+    VkSurfaceKHR fSurface;
+    VkSwapchainKHR fSwapchain;
+    uint32_t       fPresentQueueIndex;
+    VkQueue        fPresentQueue;
+    int            fWidth;
+    int            fHeight;
+    GrPixelConfig  fPixelConfig;
+
+    uint32_t          fImageCount;
+    VkImage*          fImages;         // images in the swapchain
+    VkImageLayout*    fImageLayouts;   // layouts of these images when not color attachment
+    sk_sp<SkSurface>* fSurfaces;       // wrapped surface for those images
+    VkCommandPool     fCommandPool;
+    BackbufferInfo*   fBackbuffers;
+    uint32_t          fCurrentBackbufferIndex;
+};
+
+#endif // SK_VULKAN
+
+#endif