Refactor Vulkan support to support Fuchsia

- Refactor runtime lookup of Vulkan functions
- Support Magma surfaces
- Add build flags to toggle Vulkan support

BUG=skia:

Change-Id: Ic71965c453507882521443006c4155c7481a9a3f
Reviewed-on: https://skia-review.googlesource.com/9342
Commit-Queue: Greg Daniel <egdaniel@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
Reviewed-by: Michael Jurka <mikejurka@google.com>
Reviewed-by: Mike Klein <mtklein@chromium.org>

3 files changed, 29 insertions, 21 deletions

diff --git a/include/gpu/vk/GrVkBackendContext.h b/include/gpu/vk/GrVkBackendContext.h
index 5e51beea6b..5ae7b31656 100644
--- a/include/gpu/vk/GrVkBackendContext.h
+++ b/include/gpu/vk/GrVkBackendContext.h
@@ -11,8 +11,7 @@
 #include "SkRefCnt.h"
 
 #include "vk/GrVkDefines.h"
-
-struct GrVkInterface;
+#include "vk/GrVkInterface.h"
 
 enum GrVkExtensionFlags {
     kEXT_debug_report_GrVkExtensionFlag    = 0x0001,
@@ -51,10 +50,13 @@ struct GrVkBackendContext : public SkRefCnt {
                                             uint32_t queueFamilyIndex)>;
 
     // Helper function to create the default Vulkan objects needed by the GrVkGpu object
+    // If getProc is NULL, a default getProc will be constructed if we are statically linking
+    // against Vulkan.
     // If presentQueueIndex is non-NULL, will try to set up presentQueue as part of device
     // creation using the platform-specific canPresent() function.
     static const GrVkBackendContext* Create(uint32_t* presentQueueIndex = nullptr,
-                                            CanPresentFn = CanPresentFn());
+                                            CanPresentFn = CanPresentFn(),
+                                            GrVkInterface::GetProc getProc = nullptr);
 
     ~GrVkBackendContext() override;
 };
diff --git a/include/gpu/vk/GrVkDefines.h b/include/gpu/vk/GrVkDefines.h
index 9caf2d75e5..ff8f2131f6 100644
--- a/include/gpu/vk/GrVkDefines.h
+++ b/include/gpu/vk/GrVkDefines.h
@@ -10,11 +10,23 @@
 #define GrVkDefines_DEFINED
 
 #if defined(SK_BUILD_FOR_WIN) || defined(SK_BUILD_FOR_WIN32)
-#   define VK_USE_PLATFORM_WIN32_KHR
+#   if !defined(VK_USE_PLATFORM_WIN32_KHR)
+#      define VK_USE_PLATFORM_WIN32_KHR
+#   endif
 #elif defined(SK_BUILD_FOR_ANDROID)
-#   define VK_USE_PLATFORM_ANDROID_KHR
+#   if !defined(VK_USE_PLATFORM_ANDROID_KHR)
+#      define VK_USE_PLATFORM_ANDROID_KHR
+#   endif
 #elif defined(SK_BUILD_FOR_UNIX)
-#   define VK_USE_PLATFORM_XCB_KHR
+#   if defined(__Fuchsia__)
+#     if !defined(VK_USE_PLATFORM_MAGMA_KHR)
+#       define VK_USE_PLATFORM_MAGMA_KHR
+#     endif
+#   else
+#     if !defined(VK_USE_PLATFORM_XCB_KHR)
+#        define VK_USE_PLATFORM_XCB_KHR
+#     endif
+#   endif
 #endif
 
 #if defined(Bool) || defined(Status) || defined(True) || defined(False)
diff --git a/include/gpu/vk/GrVkInterface.h b/include/gpu/vk/GrVkInterface.h
index 9dc033392c..dca47ffc4c 100644
--- a/include/gpu/vk/GrVkInterface.h
+++ b/include/gpu/vk/GrVkInterface.h
@@ -15,20 +15,6 @@
 ////////////////////////////////////////////////////////////////////////////////
 
 /**
- * The default interface is returned by GrVkCreateInterface. This function's
- * implementation is platform-specific.
- */
-
-struct GrVkInterface;
-
-/**
- * Creates a GrVkInterface.
- */
-const GrVkInterface* GrVkCreateInterface(VkInstance instance, VkDevice device,
-                                         uint32_t extensionFlags);
-
-
-/**
  * GrContext uses the following interface to make all calls into Vulkan. When a
  * GrContext is created it is given a GrVkInterface. All functions that should be
  * available based on the Vulkan's version must be non-NULL or GrContext creation
@@ -49,7 +35,15 @@ private:
     typedef SkRefCnt INHERITED;
 
 public:
-    GrVkInterface();
+    using GetProc = std::function<PFN_vkVoidFunction(
+        const char*, // function name
+        VkInstance,  // instance or VK_NULL_HANDLE
+        VkDevice     // device or VK_NULL_HANDLE
+        )>;
+    GrVkInterface(GetProc getProc,
+                  VkInstance instance,
+                  VkDevice device,
+                  uint32_t extensionFlags);
 
     // Validates that the GrVkInterface supports its advertised standard. This means the necessary
     // function pointers have been initialized for Vulkan version.