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>

1 files changed, 13 insertions, 5 deletions

diff --git a/src/gpu/vk/GrVkExtensions.cpp b/src/gpu/vk/GrVkExtensions.cpp
index 03b453090f..17737f1799 100644
--- a/src/gpu/vk/GrVkExtensions.cpp
+++ b/src/gpu/vk/GrVkExtensions.cpp
@@ -30,17 +30,21 @@ static int find_string(const SkTArray<SkString>& strings, const char ext[]) {
     return idx;
 }
 
-#define GET_PROC_LOCAL(inst, F) PFN_vk ## F F = (PFN_vk ## F) vkGetInstanceProcAddr(inst, "vk" #F)
+#define GET_PROC_LOCAL(F, inst, device) PFN_vk ## F F = (PFN_vk ## F) fGetProc("vk" #F, inst, device)
 
 static uint32_t remove_patch_version(uint32_t specVersion) {
     return (specVersion >> 12) << 12;
 }
 
 bool GrVkExtensions::initInstance(uint32_t specVersion) {
+    if (fGetProc == nullptr) {
+        return false;
+    }
+
     uint32_t nonPatchVersion = remove_patch_version(specVersion);
 
-    GET_PROC_LOCAL(nullptr, EnumerateInstanceExtensionProperties);
-    GET_PROC_LOCAL(nullptr, EnumerateInstanceLayerProperties);
+    GET_PROC_LOCAL(EnumerateInstanceExtensionProperties, VK_NULL_HANDLE, VK_NULL_HANDLE);
+    GET_PROC_LOCAL(EnumerateInstanceLayerProperties, VK_NULL_HANDLE, VK_NULL_HANDLE);
 
     SkTLessFunctionToFunctorAdaptor<SkString, extension_compare> cmp;
 
@@ -126,10 +130,14 @@ bool GrVkExtensions::initInstance(uint32_t specVersion) {
 }
 
 bool GrVkExtensions::initDevice(uint32_t specVersion, VkInstance inst, VkPhysicalDevice physDev) {
+    if (fGetProc == nullptr) {
+        return false;
+    }
+
     uint32_t nonPatchVersion = remove_patch_version(specVersion);
 
-    GET_PROC_LOCAL(inst, EnumerateDeviceExtensionProperties);
-    GET_PROC_LOCAL(inst, EnumerateDeviceLayerProperties);
+    GET_PROC_LOCAL(EnumerateDeviceExtensionProperties, inst, VK_NULL_HANDLE);
+    GET_PROC_LOCAL(EnumerateDeviceLayerProperties, inst, VK_NULL_HANDLE);
 
     SkTLessFunctionToFunctorAdaptor<SkString, extension_compare> cmp;