Vulkan backend render targets don't allow client to specify stencil bits

We already always create the stencil buffer even for wrapped RTs.

Make VulkanWindowContext use SkSurface::MakeFromBackendRenderTarget.

Change-Id: I5df429d347331801954ec17cb9d75e323a7af345
Reviewed-on: https://skia-review.googlesource.com/113206
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>

4 files changed, 26 insertions, 13 deletions

diff --git a/include/gpu/GrBackendSurface.h b/include/gpu/GrBackendSurface.h
index c2fc619d8a..a2df90cd0d 100644
--- a/include/gpu/GrBackendSurface.h
+++ b/include/gpu/GrBackendSurface.h
@@ -194,11 +194,13 @@ public:
                           const GrGLFramebufferInfo& glInfo);
 
 #ifdef SK_VULKAN
+    /** Deprecated, use version that does not take stencil bits. */
     GrBackendRenderTarget(int width,
                           int height,
                           int sampleCnt,
                           int stencilBits,
                           const GrVkImageInfo& vkInfo);
+    GrBackendRenderTarget(int width, int height, int sampleCnt, const GrVkImageInfo& vkInfo);
 #endif
 
     int width() const { return fWidth; }
diff --git a/src/gpu/GrBackendSurface.cpp b/src/gpu/GrBackendSurface.cpp
index 73135dc42c..6db618f717 100644
--- a/src/gpu/GrBackendSurface.cpp
+++ b/src/gpu/GrBackendSurface.cpp
@@ -153,10 +153,19 @@ GrBackendRenderTarget::GrBackendRenderTarget(int width,
                                              int sampleCnt,
                                              int stencilBits,
                                              const GrVkImageInfo& vkInfo)
+        : GrBackendRenderTarget(width, height, sampleCnt, vkInfo) {
+    // This is a deprecated constructor that takes a bogus stencil bits.
+    SkASSERT(0 == stencilBits);
+}
+
+GrBackendRenderTarget::GrBackendRenderTarget(int width,
+                                             int height,
+                                             int sampleCnt,
+                                             const GrVkImageInfo& vkInfo)
         : fWidth(width)
         , fHeight(height)
         , fSampleCnt(SkTMax(1, sampleCnt))
-        , fStencilBits(stencilBits)
+        , fStencilBits(0)  // We always create stencil buffers internally for vulkan
         , fConfig(GrVkFormatToPixelConfig(vkInfo.fFormat))
         , fBackend(kVulkan_GrBackend)
         , fVkInfo(vkInfo) {}
diff --git a/src/gpu/vk/GrVkGpu.cpp b/src/gpu/vk/GrVkGpu.cpp
index b674185a00..1acbf02627 100644
--- a/src/gpu/vk/GrVkGpu.cpp
+++ b/src/gpu/vk/GrVkGpu.cpp
@@ -942,11 +942,13 @@ sk_sp<GrRenderTarget> GrVkGpu::onWrapBackendRenderTarget(const GrBackendRenderTa
     desc.fSampleCnt = 1;
 
     sk_sp<GrVkRenderTarget> tgt = GrVkRenderTarget::MakeWrappedRenderTarget(this, desc, info);
-    if (tgt && backendRT.stencilBits()) {
-        if (!createStencilAttachmentForRenderTarget(tgt.get(), desc.fWidth, desc.fHeight)) {
-            return nullptr;
-        }
+
+    // We don't allow the client to supply a premade stencil buffer. We always create one if needed.
+    SkASSERT(!backendRT.stencilBits());
+    if (tgt) {
+        SkASSERT(tgt->canAttemptStencilAttachment());
     }
+
     return tgt;
 }
 
diff --git a/tools/sk_app/VulkanWindowContext.cpp b/tools/sk_app/VulkanWindowContext.cpp
index d7839bc189..b39c564eca 100644
--- a/tools/sk_app/VulkanWindowContext.cpp
+++ b/tools/sk_app/VulkanWindowContext.cpp
@@ -293,14 +293,14 @@ void VulkanWindowContext::createBuffers(VkFormat format, SkColorType colorType)
         info.fFormat = format;
         info.fLevelCount = 1;
 
-        GrBackendTexture backendTex(fWidth, fHeight, info);
-
-        fSurfaces[i] = SkSurface::MakeFromBackendTextureAsRenderTarget(fContext.get(), backendTex,
-                                                                       kTopLeft_GrSurfaceOrigin,
-                                                                       fSampleCount,
-                                                                       colorType,
-                                                                       fDisplayParams.fColorSpace,
-                                                                       &fSurfaceProps);
+        GrBackendRenderTarget backendRT(fWidth, fHeight, fSampleCount, info);
+
+        fSurfaces[i] = SkSurface::MakeFromBackendRenderTarget(fContext.get(),
+                                                              backendRT,
+                                                              kTopLeft_GrSurfaceOrigin,
+                                                              colorType,
+                                                              fDisplayParams.fColorSpace,
+                                                              &fSurfaceProps);
     }
 
     // create the command pool for the command buffers