Move memoization of multisample specs id to GrRenderTarget

GrGpu used to perform the memoization on behalf of GrRenderTarget via
a public accessor. This change updates GrRenderTarget to do its own
work.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2467593002

Review-Url: https://codereview.chromium.org/2467593002

8 files changed, 34 insertions, 30 deletions

diff --git a/src/gpu/GrGpu.cpp b/src/gpu/GrGpu.cpp
index f576424889..bee578a764 100644
--- a/src/gpu/GrGpu.cpp
+++ b/src/gpu/GrGpu.cpp
@@ -442,21 +442,13 @@ void GrGpu::didWriteToSurface(GrSurface* surface, const SkIRect* bounds, uint32_
     }
 }
 
-const GrGpu::MultisampleSpecs& GrGpu::getMultisampleSpecs(GrRenderTarget* rt,
-                                                          const GrStencilSettings& stencil) {
+const GrGpu::MultisampleSpecs& GrGpu::queryMultisampleSpecs(GrRenderTarget* rt,
+                                                            const GrStencilSettings& stencil) {
     SkASSERT(rt->desc().fSampleCnt > 1);
 
-#ifndef SK_DEBUG
-    // In debug mode we query the multisample info every time to verify the caching is correct.
-    if (uint8_t id = rt->renderTargetPriv().accessMultisampleSpecsID()) {
-        SkASSERT(id > 0 && id < fMultisampleSpecs.count());
-        return fMultisampleSpecs[id];
-    }
-#endif
-
     int effectiveSampleCnt;
     SkSTArray<16, SkPoint, true> pattern;
-    this->onGetMultisampleSpecs(rt, stencil, &effectiveSampleCnt, &pattern);
+    this->onQueryMultisampleSpecs(rt, stencil, &effectiveSampleCnt, &pattern);
     SkASSERT(effectiveSampleCnt >= rt->desc().fSampleCnt);
 
     uint8_t id;
@@ -479,10 +471,7 @@ const GrGpu::MultisampleSpecs& GrGpu::getMultisampleSpecs(GrRenderTarget* rt,
         }
     }
     SkASSERT(id > 0);
-    SkASSERT(!rt->renderTargetPriv().accessMultisampleSpecsID() ||
-             rt->renderTargetPriv().accessMultisampleSpecsID() == id);
 
-    rt->renderTargetPriv().accessMultisampleSpecsID() = id;
     return fMultisampleSpecs[id];
 }
 
diff --git a/src/gpu/GrGpu.h b/src/gpu/GrGpu.h
index 8e9407a458..48005ec16f 100644
--- a/src/gpu/GrGpu.h
+++ b/src/gpu/GrGpu.h
@@ -355,10 +355,16 @@ public:
         const SkPoint*   fSampleLocations;
     };
 
-    // Finds a render target's multisample specs. The stencil settings are only needed to flush the
-    // draw state prior to querying multisample information; they should not have any effect on the
-    // multisample information itself.
-    const MultisampleSpecs& getMultisampleSpecs(GrRenderTarget*, const GrStencilSettings&);
+    // Finds a render target's multisample specs. The stencil settings are only needed in case we
+    // need to flush the draw state prior to querying multisample info. They are not expected to
+    // affect the multisample information itself.
+    const MultisampleSpecs& queryMultisampleSpecs(GrRenderTarget*, const GrStencilSettings&);
+
+    // Finds the multisample specs with a given unique id.
+    const MultisampleSpecs& getMultisampleSpecs(uint8_t uniqueID) {
+        SkASSERT(uniqueID > 0 && uniqueID < fMultisampleSpecs.count());
+        return fMultisampleSpecs[uniqueID];
+    }
 
     // Creates a GrGpuCommandBuffer in which the GrOpList can send draw commands to instead of
     // directly to the Gpu object.
@@ -581,8 +587,8 @@ private:
                                const SkIPoint& dstPoint) = 0;
 
     // overridden by backend specific derived class to perform the multisample queries
-    virtual void onGetMultisampleSpecs(GrRenderTarget*, const GrStencilSettings&,
-                                       int* effectiveSampleCnt, SamplePattern*) = 0;
+    virtual void onQueryMultisampleSpecs(GrRenderTarget*, const GrStencilSettings&,
+                                         int* effectiveSampleCnt, SamplePattern*) = 0;
 
     void resetContext() {
         this->onResetContext(fResetBits);
diff --git a/src/gpu/GrRenderTarget.cpp b/src/gpu/GrRenderTarget.cpp
index 0bcde3bafe..09d43f99e4 100644
--- a/src/gpu/GrRenderTarget.cpp
+++ b/src/gpu/GrRenderTarget.cpp
@@ -105,7 +105,14 @@ int GrRenderTargetPriv::numStencilBits() const {
 
 const GrGpu::MultisampleSpecs&
 GrRenderTargetPriv::getMultisampleSpecs(const GrStencilSettings& stencil) const {
-    return fRenderTarget->getGpu()->getMultisampleSpecs(fRenderTarget, stencil);
+    GrGpu* gpu = fRenderTarget->getGpu();
+    if (auto id = fRenderTarget->fMultisampleSpecsID) {
+        SkASSERT(gpu->queryMultisampleSpecs(fRenderTarget, stencil).fUniqueID == id);
+        return gpu->getMultisampleSpecs(id);
+    }
+    const GrGpu::MultisampleSpecs& specs = gpu->queryMultisampleSpecs(fRenderTarget, stencil);
+    fRenderTarget->fMultisampleSpecsID = specs.fUniqueID;
+    return specs;
 }
 
 int GrRenderTargetPriv::maxWindowRectangles() const {
diff --git a/src/gpu/GrRenderTargetPriv.h b/src/gpu/GrRenderTargetPriv.h
index 698288e1cd..922d9b3071 100644
--- a/src/gpu/GrRenderTargetPriv.h
+++ b/src/gpu/GrRenderTargetPriv.h
@@ -32,8 +32,10 @@ public:
 
     int numStencilBits() const;
 
+    // Finds a render target's multisample specs. The stencil settings are only needed in case the
+    // info isn't cached and we need to flush the draw state in order to query it. They are not
+    // expected to affect the multisample information itself.
     const GrGpu::MultisampleSpecs& getMultisampleSpecs(const GrStencilSettings& stencil) const;
-    uint8_t& accessMultisampleSpecsID() { return fRenderTarget->fMultisampleSpecsID; }
 
     typedef GrRenderTarget::Flags Flags;
 
diff --git a/src/gpu/gl/GrGLGpu.cpp b/src/gpu/gl/GrGLGpu.cpp
index 485a9bd09a..454753c4e9 100644
--- a/src/gpu/gl/GrGLGpu.cpp
+++ b/src/gpu/gl/GrGLGpu.cpp
@@ -4474,8 +4474,8 @@ bool GrGLGpu::generateMipmap(GrGLTexture* texture, bool gammaCorrect) {
     return true;
 }
 
-void GrGLGpu::onGetMultisampleSpecs(GrRenderTarget* rt, const GrStencilSettings& stencil,
-                                    int* effectiveSampleCnt, SamplePattern* samplePattern) {
+void GrGLGpu::onQueryMultisampleSpecs(GrRenderTarget* rt, const GrStencilSettings& stencil,
+                                      int* effectiveSampleCnt, SamplePattern* samplePattern) {
     SkASSERT(!rt->isMixedSampled() || rt->renderTargetPriv().getStencilAttachment() ||
              stencil.isDisabled());
 
diff --git a/src/gpu/gl/GrGLGpu.h b/src/gpu/gl/GrGLGpu.h
index 4420c658fe..12633eef8b 100644
--- a/src/gpu/gl/GrGLGpu.h
+++ b/src/gpu/gl/GrGLGpu.h
@@ -225,8 +225,8 @@ private:
                        const SkIRect& srcRect,
                        const SkIPoint& dstPoint) override;
 
-    void onGetMultisampleSpecs(GrRenderTarget*, const GrStencilSettings&,
-                               int* effectiveSampleCnt, SamplePattern*) override;
+    void onQueryMultisampleSpecs(GrRenderTarget*, const GrStencilSettings&,
+                                 int* effectiveSampleCnt, SamplePattern*) override;
 
     // binds texture unit in GL
     void setTextureUnit(int unitIdx);
diff --git a/src/gpu/vk/GrVkGpu.cpp b/src/gpu/vk/GrVkGpu.cpp
index f7239d64ba..f34c76cd92 100644
--- a/src/gpu/vk/GrVkGpu.cpp
+++ b/src/gpu/vk/GrVkGpu.cpp
@@ -1630,8 +1630,8 @@ bool GrVkGpu::initDescForDstCopy(const GrRenderTarget* src, GrSurfaceDesc* desc)
     return true;
 }
 
-void GrVkGpu::onGetMultisampleSpecs(GrRenderTarget* rt, const GrStencilSettings&,
-                                    int* effectiveSampleCnt, SamplePattern*) {
+void GrVkGpu::onQueryMultisampleSpecs(GrRenderTarget* rt, const GrStencilSettings&,
+                                      int* effectiveSampleCnt, SamplePattern*) {
     // TODO: stub.
     SkASSERT(!this->caps()->sampleLocationsSupport());
     *effectiveSampleCnt = rt->desc().fSampleCnt;
diff --git a/src/gpu/vk/GrVkGpu.h b/src/gpu/vk/GrVkGpu.h
index b62278337b..6f0380302b 100644
--- a/src/gpu/vk/GrVkGpu.h
+++ b/src/gpu/vk/GrVkGpu.h
@@ -82,8 +82,8 @@ public:
                        const SkIRect& srcRect,
                        const SkIPoint& dstPoint) override;
 
-    void onGetMultisampleSpecs(GrRenderTarget* rt, const GrStencilSettings&,
-                               int* effectiveSampleCnt, SamplePattern*) override;
+    void onQueryMultisampleSpecs(GrRenderTarget* rt, const GrStencilSettings&,
+                                 int* effectiveSampleCnt, SamplePattern*) override;
 
     bool initDescForDstCopy(const GrRenderTarget* src, GrSurfaceDesc* desc) const override;