Make GrRenderTarget[(Proxy)|(Context)]? advertise a "full scene aa type".

Bug: skia:
Change-Id: I24549604e8305028e34e0022bfef992a8e8c33f7
Reviewed-on: https://skia-review.googlesource.com/16230
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>

4 files changed, 60 insertions, 28 deletions

diff --git a/include/gpu/GrRenderTarget.h b/include/gpu/GrRenderTarget.h
index 05d1239f84..fdf6f9cddc 100644
--- a/include/gpu/GrRenderTarget.h
+++ b/include/gpu/GrRenderTarget.h
@@ -32,16 +32,14 @@ public:
     // GrRenderTarget
     bool isStencilBufferMultisampled() const { return fDesc.fSampleCnt > 0; }
 
-    /**
-     * For our purposes, "Mixed Sampled" means the stencil buffer is multisampled but the color
-     * buffer is not.
-     */
-    bool isMixedSampled() const { return fFlags & Flags::kMixedSampled; }
-
-    /**
-     * "Unified Sampled" means the stencil and color buffers are both multisampled.
-     */
-    bool isUnifiedMultisampled() const { return fDesc.fSampleCnt > 0 && !this->isMixedSampled(); }
+    GrFSAAType fsaaType() const {
+        if (!fDesc.fSampleCnt) {
+            SkASSERT(!(fFlags & Flags::kMixedSampled));
+            return GrFSAAType::kNone;
+        }
+        return (fFlags & Flags::kMixedSampled) ? GrFSAAType::kMixedSamples
+                                               : GrFSAAType::kUnifiedMSAA;
+    }
 
     /**
      * Returns the number of samples/pixel in the stencil buffer (Zero if non-MSAA).
@@ -51,7 +49,9 @@ public:
     /**
      * Returns the number of samples/pixel in the color buffer (Zero if non-MSAA or mixed sampled).
      */
-    int numColorSamples() const { return this->isMixedSampled() ? 0 : fDesc.fSampleCnt; }
+    int numColorSamples() const {
+        return GrFSAAType::kMixedSamples == this->fsaaType() ? 0 : fDesc.fSampleCnt;
+    }
 
     /**
      * Call to indicate the multisample contents were modified such that the
diff --git a/include/gpu/GrTypesPriv.h b/include/gpu/GrTypesPriv.h
index 8f828e67d6..42da3d4481 100644
--- a/include/gpu/GrTypesPriv.h
+++ b/include/gpu/GrTypesPriv.h
@@ -51,6 +51,40 @@ static inline bool GrAATypeIsHW(GrAAType type) {
     return false;
 }
 
+/** The type of full scene antialiasing supported by a render target. */
+enum class GrFSAAType {
+    /** No FSAA */
+    kNone,
+    /** Regular MSAA where each attachment has the same sample count. */
+    kUnifiedMSAA,
+    /** One color sample, N stencil samples. */
+    kMixedSamples,
+};
+
+/**
+ * Not all drawing code paths support using mixed samples when available and instead use
+ * coverage-based aa.
+ */
+enum class GrAllowMixedSamples { kNo, kYes };
+
+static inline GrAAType GrChooseAAType(GrAA aa, GrFSAAType fsaaType,
+                                      GrAllowMixedSamples allowMixedSamples) {
+    if (GrAA::kNo == aa) {
+        return GrAAType::kNone;
+    }
+    switch (fsaaType) {
+        case GrFSAAType::kNone:
+            return GrAAType::kCoverage;
+        case GrFSAAType::kUnifiedMSAA:
+            return GrAAType::kMSAA;
+        case GrFSAAType::kMixedSamples:
+            return GrAllowMixedSamples::kYes == allowMixedSamples ? GrAAType::kMixedSamples
+                                                                  : GrAAType::kCoverage;
+    }
+    SkFAIL("Unexpected fsaa type");
+    return GrAAType::kNone;
+}
+
 /**
  * Types of shader-language-specific boxed variables we can create. (Currently only GrGLShaderVars,
  * but should be applicable to other shader languages.)
diff --git a/include/private/GrInstancedPipelineInfo.h b/include/private/GrInstancedPipelineInfo.h
index 196c35b96f..c07425909a 100644
--- a/include/private/GrInstancedPipelineInfo.h
+++ b/include/private/GrInstancedPipelineInfo.h
@@ -16,9 +16,9 @@
  */
 struct GrInstancedPipelineInfo {
     GrInstancedPipelineInfo(const GrRenderTargetProxy* rtp)
-        : fIsMultisampled(rtp->isStencilBufferMultisampled())
-        , fIsMixedSampled(rtp->isMixedSampled())
-        , fIsRenderingToFloat(GrPixelConfigIsFloatingPoint(rtp->desc().fConfig)) {}
+            : fIsMultisampled(GrFSAAType::kNone != rtp->fsaaType())
+            , fIsMixedSampled(GrFSAAType::kMixedSamples == rtp->fsaaType())
+            , fIsRenderingToFloat(GrPixelConfigIsFloatingPoint(rtp->desc().fConfig)) {}
 
     bool canUseCoverageAA() const { return !fIsMultisampled || fIsMixedSampled; }
 
diff --git a/include/private/GrRenderTargetProxy.h b/include/private/GrRenderTargetProxy.h
index adc7553941..dd28b0f86d 100644
--- a/include/private/GrRenderTargetProxy.h
+++ b/include/private/GrRenderTargetProxy.h
@@ -26,28 +26,26 @@ public:
     // Actually instantiate the backing rendertarget, if necessary.
     GrRenderTarget* instantiate(GrResourceProvider* resourceProvider);
 
-    bool isStencilBufferMultisampled() const { return fDesc.fSampleCnt > 0; }
-
-    /**
-     * For our purposes, "Mixed Sampled" means the stencil buffer is multisampled but the color
-     * buffer is not.
-     */
-    bool isMixedSampled() const { return fRenderTargetFlags & GrRenderTarget::Flags::kMixedSampled; }
-
-    /**
-     * "Unified Sampled" means the stencil and color buffers are both multisampled.
-     */
-    bool isUnifiedMultisampled() const { return fDesc.fSampleCnt > 0 && !this->isMixedSampled(); }
-
     /**
      * Returns the number of samples/pixel in the stencil buffer (Zero if non-MSAA).
      */
     int numStencilSamples() const { return fDesc.fSampleCnt; }
 
+    GrFSAAType fsaaType() const {
+        if (!fDesc.fSampleCnt) {
+            SkASSERT(!(fRenderTargetFlags & GrRenderTarget::Flags::kMixedSampled));
+            return GrFSAAType::kNone;
+        }
+        return (fRenderTargetFlags & GrRenderTarget::Flags::kMixedSampled)
+                       ? GrFSAAType::kMixedSamples
+                       : GrFSAAType::kUnifiedMSAA;
+    }
     /**
      * Returns the number of samples/pixel in the color buffer (Zero if non-MSAA or mixed sampled).
      */
-    int numColorSamples() const { return this->isMixedSampled() ? 0 : fDesc.fSampleCnt; }
+    int numColorSamples() const {
+        return GrFSAAType::kMixedSamples == this->fsaaType() ? 0 : fDesc.fSampleCnt;
+    }
 
     int maxWindowRectangles(const GrCaps& caps) const;