Revert "Revert "Revert "Revert "Redefine the meaning of sample counts in GPU backend.""""

This reverts commit 18c52a7b52211de5d0dcd86dc048adef758c6c75.

Also relands "More sample count cleanup:" and "Add new GrContext queries for imagability, surfacability, and max sample count of color types"


Bug: skia:
Change-Id: I4028105a3a1f16ce3944e134619eb6245af6b947
Reviewed-on: https://skia-review.googlesource.com/102940
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>

3 files changed, 26 insertions, 21 deletions

diff --git a/src/gpu/mtl/GrMtlCaps.h b/src/gpu/mtl/GrMtlCaps.h
index 6204eaac5a..935cb07822 100644
--- a/src/gpu/mtl/GrMtlCaps.h
+++ b/src/gpu/mtl/GrMtlCaps.h
@@ -24,20 +24,12 @@ public:
     GrMtlCaps(const GrContextOptions& contextOptions, id<MTLDevice> device,
               MTLFeatureSet featureSet);
 
-    int getSampleCount(int requestedCount, GrPixelConfig config) const override;
-
     bool isConfigTexturable(GrPixelConfig config) const override {
         return SkToBool(fConfigTable[config].fFlags & ConfigInfo::kTextureable_Flag);
     }
 
-    bool isConfigRenderable(GrPixelConfig config, bool withMSAA) const override {
-        if (withMSAA) {
-            return SkToBool(fConfigTable[config].fFlags & ConfigInfo::kRenderable_Flag) &&
-                   SkToBool(fConfigTable[config].fFlags & ConfigInfo::kMSAA_Flag);
-        } else {
-            return SkToBool(fConfigTable[config].fFlags & ConfigInfo::kRenderable_Flag);
-        }
-    }
+    int getRenderTargetSampleCount(int requestedCount, GrPixelConfig) const override;
+    int maxRenderTargetSampleCount(GrPixelConfig) const override;
 
     bool isConfigCopyable(GrPixelConfig config) const override {
         return true;
diff --git a/src/gpu/mtl/GrMtlCaps.mm b/src/gpu/mtl/GrMtlCaps.mm
index 2bce74a261..0bb7530fe2 100644
--- a/src/gpu/mtl/GrMtlCaps.mm
+++ b/src/gpu/mtl/GrMtlCaps.mm
@@ -121,7 +121,7 @@ void GrMtlCaps::initGrCaps(const id<MTLDevice> device) {
     fMaxTextureSize = fMaxRenderTargetSize;
 
     // Init sample counts. All devices support 1 (i.e. 0 in skia).
-    fSampleCounts.push(0);
+    fSampleCounts.push(1);
     for (auto sampleCnt : {2, 4, 8}) {
         if ([device supportsTextureSampleCount:sampleCnt]) {
             fSampleCounts.push(sampleCnt);
@@ -164,19 +164,29 @@ void GrMtlCaps::initGrCaps(const id<MTLDevice> device) {
     fCrossContextTextureSupport = false;
 }
 
-int GrMtlCaps::getSampleCount(int requestedCount, GrPixelConfig config) const {
-    int count = fSampleCounts.count();
-    SkASSERT(count > 0); // We always add 0 as a valid sample count
-    if (!this->isConfigRenderable(config, true)) {
-        return 0;
+
+int GrMtlCaps::maxRenderTargetSampleCount(GrPixelConfig config) const {
+    if (fConfigTable[config].fFlags & ConfigInfo::kMSAA_Flag) {
+        return fSampleCounts[fSampleCounts.count() - 1];
+    } else if (fConfigTable[config].fFlags & ConfigInfo::kRenderable_Flag) {
+        return 1;
     }
+    return 0;
+}
 
-    for (int i = 0; i < count; ++i) {
-        if (fSampleCounts[i] >= requestedCount) {
-            return fSampleCounts[i];
+int GrMtlCaps::getRenderTargetSampleCount(int requestedCount, GrPixelConfig config) const {
+    requestedCount = SkTMax(requestedCount, 1);
+    if (fConfigTable[config].fFlags & ConfigInfo::kMSAA_Flag) {
+        int count = fSampleCounts.count();
+        for (int i = 0; i < count; ++i) {
+            if (fSampleCounts[i] >= requestedCount) {
+                return fSampleCounts[i];
+            }
         }
+    } else if (fConfigTable[config].fFlags & ConfigInfo::kRenderable_Flag) {
+        return 1 == requestedCount ? 1 : 0;
     }
-    return fSampleCounts[count-1];
+    return 0;
 }
 
 void GrMtlCaps::initShaderCaps() {
diff --git a/src/gpu/mtl/GrMtlRenderTarget.h b/src/gpu/mtl/GrMtlRenderTarget.h
index 4dac306e7e..83e7d3c240 100644
--- a/src/gpu/mtl/GrMtlRenderTarget.h
+++ b/src/gpu/mtl/GrMtlRenderTarget.h
@@ -63,8 +63,11 @@ protected:
 
     // This accounts for the texture's memory and any MSAA renderbuffer's memory.
     size_t onGpuMemorySize() const override {
+        int numColorSamples = this->numColorSamples();
         // The plus 1 is to account for the resolve texture or if not using msaa the RT itself
-        int numColorSamples = this->numColorSamples() + 1;
+        if (numColorSamples > 1) {
+            ++numColorSamples;
+        }
         return GrSurface::ComputeSize(this->config(), this->width(), this->height(),
                                       numColorSamples, GrMipMapped::kNo);
     }