Query API: Non-precise occlusion query on Metal

- Add occlusionQuerySet to BeginRenderPassCmd
- Implement BeginOcclusionQuery/EndOcclusionQuery on Metal
- Enable occlusion end2end tests on Metal

Bug: dawn:434
Change-Id: I6c6ed74c77eb7e66f21fc5b8aa97b80eddb1111f
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/38784
Commit-Queue: Hao Li <hao.x.li@intel.com>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>

src/dawn_native/CommandEncoder.cpp

@@ -563,6 +563,8 @@ namespace dawn_native {
                 cmd->width = width;
                 cmd->height = height;
 
+                cmd->occlusionQuerySet = descriptor->occlusionQuerySet;
+
                 return {};
             });
 

src/dawn_native/Commands.h

@@ -100,6 +100,8 @@ namespace dawn_native {
         // Cache the width and height of all attachments for convenience
         uint32_t width;
         uint32_t height;
+
+        Ref<QuerySetBase> occlusionQuerySet;
     };
 
     struct BufferCopy {

src/dawn_native/metal/CommandBufferMTL.mm

@@ -176,6 +176,11 @@ namespace dawn_native { namespace metal {
                 }
             }
 
+            if (renderPass->occlusionQuerySet.Get() != nullptr) {
+                descriptor.visibilityResultBuffer =
+                    ToBackend(renderPass->occlusionQuerySet.Get())->GetVisibilityBuffer();
+            }
+
             return descriptorRef;
         }
 
@@ -756,6 +761,14 @@ namespace dawn_native { namespace metal {
                     destination->EnsureDataInitializedAsDestination(
                         commandContext, cmd->destinationOffset, cmd->queryCount * sizeof(uint64_t));
 
+                    if (querySet->GetQueryType() == wgpu::QueryType::Occlusion) {
+                        [commandContext->EnsureBlit()
+                               copyFromBuffer:querySet->GetVisibilityBuffer()
+                                 sourceOffset:NSUInteger(cmd->firstQuery * sizeof(uint64_t))
+                                     toBuffer:destination->GetMTLBuffer()
+                            destinationOffset:NSUInteger(cmd->destinationOffset)
+                                         size:NSUInteger(cmd->queryCount * sizeof(uint64_t))];
+                    } else {
                         if (@available(macos 10.15, iOS 14.0, *)) {
                             [commandContext->EnsureBlit()
                                   resolveCounters:querySet->GetCounterSampleBuffer()
@@ -766,6 +779,7 @@ namespace dawn_native { namespace metal {
                         } else {
                             UNREACHABLE();
                         }
+                    }
                     break;
                 }
 
@@ -1284,11 +1298,19 @@ namespace dawn_native { namespace metal {
                 }
 
                 case Command::BeginOcclusionQuery: {
-                    return DAWN_UNIMPLEMENTED_ERROR("Waiting for implementation.");
+                    BeginOcclusionQueryCmd* cmd = mCommands.NextCommand<BeginOcclusionQueryCmd>();
+
+                    [encoder setVisibilityResultMode:MTLVisibilityResultModeBoolean
+                                              offset:cmd->queryIndex * sizeof(uint64_t)];
+                    break;
                 }
 
                 case Command::EndOcclusionQuery: {
-                    return DAWN_UNIMPLEMENTED_ERROR("Waiting for implementation.");
+                    EndOcclusionQueryCmd* cmd = mCommands.NextCommand<EndOcclusionQueryCmd>();
+
+                    [encoder setVisibilityResultMode:MTLVisibilityResultModeDisabled
+                                              offset:cmd->queryIndex * sizeof(uint64_t)];
+                    break;
                 }
 
                 case Command::WriteTimestamp: {

src/tests/end2end/QueryTests.cpp

@@ -227,9 +227,6 @@ TEST_P(OcclusionQueryTests, QuerySetDestroy) {
 // zero indicates that no sample passed depth/stencil testing,
 // non-zero indicates that at least one sample passed depth/stencil testing.
 TEST_P(OcclusionQueryTests, QueryWithDepthStencilTest) {
-    // TODO(hao.x.li@intel.com): Implement non-precise occlusion on Metal
-    DAWN_SKIP_TEST_IF(IsMetal());
-
     // Disable depth/stencil testing, the samples always pass the testing, the expected occlusion
     // result is non-zero.
     TestOcclusionQueryWithDepthStencilTest(false, false, OcclusionExpectation::Result::NonZero);
@@ -248,9 +245,6 @@ TEST_P(OcclusionQueryTests, QueryWithDepthStencilTest) {
 // zero indicates that no sample passed scissor testing,
 // non-zero indicates that at least one sample passed scissor testing.
 TEST_P(OcclusionQueryTests, QueryWithScissorTest) {
-    // TODO(hao.x.li@intel.com): Implement non-precise occlusion on Metal
-    DAWN_SKIP_TEST_IF(IsMetal());
-
     // Test there are samples passed scissor testing, the expected occlusion result is non-zero.
     TestOcclusionQueryWithScissorTest({2, 1, 2, 1}, OcclusionExpectation::Result::NonZero);