When merging into an already chained op update the head's op bounds.

Also assert in GrRenderTargetOpList that chained ops' bounds are
contained in head op's bounds.

Change-Id: I70303ecfbb314d7d04d03f6ae6eae27e9956a7ce
Reviewed-on: https://skia-review.googlesource.com/154981
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>

2 files changed, 12 insertions, 1 deletions

diff --git a/src/gpu/GrRenderTargetOpList.cpp b/src/gpu/GrRenderTargetOpList.cpp
index d7ace8f5d4..6ca4936fcd 100644
--- a/src/gpu/GrRenderTargetOpList.cpp
+++ b/src/gpu/GrRenderTargetOpList.cpp
@@ -78,6 +78,14 @@ void GrRenderTargetOpList::visitProxies_debugOnly(const GrOp::VisitProxyFunc& fu
         recordedOp.visitProxies(func);
     }
 }
+
+static void assert_chain_bounds(const GrOp* op) {
+    SkASSERT(op->isChainHead());
+    auto headBounds = op->bounds();
+    while ((op = op->nextInChain())) {
+        SkASSERT(headBounds.contains(op->bounds()));
+    }
+}
 #endif
 
 void GrRenderTargetOpList::onPrepare(GrOpFlushState* flushState) {
@@ -99,7 +107,7 @@ void GrRenderTargetOpList::onPrepare(GrOpFlushState* flushState) {
                 fRecordedOps[i].fAppliedClip,
                 fRecordedOps[i].fDstProxy
             };
-
+            SkDEBUGCODE(assert_chain_bounds(opArgs.fOp));
             flushState->setOpArgs(&opArgs);
             fRecordedOps[i].fOp->prepare(flushState);
             flushState->setOpArgs(nullptr);
diff --git a/src/gpu/ops/GrOp.cpp b/src/gpu/ops/GrOp.cpp
index ed94d9902c..a5f6b172da 100644
--- a/src/gpu/ops/GrOp.cpp
+++ b/src/gpu/ops/GrOp.cpp
@@ -41,6 +41,9 @@ GrOp::CombineResult GrOp::combineIfPossible(GrOp* that, const GrCaps& caps) {
     auto result = this->onCombineIfPossible(that, caps);
     // Merging a chained 'that' would cause problems given the way op lists currently manage chains.
     SkASSERT(!(thatWasChained && result == CombineResult::kMerged));
+    if (fChainHead) {
+        fChainHead->joinBounds(*that);
+    }
     return result;
 }