Push full screen clears up to OpList

Change-Id: Icfc09b3b25f4d3834bee93286e2b24a559f44ed8
Reviewed-on: https://skia-review.googlesource.com/40120
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>

1 files changed, 27 insertions, 25 deletions

diff --git a/src/gpu/GrRenderTargetOpList.cpp b/src/gpu/GrRenderTargetOpList.cpp
index ce34be7495..77b6eca3bc 100644
--- a/src/gpu/GrRenderTargetOpList.cpp
+++ b/src/gpu/GrRenderTargetOpList.cpp
@@ -133,7 +133,7 @@ static inline void finish_command_buffer(GrGpuRTCommandBuffer* buffer) {
 // is at flush time). However, we need to store the RenderTargetProxy in the
 // Ops and instantiate them here.
 bool GrRenderTargetOpList::onExecute(GrOpFlushState* flushState) {
-    if (0 == fRecordedOps.count()) {
+    if (0 == fRecordedOps.count() && GrLoadOp::kClear != fColorLoadOp) {
         return false;
     }
 
@@ -180,7 +180,6 @@ bool GrRenderTargetOpList::onExecute(GrOpFlushState* flushState) {
 }
 
 void GrRenderTargetOpList::reset() {
-    fLastFullClearOp = nullptr;
     fLastClipStackGenID = SK_InvalidUniqueID;
     fRecordedOps.reset();
     if (fInstancedRendering) {
@@ -203,30 +202,35 @@ void GrRenderTargetOpList::freeGpuResources() {
     }
 }
 
+void GrRenderTargetOpList::discard() {
+    // Discard calls to in-progress opLists are ignored. Calls at the start update the
+    // opLists' color & stencil load ops.
+    if (this->isEmpty()) {
+        fColorLoadOp = GrLoadOp::kDiscard;
+        fStencilLoadOp = GrLoadOp::kDiscard;
+    }
+}
+
 void GrRenderTargetOpList::fullClear(const GrCaps& caps, GrColor color) {
-    // Currently this just inserts or updates the last clear op. However, once in MDB this can
-    // remove all the previously recorded ops and change the load op to clear with supplied
-    // color.
-    if (fLastFullClearOp) {
-        // As currently implemented, fLastFullClearOp should be the last op because we would
-        // have cleared it when another op was recorded.
-        SkASSERT(fRecordedOps.back().fOp.get() == fLastFullClearOp);
-        GrOP_INFO("opList: %d Fusing clears (opID: %d Color: 0x%08x -> 0x%08x)\n",
-                  this->uniqueID(),
-                  fLastFullClearOp->uniqueID(),
-                  fLastFullClearOp->color(), color);
-        fLastFullClearOp->setColor(color);
+
+    // This is conservative. If the opList is marked as needing a stencil buffer then there
+    // may be a prior op that writes to the stencil buffer. Although the clear will ignore the
+    // stencil buffer, following draw ops may not so we can't get rid of all the preceding ops.
+    // Beware! If we ever add any ops that have a side effect beyond modifying the stencil
+    // buffer we will need a more elaborate tracking system (skbug.com/7002).
+    if (this->isEmpty() || !fTarget.get()->asRenderTargetProxy()->needsStencil()) {
+        fRecordedOps.reset();
+        fColorLoadOp = GrLoadOp::kClear;
+        fLoadClearColor = color;
         return;
     }
+
     std::unique_ptr<GrClearOp> op(GrClearOp::Make(GrFixedClip::Disabled(), color, fTarget.get()));
     if (!op) {
         return;
     }
 
-    if (GrOp* clearOp = this->recordOp(std::move(op), caps)) {
-        // This is either the clear op we just created or another one that it combined with.
-        fLastFullClearOp = static_cast<GrClearOp*>(clearOp);
-    }
+    this->recordOp(std::move(op), caps);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -277,10 +281,10 @@ bool GrRenderTargetOpList::combineIfPossible(const RecordedOp& a, GrOp* b,
     return a.fOp->combineIfPossible(b, caps);
 }
 
-GrOp* GrRenderTargetOpList::recordOp(std::unique_ptr<GrOp> op,
-                                     const GrCaps& caps,
-                                     GrAppliedClip* clip,
-                                     const DstProxy* dstProxy) {
+void GrRenderTargetOpList::recordOp(std::unique_ptr<GrOp> op,
+                                    const GrCaps& caps,
+                                    GrAppliedClip* clip,
+                                    const DstProxy* dstProxy) {
     SkASSERT(fTarget.get());
 
     // A closed GrOpList should never receive new/more ops
@@ -313,7 +317,7 @@ GrOp* GrRenderTargetOpList::recordOp(std::unique_ptr<GrOp> op,
                 GrOP_INFO("\t\t\tBackward: Combined op info:\n");
                 GrOP_INFO(SkTabString(candidate.fOp->dumpInfo(), 4).c_str());
                 GR_AUDIT_TRAIL_OPS_RESULT_COMBINED(fAuditTrail, candidate.fOp.get(), op.get());
-                return candidate.fOp.get();
+                return;
             }
             // Stop going backwards if we would cause a painter's order violation.
             if (!can_reorder(fRecordedOps.fromBack(i).fOp->bounds(), op->bounds())) {
@@ -337,8 +341,6 @@ GrOp* GrRenderTargetOpList::recordOp(std::unique_ptr<GrOp> op,
     }
     fRecordedOps.emplace_back(std::move(op), clip, dstProxy);
     fRecordedOps.back().fOp->wasRecorded(this);
-    fLastFullClearOp = nullptr;
-    return fRecordedOps.back().fOp.get();
 }
 
 void GrRenderTargetOpList::forwardCombine(const GrCaps& caps) {