Attempt to combine batches in forward direction before flush

src/gpu/GrDrawTarget.cpp

 
 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrDrawTarget.h"
 
@@ skipping 17 matching lines @@
 #include "batches/GrCopySurfaceBatch.h"
 #include "batches/GrDiscardBatch.h"
 #include "batches/GrDrawBatch.h"
 #include "batches/GrDrawPathBatch.h"
 #include "batches/GrRectBatchFactory.h"
 #include "batches/GrStencilPathBatch.h"
 
 ////////////////////////////////////////////////////////////////////////////////
 
 // Experimentally we have found that most batching occurs within the first 10 comparisons.
-static const int kDefaultMaxBatchLookback = 10;
+static const int kDefaultMaxBatchLookback  = 10;
+static const int kDefaultMaxBatchLookahead = 10;
 
 GrDrawTarget::GrDrawTarget(GrRenderTarget* rt, GrGpu* gpu, GrResourceProvider* resourceProvider,
                            GrAuditTrail* auditTrail, const Options& options)
     : fGpu(SkRef(gpu))
     , fResourceProvider(resourceProvider)
     , fAuditTrail(auditTrail)
     , fFlags(0)
     , fRenderTarget(rt) {
     // TODO: Stop extracting the context (currently needed by GrClipMaskManager)
     fContext = fGpu->getContext();
     fClipMaskManager.reset(new GrClipMaskManager(this, options.fClipBatchToBounds));
 
     fDrawBatchBounds = options.fDrawBatchBounds;
     fMaxBatchLookback = (options.fMaxBatchLookback < 0) ? kDefaultMaxBatchLookback :
                                                           options.fMaxBatchLookback;
+    fMaxBatchLookahead = (options.fMaxBatchLookahead < 0) ? kDefaultMaxBatchLookahead :
+                                                           options.fMaxBatchLookahead;
 
     rt->setLastDrawTarget(this);
 
 #ifdef SK_DEBUG
     static int debugID = 0;
     fDebugID = debugID++;
 #endif
 }
 
 GrDrawTarget::~GrDrawTarget() {
@@ skipping 42 matching lines @@
     SkDebugf("relies On (%d): ", fDependencies.count());
     for (int i = 0; i < fDependencies.count(); ++i) {
         SkDebugf("%d, ", fDependencies[i]->fDebugID);
     }
     SkDebugf("\n");
     SkDebugf("batches (%d):\n", fBatches.count());
     for (int i = 0; i < fBatches.count(); ++i) {
 #if 0
         SkDebugf("*******************************\n");
 #endif
-        SkDebugf("%d: %s\n", i, fBatches[i]->name());
+        if (fBatches[i]) {
+            SkDebugf("%d: <combined forward>\n", i);
+        } else {
+            SkDebugf("%d: %s\n", i, fBatches[i]->name());
 #if 0
-        SkString str = fBatches[i]->dumpInfo();
-        SkDebugf("%s\n", str.c_str());
+            SkString str = fBatches[i]->dumpInfo();
+            SkDebugf("%s\n", str.c_str());
 #endif
+        }
     }
 }
 #endif
 
 bool GrDrawTarget::setupDstReadIfNecessary(const GrPipelineBuilder& pipelineBuilder,
                                            const GrPipelineOptimizations& optimizations,
                                            GrXferProcessor::DstTexture* dstTexture,
                                            const SkRect& batchBounds) {
     SkRect bounds = batchBounds;
     bounds.outset(0.5f, 0.5f);
@@ skipping 55 matching lines @@
 
 void GrDrawTarget::prepareBatches(GrBatchFlushState* flushState) {
     // Semi-usually the drawTargets are already closed at this point, but sometimes Ganesh
     // needs to flush mid-draw. In that case, the SkGpuDevice's drawTargets won't be closed
     // but need to be flushed anyway. Closing such drawTargets here will mean new
     // drawTargets will be created to replace them if the SkGpuDevice(s) write to them again.
     this->makeClosed();
 
     // Loop over the batches that haven't yet generated their geometry
     for (int i = 0; i < fBatches.count(); ++i) {
-        fBatches[i]->prepare(flushState);
+        if (fBatches[i]) {
+            fBatches[i]->prepare(flushState);
+        }
     }
 }
 
 void GrDrawTarget::drawBatches(GrBatchFlushState* flushState) {
     // Draw all the generated geometry.
     SkRandom random;
     for (int i = 0; i < fBatches.count(); ++i) {
+        if (!fBatches[i]) {
+            continue;
+        }
         if (fDrawBatchBounds) {
             const SkRect& bounds = fBatches[i]->bounds();
             SkIRect ibounds;
             bounds.roundOut(&ibounds);
             // In multi-draw buffer all the batches use the same render target and we won't need to
             // get the batchs bounds.
             if (GrRenderTarget* rt = fBatches[i]->renderTarget()) {
                 fGpu->drawDebugWireRect(rt, ibounds, 0xFF000000 | random.nextU());
             }
         }
@@ skipping 275 matching lines @@
                 break;
             }
         }
     } else {
         GrBATCH_INFO("\t\tFirstBatch\n");
     }
     GR_AUDIT_TRAIL_BATCHING_RESULT_NEW(fAuditTrail, batch);
     fBatches.push_back().reset(SkRef(batch));
 }
 
+void GrDrawTarget::forwardCombine() {
+    for (int i = 0; i < fBatches.count() - 2; ++i) {
+        GrBatch* batch = fBatches[i];
+        int maxCandidateIdx = SkTMin(i + fMaxBatchLookahead, fBatches.count() - 1);
+        int j = i + 1;
+        while (true) {
+            GrBatch* candidate = fBatches[j];
+            // We cannot continue to search if the render target changes
+            if (candidate->renderTargetUniqueID() != batch->renderTargetUniqueID()) {
+                GrBATCH_INFO("\t\tBreaking because of (%s, B%u) Rendertarget\n",
+                             candidate->name(), candidate->uniqueID());
+                break;
+            }
+            if (j == i +1) {
+                // We assume batch would have combined with candidate when the candidate was added
+                // via backwards combining in recordBatch.
+                SkASSERT(!batch->combineIfPossible(candidate, *this->caps()));
+            } else if (batch->combineIfPossible(candidate, *this->caps())) {
+                GrBATCH_INFO("\t\tCombining with (%s, B%u)\n", candidate->name(),
+                             candidate->uniqueID());
+                GR_AUDIT_TRAIL_BATCHING_RESULT_COMBINED(fAuditTrail, candidate);
+                fBatches[j].reset(SkRef(batch));
+                fBatches[i].reset(nullptr);
+                break;
+            }
+            // Stop going traversing if we would cause a painter's order violation.
+            // TODO: The bounds used here do not fully consider the clip. It may be advantageous
+            // to clip each batch's bounds to the clip.
+            if (intersect(candidate->bounds(), batch->bounds())) {
+                GrBATCH_INFO("\t\tIntersects with (%s, B%u)\n", candidate->name(),
+                             candidate->uniqueID());
+                break;
+            }
+            ++j;
+            if (j > maxCandidateIdx) {
+                GrBATCH_INFO("\t\tReached max lookahead or end of batch array %d\n", i);
+                break;
+            }
+        }
+    }
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 bool GrDrawTarget::installPipelineInDrawBatch(const GrPipelineBuilder* pipelineBuilder,
                                               const GrScissorState* scissor,
                                               GrDrawBatch* batch) {
     GrPipeline::CreateArgs args;
     args.fPipelineBuilder = pipelineBuilder;
     args.fCaps = this->caps();
     args.fScissor = scissor;
     batch->getPipelineOptimizations(&args.fOpts);
@@ skipping 37 matching lines @@
     }
 
     return true;
 }
 
 void GrDrawTarget::clearStencilClip(const SkIRect& rect, bool insideClip, GrRenderTarget* rt) {
     GrBatch* batch = new GrClearStencilClipBatch(rect, insideClip, rt);
     this->recordBatch(batch);
     batch->unref();
 }