Incrementally flush GrDrawTarget

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/GrRectBatchFactory.h"
 #include "batches/GrStencilPathBatch.h"
 
 #include "SkStrokeRec.h"
 
 ////////////////////////////////////////////////////////////////////////////////
 
 GrDrawTarget::GrDrawTarget(GrGpu* gpu, GrResourceProvider* resourceProvider)
     : fGpu(SkRef(gpu))
     , fResourceProvider(resourceProvider)
+    , fFlushState(fGpu, fResourceProvider, 0)
     , fFlushing(false)
-    , fLastFlushToken(0) {
+    , fLastPreparedBatch(0) {
     // TODO: Stop extracting the context (currently needed by GrClipMaskManager)
     fContext = fGpu->getContext();
     fClipMaskManager.reset(new GrClipMaskManager(this));
 }
 
 GrDrawTarget::~GrDrawTarget() {
     fGpu->unref();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ skipping 54 matching lines @@
         SkDebugf("Failed to create temporary copy of destination texture.\n");
         return false;
     }
     SkIPoint dstPoint = {0, 0};
     this->copySurface(copy, rt, copyRect, dstPoint);
     dstTexture->setTexture(copy);
     dstTexture->setOffset(copyRect.fLeft, copyRect.fTop);
     return true;
 }
 
+void GrDrawTarget::prepareN(int N) {

[bsalomon, 2015/10/02 14:40:17]

I'm wondering how helpful this helper function is, rather than just inlining and
reducing into the two callers. One is just

for (int i = fLastPreparedBatch; i < fBatches.count(); ++i) {
    fBatches[i]->prepare(&fFlushState);
}

and the other is just:

batch->prepare(&fFlushState);
++fLastPreparedBatch;

Also, isn't fLastPreparedBatch really fFirstUnpreparedBatch?

And why is the code that is preparing not also updating fLastPreparedBatch?

+    SkASSERT(fLastPreparedBatch + N <= fBatches.count());
+
+    int flushTo = fLastPreparedBatch + N;
+
+    // Loop over all batches and generate geometry
+    for (int i = fLastPreparedBatch; i < flushTo; ++i) {
+        fBatches[i]->prepare(&fFlushState);
+    }
+}
+
 void GrDrawTarget::flush() {
     if (fFlushing) {
         return;
     }
     fFlushing = true;
 
-    GrBatchFlushState flushState(fGpu, fResourceProvider, fLastFlushToken);
-
-    // Loop over all batches and generate geometry
-    for (int i = 0; i < fBatches.count(); ++i) {
-        fBatches[i]->prepare(&flushState);
-    }
+    this->prepareN(fBatches.count() - fLastPreparedBatch);
 
     // Upload all data to the GPU
-    flushState.preIssueDraws();
+    fFlushState.preIssueDraws();
 
     // Draw all the generated geometry.
     for (int i = 0; i < fBatches.count(); ++i) {
-        fBatches[i]->draw(&flushState);
+        fBatches[i]->draw(&fFlushState);
     }
 
-    fLastFlushToken = flushState.lastFlushedToken();
+    this->reset();
 
     fFlushing = false;
-    this->reset();
 }
 
 void GrDrawTarget::reset() {
+    fLastPreparedBatch = 0;
     fBatches.reset();
 }
 
 void GrDrawTarget::drawBatch(const GrPipelineBuilder& pipelineBuilder, GrDrawBatch* batch) {
     // Setup clip
     GrScissorState scissorState;
     GrPipelineBuilder::AutoRestoreFragmentProcessorState arfps;
     GrPipelineBuilder::AutoRestoreStencil ars;
     if (!fClipMaskManager->setupClipping(pipelineBuilder, &arfps, &ars, &scissorState,
                                          &batch->bounds())) {
@@ skipping 275 matching lines @@
             ++i;
             if (i == maxCandidates) {
                 GrBATCH_INFO("\t\tReached max lookback or beginning of batch array %d\n", i);
                 break;
             }
         }
     } else {
         GrBATCH_INFO("\t\tFirstBatch\n");
     }
     fBatches.push_back().reset(SkRef(batch));
+    if (fBatches.count() > kMaxLookback) {
+        SkASSERT(fBatches.count() - kMaxLookback - fLastPreparedBatch == 1);
+        this->prepareN(1);
+        fLastPreparedBatch++;
+    }
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 bool GrDrawTarget::installPipelineInDrawBatch(const GrPipelineBuilder* pipelineBuilder,
                                               const GrScissorState* scissor,
                                               GrDrawBatch* batch) {
     GrPipeline::CreateArgs args;
     args.fPipelineBuilder = pipelineBuilder;
     args.fCaps = this->caps();
@@ skipping 11 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();
 }