Refugee from Dead Machine 4: MDB Monster

src/gpu/GrReorderCommandBuilder.cpp

Index: src/gpu/GrReorderCommandBuilder.cpp
diff --git a/src/gpu/GrReorderCommandBuilder.cpp b/src/gpu/GrReorderCommandBuilder.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..b42a8016d8c60e4e64133462b852bd9ec6888c47
--- /dev/null
+++ b/src/gpu/GrReorderCommandBuilder.cpp
@@ -0,0 +1,84 @@
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "GrReorderCommandBuilder.h"
+#include "SkStringUtils.h"
+
+template <class Left, class Right>
+static bool intersect(const Left& a, const Right& b) {
+    SkASSERT(a.fLeft <= a.fRight && a.fTop <= a.fBottom &&
+             b.fLeft <= b.fRight && b.fTop <= b.fBottom);
+    return a.fLeft < b.fRight && b.fLeft < a.fRight &&
+           a.fTop < b.fBottom && b.fTop < a.fBottom;
+}
+
+GrTargetCommands::Cmd* GrReorderCommandBuilder::recordDrawBatch(GrBatch* batch,
+                                                                const GrCaps& caps) {
+    // Check if there is a Batch Draw we can batch with by linearly searching back until we either
+    // 1) check every draw
+    // 2) intersect with something
+    // 3) find a 'blocker'
+    // Experimentally we have found that most batching occurs within the first 10 comparisons.
+    static const int kMaxLookback = 10;
+    int i = 0;
+
+    //GrRenderTarget* rt = batch->rt2(); //batch->pipeline()->getRenderTarget1();
+
+    GrBATCH_INFO("Re-Recording (%s, B%u)\n"
+                 "\tBounds (%f, %f, %f, %f)\n",
+                 batch->name(),
+                 batch->uniqueID(),
+                 batch->bounds().fLeft, batch->bounds().fRight,
+                 batch->bounds().fTop, batch->bounds().fBottom);
+    GrBATCH_INFO(SkTabString(batch->dumpInfo(), 1).c_str());
+    GrBATCH_INFO("\tOutcome:\n");
+    if (!this->cmdBuffer()->empty()) {
+        GrTargetCommands::CmdBuffer::ReverseIter reverseIter(*this->cmdBuffer());
+
+        do {
+            if (Cmd::kDrawBatch_CmdType == reverseIter->type()) {
+                DrawBatch* previous = static_cast<DrawBatch*>(reverseIter.get());
+
+                if (previous->batch()->renderTargetUniqueID() != batch->renderTargetUniqueID()) {
+                    GrBATCH_INFO("\t\tBreaking because of (%s, B%u) Rendertarget\n",
+                                 previous->batch()->name(), previous->batch()->uniqueID());
+                    break;
+                }
+                // We cannot continue to search backwards if the render target changes
+                if (previous->batch()->combineIfPossible(batch, caps)) {
+                    GrBATCH_INFO("\t\tCombining with (%s, B%u)\n",
+                                 previous->batch()->name(), previous->batch()->uniqueID());
+                    return nullptr;
+                }
+
+                if (intersect(previous->batch()->bounds(), batch->bounds())) {
+                    GrBATCH_INFO("\t\tIntersects with (%s, B%u)\n",
+                                 previous->batch()->name(), previous->batch()->uniqueID());
+                    break;
+                }
+            } else {
+                GrBATCH_INFO("\t\tBreaking because of other %08x\n", reverseIter->type());
+                // TODO temporary until we only have batches.
+                break;
+            }
+        } while (reverseIter.previous() && ++i < kMaxLookback);
+#if GR_BATCH_SPEW
+        if (!reverseIter.get()) {
+            GrBATCH_INFO("\t\tNo more commands to try and batch with\n");
+        } else if (i >= kMaxLookback) {
+            GrBATCH_INFO("\t\tReached max lookback %d\n", i);
+        }
+#endif
+    }
+#if GR_BATCH_SPEW
+    else {
+        GrBATCH_INFO("\t\tBreaking because empty command buffer\n");
+    }
+#endif
+
+    return GrNEW_APPEND_TO_RECORDER(*this->cmdBuffer(), DrawBatch, (batch));
+}