Reorder across clears

BUG=skia:

Review URL: https://codereview.chromium.org/1161643002

3 files changed, 24 insertions, 7 deletions

diff --git a/src/gpu/GrCommandBuilder.cpp b/src/gpu/GrCommandBuilder.cpp
index b3f6d7185b..6b56dea421 100644
--- a/src/gpu/GrCommandBuilder.cpp
+++ b/src/gpu/GrCommandBuilder.cpp
@@ -32,6 +32,11 @@ GrTargetCommands::Cmd* GrCommandBuilder::recordClear(const SkIRect* rect,
         r.setLTRB(0, 0, renderTarget->width(), renderTarget->height());
         rect = &r;
     }
+
+    SkASSERT(color == GrColor_ILLEGAL ||
+             canIgnoreRect ||
+             (rect->fLeft <= rect->fRight && rect->fTop <= rect->fBottom));
+
     Clear* clr = GrNEW_APPEND_TO_RECORDER(*this->cmdBuffer(), Clear, (renderTarget));
     GrColorIsPMAssert(color);
     clr->fColor = color;
diff --git a/src/gpu/GrReorderCommandBuilder.cpp b/src/gpu/GrReorderCommandBuilder.cpp
index 14279de824..e373381cb2 100644
--- a/src/gpu/GrReorderCommandBuilder.cpp
+++ b/src/gpu/GrReorderCommandBuilder.cpp
@@ -7,7 +7,8 @@
 
 #include "GrReorderCommandBuilder.h"
 
-static bool intersect(const SkRect& a, const SkRect& b) {
+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 &&
@@ -37,6 +38,16 @@ GrTargetCommands::Cmd* GrReorderCommandBuilder::recordDrawBatch(State* state, Gr
                 if (intersect(previous->fBatch->bounds(), batch->bounds())) {
                     break;
                 }
+            } else if (Cmd::kClear_CmdType == reverseIter->type()) {
+                Clear* previous = static_cast<Clear*>(reverseIter.get());
+
+                // We set the color to illegal if we are doing a discard.
+                // If we can ignore the rect, then we do a full clear
+                if (previous->fColor == GrColor_ILLEGAL ||
+                    previous->fCanIgnoreRect ||
+                    intersect(batch->bounds(), previous->fRect)) {
+                    break;
+                }
             } else {
                 // TODO temporary until we can navigate the other types of commands
                 break;
diff --git a/src/gpu/GrTargetCommands.h b/src/gpu/GrTargetCommands.h
index 2f9909bb02..e5f3cd5a11 100644
--- a/src/gpu/GrTargetCommands.h
+++ b/src/gpu/GrTargetCommands.h
@@ -35,11 +35,12 @@ public:
             kStencilPath_CmdType       = 1,
             kSetState_CmdType          = 2,
             kClear_CmdType             = 3,
-            kCopySurface_CmdType       = 4,
-            kDrawPath_CmdType          = 5,
-            kDrawPaths_CmdType         = 6,
-            kDrawBatch_CmdType         = 7,
-            kXferBarrier_CmdType       = 8,
+            kClearStencil_CmdType      = 4,
+            kCopySurface_CmdType       = 5,
+            kDrawPath_CmdType          = 6,
+            kDrawPaths_CmdType         = 7,
+            kDrawBatch_CmdType         = 8,
+            kXferBarrier_CmdType       = 9,
         };
 
         Cmd(CmdType type) : fMarkerID(-1), fType(type) {}
@@ -190,7 +191,7 @@ private:
 
     // This command is ONLY used by the clip mask manager to clear the stencil clip bits
     struct ClearStencilClip : public Cmd {
-        ClearStencilClip(GrRenderTarget* rt) : Cmd(kClear_CmdType), fRenderTarget(rt) {}
+        ClearStencilClip(GrRenderTarget* rt) : Cmd(kClearStencil_CmdType), fRenderTarget(rt) {}
 
         GrRenderTarget* renderTarget() const { return fRenderTarget.get(); }