Begin instanced rendering for simple shapes

Adds a module that performs instanced rendering and starts using it
for a select subset of draws on Mac GL platforms. The instance
processor can currently handle rects, ovals, round rects, and double
round rects. It can generalize shapes as round rects in order to
improve batching. The instance processor also employs new drawing
algorithms, irrespective of instanced rendering, that improve GPU-side
performance (e.g. sample mask, different triangle layouts, etc.).

This change only scratches the surface of instanced rendering. The
majority of draws still only have one instance. Future work may
include:

 * Passing coord transforms through the texel buffer.
 * Sending FP uniforms through instanced vertex attribs.
 * Using instanced rendering for more draws (stencil writes,
   drawAtlas, etc.).
 * Adding more shapes to the instance processor’s repertoire.
 * Batching draws that have mismatched scissors (analyzing draw
   bounds, inserting clip planes, etc.).
 * Bindless textures.
 * Uber shaders.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2066993003

Review-Url: https://codereview.chromium.org/2066993003

1 files changed, 60 insertions, 0 deletions

diff --git a/src/gpu/instanced/GLInstancedRendering.h b/src/gpu/instanced/GLInstancedRendering.h
new file mode 100644
index 0000000000..569e6e3160
--- /dev/null
+++ b/src/gpu/instanced/GLInstancedRendering.h
@@ -0,0 +1,60 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef gr_instanced_GLInstancedRendering_DEFINED
+#define gr_instanced_GLInstancedRendering_DEFINED
+
+#include "gl/GrGLBuffer.h"
+#include "instanced/InstancedRendering.h"
+
+class GrGLGpu;
+
+#define GR_GL_LOG_INSTANCED_BATCHES 0
+
+namespace gr_instanced {
+
+class GLInstancedRendering final : public InstancedRendering {
+public:
+    static GLInstancedRendering* CreateIfSupported(GrGLGpu*);
+    ~GLInstancedRendering() override;
+
+private:
+    GLInstancedRendering(GrGLGpu*, AntialiasMode lastSupportedAAMode);
+
+    GrGLGpu* glGpu() const;
+
+    Batch* createBatch() override;
+
+    void onBeginFlush(GrResourceProvider*) override;
+    void onDraw(const GrPipeline&, const InstanceProcessor&, const Batch*) override;
+    void onEndFlush() override;
+    void onResetGpuResources(ResetType) override;
+
+    void flushInstanceAttribs(int baseInstance);
+
+    struct GLDrawCmdInfo {
+        int fInstanceCount;
+#if GR_GL_LOG_INSTANCED_BATCHES
+        IndexRange fGeometry;
+#endif
+    };
+
+    GrGLuint                              fVertexArrayID;
+    SkAutoTUnref<GrGLBuffer>              fInstanceBuffer;
+    SkAutoTUnref<GrGLBuffer>              fDrawIndirectBuffer;
+    SkAutoSTMalloc<1024, GLDrawCmdInfo>   fGLDrawCmdsInfo;
+    uint32_t                              fInstanceAttribsBufferUniqueId;
+    int                                   fInstanceAttribsBaseInstance;
+
+    class GLBatch;
+
+    typedef InstancedRendering INHERITED;
+};
+
+}
+
+#endif