Add getReducedClipStack to lua canvas

src/utils/SkLua.cpp

Index: src/utils/SkLua.cpp
diff --git a/src/utils/SkLua.cpp b/src/utils/SkLua.cpp
index ec276db1f607b416efdea4bccdb8f3883fdf2d0d..282e4ef4405cba23a34781010677fd892e9ecfab 100644
--- a/src/utils/SkLua.cpp
+++ b/src/utils/SkLua.cpp
@@ -6,8 +6,9 @@
  */
 
 #include "SkLua.h"
+
+#include "GrReducedClip.h"
 #include "SkCanvas.h"
-#include "SkClipStack.h"
 #include "SkData.h"
 #include "SkDocument.h"
 #include "SkImage.h"
@@ -273,29 +274,35 @@ void SkLua::pushClipStack(const SkClipStack& stack, const char* key) {
     const SkClipStack::Element* element;
     int i = 0;
     while (NULL != (element = iter.next())) {
-        lua_newtable(fL);
-        SkClipStack::Element::Type type = element->getType();
-        this->pushString(element_type(type), "type");
-        switch (type) {
-            case SkClipStack::Element::kEmpty_Type:
-                break;
-            case SkClipStack::Element::kRect_Type:
-                this->pushRect(element->getRect(), "rect");
-                break;
-            case SkClipStack::Element::kRRect_Type:
-                this->pushRRect(element->getRRect(), "rrect");
-                break;
-            case SkClipStack::Element::kPath_Type:
-                this->pushPath(element->getPath(), "path");
-                break;
-        }
-        this->pushString(region_op(element->getOp()), "op");
-        this->pushBool(element->isAA(), "aa");
+        this->pushClipStackElement(*element);
         lua_rawseti(fL, -2, ++i);
     }
     CHECK_SETFIELD(key);
 }
 
+void SkLua::pushClipStackElement(const SkClipStack::Element& element, const char* key) {
+    lua_newtable(fL);
+    SkClipStack::Element::Type type = element.getType();
+    this->pushString(element_type(type), "type");
+    switch (type) {
+        case SkClipStack::Element::kEmpty_Type:
+            break;
+        case SkClipStack::Element::kRect_Type:
+            this->pushRect(element.getRect(), "rect");
+            break;
+        case SkClipStack::Element::kRRect_Type:
+            this->pushRRect(element.getRRect(), "rrect");
+            break;
+        case SkClipStack::Element::kPath_Type:
+            this->pushPath(element.getPath(), "path");
+            break;
+    }
+    this->pushString(region_op(element.getOp()), "op");
+    this->pushBool(element.isAA(), "aa");
+    CHECK_SETFIELD(key);
+}
+
+
 ///////////////////////////////////////////////////////////////////////////////
 ///////////////////////////////////////////////////////////////////////////////
 
@@ -444,6 +451,41 @@ static int lcanvas_getClipStack(lua_State* L) {
     return 1;
 }
 
+int SkLua::lcanvas_getReducedClipStack(lua_State* L) {
+    const SkCanvas* canvas = get_ref<SkCanvas>(L, 1);
+    SkISize layerSize = canvas->getTopLayerSize();
+    SkIPoint layerOrigin = canvas->getTopLayerOrigin();
+    SkIRect queryBounds = SkIRect::MakeXYWH(layerOrigin.fX, layerOrigin.fY,
+                                            layerSize.fWidth, layerSize.fHeight);
+
+    GrReducedClip::ElementList elements;
+    GrReducedClip::InitialState initialState;
+    int32_t genID;
+    SkIRect resultBounds;
+
+    const SkClipStack& stack = *canvas->getClipStack();
+
+    GrReducedClip::ReduceClipStack(stack,
+                                   queryBounds,
+                                   &elements,
+                                   &genID,
+                                   &initialState,
+                                   &resultBounds,
+                                   NULL);
+
+    GrReducedClip::ElementList::Iter iter(elements);
+    int i = 0;
+    lua_newtable(L);
+    while(NULL != iter.get()) {
+        SkLua(L).pushClipStackElement(*iter.get());
+        iter.next();
+        lua_rawseti(L, -2, ++i);
+    }
+    // Currently this only returns the element list to lua, not the initial state or result bounds.
+    // It could return these as additional items on the lua stack.
+    return 1;
+}
+
 static int lcanvas_save(lua_State* L) {
     lua_pushinteger(L, get_ref<SkCanvas>(L, 1)->save());
     return 1;
@@ -479,7 +521,7 @@ static int lcanvas_gc(lua_State* L) {
     return 0;
 }
 
-static const struct luaL_Reg gSkCanvas_Methods[] = {
+const struct luaL_Reg gSkCanvas_Methods[] = {
     { "drawColor", lcanvas_drawColor },
     { "drawRect", lcanvas_drawRect },
     { "drawOval", lcanvas_drawOval },
@@ -490,6 +532,7 @@ static const struct luaL_Reg gSkCanvas_Methods[] = {
     { "getSaveCount", lcanvas_getSaveCount },
     { "getTotalMatrix", lcanvas_getTotalMatrix },
     { "getClipStack", lcanvas_getClipStack },
+    { "getReducedClipStack", SkLua::lcanvas_getReducedClipStack },
     { "save", lcanvas_save },
     { "restore", lcanvas_restore },
     { "scale", lcanvas_scale },