Preliminary support for clipRect(Rect, Op)

This adds basic support for clip regions. It is currently disabled at compile
time. Enabling clip regions will require setting up a stencil buffer.

Change-Id: I638616a972276e38737f8ac0633692c3845eaa74

2 files changed, 33 insertions, 0 deletions

diff --git a/include/ui/Region.h b/include/ui/Region.h
index 6c9a6203e7..f242f18eb2 100644
--- a/include/ui/Region.h
+++ b/include/ui/Region.h
@@ -55,43 +55,51 @@ public:
             void        set(uint32_t w, uint32_t h);
         
             Region&     orSelf(const Rect& rhs);
+            Region&     xorSelf(const Rect& rhs);
             Region&     andSelf(const Rect& rhs);
             Region&     subtractSelf(const Rect& rhs);
 
             // boolean operators, applied on this
             Region&     orSelf(const Region& rhs);
+            Region&     xorSelf(const Region& rhs);
             Region&     andSelf(const Region& rhs);
             Region&     subtractSelf(const Region& rhs);
 
             // boolean operators
     const   Region      merge(const Rect& rhs) const;
+    const   Region      mergeExclusive(const Rect& rhs) const;
     const   Region      intersect(const Rect& rhs) const;
     const   Region      subtract(const Rect& rhs) const;
 
             // boolean operators
     const   Region      merge(const Region& rhs) const;
+    const   Region      mergeExclusive(const Region& rhs) const;
     const   Region      intersect(const Region& rhs) const;
     const   Region      subtract(const Region& rhs) const;
 
             // these translate rhs first
             Region&     translateSelf(int dx, int dy);
             Region&     orSelf(const Region& rhs, int dx, int dy);
+            Region&     xorSelf(const Region& rhs, int dx, int dy);
             Region&     andSelf(const Region& rhs, int dx, int dy);
             Region&     subtractSelf(const Region& rhs, int dx, int dy);
 
             // these translate rhs first
     const   Region      translate(int dx, int dy) const;
     const   Region      merge(const Region& rhs, int dx, int dy) const;
+    const   Region      mergeExclusive(const Region& rhs, int dx, int dy) const;
     const   Region      intersect(const Region& rhs, int dx, int dy) const;
     const   Region      subtract(const Region& rhs, int dx, int dy) const;
 
     // convenience operators overloads
     inline  const Region      operator | (const Region& rhs) const;
+    inline  const Region      operator ^ (const Region& rhs) const;
     inline  const Region      operator & (const Region& rhs) const;
     inline  const Region      operator - (const Region& rhs) const;
     inline  const Region      operator + (const Point& pt) const;
 
     inline  Region&     operator |= (const Region& rhs);
+    inline  Region&     operator ^= (const Region& rhs);
     inline  Region&     operator &= (const Region& rhs);
     inline  Region&     operator -= (const Region& rhs);
     inline  Region&     operator += (const Point& pt);
@@ -158,6 +166,9 @@ private:
 const Region Region::operator | (const Region& rhs) const {
     return merge(rhs);
 }
+const Region Region::operator ^ (const Region& rhs) const {
+    return mergeExclusive(rhs);
+}
 const Region Region::operator & (const Region& rhs) const {
     return intersect(rhs);
 }
@@ -172,6 +183,9 @@ const Region Region::operator + (const Point& pt) const {
 Region& Region::operator |= (const Region& rhs) {
     return orSelf(rhs);
 }
+Region& Region::operator ^= (const Region& rhs) {
+    return xorSelf(rhs);
+}
 Region& Region::operator &= (const Region& rhs) {
     return andSelf(rhs);
 }
diff --git a/libs/ui/Region.cpp b/libs/ui/Region.cpp
index 8cd047afb8..6e2e731e3d 100644
--- a/libs/ui/Region.cpp
+++ b/libs/ui/Region.cpp
@@ -126,6 +126,9 @@ void Region::addRectUnchecked(int l, int t, int r, int b)
 Region& Region::orSelf(const Rect& r) {
     return operationSelf(r, op_or);
 }
+Region& Region::xorSelf(const Rect& r) {
+    return operationSelf(r, op_xor);
+}
 Region& Region::andSelf(const Rect& r) {
     return operationSelf(r, op_and);
 }
@@ -143,6 +146,9 @@ Region& Region::operationSelf(const Rect& r, int op) {
 Region& Region::orSelf(const Region& rhs) {
     return operationSelf(rhs, op_or);
 }
+Region& Region::xorSelf(const Region& rhs) {
+    return operationSelf(rhs, op_xor);
+}
 Region& Region::andSelf(const Region& rhs) {
     return operationSelf(rhs, op_and);
 }
@@ -165,6 +171,9 @@ Region& Region::translateSelf(int x, int y) {
 const Region Region::merge(const Rect& rhs) const {
     return operation(rhs, op_or);
 }
+const Region Region::mergeExclusive(const Rect& rhs) const {
+    return operation(rhs, op_xor);
+}
 const Region Region::intersect(const Rect& rhs) const {
     return operation(rhs, op_and);
 }
@@ -182,6 +191,9 @@ const Region Region::operation(const Rect& rhs, int op) const {
 const Region Region::merge(const Region& rhs) const {
     return operation(rhs, op_or);
 }
+const Region Region::mergeExclusive(const Region& rhs) const {
+    return operation(rhs, op_xor);
+}
 const Region Region::intersect(const Region& rhs) const {
     return operation(rhs, op_and);
 }
@@ -205,6 +217,9 @@ const Region Region::translate(int x, int y) const {
 Region& Region::orSelf(const Region& rhs, int dx, int dy) {
     return operationSelf(rhs, dx, dy, op_or);
 }
+Region& Region::xorSelf(const Region& rhs, int dx, int dy) {
+    return operationSelf(rhs, dx, dy, op_xor);
+}
 Region& Region::andSelf(const Region& rhs, int dx, int dy) {
     return operationSelf(rhs, dx, dy, op_and);
 }
@@ -222,6 +237,9 @@ Region& Region::operationSelf(const Region& rhs, int dx, int dy, int op) {
 const Region Region::merge(const Region& rhs, int dx, int dy) const {
     return operation(rhs, dx, dy, op_or);
 }
+const Region Region::mergeExclusive(const Region& rhs, int dx, int dy) const {
+    return operation(rhs, dx, dy, op_xor);
+}
 const Region Region::intersect(const Region& rhs, int dx, int dy) const {
     return operation(rhs, dx, dy, op_and);
 }
@@ -421,6 +439,7 @@ void Region::boolean_operation(int op, Region& dst,
     SkRegion::Op sk_op;
     switch (op) {
         case op_or: sk_op = SkRegion::kUnion_Op; name="OR"; break;
+        case op_xor: sk_op = SkRegion::kUnion_XOR; name="XOR"; break;
         case op_and: sk_op = SkRegion::kIntersect_Op; name="AND"; break;
         case op_nand: sk_op = SkRegion::kDifference_Op; name="NAND"; break;
     }