fix the float Rect in OpenGLRenderer to handle NANs

- we want functions like isEmpty() to return true if NANs are
involved in the Rect

- also clean-up the intersect familly of calls

- minor cleanup in the int32_t Rect as well

These played a role in http://b/5331198.

Bug: 5331198

Change-Id: I5369725ab482e4b83da9f1bd4cee5256e5de75b2

3 files changed, 30 insertions, 37 deletions

diff --git a/include/ui/Rect.h b/include/ui/Rect.h
index 4e65a2d..9e98bc5 100644
--- a/include/ui/Rect.h
+++ b/include/ui/Rect.h
@@ -27,7 +27,7 @@ namespace android {
 class Rect : public ARect
 {
 public:
-    typedef int32_t value_type;
+    typedef ARect::value_type value_type;
 
     // we don't provide copy-ctor and operator= on purpose
     // because we want the compiler generated versions
diff --git a/libs/hwui/Rect.h b/libs/hwui/Rect.h
index 71951b7..edc90e1 100644
--- a/libs/hwui/Rect.h
+++ b/libs/hwui/Rect.h
@@ -28,7 +28,19 @@ namespace uirenderer {
 // Structs
 ///////////////////////////////////////////////////////////////////////////////
 
-struct Rect {
+class Rect {
+    static inline float min(float a, float b) { return (a<b) ? a : b; }
+    static inline float max(float a, float b) { return (a>b) ? a : b; }
+    Rect intersectWith(float l, float t, float r, float b) const {
+        Rect tmp;
+        tmp.left    = max(left, l);
+        tmp.top     = max(top, t);
+        tmp.right   = min(right, r);
+        tmp.bottom  = min(bottom, b);
+        return tmp;
+    }
+
+public:
     float left;
     float top;
     float right;
@@ -37,6 +49,9 @@ struct Rect {
     // Used by Region
     typedef float value_type;
 
+    // we don't provide copy-ctor and operator= on purpose
+    // because we want the compiler generated versions
+
     inline Rect():
             left(0),
             top(0),
@@ -58,24 +73,6 @@ struct Rect {
             bottom(height) {
     }
 
-    inline Rect(const Rect& r) {
-        set(r);
-    }
-
-    inline Rect(Rect& r) {
-        set(r);
-    }
-
-    Rect& operator=(const Rect& r) {
-        set(r);
-        return *this;
-    }
-
-    Rect& operator=(Rect& r) {
-        set(r);
-        return *this;
-    }
-
     friend int operator==(const Rect& a, const Rect& b) {
         return !memcmp(&a, &b, sizeof(a));
     }
@@ -89,7 +86,9 @@ struct Rect {
     }
 
     inline bool isEmpty() const {
-        return left >= right || top >= bottom;
+        // this is written in such way this it'll handle NANs to return
+        // true (empty)
+        return !((left < right) && (top < bottom));
     }
 
     inline void setEmpty() {
@@ -115,27 +114,18 @@ struct Rect {
         return bottom - top;
     }
 
-    bool intersects(float left, float top, float right, float bottom) const {
-        return left < right && top < bottom &&
-                this->left < this->right && this->top < this->bottom &&
-                this->left < right && left < this->right &&
-                this->top < bottom && top < this->bottom;
+    bool intersects(float l, float t, float r, float b) const {
+        return !intersectWith(l,t,r,b).isEmpty();
     }
 
     bool intersects(const Rect& r) const {
         return intersects(r.left, r.top, r.right, r.bottom);
     }
 
-    bool intersect(float left, float top, float right, float bottom) {
-        if (left < right && top < bottom && !this->isEmpty() &&
-                this->left < right && left < this->right &&
-                this->top < bottom && top < this->bottom) {
-
-            if (this->left < left) this->left = left;
-            if (this->top < top) this->top = top;
-            if (this->right > right) this->right = right;
-            if (this->bottom > bottom) this->bottom = bottom;
-
+    bool intersect(float l, float t, float r, float b) {
+        Rect tmp(intersectWith(l,t,r,b));
+        if (!tmp.isEmpty()) {
+            set(tmp);
             return true;
         }
         return false;
@@ -182,7 +172,7 @@ struct Rect {
         LOGD("Rect[l=%f t=%f r=%f b=%f]", left, top, right, bottom);
     }
 
-}; // struct Rect
+}; // class Rect
 
 }; // namespace uirenderer
 }; // namespace android
diff --git a/native/include/android/rect.h b/native/include/android/rect.h
index 3e81f53..64d487d 100644
--- a/native/include/android/rect.h
+++ b/native/include/android/rect.h
@@ -23,6 +23,9 @@ extern "C" {
 #endif
 
 typedef struct ARect {
+#ifdef __cplusplus
+    typedef int32_t value_type;
+#endif
     int32_t left;
     int32_t top;
     int32_t right;