Add nine patch type to SkRRect.

src/core/SkRRect.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkRRect.h"
 #include "SkMatrix.h"
 
@@ skipping 25 matching lines @@
     }
     fType = kSimple_Type;
     if (xRad >= SkScalarHalf(fRect.width()) && yRad >= SkScalarHalf(fRect.height())) {
         fType = kOval_Type;
         // TODO: assert that all the x&y radii are already W/2 & H/2
     }
 
     SkDEBUGCODE(this->validate();)
 }
 
+void SkRRect::setNinePatch(const SkRect& rect, SkScalar leftRad, SkScalar topRad,
+                           SkScalar rightRad, SkScalar bottomRad) {
+    if (rect.isEmpty()) {
+        this->setEmpty();
+        return;
+    }
+
+    leftRad = SkMaxScalar(leftRad, 0);
+    topRad = SkMaxScalar(topRad, 0);
+    rightRad = SkMaxScalar(rightRad, 0);
+    bottomRad = SkMaxScalar(bottomRad, 0);
+
+    SkScalar scale = SK_Scalar1;
+    if (leftRad + rightRad > rect.width()) {
+        scale = SkScalarDiv(rect.width(), leftRad + rightRad);
+    }
+    if (topRad + bottomRad > rect.height()) {
+        scale = SkMinScalar(scale, SkScalarDiv(rect.width(), leftRad + rightRad));
+    }
+
+    if (scale < SK_Scalar1) {
+        leftRad = SkScalarMul(leftRad, scale);
+        topRad = SkScalarMul(topRad, scale);
+        rightRad = SkScalarMul(rightRad, scale);
+        bottomRad = SkScalarMul(bottomRad, scale);
+    }
+
+    if (leftRad == rightRad && topRad == bottomRad) {
+        if (leftRad >= SkScalarHalf(rect.width()) && topRad >= SkScalarHalf(rect.height())) {
+            fType = kOval_Type;
+        } else if (0 == leftRad || 0 == topRad) {
+            // If the left and (by equality check above) right radii are zero then it is a rect.
+            // Same goes for top/bottom.
+            fType = kRect_Type;
+            leftRad = 0;
+            topRad = 0;
+            rightRad = 0;
+            bottomRad = 0;
+        } else {
+            fType = kSimple_Type;
+        }
+    } else {
+        fType = kNinePatch_Type;
+    }
+
+    fRect = rect;
+    fRadii[kUpperLeft_Corner].set(leftRad, topRad);
+    fRadii[kUpperRight_Corner].set(rightRad, topRad);
+    fRadii[kLowerRight_Corner].set(rightRad, bottomRad);
+    fRadii[kLowerLeft_Corner].set(leftRad, bottomRad);
+
+    SkDEBUGCODE(this->validate();)
+}
+
+
 void SkRRect::setRectRadii(const SkRect& rect, const SkVector radii[4]) {
     if (rect.isEmpty()) {
         this->setEmpty();
         return;
     }
 
     fRect = rect;
     memcpy(fRadii, radii, sizeof(fRadii));
 
     bool allCornersSquare = true;
@@ skipping 137 matching lines @@
 
     // At this point we know all four corners of 'rect' are inside the
     // bounds of of this RR. Check to make sure all the corners are inside
     // all the curves
     return this->checkCornerContainment(rect.fLeft, rect.fTop) &&
            this->checkCornerContainment(rect.fRight, rect.fTop) &&
            this->checkCornerContainment(rect.fRight, rect.fBottom) &&
            this->checkCornerContainment(rect.fLeft, rect.fBottom);
 }
 
+static bool radii_are_nine_patch(const SkVector radii[4]) {
+    return radii[SkRRect::kUpperLeft_Corner].fX == radii[SkRRect::kLowerLeft_Corner].fX &&
+           radii[SkRRect::kUpperLeft_Corner].fY == radii[SkRRect::kUpperRight_Corner].fY &&
+           radii[SkRRect::kUpperRight_Corner].fX == radii[SkRRect::kLowerRight_Corner].fX &&
+           radii[SkRRect::kLowerLeft_Corner].fY == radii[SkRRect::kLowerRight_Corner].fY;
+}
+
 // There is a simplified version of this method in setRectXY
 void SkRRect::computeType() const {
     SkDEBUGCODE(this->validate();)
 
     if (fRect.isEmpty()) {
         fType = kEmpty_Type;
         return;
     }
 
     bool allRadiiEqual = true; // are all x radii equal and all y radii?
@@ skipping 18 matching lines @@
     if (allRadiiEqual) {
         if (fRadii[0].fX >= SkScalarHalf(fRect.width()) &&
             fRadii[0].fY >= SkScalarHalf(fRect.height())) {
             fType = kOval_Type;
         } else {
             fType = kSimple_Type;
         }
         return;
     }
 
-    fType = kComplex_Type;
+    if (radii_are_nine_patch(fRadii)) {
+        fType = kNinePatch_Type;
+    } else {
+        fType = kComplex_Type;
+    }
 }
 
 static bool matrix_only_scale_and_translate(const SkMatrix& matrix) {
     const SkMatrix::TypeMask m = (SkMatrix::TypeMask) (SkMatrix::kAffine_Mask
                                     | SkMatrix::kPerspective_Mask);
     return (matrix.getType() & m) == 0;
 }
 
 bool SkRRect::transform(const SkMatrix& matrix, SkRRect* dst) const {
     if (NULL == dst) {
@@ skipping 132 matching lines @@
         }
 
         if (fRadii[i].fX != fRadii[i-1].fX || fRadii[i].fY != fRadii[i-1].fY) {
             allRadiiSame = false;
         }
 
         if (0 != fRadii[i].fX && 0 != fRadii[i].fY) {
             allCornersSquare = false;
         }
     }
+    bool patchesOfNine = radii_are_nine_patch(fRadii);
 
     switch (fType) {
         case kEmpty_Type:
             SkASSERT(fRect.isEmpty());
             SkASSERT(allRadiiZero && allRadiiSame && allCornersSquare);
 
             SkASSERT(0 == fRect.fLeft && 0 == fRect.fTop &&
                      0 == fRect.fRight && 0 == fRect.fBottom);
             break;
         case kRect_Type:
             SkASSERT(!fRect.isEmpty());
             SkASSERT(allRadiiZero && allRadiiSame && allCornersSquare);
             break;
         case kOval_Type:
             SkASSERT(!fRect.isEmpty());
             SkASSERT(!allRadiiZero && allRadiiSame && !allCornersSquare);
 
             for (int i = 0; i < 4; ++i) {
                 SkASSERT(SkScalarNearlyEqual(fRadii[i].fX, SkScalarHalf(fRect.width())));
                 SkASSERT(SkScalarNearlyEqual(fRadii[i].fY, SkScalarHalf(fRect.height())));
             }
             break;
         case kSimple_Type:
             SkASSERT(!fRect.isEmpty());
             SkASSERT(!allRadiiZero && allRadiiSame && !allCornersSquare);
             break;
+        case kNinePatch_Type:
+            SkASSERT(!fRect.isEmpty());
+            SkASSERT(!allRadiiZero && !allRadiiSame && !allCornersSquare);
+            SkASSERT(patchesOfNine);
+            break;
         case kComplex_Type:
             SkASSERT(!fRect.isEmpty());
             SkASSERT(!allRadiiZero && !allRadiiSame && !allCornersSquare);
+            SkASSERT(!patchesOfNine);
             break;
         case kUnknown_Type:
             // no limits on this
             break;
     }
 }
 #endif // SK_DEBUG
 
 ///////////////////////////////////////////////////////////////////////////////