Initial implementation of GPU no filter NinePatch

TBR=bsalomon@google.com
BUG=skia:

Review URL: https://codereview.chromium.org/1454933002

1 files changed, 21 insertions, 0 deletions

diff --git a/include/gpu/GrDrawContext.h b/include/gpu/GrDrawContext.h
index d55818b6d7..f051ebd994 100644
--- a/include/gpu/GrDrawContext.h
+++ b/include/gpu/GrDrawContext.h
@@ -242,6 +242,27 @@ public:
                   const SkRect& oval,
                   const GrStrokeInfo& strokeInfo);
 
+    /**
+     *  Draw the image stretched differentially to fit into dst.
+     *  center is a rect within the image, and logically divides the image
+     *  into 9 sections (3x3). For example, if the middle pixel of a [5x5]
+     *  image is the "center", then the center-rect should be [2, 2, 3, 3].
+     *
+     *  If the dst is >= the image size, then...
+     *  - The 4 corners are not stretched at all.
+     *  - The sides are stretched in only one axis.
+     *  - The center is stretched in both axes.
+     * Else, for each axis where dst < image,
+     *  - The corners shrink proportionally
+     *  - The sides (along the shrink axis) and center are not drawn
+     */
+    void drawImageNine(const GrClip&,
+                       const GrPaint& paint,
+                       const SkMatrix& viewMatrix,
+                       int imageWidth,
+                       int imageHeight,
+                       const SkIRect& center,
+                       const SkRect& dst);
 
     /**
      * Draws a batch