Fix SkTileImageFilter when srcRect is a superset of bitmap bounds.

If the input bitmap passed to SkTileImageFilter does not fill the
srcRect, we were tiling this incorrectly (see the first sample
from tileimage filter -- it draws from a srcRect of 12,12 50x50
to a dstRect of 0,0 50x50. There should be no tiling at all
in this case!)

In order to fix this, we need to pad the bitmap out to srcRect,
and tile with that. In order to tile correctly in the GPU case,
we need to request a tileable texture.

NOTE: this will change the results of the tileimagefilter GM (correctness,
and added src / dest rects).

BUG=skia:4774
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1570133003

Review URL: https://codereview.chromium.org/1570133003

1 files changed, 10 insertions, 0 deletions

diff --git a/gm/tileimagefilter.cpp b/gm/tileimagefilter.cpp
index 10086c9c17..eb0ad09f4b 100644
--- a/gm/tileimagefilter.cpp
+++ b/gm/tileimagefilter.cpp
@@ -47,6 +47,12 @@ protected:
 
     void onDraw(SkCanvas* canvas) override {
         canvas->clear(SK_ColorBLACK);
+        SkPaint red;
+        red.setColor(SK_ColorRED);
+        red.setStyle(SkPaint::kStroke_Style);
+        SkPaint blue;
+        blue.setColor(SK_ColorBLUE);
+        blue.setStyle(SkPaint::kStroke_Style);
 
         int x = 0, y = 0;
         for (size_t i = 0; i < 4; i++) {
@@ -67,6 +73,8 @@ protected:
             SkPaint paint;
             paint.setImageFilter(filter);
             canvas->drawImage(fBitmap, 0, 0, &paint);
+            canvas->drawRect(srcRect, red);
+            canvas->drawRect(dstRect, blue);
             canvas->restore();
             x += image->width() + MARGIN;
             if (x + image->width() > WIDTH) {
@@ -96,6 +104,8 @@ protected:
         canvas->saveLayer(&dstRect, &paint);
         canvas->drawImage(fBitmap, 0, 0);
         canvas->restore();
+        canvas->drawRect(srcRect, red);
+        canvas->drawRect(dstRect, blue);
         canvas->restore();
     }
 private: