'F' will toggle filtering for the --picture sample

samplecode/SamplePictFile.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "DecodeFile.h"
 #include "SampleCode.h"
 #include "SkDumpCanvas.h"
@@ skipping 37 matching lines @@
     PictFileView(const char name[] = nullptr)
         : fFilename(name)
         , fBBox(kNo_BBoxType)
         , fTileSize(SkSize::Make(0, 0)) {
         for (int i = 0; i < kBBoxTypeCount; ++i) {
             fPictures[i] = nullptr;
         }
         fCount = 0;
     }
 
-    virtual ~PictFileView() {
+    ~PictFileView() override {
+        this->freePictures();
+    }
+    
+    void freePictures() {
         for (int i = 0; i < kBBoxTypeCount; ++i) {
             SkSafeUnref(fPictures[i]);
+            fPictures[i] = nullptr;
         }
     }
 
     void onTileSizeChanged(const SkSize &tileSize) override {
         if (tileSize != fTileSize) {
             fTileSize = tileSize;
         }
     }
 
 protected:
@@ skipping 16 matching lines @@
             }
             SampleCode::TitleR(evt, name.c_str());
             return true;
         }
         SkUnichar uni;
         if (SampleCode::CharQ(*evt, &uni)) {
             switch (uni) {
                 case 'n': fCount += 1; this->inval(nullptr); return true;
                 case 'p': fCount -= 1; this->inval(nullptr); return true;
                 case 's': fCount =  0; this->inval(nullptr); return true;
+                case 'F':
+                    fFilterQuality = (kNone_SkFilterQuality == fFilterQuality) ?
+                                     kHigh_SkFilterQuality : kNone_SkFilterQuality;
+                    this->freePictures();
+                    this->inval(nullptr);
+                    return true;
                 default: break;
             }
         }
         return this->INHERITED::onQuery(evt);
     }
 
     bool onEvent(const SkEvent& evt) override {
         if (evt.isType("PictFileView::toggleBBox")) {
             fBBox = (BBoxType)((fBBox + 1) % kBBoxTypeCount);
             return true;
@@ skipping 34 matching lines @@
 
         kLast_BBoxType = kRTree_BBoxType,
     };
     static const int kBBoxTypeCount = kLast_BBoxType + 1;
 
     SkString    fFilename;
     SkPicture*  fPictures[kBBoxTypeCount];
     BBoxType    fBBox;
     SkSize      fTileSize;
     int         fCount;
+    SkFilterQuality fFilterQuality = kNone_SkFilterQuality;
 
     sk_sp<SkPicture> LoadPicture(const char path[], BBoxType bbox) {
         sk_sp<SkPicture> pic;
 
-        SkBitmap bm;
-        if (decode_file(path, &bm)) {
-            bm.setImmutable();
+        if (sk_sp<SkImage> img = decode_file(path)) {
             SkPictureRecorder recorder;
-            SkCanvas* can = recorder.beginRecording(SkIntToScalar(bm.width()),
-                                                    SkIntToScalar(bm.height()),
+            SkCanvas* can = recorder.beginRecording(SkIntToScalar(img->width()),
+                                                    SkIntToScalar(img->height()),
                                                     nullptr, 0);
-            can->drawBitmap(bm, 0, 0, nullptr);
+            SkPaint paint;
+            paint.setFilterQuality(fFilterQuality);
+            can->drawImage(img, 0, 0, &paint);
             pic = recorder.finishRecordingAsPicture();
         } else {
             SkFILEStream stream(path);
             if (stream.isValid()) {
                 pic = SkPicture::MakeFromStream(&stream);
             } else {
                 SkDebugf("coun't load picture at \"path\"\n", path);
             }
 
             if (false) { // re-record
@@ skipping 40 matching lines @@
 SampleView* CreateSamplePictFileView(const char filename[]) {
     return new PictFileView(filename);
 }
 
 //////////////////////////////////////////////////////////////////////////////
 
 #if 0
 static SkView* MyFactory() { return new PictFileView; }
 static SkViewRegister reg(MyFactory);
 #endif