samplecode/SampleIdentityScale.cpp

   1 /*
   2  * Copyright 2014 Google Inc.
   3  *
   4  * Use of this source code is governed by a BSD-style license that can be
   5  * found in the LICENSE file.
   6  */
   7
   8 #include "gm.h"
   9
  10 #include "Resources.h"
  11 #include "SampleCode.h"
  12 #include "SkBlurMaskFilter.h"
  13 #include "SkCanvas.h"
  14 #include "SkColorPriv.h"
  15 #include "SkImageDecoder.h"
  16 #include "SkRandom.h"
  17 #include "SkStream.h"
  18 #include "SkTime.h"
  19
  20 // Intended to exercise pixel snapping observed with scaled images (and
  21 // with non-scaled images, but for a different reason):  Bug 1145
  22
  23 class IdentityScaleView : public SampleView {
  24 public:
  25     IdentityScaleView(const char imageFilename[]) {
  26       SkString resourcePath = GetResourcePath(imageFilename);
  27       SkImageDecoder* codec = NULL;
  28       SkFILEStream stream(resourcePath.c_str());
  29       if (stream.isValid()) {
  30           codec = SkImageDecoder::Factory(&stream);
  31       }
  32       if (codec) {
  33           stream.rewind();
  34           codec->decode(&stream, &fBM, kN32_SkColorType, SkImageDecoder::kDecodePixels_Mode);
  35           SkDELETE(codec);
  36       } else {
  37           fBM.allocN32Pixels(1, 1);
  38           *(fBM.getAddr32(0,0)) = 0xFF0000FF; // red == bad
  39       }
  40     }
  41
  42 protected:
  43     SkBitmap fBM;
  44
  45     // overrides from SkEventSink
  46     bool onQuery(SkEvent* evt) SK_OVERRIDE {
  47         if (SampleCode::TitleQ(*evt)) {
  48             SampleCode::TitleR(evt, "IdentityScale");
  49             return true;
  50         }
  51         return this->INHERITED::onQuery(evt);
  52     }
  53
  54     void onDrawContent(SkCanvas* canvas) SK_OVERRIDE {
  55
  56         SkPaint paint;
  57
  58         paint.setAntiAlias(true);
  59         paint.setTextSize(48);
  60         paint.setFilterQuality(kHigh_SkFilterQuality);
  61
  62         SkTime::DateTime time;
  63         SkTime::GetDateTime(&time);
  64
  65         bool use_scale = (time.fSecond % 2 == 1);
  66         const char *text;
  67
  68         canvas->save();
  69         if (use_scale) {
  70           text = "Scaled = 1";
  71         } else {
  72
  73           SkRect r = { 100, 100, 356, 356 };
  74           SkPath clipPath;
  75           clipPath.addRoundRect(r, SkIntToScalar(5), SkIntToScalar(5));
  76           canvas->clipPath(clipPath, SkRegion::kIntersect_Op, SkToBool(1));
  77           text = "Scaled = 0";
  78         }
  79         canvas->drawBitmap( fBM, 100, 100, &paint );
  80         canvas->restore();
  81         canvas->drawText( text, strlen(text), 100, 400, paint );
  82         this->inval(NULL);
  83     }
  84
  85 private:
  86     typedef SampleView INHERITED;
  87 };
  88
  89 //////////////////////////////////////////////////////////////////////////////
  90
  91 static SkView* MyFactory() { return new IdentityScaleView("mandrill_256.png"); }
  92 static SkViewRegister reg(MyFactory);