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      1 /*
      2  * Copyright 2015 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 #include "SkCanvas.h"
     10 #include "SkRSXform.h"
     11 #include "SkSurface.h"
     12 
     13 class DrawAtlasGM : public skiagm::GM {
     14     static SkImage* MakeAtlas(SkCanvas* caller, const SkRect& target) {
     15         SkImageInfo info = SkImageInfo::MakeN32Premul(100, 100);
     16         SkAutoTUnref<SkSurface> surface(caller->newSurface(info));
     17         if (nullptr == surface) {
     18             surface.reset(SkSurface::NewRaster(info));
     19         }
     20         SkCanvas* canvas = surface->getCanvas();
     21         // draw red everywhere, but we don't expect to see it in the draw, testing the notion
     22         // that drawAtlas draws a subset-region of the atlas.
     23         canvas->clear(SK_ColorRED);
     24 
     25         SkPaint paint;
     26         paint.setXfermodeMode(SkXfermode::kClear_Mode);
     27         SkRect r(target);
     28         r.inset(-1, -1);
     29         // zero out a place (with a 1-pixel border) to land our drawing.
     30         canvas->drawRect(r, paint);
     31         paint.setXfermode(nullptr);
     32         paint.setColor(SK_ColorBLUE);
     33         paint.setAntiAlias(true);
     34         canvas->drawOval(target, paint);
     35         return surface->newImageSnapshot();
     36     }
     37 
     38     SkAutoTUnref<SkImage> fAtlas;
     39 
     40 public:
     41     DrawAtlasGM() {}
     42 
     43 protected:
     44 
     45     SkString onShortName() override {
     46         return SkString("draw-atlas");
     47     }
     48 
     49     SkISize onISize() override {
     50         return SkISize::Make(640, 480);
     51     }
     52 
     53     void onDraw(SkCanvas* canvas) override {
     54         const SkRect target = { 50, 50, 80, 90 };
     55         if (nullptr == fAtlas) {
     56             fAtlas.reset(MakeAtlas(canvas, target));
     57         }
     58 
     59         const struct {
     60             SkScalar fScale;
     61             SkScalar fDegrees;
     62             SkScalar fTx;
     63             SkScalar fTy;
     64 
     65             void apply(SkRSXform* xform) const {
     66                 const SkScalar rad = SkDegreesToRadians(fDegrees);
     67                 xform->fSCos = fScale * SkScalarCos(rad);
     68                 xform->fSSin = fScale * SkScalarSin(rad);
     69                 xform->fTx   = fTx;
     70                 xform->fTy   = fTy;
     71             }
     72         } rec[] = {
     73             { 1, 0, 10, 10 },       // just translate
     74             { 2, 0, 110, 10 },      // scale + translate
     75             { 1, 30, 210, 10 },     // rotate + translate
     76             { 2, -30, 310, 30 },    // scale + rotate + translate
     77         };
     78 
     79         const int N = SK_ARRAY_COUNT(rec);
     80         SkRSXform xform[N];
     81         SkRect tex[N];
     82         SkColor colors[N];
     83 
     84         for (int i = 0; i < N; ++i) {
     85             rec[i].apply(&xform[i]);
     86             tex[i] = target;
     87             colors[i] = 0x80FF0000 + (i * 40 * 256);
     88         }
     89 
     90         SkPaint paint;
     91         paint.setFilterQuality(kLow_SkFilterQuality);
     92         paint.setAntiAlias(true);
     93 
     94         canvas->drawAtlas(fAtlas, xform, tex, N, nullptr, &paint);
     95         canvas->translate(0, 100);
     96         canvas->drawAtlas(fAtlas, xform, tex, colors, N, SkXfermode::kSrcIn_Mode, nullptr, &paint);
     97     }
     98 
     99 private:
    100     typedef GM INHERITED;
    101 };
    102 DEF_GM( return new DrawAtlasGM; )
    103 
    104