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      1 /*
      2  * Copyright 2013 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 "SkBitmap.h"
     10 #include "SkCanvas.h"
     11 #include "SkColor.h"
     12 #include "SkShader.h"
     13 
     14 namespace skiagm {
     15 
     16 // This GM draws a 3x3 grid (with the center element excluded) of rectangles
     17 // filled with a bitmap shader. The bitmap shader is transformed so that the
     18 // pattern cell is at the center (excluded) region.
     19 //
     20 // In Repeat and Mirror mode, this tests that the bitmap shader still draws
     21 // even though the pattern cell is outside the clip.
     22 //
     23 // In Clamp mode, this tests that the clamp is handled properly. For PDF,
     24 // (and possibly other exported formats) this also "tests" that the image itself
     25 // is not stored (well, you'll need to open it up with an external tool to
     26 // verify that).
     27 
     28 static SkBitmap create_bitmap() {
     29     SkBitmap bmp;
     30     bmp.allocN32Pixels(2, 2);
     31     uint32_t* pixels = reinterpret_cast<uint32_t*>(bmp.getPixels());
     32     pixels[0] = SkPreMultiplyColor(SK_ColorRED);
     33     pixels[1] = SkPreMultiplyColor(SK_ColorGREEN);
     34     pixels[2] = SkPreMultiplyColor(SK_ColorBLACK);
     35     pixels[3] = SkPreMultiplyColor(SK_ColorBLUE);
     36 
     37     return bmp;
     38 }
     39 
     40 constexpr SkScalar RECT_SIZE = 64;
     41 constexpr SkScalar SLIDE_SIZE = 300;
     42 
     43 class ClippedBitmapShadersGM : public GM {
     44 public:
     45     ClippedBitmapShadersGM(SkShader::TileMode mode, bool hq=false)
     46     : fMode(mode), fHQ(hq) {
     47     }
     48 
     49 protected:
     50     SkShader::TileMode fMode;
     51     bool fHQ;
     52 
     53     virtual SkString onShortName() {
     54         SkString descriptor;
     55         switch (fMode) {
     56             case SkShader::kRepeat_TileMode:
     57                 descriptor = "tile";
     58             break;
     59             case SkShader::kMirror_TileMode:
     60                 descriptor = "mirror";
     61             break;
     62             case SkShader::kClamp_TileMode:
     63                 descriptor = "clamp";
     64             break;
     65             default:
     66                 SkASSERT(false);
     67         }
     68         descriptor.prepend("clipped-bitmap-shaders-");
     69         if (fHQ) {
     70             descriptor.append("-hq");
     71         }
     72         return descriptor;
     73     }
     74 
     75     virtual SkISize onISize() {
     76         return SkISize::Make(300, 300);
     77     }
     78 
     79     virtual void onDraw(SkCanvas* canvas) {
     80         SkBitmap bmp = create_bitmap();
     81         SkMatrix s;
     82         s.reset();
     83         s.setScale(8, 8);
     84         s.postTranslate(SLIDE_SIZE / 2, SLIDE_SIZE / 2);
     85         SkPaint paint;
     86         paint.setShader(SkShader::MakeBitmapShader(bmp, fMode, fMode, &s));
     87 
     88         if (fHQ) {
     89             paint.setFilterQuality(kHigh_SkFilterQuality);
     90         }
     91 
     92         SkScalar margin = (SLIDE_SIZE / 3 - RECT_SIZE) / 2;
     93         for (int i = 0; i < 3; i++) {
     94             SkScalar yOrigin = SLIDE_SIZE / 3 * i + margin;
     95             for (int j = 0; j < 3; j++) {
     96                 SkScalar xOrigin = SLIDE_SIZE / 3 * j + margin;
     97                 if (i == 1 && j == 1) {
     98                     continue;   // skip center element
     99                 }
    100                 SkRect rect = SkRect::MakeXYWH(xOrigin, yOrigin,
    101                                                RECT_SIZE, RECT_SIZE);
    102                 canvas->save();
    103                 canvas->clipRect(rect);
    104                 canvas->drawRect(rect, paint);
    105                 canvas->restore();
    106             }
    107         }
    108     }
    109 
    110 private:
    111     typedef GM INHERITED;
    112 };
    113 
    114 //////////////////////////////////////////////////////////////////////////////
    115 
    116 DEF_GM( return new ClippedBitmapShadersGM(SkShader::kRepeat_TileMode); )
    117 DEF_GM( return new ClippedBitmapShadersGM(SkShader::kMirror_TileMode); )
    118 DEF_GM( return new ClippedBitmapShadersGM(SkShader::kClamp_TileMode); )
    119 
    120 DEF_GM( return new ClippedBitmapShadersGM(SkShader::kRepeat_TileMode, true); )
    121 DEF_GM( return new ClippedBitmapShadersGM(SkShader::kMirror_TileMode, true); )
    122 DEF_GM( return new ClippedBitmapShadersGM(SkShader::kClamp_TileMode, true); )
    123 
    124 
    125 }
    126