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      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 "SkCanvas.h"
     11 #include "SkGradientShader.h"
     12 #include "SkPoint.h"
     13 #include "SkShader.h"
     14 #include "SkTextBlob.h"
     15 #include "SkTDArray.h"
     16 #include "SkTypeface.h"
     17 
     18 // This GM exercises drawTextBlob offset vs. shader space behavior.
     19 class TextBlobShaderGM : public skiagm::GM {
     20 public:
     21     TextBlobShaderGM(const char* txt) {
     22         SkPaint p;
     23         size_t txtLen = strlen(txt);
     24         fGlyphs.append(p.textToGlyphs(txt, txtLen, NULL));
     25         p.textToGlyphs(txt, txtLen, fGlyphs.begin());
     26     }
     27 
     28 protected:
     29 
     30     void onOnceBeforeDraw() override {
     31         SkPaint p;
     32         p.setAntiAlias(true);
     33         p.setSubpixelText(true);
     34         p.setTextSize(30);
     35         p.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
     36 
     37         SkTextBlobBuilder builder;
     38         int glyphCount = fGlyphs.count();
     39         const SkTextBlobBuilder::RunBuffer* run;
     40 
     41         run = &builder.allocRun(p, glyphCount, 10, 10, NULL);
     42         memcpy(run->glyphs, fGlyphs.begin(), glyphCount * sizeof(uint16_t));
     43 
     44         run = &builder.allocRunPosH(p, glyphCount,  80, NULL);
     45         memcpy(run->glyphs, fGlyphs.begin(), glyphCount * sizeof(uint16_t));
     46         for (int i = 0; i < glyphCount; ++i) {
     47             run->pos[i] = p.getTextSize() * i * .75f;
     48         }
     49 
     50         run = &builder.allocRunPos(p, glyphCount, NULL);
     51         memcpy(run->glyphs, fGlyphs.begin(), glyphCount * sizeof(uint16_t));
     52         for (int i = 0; i < glyphCount; ++i) {
     53             run->pos[i * 2] = p.getTextSize() * i * .75f;
     54             run->pos[i * 2 + 1] = 150 + 5 * sinf((float)i * 8 / glyphCount);
     55         }
     56 
     57         fBlob.reset(builder.build());
     58 
     59         SkColor  colors[2];
     60         colors[0] = SK_ColorRED;
     61         colors[1] = SK_ColorGREEN;
     62 
     63         SkScalar pos[SK_ARRAY_COUNT(colors)];
     64         for (unsigned i = 0; i < SK_ARRAY_COUNT(pos); ++i) {
     65             pos[i] = (float)i / (SK_ARRAY_COUNT(pos) - 1);
     66         }
     67 
     68         SkISize sz = this->onISize();
     69         fShader.reset(SkGradientShader::CreateRadial(SkPoint::Make(SkIntToScalar(sz.width() / 2),
     70                                                                    SkIntToScalar(sz.height() / 2)),
     71                                                      sz.width() * .66f, colors, pos,
     72                                                      SK_ARRAY_COUNT(colors),
     73                                                      SkShader::kRepeat_TileMode));
     74     }
     75 
     76     SkString onShortName() override {
     77         return SkString("textblobshader");
     78     }
     79 
     80     SkISize onISize() override {
     81         return SkISize::Make(640, 480);
     82     }
     83 
     84     void onDraw(SkCanvas* canvas) override {
     85         SkPaint p;
     86         p.setStyle(SkPaint::kFill_Style);
     87         p.setShader(fShader);
     88 
     89         SkISize sz = this->onISize();
     90         static const int kXCount = 4;
     91         static const int kYCount = 3;
     92         for (int i = 0; i < kXCount; ++i) {
     93             for (int j = 0; j < kYCount; ++j) {
     94                 canvas->drawTextBlob(fBlob,
     95                                      SkIntToScalar(i * sz.width() / kXCount),
     96                                      SkIntToScalar(j * sz.height() / kYCount),
     97                                      p);
     98             }
     99         }
    100     }
    101 
    102 private:
    103     SkTDArray<uint16_t>            fGlyphs;
    104     SkAutoTUnref<const SkTextBlob> fBlob;
    105     SkAutoTUnref<SkShader>         fShader;
    106 
    107     typedef skiagm::GM INHERITED;
    108 };
    109 
    110 DEF_GM( return SkNEW_ARGS(TextBlobShaderGM, ("Blobber")); )
    111