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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         sk_tool_utils::set_portable_typeface(&p);
     24         size_t txtLen = strlen(txt);
     25         fGlyphs.append(p.textToGlyphs(txt, txtLen, nullptr));
     26         p.textToGlyphs(txt, txtLen, fGlyphs.begin());
     27     }
     28 
     29 protected:
     30 
     31     void onOnceBeforeDraw() override {
     32         SkPaint p;
     33         p.setAntiAlias(true);
     34         p.setSubpixelText(true);
     35         p.setTextSize(30);
     36         p.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
     37         sk_tool_utils::set_portable_typeface(&p);
     38 
     39         SkTextBlobBuilder builder;
     40         int glyphCount = fGlyphs.count();
     41         const SkTextBlobBuilder::RunBuffer* run;
     42 
     43         run = &builder.allocRun(p, glyphCount, 10, 10, nullptr);
     44         memcpy(run->glyphs, fGlyphs.begin(), glyphCount * sizeof(uint16_t));
     45 
     46         run = &builder.allocRunPosH(p, glyphCount,  80, nullptr);
     47         memcpy(run->glyphs, fGlyphs.begin(), glyphCount * sizeof(uint16_t));
     48         for (int i = 0; i < glyphCount; ++i) {
     49             run->pos[i] = p.getTextSize() * i * .75f;
     50         }
     51 
     52         run = &builder.allocRunPos(p, glyphCount, nullptr);
     53         memcpy(run->glyphs, fGlyphs.begin(), glyphCount * sizeof(uint16_t));
     54         for (int i = 0; i < glyphCount; ++i) {
     55             run->pos[i * 2] = p.getTextSize() * i * .75f;
     56             run->pos[i * 2 + 1] = 150 + 5 * sinf((float)i * 8 / glyphCount);
     57         }
     58 
     59         fBlob.reset(builder.build());
     60 
     61         SkColor  colors[2];
     62         colors[0] = SK_ColorRED;
     63         colors[1] = SK_ColorGREEN;
     64 
     65         SkScalar pos[SK_ARRAY_COUNT(colors)];
     66         for (unsigned i = 0; i < SK_ARRAY_COUNT(pos); ++i) {
     67             pos[i] = (float)i / (SK_ARRAY_COUNT(pos) - 1);
     68         }
     69 
     70         SkISize sz = this->onISize();
     71         fShader.reset(SkGradientShader::CreateRadial(SkPoint::Make(SkIntToScalar(sz.width() / 2),
     72                                                                    SkIntToScalar(sz.height() / 2)),
     73                                                      sz.width() * .66f, colors, pos,
     74                                                      SK_ARRAY_COUNT(colors),
     75                                                      SkShader::kRepeat_TileMode));
     76     }
     77 
     78     SkString onShortName() override {
     79         return SkString("textblobshader");
     80     }
     81 
     82     SkISize onISize() override {
     83         return SkISize::Make(640, 480);
     84     }
     85 
     86     void onDraw(SkCanvas* canvas) override {
     87         SkPaint p;
     88         p.setStyle(SkPaint::kFill_Style);
     89         p.setShader(fShader);
     90 
     91         SkISize sz = this->onISize();
     92         static const int kXCount = 4;
     93         static const int kYCount = 3;
     94         for (int i = 0; i < kXCount; ++i) {
     95             for (int j = 0; j < kYCount; ++j) {
     96                 canvas->drawTextBlob(fBlob,
     97                                      SkIntToScalar(i * sz.width() / kXCount),
     98                                      SkIntToScalar(j * sz.height() / kYCount),
     99                                      p);
    100             }
    101         }
    102     }
    103 
    104 private:
    105     SkTDArray<uint16_t>            fGlyphs;
    106     SkAutoTUnref<const SkTextBlob> fBlob;
    107     SkAutoTUnref<SkShader>         fShader;
    108 
    109     typedef skiagm::GM INHERITED;
    110 };
    111 
    112 DEF_GM(return new TextBlobShaderGM("Blobber");)
    113