gm/lcdoverlap.cpp

   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
   9 /*
  10  * Tests overlapping LCD text
  11  */
  12
  13 #include "gm.h"
  14 #include "SkCanvas.h"
  15 #include "SkSurface.h"
  16 #include "SkTextBlob.h"
  17
  18 namespace skiagm {
  19
  20 constexpr int kWidth = 750;
  21 constexpr int kHeight = 750;
  22
  23 class LcdOverlapGM : public skiagm::GM {
  24 public:
  25     LcdOverlapGM() {
  26         const int kPointSize = 25;
  27         fTextHeight = SkIntToScalar(kPointSize);
  28     }
  29
  30 protected:
  31     SkString onShortName() override {
  32         return SkString("lcdoverlap");
  33     }
  34
  35     void onOnceBeforeDraw() override {
  36         // build text blob
  37         SkTextBlobBuilder builder;
  38
  39         SkPaint paint;
  40         sk_tool_utils::set_portable_typeface(&paint);
  41         paint.setTextSize(32);
  42         const char* text = "able was I ere I saw elba";
  43         paint.setAntiAlias(true);
  44         paint.setSubpixelText(true);
  45         paint.setLCDRenderText(true);
  46         sk_tool_utils::add_to_text_blob(&builder, text, paint, 0, 0);
  47         fBlob = builder.make();
  48     }
  49
  50     SkISize onISize() override { return SkISize::Make(kWidth, kHeight); }
  51
  52     void drawTestCase(SkCanvas* canvas, SkScalar x, SkScalar y, SkBlendMode mode,
  53                       SkBlendMode mode2) {
  54         const SkColor colors[] {
  55                 SK_ColorRED,
  56                 SK_ColorGREEN,
  57                 SK_ColorBLUE,
  58                 SK_ColorYELLOW,
  59                 SK_ColorCYAN,
  60                 SK_ColorMAGENTA,
  61         };
  62
  63         for (size_t i = 0; i < SK_ARRAY_COUNT(colors); i++) {
  64             canvas->save();
  65             canvas->translate(x, y);
  66             canvas->rotate(360.0f / SK_ARRAY_COUNT(colors) * i);
  67             canvas->translate(-fBlob->bounds().width() / 2.0f + 0.5f, 0);
  68
  69             SkPaint textPaint;
  70             textPaint.setColor(colors[i]);
  71             textPaint.setBlendMode(i % 2 == 0 ? mode : mode2);
  72             canvas->drawTextBlob(fBlob, 0, 0, textPaint);
  73             canvas->restore();
  74         }
  75     }
  76
  77     void onDraw(SkCanvas* canvas) override {
  78         SkScalar offsetX = kWidth / 4.0f;
  79         SkScalar offsetY = kHeight / 4.0f;
  80         drawTestCase(canvas, offsetX, offsetY,  SkBlendMode::kSrc, SkBlendMode::kSrc);
  81         drawTestCase(canvas, 3 * offsetX, offsetY,  SkBlendMode::kSrcOver, SkBlendMode::kSrcOver);
  82         drawTestCase(canvas, offsetX, 3 * offsetY,  SkBlendMode::kHardLight,
  83                      SkBlendMode::kLuminosity);
  84         drawTestCase(canvas, 3 * offsetX, 3 * offsetY,  SkBlendMode::kSrcOver, SkBlendMode::kSrc);
  85     }
  86
  87 private:
  88     SkScalar fTextHeight;
  89     sk_sp<SkTextBlob> fBlob;
  90     typedef skiagm::GM INHERITED;
  91 };
  92
  93 //////////////////////////////////////////////////////////////////////////////
  94
  95 DEF_GM( return new LcdOverlapGM; )
  96 }