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 "sk_tool_utils.h"
  15 #include "SkCanvas.h"
  16 #include "SkSurface.h"
  17 #include "SkTextBlob.h"
  18
  19 namespace skiagm {
  20
  21 constexpr int kWidth = 750;
  22 constexpr int kHeight = 750;
  23
  24 class LcdOverlapGM : public skiagm::GM {
  25 public:
  26     LcdOverlapGM() {
  27         const int kPointSize = 25;
  28         fTextHeight = SkIntToScalar(kPointSize);
  29     }
  30
  31 protected:
  32     SkString onShortName() override {
  33         return SkString("lcdoverlap");
  34     }
  35
  36     void onOnceBeforeDraw() override {
  37         // build text blob
  38         SkTextBlobBuilder builder;
  39
  40         SkPaint paint;
  41         sk_tool_utils::set_portable_typeface(&paint);
  42         paint.setTextSize(32);
  43         const char* text = "able was I ere I saw elba";
  44         paint.setAntiAlias(true);
  45         paint.setSubpixelText(true);
  46         paint.setLCDRenderText(true);
  47         sk_tool_utils::add_to_text_blob(&builder, text, paint, 0, 0);
  48         fBlob = builder.make();
  49     }
  50
  51     SkISize onISize() override { return SkISize::Make(kWidth, kHeight); }
  52
  53     void drawTestCase(SkCanvas* canvas, SkScalar x, SkScalar y, SkBlendMode mode,
  54                       SkBlendMode mode2) {
  55         const SkColor colors[] {
  56                 SK_ColorRED,
  57                 SK_ColorGREEN,
  58                 SK_ColorBLUE,
  59                 SK_ColorYELLOW,
  60                 SK_ColorCYAN,
  61                 SK_ColorMAGENTA,
  62         };
  63
  64         for (size_t i = 0; i < SK_ARRAY_COUNT(colors); i++) {
  65             canvas->save();
  66             canvas->translate(x, y);
  67             canvas->rotate(360.0f / SK_ARRAY_COUNT(colors) * i);
  68             canvas->translate(-fBlob->bounds().width() / 2.0f + 0.5f, 0);
  69
  70             SkPaint textPaint;
  71             textPaint.setColor(colors[i]);
  72             textPaint.setBlendMode(i % 2 == 0 ? mode : mode2);
  73             canvas->drawTextBlob(fBlob, 0, 0, textPaint);
  74             canvas->restore();
  75         }
  76     }
  77
  78     void onDraw(SkCanvas* canvas) override {
  79         SkScalar offsetX = kWidth / 4.0f;
  80         SkScalar offsetY = kHeight / 4.0f;
  81         drawTestCase(canvas, offsetX, offsetY,  SkBlendMode::kSrc, SkBlendMode::kSrc);
  82         drawTestCase(canvas, 3 * offsetX, offsetY,  SkBlendMode::kSrcOver, SkBlendMode::kSrcOver);
  83         drawTestCase(canvas, offsetX, 3 * offsetY,  SkBlendMode::kHardLight,
  84                      SkBlendMode::kLuminosity);
  85         drawTestCase(canvas, 3 * offsetX, 3 * offsetY,  SkBlendMode::kSrcOver, SkBlendMode::kSrc);
  86     }
  87
  88 private:
  89     SkScalar fTextHeight;
  90     sk_sp<SkTextBlob> fBlob;
  91     typedef skiagm::GM INHERITED;
  92 };
  93
  94 //////////////////////////////////////////////////////////////////////////////
  95
  96 DEF_GM( return new LcdOverlapGM; )
  97 }