text: /*
   * Copyright 2011 Google Inc.
   *
   * Use of this source code is governed by a BSD-style license that can be
   * found in the LICENSE file.
   */
  #include "gm.h"
  #include "sk_tool_utils.h"
  #include "SkCanvas.h"
  #include "SkGradientShader.h"
  #include "SkPath.h"
  
  static void makebm(SkBitmap* bm, int w, int h) {
      bm->allocN32Pixels(w, h);
      bm->eraseColor(SK_ColorTRANSPARENT);
  
      SkCanvas    canvas(*bm);
      SkScalar    s = SkIntToScalar(SkMin32(w, h));
      const SkPoint     kPts0[] = { { 0, 0 }, { s, s } };
      const SkPoint     kPts1[] = { { s, 0 }, { 0, s } };
      const SkScalar    kPos[] = { 0, SK_Scalar1/2, SK_Scalar1 };
      const SkColor kColors0[] = {0x40FF00FF, 0xF0FFFF00, 0x4000FFFF };
      const SkColor kColors1[] = {0xF0FF00FF, 0x80FFFF00, 0xF000FFFF };
  
  
      SkPaint     paint;
  
      paint.setShader(SkGradientShader::MakeLinear(kPts0, kColors0, kPos,
                      SK_ARRAY_COUNT(kColors0), SkShader::kClamp_TileMode));
      canvas.drawPaint(paint);
      paint.setShader(SkGradientShader::MakeLinear(kPts1, kColors1, kPos,
                      SK_ARRAY_COUNT(kColors1), SkShader::kClamp_TileMode));
      canvas.drawPaint(paint);
  }
  
  ///////////////////////////////////////////////////////////////////////////////
  
  struct LabeledMatrix {
      SkMatrix    fMatrix;
      const char* fLabel;
  };
  
  DEF_SIMPLE_GM_BG(shadertext2, canvas, 1800, 900,
                   sk_tool_utils::color_to_565(0xFFDDDDDD)) {
          constexpr char kText[] = "SKIA";
          constexpr int kTextLen = SK_ARRAY_COUNT(kText) - 1;
          constexpr int kPointSize = 55;
  
          SkTDArray<LabeledMatrix> matrices;
          matrices.append()->fMatrix.reset();
          matrices.top().fLabel = "Identity";
          matrices.append()->fMatrix.setScale(1.2f, 0.8f);
          matrices.top().fLabel = "Scale";
          matrices.append()->fMatrix.setRotate(10.f);
          matrices.top().fLabel = "Rotate";
          matrices.append()->fMatrix.reset();
          matrices.top().fMatrix.setPerspX(-0.0015f);
          matrices.top().fMatrix.setPerspY(+0.0015f);
          matrices.top().fLabel = "Persp";
  
          SkTDArray<LabeledMatrix> localMatrices;
          localMatrices.append()->fMatrix.reset();
          localMatrices.top().fLabel = "Identity";
          localMatrices.append()->fMatrix.setScale(2.5f, 0.2f);
          localMatrices.top().fLabel = "Scale";
          localMatrices.append()->fMatrix.setRotate(45.f);
          localMatrices.top().fLabel = "Rotate";
          localMatrices.append()->fMatrix.reset();
          localMatrices.top().fMatrix.setPerspX(-0.007f);
          localMatrices.top().fMatrix.setPerspY(+0.008f);
          localMatrices.top().fLabel = "Persp";
  
          static SkBitmap bmp;
          if (bmp.isNull()) {
              makebm(&bmp, kPointSize / 2, kPointSize / 2);
          }
  
          SkPaint fillPaint;
          fillPaint.setAntiAlias(true);
          sk_tool_utils::set_portable_typeface(&fillPaint);
          fillPaint.setTextSize(SkIntToScalar(kPointSize));
          fillPaint.setFilterQuality(kLow_SkFilterQuality);
  
          SkPaint outlinePaint;
          outlinePaint.setAntiAlias(true);
          sk_tool_utils::set_portable_typeface(&outlinePaint);
          outlinePaint.setTextSize(SkIntToScalar(kPointSize));
          outlinePaint.setStyle(SkPaint::kStroke_Style);
          outlinePaint.setStrokeWidth(0.f);
  
          SkScalar w = fillPaint.measureText(kText, kTextLen);
          static SkScalar kPadY = 0.5f * kPointSize;
          static SkScalar kPadX = 1.5f * kPointSize;
  
          SkPaint strokePaint(fillPaint);
          strokePaint.setStyle(SkPaint::kStroke_Style);
          strokePaint.setStrokeWidth(kPointSize * 0.1f);
  
          SkPaint labelPaint;
          labelPaint.setColor(0xff000000);
          labelPaint.setAntiAlias(true);
          sk_tool_utils::set_portable_typeface(&labelPaint);
          labelPaint.setTextSize(12.f);
  
          canvas->translate(15.f, 15.f);
          canvas->drawBitmap(bmp, 0, 0);
          canvas->translate(0, bmp.height() + labelPaint.getTextSize() + 15.f);
  
          constexpr char kLabelLabel[] = "localM / canvasM";
          canvas->drawString(kLabelLabel, 0, 0, labelPaint);
          canvas->translate(0, 15.f);
  
          canvas->save();
          SkScalar maxLabelW = 0;
          canvas->translate(0, kPadY / 2 + kPointSize);
          for (int lm = 0; lm < localMatrices.count(); ++lm) {
              canvas->drawString(matrices[lm].fLabel,
                               0, labelPaint.getTextSize() - 1, labelPaint);
              SkScalar labelW = labelPaint.measureText(matrices[lm].fLabel,
                                                       strlen(matrices[lm].fLabel));
              maxLabelW = SkMaxScalar(maxLabelW, labelW);
              canvas->translate(0.f, 2 * kPointSize + 2.5f * kPadY);
          }
          canvas->restore();
  
          canvas->translate(maxLabelW + kPadX / 2.f, 0.f);
  
          for (int s = 0; s < 2; ++s) {
              SkPaint& paint = s ? strokePaint : fillPaint;
  
              SkScalar columnH = 0;
              for (int m = 0; m < matrices.count(); ++m) {
                  columnH = 0;
                  canvas->save();
                  canvas->drawString(matrices[m].fLabel,
                                   0, labelPaint.getTextSize() - 1, labelPaint);
                  canvas->translate(0, kPadY / 2 + kPointSize);
                  columnH += kPadY / 2 + kPointSize;
                  for (int lm = 0; lm < localMatrices.count(); ++lm) {
                      paint.setShader(SkShader::MakeBitmapShader(bmp, SkShader::kMirror_TileMode,
                                                                 SkShader::kRepeat_TileMode,
                                                                 &localMatrices[lm].fMatrix));
  
                      canvas->save();
                          canvas->concat(matrices[m].fMatrix);
                          canvas->drawText(kText, kTextLen, 0, 0, paint);
                          canvas->drawText(kText, kTextLen, 0, 0, outlinePaint);
                      canvas->restore();
  
                      SkPath path;
                      path.arcTo(SkRect::MakeXYWH(-0.1f * w, 0.f,
                                                  1.2f * w, 2.f * kPointSize),
                                                  225.f, 359.f,
                                                  false);
                      path.close();
  
                      canvas->translate(0.f, kPointSize + kPadY);
                      columnH += kPointSize + kPadY;
  
                      canvas->save();
                          canvas->concat(matrices[m].fMatrix);
                          canvas->drawTextOnPath(kText, kTextLen, path, nullptr, paint);
                          canvas->drawTextOnPath(kText, kTextLen, path, nullptr, outlinePaint);
                      canvas->restore();
                      SkPaint stroke;
                      stroke.setStyle(SkPaint::kStroke_Style);
                      canvas->translate(0.f, kPointSize + kPadY);
                      columnH += kPointSize + kPadY;
                  }
                  canvas->restore();
                  canvas->translate(w + kPadX, 0.f);
              }
              if (0 == s) {
                  canvas->drawLine(0.f, -kPadY, 0.f, columnH + kPadY, outlinePaint);
                  canvas->translate(kPadX / 2, 0.f);
                  constexpr char kFillLabel[] = "Filled";
                  constexpr char kStrokeLabel[] = "Stroked";
                  SkScalar y = columnH + kPadY / 2;
                  SkScalar fillX = -outlinePaint.measureText(kFillLabel, strlen(kFillLabel)) - kPadX;
                  SkScalar strokeX = kPadX;
                  canvas->drawString(kFillLabel, fillX, y, labelPaint);
                  canvas->drawString(kStrokeLabel, strokeX, y, labelPaint);
              }
          }
  }
  