text: /*
   * Copyright 2019 Google LLC
   *
   * Use of this source code is governed by a BSD-style license that can be
   * found in the LICENSE file.
   */
  
  #include "gm/gm.h"
  #include "include/core/SkCanvas.h"
  #include "include/core/SkData.h"
  #include "include/core/SkPaint.h"
  #include "include/core/SkShader.h"
  #include "include/core/SkSize.h"
  #include "include/core/SkString.h"
  #include "include/effects/SkRuntimeEffect.h"
  
  static const char* RUNTIME_FUNCTIONS_SRC = R"(
      uniform half4 gColor;
  
      half scale(float x) {
          return x / 255;
      }
  
      half4 blackAndWhite(half4 raw) {
          half value = raw.r * 0.22 + raw.g * 0.67 + raw.b * 0.11;
          return half4(value.xxx, raw.a);
      }
  
      half4 main(float2 p) {
          return blackAndWhite(half4(scale(p.x), scale(p.y), gColor.b, 1));
      }
  )";
  
  class RuntimeFunctions : public skiagm::GM {
      bool runAsBench() const override { return true; }
  
      SkString onShortName() override { return SkString("runtimefunctions"); }
  
      SkISize onISize() override { return {256, 256}; }
  
      void onDraw(SkCanvas* canvas) override {
          sk_sp<SkRuntimeEffect> gEffect =
                  SkRuntimeEffect::Make(SkString(RUNTIME_FUNCTIONS_SRC)).effect;
          SkASSERT(gEffect);
  
          SkMatrix localM;
          localM.setRotate(90, 128, 128);
  
          SkColor4f inputColor = { 1, 0, 0, 1 };
          auto shader = gEffect->makeShader(SkData::MakeWithCopy(&inputColor, sizeof(inputColor)),
                                            nullptr, 0, &localM, true);
          SkPaint p;
          p.setShader(std::move(shader));
          canvas->drawRect({0, 0, 256, 256}, p);
      }
  };
  
  DEF_GM(return new RuntimeFunctions;)
  