// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <stdio.h>
#include <cmath>
#include <string>
#include <vector>

#include <GLES2/gl2.h>
#include <GLES2/gl2ext.h>
#include <GLES2/gl2extchromium.h>

#include "base/at_exit.h"
#include "base/bind.h"
#include "base/command_line.h"
#include "base/debug/trace_event.h"
#include "base/file_util.h"
#include "base/json/json_reader.h"
#include "base/message_loop/message_loop.h"
#include "base/run_loop.h"
#include "base/strings/stringprintf.h"
#include "base/synchronization/waitable_event.h"
#include "base/time/time.h"
#include "content/common/gpu/client/gl_helper.h"
#include "content/common/gpu/client/gl_helper_scaling.h"
#include "content/public/test/unittest_test_suite.h"
#include "content/test/content_test_suite.h"
#include "gpu/config/gpu_util.h"
#include "media/base/video_frame.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "third_party/skia/include/core/SkBitmap.h"
#include "third_party/skia/include/core/SkTypes.h"
#include "ui/gl/gl_surface.h"
#include "webkit/common/gpu/webgraphicscontext3d_in_process_command_buffer_impl.h"

#if defined(OS_MACOSX)
#include "base/mac/scoped_nsautorelease_pool.h"
#endif

#if defined(TOOLKIT_GTK)
#include "ui/gfx/gtk_util.h"
#endif

namespace content {

using blink::WebGLId;
using blink::WebGraphicsContext3D;
using webkit::gpu::WebGraphicsContext3DInProcessCommandBufferImpl;

content::GLHelper::ScalerQuality kQualities[] = {
  content::GLHelper::SCALER_QUALITY_BEST,
  content::GLHelper::SCALER_QUALITY_GOOD,
  content::GLHelper::SCALER_QUALITY_FAST,
};

const char *kQualityNames[] = {
  "best",
  "good",
  "fast",
};

class GLHelperTest : public testing::Test {
 protected:
  virtual void SetUp() {
    WebGraphicsContext3D::Attributes attributes;
    context_ = WebGraphicsContext3DInProcessCommandBufferImpl::
        CreateOffscreenContext(attributes);
    context_->makeContextCurrent();
    context_support_ = context_->GetContextSupport();
    helper_.reset(new content::GLHelper(context_.get(), context_support_));
    helper_scaling_.reset(new content::GLHelperScaling(
        context_.get(),
        helper_.get()));
  }

  virtual void TearDown() {
    helper_scaling_.reset(NULL);
    helper_.reset(NULL);
    context_.reset(NULL);
  }

  void StartTracing(const std::string& filter) {
    base::debug::TraceLog::GetInstance()->SetEnabled(
        base::debug::CategoryFilter(filter),
        base::debug::TraceLog::RECORD_UNTIL_FULL);
  }

  static void TraceDataCB(
      const base::Callback<void()>& callback,
      std::string* output,
      const scoped_refptr<base::RefCountedString>& json_events_str,
      bool has_more_events) {
    if (output->size() > 1) {
      output->append(",");
    }
    output->append(json_events_str->data());
    if (!has_more_events) {
      callback.Run();
    }
  }

  // End tracing, return tracing data in a simple map
  // of event name->counts.
  void EndTracing(std::map<std::string, int> *event_counts) {
    std::string json_data = "[";
    base::debug::TraceLog::GetInstance()->SetDisabled();
    base::RunLoop run_loop;
    base::debug::TraceLog::GetInstance()->Flush(
        base::Bind(&GLHelperTest::TraceDataCB,
                   run_loop.QuitClosure(),
                   base::Unretained(&json_data)));
    run_loop.Run();
    json_data.append("]");

    scoped_ptr<Value> trace_data(base::JSONReader::Read(json_data));
    ListValue* list;
    CHECK(trace_data->GetAsList(&list));
    for (size_t i = 0; i < list->GetSize(); i++) {
      base::Value *item = NULL;
      if (list->Get(i, &item)) {
        base::DictionaryValue *dict;
        CHECK(item->GetAsDictionary(&dict));
        std::string name;
        CHECK(dict->GetString("name", &name));
        (*event_counts)[name]++;
        VLOG(1) << "trace name: " << name;
      }
    }
  }

  // Bicubic filter kernel function.
  static float Bicubic(float x) {
    const float a = -0.5;
    x = std::abs(x);
    float x2 = x * x;
    float x3 = x2 * x;
    if (x <= 1) {
      return (a + 2) * x3 - (a + 3) * x2 + 1;
    } else if (x < 2) {
      return a * x3 - 5 * a * x2 + 8 * a * x - 4 * a;
    } else {
      return 0.0f;
    }
  }

  // Look up a single R/G/B/A value.
  // Clamp x/y.
  int Channel(SkBitmap* pixels, int x, int y, int c) {
    uint32 *data = pixels->getAddr32(
        std::max(0, std::min(x, pixels->width() - 1)),
        std::max(0, std::min(y, pixels->height() - 1)));
    return (*data) >> (c * 8) & 0xff;
  }

  // Set a single R/G/B/A value.
  void SetChannel(SkBitmap* pixels, int x, int y, int c, int v) {
    DCHECK_GE(x, 0);
    DCHECK_GE(y, 0);
    DCHECK_LT(x, pixels->width());
    DCHECK_LT(y, pixels->height());
    uint32 *data = pixels->getAddr32(x, y);
    v = std::max(0, std::min(v, 255));
    *data = (*data & ~(0xffu << (c * 8))) | (v << (c * 8));
  }

  // Print all the R, G, B or A values from an SkBitmap in a
  // human-readable format.
  void PrintChannel(SkBitmap* pixels, int c) {
    for (int y = 0; y < pixels->height(); y++) {
      for (int x = 0; x < pixels->width(); x++) {
        printf("%3d, ", Channel(pixels, x, y, c));
      }
      printf("\n");
    }
  }

  // Print out the individual steps of a scaler pipeline.
  std::string PrintStages(
      const std::vector<GLHelperScaling::ScalerStage> &scaler_stages) {
    std::string ret;
    for (size_t i = 0; i < scaler_stages.size(); i++) {
      ret.append(base::StringPrintf("%dx%d -> %dx%d ",
                                    scaler_stages[i].src_size.width(),
                                    scaler_stages[i].src_size.height(),
                                    scaler_stages[i].dst_size.width(),
                                    scaler_stages[i].dst_size.height()));
      bool xy_matters = false;
      switch (scaler_stages[i].shader) {
        case GLHelperScaling::SHADER_BILINEAR:
          ret.append("bilinear");
          break;
        case GLHelperScaling::SHADER_BILINEAR2:
          ret.append("bilinear2");
          xy_matters = true;
          break;
        case GLHelperScaling::SHADER_BILINEAR3:
          ret.append("bilinear3");
          xy_matters = true;
          break;
        case GLHelperScaling::SHADER_BILINEAR4:
          ret.append("bilinear4");
          xy_matters = true;
          break;
        case GLHelperScaling::SHADER_BILINEAR2X2:
          ret.append("bilinear2x2");
          break;
        case GLHelperScaling::SHADER_BICUBIC_UPSCALE:
          ret.append("bicubic upscale");
          xy_matters = true;
          break;
        case GLHelperScaling::SHADER_BICUBIC_HALF_1D:
          ret.append("bicubic 1/2");
          xy_matters = true;
          break;
        case GLHelperScaling::SHADER_PLANAR:
          ret.append("planar");
          break;
        case GLHelperScaling::SHADER_YUV_MRT_PASS1:
          ret.append("rgb2yuv pass 1");
          break;
        case GLHelperScaling::SHADER_YUV_MRT_PASS2:
          ret.append("rgb2yuv pass 2");
          break;
      }

      if (xy_matters) {
        if (scaler_stages[i].scale_x) {
          ret.append(" X");
        } else {
          ret.append(" Y");
        }
      }
      ret.append("\n");
    }
    return ret;
  }

  bool CheckScale(double scale, int samples, bool already_scaled) {
    // 1:1 is valid if there is one sample.
    if (samples == 1 && scale == 1.0) {
      return true;
    }
    // Is it an exact down-scale (50%, 25%, etc.?)
    if (scale == 2.0 * samples) {
      return true;
    }
    // Upscales, only valid if we haven't already scaled in this dimension.
    if (!already_scaled) {
      // Is it a valid bilinear upscale?
      if (samples == 1 && scale <= 1.0) {
        return true;
      }
      // Multi-sample upscale-downscale combination?
      if (scale > samples / 2.0 && scale < samples) {
        return true;
      }
    }
    return false;
  }

  // Make sure that the stages of the scaler pipeline are sane.
  void ValidateScalerStages(
      content::GLHelper::ScalerQuality quality,
      const std::vector<GLHelperScaling::ScalerStage> &scaler_stages,
      const std::string& message) {
    bool previous_error = HasFailure();
    // First, check that the input size for each stage is equal to
    // the output size of the previous stage.
    for (size_t i = 1; i < scaler_stages.size(); i++) {
      EXPECT_EQ(scaler_stages[i - 1].dst_size.width(),
                scaler_stages[i].src_size.width());
      EXPECT_EQ(scaler_stages[i - 1].dst_size.height(),
                scaler_stages[i].src_size.height());
      EXPECT_EQ(scaler_stages[i].src_subrect.x(), 0);
      EXPECT_EQ(scaler_stages[i].src_subrect.y(), 0);
      EXPECT_EQ(scaler_stages[i].src_subrect.width(),
                scaler_stages[i].src_size.width());
      EXPECT_EQ(scaler_stages[i].src_subrect.height(),
                scaler_stages[i].src_size.height());
    }

    // Used to verify that up-scales are not attempted after some
    // other scale.
    bool scaled_x = false;
    bool scaled_y = false;

    for (size_t i = 0; i < scaler_stages.size(); i++) {
      // Note: 2.0 means scaling down by 50%
      double x_scale =
          static_cast<double>(scaler_stages[i].src_subrect.width()) /
          static_cast<double>(scaler_stages[i].dst_size.width());
      double y_scale =
          static_cast<double>(scaler_stages[i].src_subrect.height()) /
          static_cast<double>(scaler_stages[i].dst_size.height());

      int x_samples = 0;
      int y_samples = 0;

      // Codify valid scale operations.
      switch (scaler_stages[i].shader) {
        case GLHelperScaling::SHADER_PLANAR:
        case GLHelperScaling::SHADER_YUV_MRT_PASS1:
        case GLHelperScaling::SHADER_YUV_MRT_PASS2:
          EXPECT_TRUE(false) << "Invalid shader.";
          break;

        case GLHelperScaling::SHADER_BILINEAR:
          if (quality != content::GLHelper::SCALER_QUALITY_FAST) {
            x_samples = 1;
            y_samples = 1;
          }
          break;
        case GLHelperScaling::SHADER_BILINEAR2:
          x_samples = 2;
          y_samples = 1;
          break;
        case GLHelperScaling::SHADER_BILINEAR3:
          x_samples = 3;
          y_samples = 1;
          break;
        case GLHelperScaling::SHADER_BILINEAR4:
          x_samples = 4;
          y_samples = 1;
          break;
        case GLHelperScaling::SHADER_BILINEAR2X2:
          x_samples = 2;
          y_samples = 2;
          break;
        case GLHelperScaling::SHADER_BICUBIC_UPSCALE:
          if (scaler_stages[i].scale_x) {
            EXPECT_LT(x_scale, 1.0);
            EXPECT_EQ(y_scale, 1.0);
          } else {
            EXPECT_EQ(x_scale, 1.0);
            EXPECT_LT(y_scale, 1.0);
          }
          break;
        case GLHelperScaling::SHADER_BICUBIC_HALF_1D:
          if (scaler_stages[i].scale_x) {
            EXPECT_EQ(x_scale, 2.0);
            EXPECT_EQ(y_scale, 1.0);
          } else {
            EXPECT_EQ(x_scale, 1.0);
            EXPECT_EQ(y_scale, 2.0);
          }
          break;
      }

      if (!scaler_stages[i].scale_x) {
        std::swap(x_samples, y_samples);
      }

      if (x_samples) {
        EXPECT_TRUE(CheckScale(x_scale, x_samples, scaled_x))
            << "x_scale = " << x_scale;
      }
      if (y_samples) {
        EXPECT_TRUE(CheckScale(y_scale, y_samples, scaled_y))
            << "y_scale = " << y_scale;
      }

      if (x_scale != 1.0) {
        scaled_x = true;
      }
      if (y_scale != 1.0) {
        scaled_y = true;
      }
    }

    if (HasFailure() && !previous_error) {
      printf("Invalid scaler stages: %s\n", message.c_str());
      printf("Scaler stages:\n%s", PrintStages(scaler_stages).c_str());
    }
  }

  // Compare two bitmaps, make sure that each component of each pixel
  // is no more than |maxdiff| apart. If they are not similar enough,
  // prints out |truth|, |other|, |source|, |scaler_stages| and |message|.
  void Compare(SkBitmap* truth,
               SkBitmap* other,
               int maxdiff,
               SkBitmap* source,
               const std::vector<GLHelperScaling::ScalerStage> &scaler_stages,
               std::string message) {
    EXPECT_EQ(truth->width(), other->width());
    EXPECT_EQ(truth->height(), other->height());
    for (int x = 0; x < truth->width(); x++) {
      for (int y = 0; y < truth->height(); y++) {
        for (int c = 0; c < 4; c++) {
          int a = Channel(truth, x, y, c);
          int b = Channel(other, x, y, c);
          EXPECT_NEAR(a, b, maxdiff)
              << " x=" << x
              << " y=" << y
              << " c=" << c
              << " " << message;
          if (std::abs(a - b) > maxdiff) {
            printf("-------expected--------\n");
            PrintChannel(truth, c);
            printf("-------actual--------\n");
            PrintChannel(other, c);
            if (source) {
              printf("-------before scaling--------\n");
              PrintChannel(source, c);
            }
            printf("-----Scaler stages------\n%s",
                   PrintStages(scaler_stages).c_str());
            return;
          }
        }
      }
    }
  }

  // Get a single R, G, B or A value as a float.
  float ChannelAsFloat(SkBitmap* pixels, int x, int y, int c) {
    return Channel(pixels, x, y, c) / 255.0;
  }

  // Works like a GL_LINEAR lookup on an SkBitmap.
  float Bilinear(SkBitmap* pixels, float x, float y, int c) {
    x -= 0.5;
    y -= 0.5;
    int base_x = static_cast<int>(floorf(x));
    int base_y = static_cast<int>(floorf(y));
    x -= base_x;
    y -= base_y;
    return (ChannelAsFloat(pixels, base_x, base_y, c) * (1 - x) * (1 - y) +
            ChannelAsFloat(pixels, base_x + 1, base_y, c) * x * (1 - y) +
            ChannelAsFloat(pixels, base_x, base_y + 1, c) * (1 - x) * y +
            ChannelAsFloat(pixels, base_x + 1, base_y + 1, c) * x * y);
  }

  // Very slow bicubic / bilinear scaler for reference.
  void ScaleSlow(SkBitmap* input,
                 SkBitmap* output,
                 content::GLHelper::ScalerQuality quality) {
    float xscale = static_cast<float>(input->width()) / output->width();
    float yscale = static_cast<float>(input->height()) / output->height();
    float clamped_xscale = xscale < 1.0 ? 1.0 : 1.0 / xscale;
    float clamped_yscale = yscale < 1.0 ? 1.0 : 1.0 / yscale;
    for (int dst_y = 0; dst_y < output->height(); dst_y++) {
      for (int dst_x = 0; dst_x < output->width(); dst_x++) {
        for (int channel = 0; channel < 4; channel++) {
          float dst_x_in_src = (dst_x + 0.5f) * xscale;
          float dst_y_in_src = (dst_y + 0.5f) * yscale;

          float value = 0.0f;
          float sum = 0.0f;
          switch (quality) {
            case content::GLHelper::SCALER_QUALITY_BEST:
              for (int src_y = -10; src_y < input->height() + 10; ++src_y) {
                float coeff_y = Bicubic(
                    (src_y + 0.5f - dst_y_in_src) * clamped_yscale);
                if (coeff_y == 0.0f) {
                  continue;
                }
                for (int src_x = -10; src_x < input->width() + 10; ++src_x) {
                  float coeff = coeff_y * Bicubic(
                      (src_x + 0.5f - dst_x_in_src) * clamped_xscale);
                  if (coeff == 0.0f) {
                    continue;
                  }
                  sum += coeff;
                  float c = ChannelAsFloat(input, src_x, src_y, channel);
                  value += c * coeff;
                }
              }
              break;

            case content::GLHelper::SCALER_QUALITY_GOOD: {
              int xshift = 0, yshift = 0;
              while ((output->width() << xshift) < input->width()) {
                xshift++;
              }
              while ((output->height() << yshift) < input->height()) {
                yshift++;
              }
              int xmag = 1 << xshift;
              int ymag = 1 << yshift;
              if (xmag == 4 && output->width() * 3 >= input->width()) {
                xmag=3;
              }
              if (ymag == 4 && output->height() * 3 >= input->height()) {
                ymag=3;
              }
              for (int x = 0; x < xmag; x++) {
                for (int y = 0; y < ymag; y++) {
                  value += Bilinear(input,
                                    (dst_x * xmag + x + 0.5) * xscale / xmag,
                                    (dst_y * ymag + y + 0.5) * yscale / ymag,
                      channel);
                  sum += 1.0;
                }
              }
              break;
            }

            case content::GLHelper::SCALER_QUALITY_FAST:
              value = Bilinear(input, dst_x_in_src, dst_y_in_src, channel);
              sum = 1.0;
          }
          value /= sum;
          SetChannel(output, dst_x, dst_y, channel,
                     static_cast<int>(value * 255.0f + 0.5f));
        }
      }
    }
  }

  void FlipSKBitmap(SkBitmap* bitmap) {
    int top_line = 0;
    int bottom_line = bitmap->height() - 1;
    while (top_line < bottom_line) {
      for (int x = 0; x < bitmap->width(); x++) {
        std::swap(*bitmap->getAddr32(x, top_line),
                  *bitmap->getAddr32(x, bottom_line));
      }
      top_line++;
      bottom_line--;
    }
  }

  // gl_helper scales recursively, so we'll need to do that
  // in the reference implementation too.
  void ScaleSlowRecursive(SkBitmap* input,
                          SkBitmap* output,
                          content::GLHelper::ScalerQuality quality) {
    if (quality == content::GLHelper::SCALER_QUALITY_FAST ||
        quality == content::GLHelper::SCALER_QUALITY_GOOD) {
      ScaleSlow(input, output, quality);
      return;
    }

    float xscale = static_cast<float>(output->width()) / input->width();

    // This corresponds to all the operations we can do directly.
    float yscale = static_cast<float>(output->height()) / input->height();
    if ((xscale == 1.0f && yscale == 1.0f) ||
        (xscale == 0.5f && yscale == 1.0f) ||
        (xscale == 1.0f && yscale == 0.5f) ||
        (xscale >= 1.0f && yscale == 1.0f) ||
        (xscale == 1.0f && yscale >= 1.0f)) {
      ScaleSlow(input, output, quality);
      return;
    }

    // Now we break the problem down into smaller pieces, using the
    // operations available.
    int xtmp = input->width();
    int ytmp = input->height();

    if (output->height() != input->height()) {
      ytmp = output->height();
      while (ytmp < input->height() && ytmp * 2 != input->height()) {
        ytmp += ytmp;
      }
    } else {
      xtmp = output->width();
      while (xtmp < input->width() && xtmp * 2 != input->width()) {
        xtmp += xtmp;
      }
    }

    SkBitmap tmp;
    tmp.setConfig(SkBitmap::kARGB_8888_Config, xtmp, ytmp);
    tmp.allocPixels();
    SkAutoLockPixels lock(tmp);

    ScaleSlowRecursive(input, &tmp, quality);
    ScaleSlowRecursive(&tmp, output, quality);
  }

  // Scaling test: Create a test image, scale it using GLHelperScaling
  // and a reference implementation and compare the results.
  void TestScale(int xsize, int ysize,
                 int scaled_xsize, int scaled_ysize,
                 int test_pattern,
                 size_t quality,
                 bool flip) {
    WebGLId src_texture = context_->createTexture();
    WebGLId framebuffer = context_->createFramebuffer();
    SkBitmap input_pixels;
    input_pixels.setConfig(SkBitmap::kARGB_8888_Config, xsize, ysize);
    input_pixels.allocPixels();
    SkAutoLockPixels lock(input_pixels);

    for (int x = 0; x < xsize; ++x) {
      for (int y = 0; y < ysize; ++y) {
        switch (test_pattern) {
          case 0:  // Smooth test pattern
            SetChannel(&input_pixels, x, y, 0, x * 10);
            SetChannel(&input_pixels, x, y, 1, y * 10);
            SetChannel(&input_pixels, x, y, 2, (x + y) * 10);
            SetChannel(&input_pixels, x, y, 3, 255);
            break;
          case 1:  // Small blocks
            SetChannel(&input_pixels, x, y, 0, x & 1 ? 255 : 0);
            SetChannel(&input_pixels, x, y, 1, y & 1 ? 255 : 0);
            SetChannel(&input_pixels, x, y, 2, (x + y) & 1 ? 255 : 0);
            SetChannel(&input_pixels, x, y, 3, 255);
            break;
          case 2:  // Medium blocks
            SetChannel(&input_pixels, x, y, 0, 10 + x/2 * 50);
            SetChannel(&input_pixels, x, y, 1, 10 + y/3 * 50);
            SetChannel(&input_pixels, x, y, 2, (x + y)/5 * 50 + 5);
            SetChannel(&input_pixels, x, y, 3, 255);
            break;
        }
      }
    }

    context_->bindFramebuffer(GL_FRAMEBUFFER, framebuffer);
    context_->bindTexture(GL_TEXTURE_2D, src_texture);
    context_->texImage2D(GL_TEXTURE_2D,
                         0,
                         GL_RGBA,
                         xsize,
                         ysize,
                         0,
                         GL_RGBA,
                         GL_UNSIGNED_BYTE,
                         input_pixels.getPixels());

    std::string message = base::StringPrintf("input size: %dx%d "
                                             "output size: %dx%d "
                                             "pattern: %d quality: %s",
                                             xsize, ysize,
                                             scaled_xsize, scaled_ysize,
                                             test_pattern,
                                             kQualityNames[quality]);


    std::vector<GLHelperScaling::ScalerStage> stages;
    helper_scaling_->ComputeScalerStages(
        kQualities[quality],
        gfx::Size(xsize, ysize),
        gfx::Rect(0, 0, xsize, ysize),
        gfx::Size(scaled_xsize, scaled_ysize),
        flip,
        false,
        &stages);
    ValidateScalerStages(kQualities[quality], stages, message);

    WebGLId dst_texture = helper_->CopyAndScaleTexture(
        src_texture,
        gfx::Size(xsize, ysize),
        gfx::Size(scaled_xsize, scaled_ysize),
        flip,
        kQualities[quality]);

    SkBitmap output_pixels;
    output_pixels.setConfig(SkBitmap::kARGB_8888_Config,
                            scaled_xsize, scaled_ysize);
    output_pixels.allocPixels();
    SkAutoLockPixels output_lock(output_pixels);

    helper_->ReadbackTextureSync(
        dst_texture,
        gfx::Rect(0, 0, scaled_xsize, scaled_ysize),
        static_cast<unsigned char *>(output_pixels.getPixels()));
    if (flip) {
      // Flip the pixels back.
      FlipSKBitmap(&output_pixels);
    }
    if (xsize == scaled_xsize && ysize == scaled_ysize) {
      Compare(&input_pixels,
              &output_pixels,
              2,
              NULL,
              stages,
              message + " comparing against input");
    }
    SkBitmap truth_pixels;
    truth_pixels.setConfig(SkBitmap::kARGB_8888_Config,
                           scaled_xsize, scaled_ysize);
    truth_pixels.allocPixels();
    SkAutoLockPixels truth_lock(truth_pixels);

    ScaleSlowRecursive(&input_pixels, &truth_pixels, kQualities[quality]);
    Compare(&truth_pixels,
            &output_pixels,
            2,
            &input_pixels,
            stages,
            message + " comparing against scaled");

    context_->deleteTexture(src_texture);
    context_->deleteTexture(dst_texture);
    context_->deleteFramebuffer(framebuffer);
  }

  // Create a scaling pipeline and check that it is made up of
  // valid scaling operations.
  void TestScalerPipeline(size_t quality,
                          int xsize, int ysize,
                          int dst_xsize, int dst_ysize) {
    std::vector<GLHelperScaling::ScalerStage> stages;
    helper_scaling_->ComputeScalerStages(
        kQualities[quality],
        gfx::Size(xsize, ysize),
        gfx::Rect(0, 0, xsize, ysize),
        gfx::Size(dst_xsize, dst_ysize),
        false,
        false,
        &stages);
    ValidateScalerStages(kQualities[quality], stages,
                         base::StringPrintf("input size: %dx%d "
                                            "output size: %dx%d "
                                            "quality: %s",
                                            xsize, ysize,
                                            dst_xsize, dst_ysize,
                                            kQualityNames[quality]));
  }

  // Create a scaling pipeline and make sure that the steps
  // are exactly the steps we expect.
  void CheckPipeline(content::GLHelper::ScalerQuality quality,
                     int xsize, int ysize,
                     int dst_xsize, int dst_ysize,
                     const std::string &description) {
    std::vector<GLHelperScaling::ScalerStage> stages;
    helper_scaling_->ComputeScalerStages(
        quality,
        gfx::Size(xsize, ysize),
        gfx::Rect(0, 0, xsize, ysize),
        gfx::Size(dst_xsize, dst_ysize),
        false,
        false,
        &stages);
    ValidateScalerStages(
        content::GLHelper::SCALER_QUALITY_GOOD,
        stages,
        "");
    EXPECT_EQ(PrintStages(stages), description);
  }

  // Note: Left/Right means Top/Bottom when used for Y dimension.
  enum Margin {
    MarginLeft,
    MarginMiddle,
    MarginRight,
    MarginInvalid,
  };

  static Margin NextMargin(Margin m) {
    switch (m) {
      case MarginLeft:
        return MarginMiddle;
      case MarginMiddle:
        return MarginRight;
      case MarginRight:
        return MarginInvalid;
      default:
        return MarginInvalid;
    }
  }

  int compute_margin(int insize, int outsize, Margin m) {
    int available = outsize - insize;
    switch (m) {
      default:
        EXPECT_TRUE(false) << "This should not happen.";
        return 0;
      case MarginLeft:
        return 0;
      case MarginMiddle:
        return (available / 2) & ~1;
      case MarginRight:
        return available;
    }
  }

  // Convert 0.0 - 1.0 to 0 - 255
  int float_to_byte(float v) {
    int ret = static_cast<int>(floorf(v * 255.0f + 0.5f));
    if (ret < 0) {
      return 0;
    }
    if (ret > 255) {
      return 255;
    }
    return ret;
  }

  static void callcallback(const base::Callback<void()>& callback,
                           bool result) {
    callback.Run();
  }

  void PrintPlane(unsigned char *plane, int xsize, int stride, int ysize) {
    for (int y = 0; y < ysize; y++) {
      for (int x = 0; x < xsize ; x++) {
        printf("%3d, ", plane[y * stride + x]);
      }
      printf("   (%p)\n", plane + y * stride);
    }
  }

  // Compare two planes make sure that each component of each pixel
  // is no more than |maxdiff| apart.
  void ComparePlane(unsigned char* truth,
                    unsigned char* other,
                    int maxdiff,
                    int xsize,
                    int stride,
                    int ysize,
                    SkBitmap* source,
                    std::string message) {
    int truth_stride = stride;
    for (int x = 0; x < xsize; x++) {
      for (int y = 0; y < ysize; y++) {
        int a = other[y * stride + x];
        int b = truth[y * stride + x];
        EXPECT_NEAR(a, b, maxdiff)
            << " x=" << x
            << " y=" << y
            << " " << message;
        if (std::abs(a - b) > maxdiff) {
          printf("-------expected--------\n");
          PrintPlane(truth, xsize, truth_stride, ysize);
          printf("-------actual--------\n");
          PrintPlane(other, xsize, stride, ysize);
          if (source) {
            printf("-------before yuv conversion: red--------\n");
            PrintChannel(source, 0);
            printf("-------before yuv conversion: green------\n");
            PrintChannel(source, 1);
            printf("-------before yuv conversion: blue-------\n");
            PrintChannel(source, 2);
          }
          return;
        }
      }
    }
  }

  // YUV readback test. Create a test pattern, convert to YUV
  // with reference implementation and compare to what gl_helper
  // returns.
  void TestYUVReadback(int xsize,
                       int ysize,
                       int output_xsize,
                       int output_ysize,
                       int xmargin,
                       int ymargin,
                       int test_pattern,
                       bool flip,
                       bool use_mrt,
                       content::GLHelper::ScalerQuality quality) {
    WebGLId src_texture = context_->createTexture();
    SkBitmap input_pixels;
    input_pixels.setConfig(SkBitmap::kARGB_8888_Config, xsize, ysize);
    input_pixels.allocPixels();
    SkAutoLockPixels lock(input_pixels);

    for (int x = 0; x < xsize; ++x) {
      for (int y = 0; y < ysize; ++y) {
        switch (test_pattern) {
          case 0:  // Smooth test pattern
            SetChannel(&input_pixels, x, y, 0, x * 10);
            SetChannel(&input_pixels, x, y, 1, y * 10);
            SetChannel(&input_pixels, x, y, 2, (x + y) * 10);
            SetChannel(&input_pixels, x, y, 3, 255);
            break;
          case 1:  // Small blocks
            SetChannel(&input_pixels, x, y, 0, x & 1 ? 255 : 0);
            SetChannel(&input_pixels, x, y, 1, y & 1 ? 255 : 0);
            SetChannel(&input_pixels, x, y, 2, (x + y) & 1 ? 255 : 0);
            SetChannel(&input_pixels, x, y, 3, 255);
            break;
          case 2:  // Medium blocks
            SetChannel(&input_pixels, x, y, 0, 10 + x/2 * 50);
            SetChannel(&input_pixels, x, y, 1, 10 + y/3 * 50);
            SetChannel(&input_pixels, x, y, 2, (x + y)/5 * 50 + 5);
            SetChannel(&input_pixels, x, y, 3, 255);
            break;
        }
      }
    }

    context_->bindTexture(GL_TEXTURE_2D, src_texture);
    context_->texImage2D(GL_TEXTURE_2D,
                         0,
                         GL_RGBA,
                         xsize,
                         ysize,
                         0,
                         GL_RGBA,
                         GL_UNSIGNED_BYTE,
                         input_pixels.getPixels());

    gpu::Mailbox mailbox;
    context_->genMailboxCHROMIUM(mailbox.name);
    EXPECT_FALSE(mailbox.IsZero());
    context_->produceTextureCHROMIUM(GL_TEXTURE_2D, mailbox.name);
    uint32 sync_point = context_->insertSyncPoint();

    std::string message = base::StringPrintf("input size: %dx%d "
                                             "output size: %dx%d "
                                             "margin: %dx%d "
                                             "pattern: %d %s %s",
                                             xsize, ysize,
                                             output_xsize, output_ysize,
                                             xmargin, ymargin,
                                             test_pattern,
                                             flip ? "flip" : "noflip",
                                             flip ? "mrt" : "nomrt");
    scoped_ptr<ReadbackYUVInterface> yuv_reader(
        helper_->CreateReadbackPipelineYUV(
            quality,
            gfx::Size(xsize, ysize),
            gfx::Rect(0, 0, xsize, ysize),
            gfx::Size(output_xsize, output_ysize),
            gfx::Rect(xmargin, ymargin, xsize, ysize),
            flip,
            use_mrt));

    scoped_refptr<media::VideoFrame> output_frame =
        media::VideoFrame::CreateFrame(
            media::VideoFrame::YV12,
            gfx::Size(output_xsize, output_ysize),
            gfx::Rect(0, 0, output_xsize, output_ysize),
            gfx::Size(output_xsize, output_ysize),
            base::TimeDelta::FromSeconds(0));
    scoped_refptr<media::VideoFrame> truth_frame =
        media::VideoFrame::CreateFrame(
            media::VideoFrame::YV12,
            gfx::Size(output_xsize, output_ysize),
            gfx::Rect(0, 0, output_xsize, output_ysize),
            gfx::Size(output_xsize, output_ysize),
            base::TimeDelta::FromSeconds(0));

    base::RunLoop run_loop;
    yuv_reader->ReadbackYUV(
        mailbox,
        sync_point,
        output_frame.get(),
        base::Bind(&callcallback, run_loop.QuitClosure()));
    run_loop.Run();

    if (flip) {
      FlipSKBitmap(&input_pixels);
    }

    unsigned char* Y = truth_frame->data(media::VideoFrame::kYPlane);
    unsigned char* U = truth_frame->data(media::VideoFrame::kUPlane);
    unsigned char* V = truth_frame->data(media::VideoFrame::kVPlane);
    int32 y_stride = truth_frame->stride(media::VideoFrame::kYPlane);
    int32 u_stride = truth_frame->stride(media::VideoFrame::kUPlane);
    int32 v_stride = truth_frame->stride(media::VideoFrame::kVPlane);
    memset(Y, 0x00, y_stride * output_ysize);
    memset(U, 0x80, u_stride * output_ysize / 2);
    memset(V, 0x80, v_stride * output_ysize / 2);

    for (int y = 0; y < ysize; y++) {
      for (int x = 0; x < xsize; x++) {
        Y[(y + ymargin) * y_stride + x + xmargin] = float_to_byte(
            ChannelAsFloat(&input_pixels, x, y, 0) * 0.257 +
            ChannelAsFloat(&input_pixels, x, y, 1) * 0.504 +
            ChannelAsFloat(&input_pixels, x, y, 2) * 0.098 +
            0.0625);
      }
    }

    for (int y = 0; y < ysize / 2; y++) {
      for (int x = 0; x < xsize / 2; x++) {
        U[(y + ymargin / 2) * u_stride + x + xmargin / 2] =
            float_to_byte(
                Bilinear(&input_pixels, x * 2 + 1.0, y * 2 + 1.0, 0) * -0.148 +
                Bilinear(&input_pixels, x * 2 + 1.0, y * 2 + 1.0, 1) * -0.291 +
                Bilinear(&input_pixels, x * 2 + 1.0, y * 2 + 1.0, 2) * 0.439 +
                0.5);
        V[(y + ymargin / 2) * v_stride + x + xmargin / 2] =
            float_to_byte(
                Bilinear(&input_pixels, x * 2 + 1.0, y * 2 + 1.0, 0) * 0.439 +
                Bilinear(&input_pixels, x * 2 + 1.0, y * 2 + 1.0, 1) * -0.368 +
                Bilinear(&input_pixels, x * 2 + 1.0, y * 2 + 1.0, 2) * -0.071 +
                0.5);
      }
    }

    ComparePlane(Y,
                 output_frame->data(media::VideoFrame::kYPlane), 2,
                 output_xsize,
                 y_stride,
                 output_ysize,
                 &input_pixels,
                 message + " Y plane");
    ComparePlane(U,
                 output_frame->data(media::VideoFrame::kUPlane), 2,
                 output_xsize / 2,
                 u_stride,
                 output_ysize / 2,
                 &input_pixels,
                 message + " U plane");
    ComparePlane(V,
                 output_frame->data(media::VideoFrame::kVPlane), 2,
                 output_xsize / 2,
                 v_stride,
                 output_ysize / 2,
                 &input_pixels,
                 message + " V plane");

    context_->deleteTexture(src_texture);
  }

  void TestAddOps(int src,
                  int dst,
                  bool scale_x,
                  bool allow3) {
    std::deque<GLHelperScaling::ScaleOp> ops;
    GLHelperScaling::ScaleOp::AddOps(src, dst, scale_x, allow3, &ops);
    // Scale factor 3 is a special case.
    // It is currently only allowed by itself.
    if (allow3 && dst * 3 >= src && dst * 2 < src) {
      EXPECT_EQ(ops[0].scale_factor, 3);
      EXPECT_EQ(ops.size(), 1U);
      EXPECT_EQ(ops[0].scale_x, scale_x);
      EXPECT_EQ(ops[0].scale_size, dst);
      return;
    }

    for (size_t i = 0; i < ops.size(); i++) {
      EXPECT_EQ(ops[i].scale_x, scale_x);
      if (i == 0) {
        // Only the first op is allowed to be a scale up.
        // (Scaling up *after* scaling down would make it fuzzy.)
        EXPECT_TRUE(ops[0].scale_factor == 0 ||
                    ops[0].scale_factor == 2);
      } else {
        // All other operations must be 50% downscales.
        EXPECT_EQ(ops[i].scale_factor, 2);
      }
    }
    // Check that the scale factors make sense and add up.
    int tmp = dst;
    for (int i = static_cast<int>(ops.size() - 1); i >= 0; i--) {
      EXPECT_EQ(tmp, ops[i].scale_size);
      if (ops[i].scale_factor == 0) {
        EXPECT_EQ(i, 0);
        EXPECT_GT(tmp, src);
        tmp = src;
      } else {
        tmp *= ops[i].scale_factor;
      }
    }
    EXPECT_EQ(tmp, src);
  }

  void CheckPipeline2(int xsize, int ysize,
                      int dst_xsize, int dst_ysize,
                      const std::string &description) {
    std::vector<GLHelperScaling::ScalerStage> stages;
    helper_scaling_->ConvertScalerOpsToScalerStages(
        content::GLHelper::SCALER_QUALITY_GOOD,
        gfx::Size(xsize, ysize),
        gfx::Rect(0, 0, xsize, ysize),
        gfx::Size(dst_xsize, dst_ysize),
        false,
        false,
        &x_ops_,
        &y_ops_,
        &stages);
    EXPECT_EQ(x_ops_.size(), 0U);
    EXPECT_EQ(y_ops_.size(), 0U);
    ValidateScalerStages(
        content::GLHelper::SCALER_QUALITY_GOOD,
        stages,
        "");
    EXPECT_EQ(PrintStages(stages), description);
  }

  void CheckOptimizationsTest() {
    // Basic upscale. X and Y should be combined into one pass.
    x_ops_.push_back(GLHelperScaling::ScaleOp(0, true, 2000));
    y_ops_.push_back(GLHelperScaling::ScaleOp(0, false, 2000));
    CheckPipeline2(1024, 768, 2000, 2000,
                   "1024x768 -> 2000x2000 bilinear\n");

    // X scaled 1/2, Y upscaled, should still be one pass.
    x_ops_.push_back(GLHelperScaling::ScaleOp(2, true, 512));
    y_ops_.push_back(GLHelperScaling::ScaleOp(0, false, 2000));
    CheckPipeline2(1024, 768, 512, 2000,
                   "1024x768 -> 512x2000 bilinear\n");

    // X upscaled, Y scaled 1/2, one bilinear pass
    x_ops_.push_back(GLHelperScaling::ScaleOp(0, true, 2000));
    y_ops_.push_back(GLHelperScaling::ScaleOp(2, false, 384));
    CheckPipeline2(1024, 768, 2000, 384,
                   "1024x768 -> 2000x384 bilinear\n");

    // X scaled 1/2, Y scaled 1/2, one bilinear pass
    x_ops_.push_back(GLHelperScaling::ScaleOp(2, true, 512));
    y_ops_.push_back(GLHelperScaling::ScaleOp(2, false, 384));
    CheckPipeline2(1024, 768, 2000, 384,
                   "1024x768 -> 512x384 bilinear\n");

    // X scaled 1/2, Y scaled to 60%, one bilinear2 pass.
    x_ops_.push_back(GLHelperScaling::ScaleOp(2, true, 50));
    y_ops_.push_back(GLHelperScaling::ScaleOp(0, false, 120));
    y_ops_.push_back(GLHelperScaling::ScaleOp(2, false, 60));
    CheckPipeline2(100, 100, 50, 60,
                   "100x100 -> 50x60 bilinear2 Y\n");

    // X scaled to 60%, Y scaled 1/2, one bilinear2 pass.
    x_ops_.push_back(GLHelperScaling::ScaleOp(0, true, 120));
    x_ops_.push_back(GLHelperScaling::ScaleOp(2, true, 60));
    y_ops_.push_back(GLHelperScaling::ScaleOp(2, false, 50));
    CheckPipeline2(100, 100, 50, 60,
                   "100x100 -> 60x50 bilinear2 X\n");

    // X scaled to 60%, Y scaled 60%, one bilinear2x2 pass.
    x_ops_.push_back(GLHelperScaling::ScaleOp(0, true, 120));
    x_ops_.push_back(GLHelperScaling::ScaleOp(2, true, 60));
    y_ops_.push_back(GLHelperScaling::ScaleOp(0, false, 120));
    y_ops_.push_back(GLHelperScaling::ScaleOp(2, false, 60));
    CheckPipeline2(100, 100, 60, 60,
                   "100x100 -> 60x60 bilinear2x2\n");

    // X scaled to 40%, Y scaled 40%, two bilinear3 passes.
    x_ops_.push_back(GLHelperScaling::ScaleOp(3, true, 40));
    y_ops_.push_back(GLHelperScaling::ScaleOp(3, false, 40));
    CheckPipeline2(100, 100, 40, 40,
                   "100x100 -> 100x40 bilinear3 Y\n"
                   "100x40 -> 40x40 bilinear3 X\n");

    // X scaled to 60%, Y scaled 40%
    x_ops_.push_back(GLHelperScaling::ScaleOp(0, true, 120));
    x_ops_.push_back(GLHelperScaling::ScaleOp(2, true, 60));
    y_ops_.push_back(GLHelperScaling::ScaleOp(3, false, 40));
    CheckPipeline2(100, 100, 60, 40,
                   "100x100 -> 100x40 bilinear3 Y\n"
                   "100x40 -> 60x40 bilinear2 X\n");

    // X scaled to 40%, Y scaled 60%
    x_ops_.push_back(GLHelperScaling::ScaleOp(3, true, 40));
    y_ops_.push_back(GLHelperScaling::ScaleOp(0, false, 120));
    y_ops_.push_back(GLHelperScaling::ScaleOp(2, false, 60));
    CheckPipeline2(100, 100, 40, 60,
                   "100x100 -> 100x60 bilinear2 Y\n"
                   "100x60 -> 40x60 bilinear3 X\n");

    // X scaled to 30%, Y scaled 30%
    x_ops_.push_back(GLHelperScaling::ScaleOp(0, true, 120));
    x_ops_.push_back(GLHelperScaling::ScaleOp(2, true, 60));
    x_ops_.push_back(GLHelperScaling::ScaleOp(2, true, 30));
    y_ops_.push_back(GLHelperScaling::ScaleOp(0, false, 120));
    y_ops_.push_back(GLHelperScaling::ScaleOp(2, false, 60));
    y_ops_.push_back(GLHelperScaling::ScaleOp(2, false, 30));
    CheckPipeline2(100, 100, 30, 30,
                   "100x100 -> 100x30 bilinear4 Y\n"
                   "100x30 -> 30x30 bilinear4 X\n");

    // X scaled to 50%, Y scaled 30%
    x_ops_.push_back(GLHelperScaling::ScaleOp(2, true, 50));
    y_ops_.push_back(GLHelperScaling::ScaleOp(0, false, 120));
    y_ops_.push_back(GLHelperScaling::ScaleOp(2, false, 60));
    y_ops_.push_back(GLHelperScaling::ScaleOp(2, false, 30));
    CheckPipeline2(100, 100, 50, 30,
                   "100x100 -> 50x30 bilinear4 Y\n");

    // X scaled to 150%, Y scaled 30%
    // Note that we avoid combinding X and Y passes
    // as that would probably be LESS efficient here.
    x_ops_.push_back(GLHelperScaling::ScaleOp(0, true, 150));
    y_ops_.push_back(GLHelperScaling::ScaleOp(0, false, 120));
    y_ops_.push_back(GLHelperScaling::ScaleOp(2, false, 60));
    y_ops_.push_back(GLHelperScaling::ScaleOp(2, false, 30));
    CheckPipeline2(100, 100, 150, 30,
                   "100x100 -> 100x30 bilinear4 Y\n"
                   "100x30 -> 150x30 bilinear\n");

    // X scaled to 1%, Y scaled 1%
    x_ops_.push_back(GLHelperScaling::ScaleOp(0, true, 128));
    x_ops_.push_back(GLHelperScaling::ScaleOp(2, true, 64));
    x_ops_.push_back(GLHelperScaling::ScaleOp(2, true, 32));
    x_ops_.push_back(GLHelperScaling::ScaleOp(2, true, 16));
    x_ops_.push_back(GLHelperScaling::ScaleOp(2, true, 8));
    x_ops_.push_back(GLHelperScaling::ScaleOp(2, true, 4));
    x_ops_.push_back(GLHelperScaling::ScaleOp(2, true, 2));
    x_ops_.push_back(GLHelperScaling::ScaleOp(2, true, 1));
    y_ops_.push_back(GLHelperScaling::ScaleOp(0, false, 128));
    y_ops_.push_back(GLHelperScaling::ScaleOp(2, false, 64));
    y_ops_.push_back(GLHelperScaling::ScaleOp(2, false, 32));
    y_ops_.push_back(GLHelperScaling::ScaleOp(2, false, 16));
    y_ops_.push_back(GLHelperScaling::ScaleOp(2, false, 8));
    y_ops_.push_back(GLHelperScaling::ScaleOp(2, false, 4));
    y_ops_.push_back(GLHelperScaling::ScaleOp(2, false, 2));
    y_ops_.push_back(GLHelperScaling::ScaleOp(2, false, 1));
    CheckPipeline2(100, 100, 30, 30,
                   "100x100 -> 100x32 bilinear4 Y\n"
                   "100x32 -> 100x4 bilinear4 Y\n"
                   "100x4 -> 64x1 bilinear2x2\n"
                   "64x1 -> 8x1 bilinear4 X\n"
                   "8x1 -> 1x1 bilinear4 X\n");
  }

  scoped_ptr<WebGraphicsContext3DInProcessCommandBufferImpl> context_;
  gpu::ContextSupport* context_support_;
  scoped_ptr<content::GLHelper> helper_;
  scoped_ptr<content::GLHelperScaling> helper_scaling_;
  std::deque<GLHelperScaling::ScaleOp> x_ops_, y_ops_;
};

TEST_F(GLHelperTest, YUVReadbackOptTest) {
  // This test uses the cb_command tracing events to detect how many
  // scaling passes are actually performed by the YUV readback pipeline.
  StartTracing(TRACE_DISABLED_BY_DEFAULT("cb_command"));

  TestYUVReadback(
      800, 400,
      800, 400,
      0,  0,
      1,
      false,
      true,
      content::GLHelper::SCALER_QUALITY_FAST);

  std::map<std::string, int> event_counts;
  EndTracing(&event_counts);
  int draw_buffer_calls = event_counts["kDrawBuffersEXTImmediate"];
  int draw_arrays_calls = event_counts["kDrawArrays"];
  VLOG(1) << "Draw buffer calls: " << draw_buffer_calls;
  VLOG(1) << "DrawArrays calls: " << draw_arrays_calls;

  if (draw_buffer_calls) {
    // When using MRT, the YUV readback code should only
    // execute two draw arrays, and scaling should be integrated
    // into those two calls since we are using the FAST scalign
    // quality.
    EXPECT_EQ(2, draw_arrays_calls);
  } else {
    // When not using MRT, there are three passes for the YUV,
    // and one for the scaling.
    EXPECT_EQ(4, draw_arrays_calls);
  }
}

TEST_F(GLHelperTest, YUVReadbackTest) {
  int sizes[] = { 2, 4, 14 };
  for (int flip = 0; flip <= 1; flip++) {
    for (int use_mrt = 0; use_mrt <= 1; use_mrt++) {
      for (unsigned int x = 0; x < arraysize(sizes); x++) {
        for (unsigned int y = 0; y < arraysize(sizes); y++) {
          for (unsigned int ox = x; ox < arraysize(sizes); ox++) {
            for (unsigned int oy = y; oy < arraysize(sizes); oy++) {
              // If output is a subsection of the destination frame, (letterbox)
              // then try different variations of where the subsection goes.
              for (Margin xm = x < ox ? MarginLeft : MarginRight;
                   xm <= MarginRight;
                   xm = NextMargin(xm)) {
                for (Margin ym = y < oy ? MarginLeft : MarginRight;
                     ym <= MarginRight;
                     ym = NextMargin(ym)) {
                  for (int pattern = 0; pattern < 3; pattern++) {
                    TestYUVReadback(
                        sizes[x],
                        sizes[y],
                        sizes[ox],
                        sizes[oy],
                        compute_margin(sizes[x], sizes[ox], xm),
                        compute_margin(sizes[y], sizes[oy], ym),
                        pattern,
                        flip == 1,
                        use_mrt == 1,
                        content::GLHelper::SCALER_QUALITY_GOOD);
                    if (HasFailure()) {
                      return;
                    }
                  }
                }
              }
            }
          }
        }
      }
    }
  }
}

// Per pixel tests, all sizes are small so that we can print
// out the generated bitmaps.
TEST_F(GLHelperTest, ScaleTest) {
  int sizes[] = {3, 6, 16};
  for (int flip = 0; flip <= 1; flip++) {
    for (size_t q = 0; q < arraysize(kQualities); q++) {
      for (int x = 0; x < 3; x++) {
        for (int y = 0; y < 3; y++) {
          for (int dst_x = 0; dst_x < 3; dst_x++) {
            for (int dst_y = 0; dst_y < 3; dst_y++) {
              for (int pattern = 0; pattern < 3; pattern++) {
                TestScale(sizes[x],
                          sizes[y],
                          sizes[dst_x],
                          sizes[dst_y],
                          pattern,
                          q,
                          flip == 1);
                if (HasFailure()) {
                  return;
                }
              }
            }
          }
        }
      }
    }
  }
}

// Validate that all scaling generates valid pipelines.
TEST_F(GLHelperTest, ValidateScalerPipelines) {
  int sizes[] = {7, 99, 128, 256, 512, 719, 720, 721, 1920, 2011, 3217, 4096};
  for (size_t q = 0; q < arraysize(kQualities); q++) {
    for (size_t x = 0; x < arraysize(sizes); x++) {
      for (size_t y = 0; y < arraysize(sizes); y++) {
        for (size_t dst_x = 0; dst_x < arraysize(sizes); dst_x++) {
          for (size_t dst_y = 0; dst_y < arraysize(sizes); dst_y++) {
            TestScalerPipeline(q,
                               sizes[x], sizes[y],
                               sizes[dst_x], sizes[dst_y]);
            if (HasFailure()) {
              return;
            }
          }
        }
      }
    }
  }
}

// Make sure we don't create overly complicated pipelines
// for a few common use cases.
TEST_F(GLHelperTest, CheckSpecificPipelines) {
  // Upscale should be single pass.
  CheckPipeline(content::GLHelper::SCALER_QUALITY_GOOD,
                1024, 700, 1280, 720,
                "1024x700 -> 1280x720 bilinear\n");
  // Slight downscale should use BILINEAR2X2.
  CheckPipeline(content::GLHelper::SCALER_QUALITY_GOOD,
                1280, 720, 1024, 700,
                "1280x720 -> 1024x700 bilinear2x2\n");
  // Most common tab capture pipeline on the Pixel.
  // Should be using two BILINEAR3 passes.
  CheckPipeline(content::GLHelper::SCALER_QUALITY_GOOD,
                2560, 1476, 1249, 720,
                "2560x1476 -> 2560x720 bilinear3 Y\n"
                "2560x720 -> 1249x720 bilinear3 X\n");
}

TEST_F(GLHelperTest, ScalerOpTest) {
  for (int allow3 = 0; allow3 <= 1; allow3++) {
    for (int dst = 1; dst < 2049; dst += 1 + (dst >> 3)) {
      for (int src = 1; src < 2049; src++) {
        TestAddOps(src, dst, allow3 == 1, (src & 1) == 1);
        if (HasFailure()) {
          LOG(ERROR) << "Failed for src=" << src
                     << " dst=" << dst
                     << " allow3=" << allow3;
          return;
        }
      }
    }
  }
}

TEST_F(GLHelperTest, CheckOptimizations) {
  // Test in baseclass since it is friends with GLHelperScaling
  CheckOptimizationsTest();
}

}  // namespace

// These tests needs to run against a proper GL environment, so we
// need to set it up before we can run the tests.
int main(int argc, char** argv) {
  CommandLine::Init(argc, argv);
  base::TestSuite* suite = new content::ContentTestSuite(argc, argv);
#if defined(OS_MACOSX)
  base::mac::ScopedNSAutoreleasePool pool;
#endif
#if defined(TOOLKIT_GTK)
  gfx::GtkInitFromCommandLine(*CommandLine::ForCurrentProcess());
#endif
  gfx::GLSurface::InitializeOneOff();
  gpu::ApplyGpuDriverBugWorkarounds(CommandLine::ForCurrentProcess());

  content::UnitTestTestSuite runner(suite);
  base::MessageLoop message_loop;
  return runner.Run();
}