// Copyright 2009 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.

#include "VideoBackends/Software/SWRenderer.h"

#include <algorithm>
#include <atomic>
#include <mutex>
#include <string>

#include "Common/CommonTypes.h"
#include "Common/Logging/Log.h"

#include "Core/Config/GraphicsSettings.h"
#include "Core/HW/Memmap.h"

#include "VideoBackends/Software/EfbCopy.h"
#include "VideoBackends/Software/SWOGLWindow.h"

#include "VideoCommon/BoundingBox.h"
#include "VideoCommon/OnScreenDisplay.h"
#include "VideoCommon/VideoBackendBase.h"
#include "VideoCommon/VideoConfig.h"

static u8* s_xfbColorTexture[2];
static int s_currentColorTexture = 0;

SWRenderer::SWRenderer()
    : ::Renderer(static_cast<int>(MAX_XFB_WIDTH), static_cast<int>(MAX_XFB_HEIGHT))
{
}

SWRenderer::~SWRenderer()
{
  delete[] s_xfbColorTexture[0];
  delete[] s_xfbColorTexture[1];
}

void SWRenderer::Init()
{
  s_xfbColorTexture[0] = new u8[MAX_XFB_WIDTH * MAX_XFB_HEIGHT * 4];
  s_xfbColorTexture[1] = new u8[MAX_XFB_WIDTH * MAX_XFB_HEIGHT * 4];

  s_currentColorTexture = 0;
}

void SWRenderer::Shutdown()
{
  g_Config.bRunning = false;
  UpdateActiveConfig();
}

void SWRenderer::RenderText(const std::string& pstr, int left, int top, u32 color)
{
  SWOGLWindow::s_instance->PrintText(pstr, left, top, color);
}

u8* SWRenderer::GetNextColorTexture()
{
  return s_xfbColorTexture[!s_currentColorTexture];
}

u8* SWRenderer::GetCurrentColorTexture()
{
  return s_xfbColorTexture[s_currentColorTexture];
}

void SWRenderer::SwapColorTexture()
{
  s_currentColorTexture = !s_currentColorTexture;
}

void SWRenderer::UpdateColorTexture(EfbInterface::yuv422_packed* xfb, u32 fbWidth, u32 fbHeight)
{
  if (fbWidth * fbHeight > MAX_XFB_WIDTH * MAX_XFB_HEIGHT)
  {
    ERROR_LOG(VIDEO, "Framebuffer is too large: %ix%i", fbWidth, fbHeight);
    return;
  }

  u32 offset = 0;
  u8* TexturePointer = GetNextColorTexture();

  for (u16 y = 0; y < fbHeight; y++)
  {
    for (u16 x = 0; x < fbWidth; x += 2)
    {
      // We do this one color sample (aka 2 RGB pixles) at a time
      int Y1 = xfb[x].Y - 16;
      int Y2 = xfb[x + 1].Y - 16;
      int U = int(xfb[x].UV) - 128;
      int V = int(xfb[x + 1].UV) - 128;

      // We do the inverse BT.601 conversion for YCbCr to RGB
      // http://www.equasys.de/colorconversion.html#YCbCr-RGBColorFormatConversion
      TexturePointer[offset++] = MathUtil::Clamp(int(1.164f * Y1 + 1.596f * V), 0, 255);
      TexturePointer[offset++] =
          MathUtil::Clamp(int(1.164f * Y1 - 0.392f * U - 0.813f * V), 0, 255);
      TexturePointer[offset++] = MathUtil::Clamp(int(1.164f * Y1 + 2.017f * U), 0, 255);
      TexturePointer[offset++] = 255;

      TexturePointer[offset++] = MathUtil::Clamp(int(1.164f * Y2 + 1.596f * V), 0, 255);
      TexturePointer[offset++] =
          MathUtil::Clamp(int(1.164f * Y2 - 0.392f * U - 0.813f * V), 0, 255);
      TexturePointer[offset++] = MathUtil::Clamp(int(1.164f * Y2 + 2.017f * U), 0, 255);
      TexturePointer[offset++] = 255;
    }
    xfb += fbWidth;
  }
  SwapColorTexture();
}

// Called on the GPU thread
void SWRenderer::SwapImpl(u32 xfbAddr, u32 fbWidth, u32 fbStride, u32 fbHeight,
                          const EFBRectangle& rc, u64 ticks, float Gamma)
{
  if (g_ActiveConfig.bUseXFB)
  {
    EfbInterface::yuv422_packed* xfb = (EfbInterface::yuv422_packed*)Memory::GetPointer(xfbAddr);
    UpdateColorTexture(xfb, fbWidth, fbHeight);
  }
  else
  {
    EfbInterface::BypassXFB(GetCurrentColorTexture(), fbWidth, fbHeight, rc, Gamma);
  }

  // Save screenshot
  if (IsFrameDumping())
  {
    AVIDump::Frame state = AVIDump::FetchState(ticks);
    DumpFrameData(GetCurrentColorTexture(), fbWidth, fbHeight, fbWidth * 4, state);
    FinishFrameData();
  }

  OSD::DoCallbacks(OSD::CallbackType::OnFrame);

  DrawDebugText();

  SWOGLWindow::s_instance->ShowImage(GetCurrentColorTexture(), fbWidth * 4, fbWidth, fbHeight, 1.0);

  UpdateActiveConfig();

  // virtual XFB is not supported
  if (g_ActiveConfig.bUseXFB)
  {
    Config::SetCurrent(Config::GFX_USE_REAL_XFB, true);
  }
}

u32 SWRenderer::AccessEFB(EFBAccessType type, u32 x, u32 y, u32 InputData)
{
  u32 value = 0;

  switch (type)
  {
  case EFBAccessType::PeekZ:
  {
    value = EfbInterface::GetDepth(x, y);
    break;
  }
  case EFBAccessType::PeekColor:
  {
    const u32 color = EfbInterface::GetColor(x, y);

    // rgba to argb
    value = (color >> 8) | (color & 0xff) << 24;
    break;
  }
  default:
    break;
  }

  return value;
}

u16 SWRenderer::BBoxRead(int index)
{
  return BoundingBox::coords[index];
}

void SWRenderer::BBoxWrite(int index, u16 value)
{
  BoundingBox::coords[index] = value;
}

TargetRectangle SWRenderer::ConvertEFBRectangle(const EFBRectangle& rc)
{
  TargetRectangle result;
  result.left = rc.left;
  result.top = rc.top;
  result.right = rc.right;
  result.bottom = rc.bottom;
  return result;
}

void SWRenderer::ClearScreen(const EFBRectangle& rc, bool colorEnable, bool alphaEnable,
                             bool zEnable, u32 color, u32 z)
{
  EfbCopy::ClearEfb();
}