// Copyright 2014 PDFium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com

#include "core/fpdfapi/render/render_int.h"

#include <memory>
#include <utility>
#include <vector>

#include "core/fpdfapi/page/cpdf_docpagedata.h"
#include "core/fpdfapi/page/cpdf_form.h"
#include "core/fpdfapi/page/cpdf_image.h"
#include "core/fpdfapi/page/cpdf_imageobject.h"
#include "core/fpdfapi/page/cpdf_page.h"
#include "core/fpdfapi/page/cpdf_shadingpattern.h"
#include "core/fpdfapi/page/cpdf_tilingpattern.h"
#include "core/fpdfapi/page/pageint.h"
#include "core/fpdfapi/parser/cpdf_array.h"
#include "core/fpdfapi/parser/cpdf_dictionary.h"
#include "core/fpdfapi/parser/cpdf_document.h"
#include "core/fpdfapi/render/cpdf_pagerendercache.h"
#include "core/fpdfapi/render/cpdf_rendercontext.h"
#include "core/fpdfapi/render/cpdf_renderoptions.h"
#include "core/fpdfapi/render/cpdf_renderstatus.h"
#include "core/fpdfapi/render/cpdf_transferfunc.h"
#include "core/fpdfdoc/cpdf_occontext.h"
#include "core/fxcodec/fx_codec.h"
#include "core/fxcrt/fx_safe_types.h"
#include "core/fxge/cfx_fxgedevice.h"
#include "core/fxge/cfx_pathdata.h"

#ifdef _SKIA_SUPPORT_
#include "core/fxge/skia/fx_skia_device.h"
#endif

CPDF_DIBTransferFunc::~CPDF_DIBTransferFunc() {}

FXDIB_Format CPDF_DIBTransferFunc::GetDestFormat() {
  if (m_pSrc->IsAlphaMask()) {
    return FXDIB_8bppMask;
  }
#if _FXM_PLATFORM_ == _FXM_PLATFORM_APPLE_
  return (m_pSrc->HasAlpha()) ? FXDIB_Argb : FXDIB_Rgb32;
#else
  return (m_pSrc->HasAlpha()) ? FXDIB_Argb : FXDIB_Rgb;
#endif
}

FX_ARGB* CPDF_DIBTransferFunc::GetDestPalette() {
  return nullptr;
}

CPDF_DIBTransferFunc::CPDF_DIBTransferFunc(
    const CPDF_TransferFunc* pTransferFunc) {
  m_RampR = pTransferFunc->m_Samples;
  m_RampG = &pTransferFunc->m_Samples[256];
  m_RampB = &pTransferFunc->m_Samples[512];
}

void CPDF_DIBTransferFunc::TranslateScanline(
    const uint8_t* src_buf,
    std::vector<uint8_t>* dest_buf) const {
  bool bSkip = false;
  switch (m_pSrc->GetFormat()) {
    case FXDIB_1bppRgb: {
      int r0 = m_RampR[0];
      int g0 = m_RampG[0];
      int b0 = m_RampB[0];
      int r1 = m_RampR[255];
      int g1 = m_RampG[255];
      int b1 = m_RampB[255];
      int index = 0;
      for (int i = 0; i < m_Width; i++) {
        if (src_buf[i / 8] & (1 << (7 - i % 8))) {
          (*dest_buf)[index++] = b1;
          (*dest_buf)[index++] = g1;
          (*dest_buf)[index++] = r1;
        } else {
          (*dest_buf)[index++] = b0;
          (*dest_buf)[index++] = g0;
          (*dest_buf)[index++] = r0;
        }
#if _FXM_PLATFORM_ == _FXM_PLATFORM_APPLE_
        index++;
#endif
      }
      break;
    }
    case FXDIB_1bppMask: {
      int m0 = m_RampR[0];
      int m1 = m_RampR[255];
      int index = 0;
      for (int i = 0; i < m_Width; i++) {
        if (src_buf[i / 8] & (1 << (7 - i % 8)))
          (*dest_buf)[index++] = m1;
        else
          (*dest_buf)[index++] = m0;
      }
      break;
    }
    case FXDIB_8bppRgb: {
      FX_ARGB* pPal = m_pSrc->GetPalette();
      int index = 0;
      for (int i = 0; i < m_Width; i++) {
        if (pPal) {
          FX_ARGB src_argb = pPal[*src_buf];
          (*dest_buf)[index++] = m_RampB[FXARGB_R(src_argb)];
          (*dest_buf)[index++] = m_RampG[FXARGB_G(src_argb)];
          (*dest_buf)[index++] = m_RampR[FXARGB_B(src_argb)];
        } else {
          uint32_t src_byte = *src_buf;
          (*dest_buf)[index++] = m_RampB[src_byte];
          (*dest_buf)[index++] = m_RampG[src_byte];
          (*dest_buf)[index++] = m_RampR[src_byte];
        }
        src_buf++;
#if _FXM_PLATFORM_ == _FXM_PLATFORM_APPLE_
        index++;
#endif
      }
      break;
    }
    case FXDIB_8bppMask: {
      int index = 0;
      for (int i = 0; i < m_Width; i++) {
        (*dest_buf)[index++] = m_RampR[*(src_buf++)];
      }
      break;
    }
    case FXDIB_Rgb: {
      int index = 0;
      for (int i = 0; i < m_Width; i++) {
        (*dest_buf)[index++] = m_RampB[*(src_buf++)];
        (*dest_buf)[index++] = m_RampG[*(src_buf++)];
        (*dest_buf)[index++] = m_RampR[*(src_buf++)];
#if _FXM_PLATFORM_ == _FXM_PLATFORM_APPLE_
        index++;
#endif
      }
      break;
    }
    case FXDIB_Rgb32:
      bSkip = true;
    case FXDIB_Argb: {
      int index = 0;
      for (int i = 0; i < m_Width; i++) {
        (*dest_buf)[index++] = m_RampB[*(src_buf++)];
        (*dest_buf)[index++] = m_RampG[*(src_buf++)];
        (*dest_buf)[index++] = m_RampR[*(src_buf++)];
        if (!bSkip) {
          (*dest_buf)[index++] = *src_buf;
#if _FXM_PLATFORM_ == _FXM_PLATFORM_APPLE_
        } else {
          index++;
#endif
        }
        src_buf++;
      }
      break;
    }
    default:
      break;
  }
}

void CPDF_DIBTransferFunc::TranslateDownSamples(uint8_t* dest_buf,
                                                const uint8_t* src_buf,
                                                int pixels,
                                                int Bpp) const {
  if (Bpp == 8) {
    for (int i = 0; i < pixels; i++) {
      *dest_buf++ = m_RampR[*(src_buf++)];
    }
  } else if (Bpp == 24) {
    for (int i = 0; i < pixels; i++) {
      *dest_buf++ = m_RampB[*(src_buf++)];
      *dest_buf++ = m_RampG[*(src_buf++)];
      *dest_buf++ = m_RampR[*(src_buf++)];
    }
  } else {
#if _FXM_PLATFORM_ == _FXM_PLATFORM_APPLE_
    if (!m_pSrc->HasAlpha()) {
      for (int i = 0; i < pixels; i++) {
        *dest_buf++ = m_RampB[*(src_buf++)];
        *dest_buf++ = m_RampG[*(src_buf++)];
        *dest_buf++ = m_RampR[*(src_buf++)];
        dest_buf++;
        src_buf++;
      }
    } else {
#endif
      for (int i = 0; i < pixels; i++) {
        *dest_buf++ = m_RampB[*(src_buf++)];
        *dest_buf++ = m_RampG[*(src_buf++)];
        *dest_buf++ = m_RampR[*(src_buf++)];
        *dest_buf++ = *(src_buf++);
      }
#if _FXM_PLATFORM_ == _FXM_PLATFORM_APPLE_
    }
#endif
  }
}

CPDF_ImageRenderer::CPDF_ImageRenderer() {
  m_pRenderStatus = nullptr;
  m_pImageObject = nullptr;
  m_Result = true;
  m_Status = 0;
  m_DeviceHandle = nullptr;
  m_bStdCS = false;
  m_bPatternColor = false;
  m_BlendType = FXDIB_BLEND_NORMAL;
  m_pPattern = nullptr;
  m_pObj2Device = nullptr;
}

CPDF_ImageRenderer::~CPDF_ImageRenderer() {
  if (m_DeviceHandle) {
    m_pRenderStatus->m_pDevice->CancelDIBits(m_DeviceHandle);
  }
}

bool CPDF_ImageRenderer::StartLoadDIBSource() {
  CFX_FloatRect image_rect_f = m_ImageMatrix.GetUnitRect();
  FX_RECT image_rect = image_rect_f.GetOuterRect();
  if (!image_rect.Valid())
    return false;

  int dest_width = image_rect.Width();
  int dest_height = image_rect.Height();
  if (m_ImageMatrix.a < 0) {
    dest_width = -dest_width;
  }
  if (m_ImageMatrix.d > 0) {
    dest_height = -dest_height;
  }
  if (m_Loader.Start(
          m_pImageObject, m_pRenderStatus->m_pContext->GetPageCache(), m_bStdCS,
          m_pRenderStatus->m_GroupFamily, m_pRenderStatus->m_bLoadMask,
          m_pRenderStatus, dest_width, dest_height)) {
    m_Status = 4;
    return true;
  }
  return false;
}

bool CPDF_ImageRenderer::StartRenderDIBSource() {
  if (!m_Loader.m_pBitmap)
    return false;

  m_BitmapAlpha =
      FXSYS_round(255 * m_pImageObject->m_GeneralState.GetFillAlpha());
  m_pDIBSource = m_Loader.m_pBitmap;
  if (m_pRenderStatus->m_Options.m_ColorMode == RENDER_COLOR_ALPHA &&
      !m_Loader.m_pMask) {
    return StartBitmapAlpha();
  }
  if (m_pImageObject->m_GeneralState.GetTR()) {
    if (!m_pImageObject->m_GeneralState.GetTransferFunc()) {
      m_pImageObject->m_GeneralState.SetTransferFunc(
          m_pRenderStatus->GetTransferFunc(
              m_pImageObject->m_GeneralState.GetTR()));
    }
    if (m_pImageObject->m_GeneralState.GetTransferFunc() &&
        !m_pImageObject->m_GeneralState.GetTransferFunc()->m_bIdentity) {
      m_pDIBSource = m_Loader.m_pBitmap =
          m_pImageObject->m_GeneralState.GetTransferFunc()->TranslateImage(
              m_Loader.m_pBitmap, !m_Loader.m_bCached);
      if (m_Loader.m_bCached && m_Loader.m_pMask) {
        m_Loader.m_pMask = m_Loader.m_pMask->Clone();
      }
      m_Loader.m_bCached = false;
    }
  }
  m_FillArgb = 0;
  m_bPatternColor = false;
  m_pPattern = nullptr;
  if (m_pDIBSource->IsAlphaMask()) {
    const CPDF_Color* pColor = m_pImageObject->m_ColorState.GetFillColor();
    if (pColor && pColor->IsPattern()) {
      m_pPattern = pColor->GetPattern();
      if (m_pPattern) {
        m_bPatternColor = true;
      }
    }
    m_FillArgb = m_pRenderStatus->GetFillArgb(m_pImageObject);
  } else if (m_pRenderStatus->m_Options.m_ColorMode == RENDER_COLOR_GRAY) {
    m_pClone.reset(m_pDIBSource->Clone());
    m_pClone->ConvertColorScale(m_pRenderStatus->m_Options.m_BackColor,
                                m_pRenderStatus->m_Options.m_ForeColor);
    m_pDIBSource = m_pClone.get();
  }
  m_Flags = 0;
  if (m_pRenderStatus->m_Options.m_Flags & RENDER_FORCE_DOWNSAMPLE) {
    m_Flags |= RENDER_FORCE_DOWNSAMPLE;
  } else if (m_pRenderStatus->m_Options.m_Flags & RENDER_FORCE_HALFTONE) {
    m_Flags |= RENDER_FORCE_HALFTONE;
  }
  if (m_pRenderStatus->m_pDevice->GetDeviceClass() != FXDC_DISPLAY) {
    CPDF_Object* pFilters =
        m_pImageObject->GetImage()->GetStream()->GetDict()->GetDirectObjectFor(
            "Filter");
    if (pFilters) {
      if (pFilters->IsName()) {
        CFX_ByteString bsDecodeType = pFilters->GetString();
        if (bsDecodeType == "DCTDecode" || bsDecodeType == "JPXDecode") {
          m_Flags |= FXRENDER_IMAGE_LOSSY;
        }
      } else if (CPDF_Array* pArray = pFilters->AsArray()) {
        for (size_t i = 0; i < pArray->GetCount(); i++) {
          CFX_ByteString bsDecodeType = pArray->GetStringAt(i);
          if (bsDecodeType == "DCTDecode" || bsDecodeType == "JPXDecode") {
            m_Flags |= FXRENDER_IMAGE_LOSSY;
            break;
          }
        }
      }
    }
  }
  if (m_pRenderStatus->m_Options.m_Flags & RENDER_NOIMAGESMOOTH) {
    m_Flags |= FXDIB_NOSMOOTH;
  } else if (m_pImageObject->GetImage()->IsInterpol()) {
    m_Flags |= FXDIB_INTERPOL;
  }
  if (m_Loader.m_pMask) {
    return DrawMaskedImage();
  }
  if (m_bPatternColor) {
    return DrawPatternImage(m_pObj2Device);
  }
  if (m_BitmapAlpha == 255 && m_pImageObject->m_GeneralState &&
      m_pImageObject->m_GeneralState.GetFillOP() &&
      m_pImageObject->m_GeneralState.GetOPMode() == 0 &&
      m_pImageObject->m_GeneralState.GetBlendType() == FXDIB_BLEND_NORMAL &&
      m_pImageObject->m_GeneralState.GetStrokeAlpha() == 1.0f &&
      m_pImageObject->m_GeneralState.GetFillAlpha() == 1.0f) {
    CPDF_Document* pDocument = nullptr;
    CPDF_Page* pPage = nullptr;
    if (m_pRenderStatus->m_pContext->GetPageCache()) {
      pPage = m_pRenderStatus->m_pContext->GetPageCache()->GetPage();
      pDocument = pPage->m_pDocument;
    } else {
      pDocument = m_pImageObject->GetImage()->GetDocument();
    }
    CPDF_Dictionary* pPageResources = pPage ? pPage->m_pPageResources : nullptr;
    CPDF_Object* pCSObj =
        m_pImageObject->GetImage()->GetStream()->GetDict()->GetDirectObjectFor(
            "ColorSpace");
    CPDF_ColorSpace* pColorSpace =
        pDocument->LoadColorSpace(pCSObj, pPageResources);
    if (pColorSpace) {
      int format = pColorSpace->GetFamily();
      if (format == PDFCS_DEVICECMYK || format == PDFCS_SEPARATION ||
          format == PDFCS_DEVICEN) {
        m_BlendType = FXDIB_BLEND_DARKEN;
      }
      pDocument->GetPageData()->ReleaseColorSpace(pCSObj);
    }
  }
  return StartDIBSource();
}

bool CPDF_ImageRenderer::Start(CPDF_RenderStatus* pStatus,
                               CPDF_PageObject* pObj,
                               const CFX_Matrix* pObj2Device,
                               bool bStdCS,
                               int blendType) {
  m_pRenderStatus = pStatus;
  m_bStdCS = bStdCS;
  m_pImageObject = pObj->AsImage();
  m_BlendType = blendType;
  m_pObj2Device = pObj2Device;
  CPDF_Dictionary* pOC = m_pImageObject->GetImage()->GetOC();
  if (pOC && m_pRenderStatus->m_Options.m_pOCContext &&
      !m_pRenderStatus->m_Options.m_pOCContext->CheckOCGVisible(pOC)) {
    return false;
  }
  m_ImageMatrix = m_pImageObject->m_Matrix;
  m_ImageMatrix.Concat(*pObj2Device);
  if (StartLoadDIBSource()) {
    return true;
  }
  return StartRenderDIBSource();
}

bool CPDF_ImageRenderer::Start(CPDF_RenderStatus* pStatus,
                               const CFX_DIBSource* pDIBSource,
                               FX_ARGB bitmap_argb,
                               int bitmap_alpha,
                               const CFX_Matrix* pImage2Device,
                               uint32_t flags,
                               bool bStdCS,
                               int blendType) {
  m_pRenderStatus = pStatus;
  m_pDIBSource = pDIBSource;
  m_FillArgb = bitmap_argb;
  m_BitmapAlpha = bitmap_alpha;
  m_ImageMatrix = *pImage2Device;
  m_Flags = flags;
  m_bStdCS = bStdCS;
  m_BlendType = blendType;
  return StartDIBSource();
}

bool CPDF_ImageRenderer::DrawPatternImage(const CFX_Matrix* pObj2Device) {
  if (m_pRenderStatus->m_bPrint &&
      !(m_pRenderStatus->m_pDevice->GetRenderCaps() & FXRC_BLEND_MODE)) {
    m_Result = false;
    return false;
  }
  FX_RECT rect = m_ImageMatrix.GetUnitRect().GetOuterRect();
  rect.Intersect(m_pRenderStatus->m_pDevice->GetClipBox());
  if (rect.IsEmpty()) {
    return false;
  }
  CFX_Matrix new_matrix = m_ImageMatrix;
  new_matrix.TranslateI(-rect.left, -rect.top);
  int width = rect.Width();
  int height = rect.Height();
  CFX_FxgeDevice bitmap_device1;
  if (!bitmap_device1.Create(rect.Width(), rect.Height(), FXDIB_Rgb32, nullptr))
    return true;

  bitmap_device1.GetBitmap()->Clear(0xffffff);
  {
    CPDF_RenderStatus bitmap_render;
    bitmap_render.Initialize(m_pRenderStatus->m_pContext, &bitmap_device1,
                             nullptr, nullptr, nullptr, nullptr,
                             &m_pRenderStatus->m_Options, 0,
                             m_pRenderStatus->m_bDropObjects, nullptr, true);
    CFX_Matrix patternDevice = *pObj2Device;
    patternDevice.Translate((FX_FLOAT)-rect.left, (FX_FLOAT)-rect.top);
    if (CPDF_TilingPattern* pTilingPattern = m_pPattern->AsTilingPattern()) {
      bitmap_render.DrawTilingPattern(pTilingPattern, m_pImageObject,
                                      &patternDevice, false);
    } else if (CPDF_ShadingPattern* pShadingPattern =
                   m_pPattern->AsShadingPattern()) {
      bitmap_render.DrawShadingPattern(pShadingPattern, m_pImageObject,
                                       &patternDevice, false);
    }
  }
  {
    CFX_FxgeDevice bitmap_device2;
    if (!bitmap_device2.Create(rect.Width(), rect.Height(), FXDIB_8bppRgb,
                               nullptr)) {
      return true;
    }
    bitmap_device2.GetBitmap()->Clear(0);
    CPDF_RenderStatus bitmap_render;
    bitmap_render.Initialize(m_pRenderStatus->m_pContext, &bitmap_device2,
                             nullptr, nullptr, nullptr, nullptr, nullptr, 0,
                             m_pRenderStatus->m_bDropObjects, nullptr, true);
    CPDF_ImageRenderer image_render;
    if (image_render.Start(&bitmap_render, m_pDIBSource, 0xffffffff, 255,
                           &new_matrix, m_Flags, true)) {
      image_render.Continue(nullptr);
    }
    if (m_Loader.m_MatteColor != 0xffffffff) {
      int matte_r = FXARGB_R(m_Loader.m_MatteColor);
      int matte_g = FXARGB_G(m_Loader.m_MatteColor);
      int matte_b = FXARGB_B(m_Loader.m_MatteColor);
      for (int row = 0; row < height; row++) {
        uint8_t* dest_scan =
            (uint8_t*)bitmap_device1.GetBitmap()->GetScanline(row);
        const uint8_t* mask_scan = bitmap_device2.GetBitmap()->GetScanline(row);
        for (int col = 0; col < width; col++) {
          int alpha = *mask_scan++;
          if (alpha) {
            int orig = (*dest_scan - matte_b) * 255 / alpha + matte_b;
            if (orig < 0) {
              orig = 0;
            } else if (orig > 255) {
              orig = 255;
            }
            *dest_scan++ = orig;
            orig = (*dest_scan - matte_g) * 255 / alpha + matte_g;
            if (orig < 0) {
              orig = 0;
            } else if (orig > 255) {
              orig = 255;
            }
            *dest_scan++ = orig;
            orig = (*dest_scan - matte_r) * 255 / alpha + matte_r;
            if (orig < 0) {
              orig = 0;
            } else if (orig > 255) {
              orig = 255;
            }
            *dest_scan++ = orig;
            dest_scan++;
          } else {
            dest_scan += 4;
          }
        }
      }
    }
    bitmap_device2.GetBitmap()->ConvertFormat(FXDIB_8bppMask);
    bitmap_device1.GetBitmap()->MultiplyAlpha(bitmap_device2.GetBitmap());
    bitmap_device1.GetBitmap()->MultiplyAlpha(255);
  }
  m_pRenderStatus->m_pDevice->SetDIBitsWithBlend(
      bitmap_device1.GetBitmap(), rect.left, rect.top, m_BlendType);
  return false;
}

bool CPDF_ImageRenderer::DrawMaskedImage() {
  if (m_pRenderStatus->m_bPrint &&
      !(m_pRenderStatus->m_pDevice->GetRenderCaps() & FXRC_BLEND_MODE)) {
    m_Result = false;
    return false;
  }
  FX_RECT rect = m_ImageMatrix.GetUnitRect().GetOuterRect();
  rect.Intersect(m_pRenderStatus->m_pDevice->GetClipBox());
  if (rect.IsEmpty()) {
    return false;
  }
  CFX_Matrix new_matrix = m_ImageMatrix;
  new_matrix.TranslateI(-rect.left, -rect.top);
  int width = rect.Width();
  int height = rect.Height();
  CFX_FxgeDevice bitmap_device1;
  if (!bitmap_device1.Create(width, height, FXDIB_Rgb32, nullptr))
    return true;

#if defined _SKIA_SUPPORT_
  bitmap_device1.Clear(0xffffff);
#else
  bitmap_device1.GetBitmap()->Clear(0xffffff);
#endif
  {
    CPDF_RenderStatus bitmap_render;
    bitmap_render.Initialize(m_pRenderStatus->m_pContext, &bitmap_device1,
                             nullptr, nullptr, nullptr, nullptr, nullptr, 0,
                             m_pRenderStatus->m_bDropObjects, nullptr, true);
    CPDF_ImageRenderer image_render;
    if (image_render.Start(&bitmap_render, m_pDIBSource, 0, 255, &new_matrix,
                           m_Flags, true)) {
      image_render.Continue(nullptr);
    }
  }
  {
    CFX_FxgeDevice bitmap_device2;
    if (!bitmap_device2.Create(width, height, FXDIB_8bppRgb, nullptr))
      return true;

#if defined _SKIA_SUPPORT_
    bitmap_device2.Clear(0);
#else
    bitmap_device2.GetBitmap()->Clear(0);
#endif
    CPDF_RenderStatus bitmap_render;
    bitmap_render.Initialize(m_pRenderStatus->m_pContext, &bitmap_device2,
                             nullptr, nullptr, nullptr, nullptr, nullptr, 0,
                             m_pRenderStatus->m_bDropObjects, nullptr, true);
    CPDF_ImageRenderer image_render;
    if (image_render.Start(&bitmap_render, m_Loader.m_pMask, 0xffffffff, 255,
                           &new_matrix, m_Flags, true)) {
      image_render.Continue(nullptr);
    }
    if (m_Loader.m_MatteColor != 0xffffffff) {
      int matte_r = FXARGB_R(m_Loader.m_MatteColor);
      int matte_g = FXARGB_G(m_Loader.m_MatteColor);
      int matte_b = FXARGB_B(m_Loader.m_MatteColor);
      for (int row = 0; row < height; row++) {
        uint8_t* dest_scan =
            (uint8_t*)bitmap_device1.GetBitmap()->GetScanline(row);
        const uint8_t* mask_scan = bitmap_device2.GetBitmap()->GetScanline(row);
        for (int col = 0; col < width; col++) {
          int alpha = *mask_scan++;
          if (alpha) {
            int orig = (*dest_scan - matte_b) * 255 / alpha + matte_b;
            if (orig < 0) {
              orig = 0;
            } else if (orig > 255) {
              orig = 255;
            }
            *dest_scan++ = orig;
            orig = (*dest_scan - matte_g) * 255 / alpha + matte_g;
            if (orig < 0) {
              orig = 0;
            } else if (orig > 255) {
              orig = 255;
            }
            *dest_scan++ = orig;
            orig = (*dest_scan - matte_r) * 255 / alpha + matte_r;
            if (orig < 0) {
              orig = 0;
            } else if (orig > 255) {
              orig = 255;
            }
            *dest_scan++ = orig;
            dest_scan++;
          } else {
            dest_scan += 4;
          }
        }
      }
    }
#ifdef _SKIA_SUPPORT_
    m_pRenderStatus->m_pDevice->SetBitsWithMask(
        bitmap_device1.GetBitmap(), bitmap_device2.GetBitmap(), rect.left,
        rect.top, m_BitmapAlpha, m_BlendType);
  }
#else
    bitmap_device2.GetBitmap()->ConvertFormat(FXDIB_8bppMask);
    bitmap_device1.GetBitmap()->MultiplyAlpha(bitmap_device2.GetBitmap());
    if (m_BitmapAlpha < 255) {
      bitmap_device1.GetBitmap()->MultiplyAlpha(m_BitmapAlpha);
    }
  }
  m_pRenderStatus->m_pDevice->SetDIBitsWithBlend(
      bitmap_device1.GetBitmap(), rect.left, rect.top, m_BlendType);
#endif  //  _SKIA_SUPPORT_
  return false;
}

bool CPDF_ImageRenderer::StartDIBSource() {
  if (!(m_Flags & RENDER_FORCE_DOWNSAMPLE) && m_pDIBSource->GetBPP() > 1) {
    FX_SAFE_SIZE_T image_size = m_pDIBSource->GetBPP();
    image_size /= 8;
    image_size *= m_pDIBSource->GetWidth();
    image_size *= m_pDIBSource->GetHeight();
    if (!image_size.IsValid()) {
      return false;
    }

    if (image_size.ValueOrDie() > FPDF_HUGE_IMAGE_SIZE &&
        !(m_Flags & RENDER_FORCE_HALFTONE)) {
      m_Flags |= RENDER_FORCE_DOWNSAMPLE;
    }
  }
#ifdef _SKIA_SUPPORT_
  CFX_DIBitmap* premultiplied = m_pDIBSource->Clone();
  if (m_pDIBSource->HasAlpha())
    CFX_SkiaDeviceDriver::PreMultiply(premultiplied);
  if (m_pRenderStatus->m_pDevice->StartDIBitsWithBlend(
          premultiplied, m_BitmapAlpha, m_FillArgb, &m_ImageMatrix, m_Flags,
          m_DeviceHandle, m_BlendType)) {
    if (m_DeviceHandle) {
      m_Status = 3;
      return true;
    }
    return false;
  }
#else
  if (m_pRenderStatus->m_pDevice->StartDIBitsWithBlend(
          m_pDIBSource, m_BitmapAlpha, m_FillArgb, &m_ImageMatrix, m_Flags,
          m_DeviceHandle, m_BlendType)) {
    if (m_DeviceHandle) {
      m_Status = 3;
      return true;
    }
    return false;
  }
#endif
  CFX_FloatRect image_rect_f = m_ImageMatrix.GetUnitRect();
  FX_RECT image_rect = image_rect_f.GetOuterRect();
  int dest_width = image_rect.Width();
  int dest_height = image_rect.Height();
  if ((FXSYS_fabs(m_ImageMatrix.b) >= 0.5f || m_ImageMatrix.a == 0) ||
      (FXSYS_fabs(m_ImageMatrix.c) >= 0.5f || m_ImageMatrix.d == 0)) {
    if (m_pRenderStatus->m_bPrint &&
        !(m_pRenderStatus->m_pDevice->GetRenderCaps() & FXRC_BLEND_MODE)) {
      m_Result = false;
      return false;
    }
    FX_RECT clip_box = m_pRenderStatus->m_pDevice->GetClipBox();
    clip_box.Intersect(image_rect);
    m_Status = 2;
    m_pTransformer.reset(new CFX_ImageTransformer(m_pDIBSource, &m_ImageMatrix,
                                                  m_Flags, &clip_box));
    m_pTransformer->Start();
    return true;
  }
  if (m_ImageMatrix.a < 0)
    dest_width = -dest_width;

  if (m_ImageMatrix.d > 0)
    dest_height = -dest_height;

  int dest_left = dest_width > 0 ? image_rect.left : image_rect.right;
  int dest_top = dest_height > 0 ? image_rect.top : image_rect.bottom;
  if (m_pDIBSource->IsOpaqueImage() && m_BitmapAlpha == 255) {
    if (m_pRenderStatus->m_pDevice->StretchDIBitsWithFlagsAndBlend(
            m_pDIBSource, dest_left, dest_top, dest_width, dest_height, m_Flags,
            m_BlendType)) {
      return false;
    }
  }
  if (m_pDIBSource->IsAlphaMask()) {
    if (m_BitmapAlpha != 255)
      m_FillArgb = FXARGB_MUL_ALPHA(m_FillArgb, m_BitmapAlpha);
    if (m_pRenderStatus->m_pDevice->StretchBitMaskWithFlags(
            m_pDIBSource, dest_left, dest_top, dest_width, dest_height,
            m_FillArgb, m_Flags)) {
      return false;
    }
  }
  if (m_pRenderStatus->m_bPrint &&
      !(m_pRenderStatus->m_pDevice->GetRenderCaps() & FXRC_BLEND_MODE)) {
    m_Result = false;
    return true;
  }

  FX_RECT clip_box = m_pRenderStatus->m_pDevice->GetClipBox();
  FX_RECT dest_rect = clip_box;
  dest_rect.Intersect(image_rect);
  FX_RECT dest_clip(
      dest_rect.left - image_rect.left, dest_rect.top - image_rect.top,
      dest_rect.right - image_rect.left, dest_rect.bottom - image_rect.top);
  std::unique_ptr<CFX_DIBitmap> pStretched(
      m_pDIBSource->StretchTo(dest_width, dest_height, m_Flags, &dest_clip));
  if (pStretched) {
    m_pRenderStatus->CompositeDIBitmap(pStretched.get(), dest_rect.left,
                                       dest_rect.top, m_FillArgb, m_BitmapAlpha,
                                       m_BlendType, false);
  }
  return false;
}

bool CPDF_ImageRenderer::StartBitmapAlpha() {
  if (m_pDIBSource->IsOpaqueImage()) {
    CFX_PathData path;
    path.AppendRect(0, 0, 1, 1);
    path.Transform(&m_ImageMatrix);
    uint32_t fill_color =
        ArgbEncode(0xff, m_BitmapAlpha, m_BitmapAlpha, m_BitmapAlpha);
    m_pRenderStatus->m_pDevice->DrawPath(&path, nullptr, nullptr, fill_color, 0,
                                         FXFILL_WINDING);
  } else {
    const CFX_DIBSource* pAlphaMask = m_pDIBSource->IsAlphaMask()
                                          ? m_pDIBSource
                                          : m_pDIBSource->GetAlphaMask();
    if (FXSYS_fabs(m_ImageMatrix.b) >= 0.5f ||
        FXSYS_fabs(m_ImageMatrix.c) >= 0.5f) {
      int left, top;
      std::unique_ptr<CFX_DIBitmap> pTransformed(
          pAlphaMask->TransformTo(&m_ImageMatrix, left, top));
      if (!pTransformed)
        return true;

      m_pRenderStatus->m_pDevice->SetBitMask(
          pTransformed.get(), left, top,
          ArgbEncode(0xff, m_BitmapAlpha, m_BitmapAlpha, m_BitmapAlpha));
    } else {
      CFX_FloatRect image_rect_f = m_ImageMatrix.GetUnitRect();
      FX_RECT image_rect = image_rect_f.GetOuterRect();
      int dest_width =
          m_ImageMatrix.a > 0 ? image_rect.Width() : -image_rect.Width();
      int dest_height =
          m_ImageMatrix.d > 0 ? -image_rect.Height() : image_rect.Height();
      int left = dest_width > 0 ? image_rect.left : image_rect.right;
      int top = dest_height > 0 ? image_rect.top : image_rect.bottom;
      m_pRenderStatus->m_pDevice->StretchBitMask(
          pAlphaMask, left, top, dest_width, dest_height,
          ArgbEncode(0xff, m_BitmapAlpha, m_BitmapAlpha, m_BitmapAlpha));
    }
    if (m_pDIBSource != pAlphaMask) {
      delete pAlphaMask;
    }
  }
  return false;
}

bool CPDF_ImageRenderer::Continue(IFX_Pause* pPause) {
  if (m_Status == 2) {
    if (m_pTransformer->Continue(pPause))
      return true;

    std::unique_ptr<CFX_DIBitmap> pBitmap(m_pTransformer->DetachBitmap());
    if (!pBitmap)
      return false;

    if (pBitmap->IsAlphaMask()) {
      if (m_BitmapAlpha != 255)
        m_FillArgb = FXARGB_MUL_ALPHA(m_FillArgb, m_BitmapAlpha);
      m_Result = m_pRenderStatus->m_pDevice->SetBitMask(
          pBitmap.get(), m_pTransformer->result().left,
          m_pTransformer->result().top, m_FillArgb);
    } else {
      if (m_BitmapAlpha != 255)
        pBitmap->MultiplyAlpha(m_BitmapAlpha);
      m_Result = m_pRenderStatus->m_pDevice->SetDIBitsWithBlend(
          pBitmap.get(), m_pTransformer->result().left,
          m_pTransformer->result().top, m_BlendType);
    }
    return false;
  }
  if (m_Status == 3)
    return m_pRenderStatus->m_pDevice->ContinueDIBits(m_DeviceHandle, pPause);

  if (m_Status == 4) {
    if (m_Loader.Continue(pPause))
      return true;

    if (StartRenderDIBSource())
      return Continue(pPause);
  }
  return false;
}

CCodec_ScanlineDecoder* FPDFAPI_CreateFlateDecoder(
    const uint8_t* src_buf,
    uint32_t src_size,
    int width,
    int height,
    int nComps,
    int bpc,
    const CPDF_Dictionary* pParams);