gecko-dev/gfx/thebes/gfxAlphaRecovery.cpp

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "gfxAlphaRecovery.h"

#include "gfxImageSurface.h"

#define MOZILLA_SSE_INCLUDE_HEADER_FOR_SSE2
#include "mozilla/SSE.h"

/* static */
bool gfxAlphaRecovery::RecoverAlpha(gfxImageSurface* blackSurf,
                                    const gfxImageSurface* whiteSurf) {
  mozilla::gfx::IntSize size = blackSurf->GetSize();

  if (size != whiteSurf->GetSize() ||
      (blackSurf->Format() != mozilla::gfx::SurfaceFormat::A8R8G8B8_UINT32 &&
       blackSurf->Format() != mozilla::gfx::SurfaceFormat::X8R8G8B8_UINT32) ||
      (whiteSurf->Format() != mozilla::gfx::SurfaceFormat::A8R8G8B8_UINT32 &&
       whiteSurf->Format() != mozilla::gfx::SurfaceFormat::X8R8G8B8_UINT32))
    return false;

#ifdef MOZILLA_MAY_SUPPORT_SSE2
  if (mozilla::supports_sse2() && RecoverAlphaSSE2(blackSurf, whiteSurf)) {
    return true;
  }
#endif

  blackSurf->Flush();
  whiteSurf->Flush();

  unsigned char* blackData = blackSurf->Data();
  unsigned char* whiteData = whiteSurf->Data();

  for (int32_t i = 0; i < size.height; ++i) {
    uint32_t* blackPixel = reinterpret_cast<uint32_t*>(blackData);
    const uint32_t* whitePixel = reinterpret_cast<uint32_t*>(whiteData);
    for (int32_t j = 0; j < size.width; ++j) {
      uint32_t recovered = RecoverPixel(blackPixel[j], whitePixel[j]);
      blackPixel[j] = recovered;
    }
    blackData += blackSurf->Stride();
    whiteData += whiteSurf->Stride();
  }

  blackSurf->MarkDirty();

  return true;
}