Move skia extensions from the port to skia/ext.

webkit/port/platform/graphics/skia/public/BitmapPlatformDeviceWin.cpp

Index: webkit/port/platform/graphics/skia/public/BitmapPlatformDeviceWin.cpp
===================================================================
--- webkit/port/platform/graphics/skia/public/BitmapPlatformDeviceWin.cpp	(revision 5845)
+++ webkit/port/platform/graphics/skia/public/BitmapPlatformDeviceWin.cpp	(working copy)
@@ -1,446 +0,0 @@
-// Copyright (c) 2006-2008 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 "BitmapPlatformDeviceWin.h"
-
-#include "base/gfx/gdi_util.h"
-#include "base/logging.h"
-#include "SkMatrix.h"
-#include "SkRegion.h"
-#include "SkUtils.h"
-
-namespace gfx {
-
-// When Windows draws text, is sets the fourth byte (which Skia uses for alpha)
-// to zero. This means that if we try compositing with text that Windows has
-// drawn, we get invalid color values (if the alpha is 0, the other channels
-// should be 0 since Skia uses premultiplied colors) and strange results.
-//
-// HTML rendering only requires one bit of transparency. When you ask for a
-// semitransparent div, the div itself is drawn in another layer as completely
-// opaque, and then composited onto the lower layer with a transfer function.
-// The only place an alpha channel is needed is to track what has been drawn
-// and what has not been drawn.
-//
-// Therefore, when we allocate a new device, we fill it with this special
-// color. Because Skia uses premultiplied colors, any color where the alpha
-// channel is smaller than any component is impossible, so we know that no
-// legitimate drawing will produce this color. We use 1 as the alpha value
-// because 0 is produced when Windows draws text (even though it should be
-// opaque).
-//
-// When a layer is done and we want to render it to a lower layer, we use
-// fixupAlphaBeforeCompositing. This replaces all 0 alpha channels with
-// opaque (to fix the text problem), and replaces this magic color value
-// with transparency. The result is something that can be correctly
-// composited. However, once this has been done, no more can be drawn to
-// the layer because fixing the alphas *again* will result in incorrect
-// values.
-static const uint32_t kMagicTransparencyColor = 0x01FFFEFD;
-
-namespace {
-
-// Constrains position and size to fit within available_size. If |size| is -1,
-// all the available_size is used. Returns false if the position is out of
-// available_size.
-bool Constrain(int available_size, int* position, int *size) {
-  if (*size < -2)
-    return false;
-
-  if (*position < 0) {
-    if (*size != -1)
-      *size += *position;
-    *position = 0;
-  }
-  if (*size == 0 || *position >= available_size)
-    return false;
-
-  if (*size > 0) {
-    int overflow = (*position + *size) - available_size;
-    if (overflow > 0) {
-      *size -= overflow;
-    }
-  } else {
-    // Fill up available size.
-    *size = available_size - *position;
-  }
-  return true;
-}
-
-// If the pixel value is 0, it gets set to kMagicTransparencyColor.
-void PrepareAlphaForGDI(uint32_t* pixel) {
-  if (*pixel == 0) {
-    *pixel = kMagicTransparencyColor;
-  }
-}
-
-// If the pixel value is kMagicTransparencyColor, it gets set to 0. Otherwise
-// if the alpha is 0, the alpha is set to 255.
-void PostProcessAlphaForGDI(uint32_t* pixel) {
-  if (*pixel == kMagicTransparencyColor) {
-    *pixel = 0;
-  } else if ((*pixel & 0xFF000000) == 0) {
-    *pixel |= 0xFF000000;
-  }
-}
-
-// Sets the opacity of the specified value to 0xFF.
-void MakeOpaqueAlphaAdjuster(uint32_t* pixel) {
-  *pixel |= 0xFF000000;
-}
-
-// See the declaration of kMagicTransparencyColor at the top of the file.
-void FixupAlphaBeforeCompositing(uint32_t* pixel) {
-  if (*pixel == kMagicTransparencyColor)
-    *pixel = 0;
-  else
-    *pixel |= 0xFF000000;
-}
-
-}  // namespace
-
-class BitmapPlatformDeviceWin::BitmapPlatformDeviceWinData
-    : public base::RefCounted<BitmapPlatformDeviceWinData> {
- public:
-  explicit BitmapPlatformDeviceWinData(HBITMAP hbitmap);
-
-  // Create/destroy hdc_, which is the memory DC for our bitmap data.
-  HDC GetBitmapDC();
-  void ReleaseBitmapDC();
-  bool IsBitmapDCCreated() const;
-
-  // Sets the transform and clip operations. This will not update the DC,
-  // but will mark the config as dirty. The next call of LoadConfig will
-  // pick up these changes.
-  void SetMatrixClip(const SkMatrix& transform, const SkRegion& region);
-
-  const SkMatrix& transform() const {
-    return transform_;
-  }
-
- protected:
-  // Loads the current transform and clip into the DC. Can be called even when
-  // the DC is NULL (will be a NOP).
-  void LoadConfig();
-
-  // Windows bitmap corresponding to our surface.
-  HBITMAP hbitmap_;
-
-  // Lazily-created DC used to draw into the bitmap, see getBitmapDC.
-  HDC hdc_;
-
-  // True when there is a transform or clip that has not been set to the DC.
-  // The DC is retrieved for every text operation, and the transform and clip
-  // do not change as much. We can save time by not loading the clip and
-  // transform for every one.
-  bool config_dirty_;
-
-  // Translation assigned to the DC: we need to keep track of this separately
-  // so it can be updated even if the DC isn't created yet.
-  SkMatrix transform_;
-
-  // The current clipping
-  SkRegion clip_region_;
-
- private:
-  friend class base::RefCounted<BitmapPlatformDeviceWinData>;
-  ~BitmapPlatformDeviceWinData();
-
-  DISALLOW_EVIL_CONSTRUCTORS(BitmapPlatformDeviceWinData);
-};
-
-BitmapPlatformDeviceWin::BitmapPlatformDeviceWinData::BitmapPlatformDeviceWinData(
-    HBITMAP hbitmap)
-    : hbitmap_(hbitmap),
-      hdc_(NULL),
-      config_dirty_(true) {  // Want to load the config next time.
-  // Initialize the clip region to the entire bitmap.
-  BITMAP bitmap_data;
-  if (GetObject(hbitmap_, sizeof(BITMAP), &bitmap_data)) {
-    SkIRect rect;
-    rect.set(0, 0, bitmap_data.bmWidth, bitmap_data.bmHeight);
-    clip_region_ = SkRegion(rect);
-  }
-
-  transform_.reset();
-}
-
-BitmapPlatformDeviceWin::BitmapPlatformDeviceWinData::~BitmapPlatformDeviceWinData() {
-  if (hdc_)
-    ReleaseBitmapDC();
-
-  // this will free the bitmap data as well as the bitmap handle
-  DeleteObject(hbitmap_);
-}
-
-HDC BitmapPlatformDeviceWin::BitmapPlatformDeviceWinData::GetBitmapDC() {
-  if (!hdc_) {
-    hdc_ = CreateCompatibleDC(NULL);
-    InitializeDC(hdc_);
-    HGDIOBJ old_bitmap = SelectObject(hdc_, hbitmap_);
-    // When the memory DC is created, its display surface is exactly one
-    // monochrome pixel wide and one monochrome pixel high. Since we select our
-    // own bitmap, we must delete the previous one.
-    DeleteObject(old_bitmap);
-  }
-
-  LoadConfig();
-  return hdc_;
-}
-
-void BitmapPlatformDeviceWin::BitmapPlatformDeviceWinData::ReleaseBitmapDC() {
-  DCHECK(hdc_);
-  DeleteDC(hdc_);
-  hdc_ = NULL;
-}
-
-bool BitmapPlatformDeviceWin::BitmapPlatformDeviceWinData::IsBitmapDCCreated()
-    const {
-  return hdc_ != NULL;
-}
-
-
-void BitmapPlatformDeviceWin::BitmapPlatformDeviceWinData::SetMatrixClip(
-    const SkMatrix& transform,
-    const SkRegion& region) {
-  transform_ = transform;
-  clip_region_ = region;
-  config_dirty_ = true;
-}
-
-void BitmapPlatformDeviceWin::BitmapPlatformDeviceWinData::LoadConfig() {
-  if (!config_dirty_ || !hdc_)
-    return;  // Nothing to do.
-  config_dirty_ = false;
-
-  // Transform.
-  SkMatrix t(transform_);
-  LoadTransformToDC(hdc_, t);
-  // We don't use transform_ for the clipping region since the translation is
-  // already applied to offset_x_ and offset_y_.
-  t.reset();
-  LoadClippingRegionToDC(hdc_, clip_region_, t);
-}
-
-// We use this static factory function instead of the regular constructor so
-// that we can create the pixel data before calling the constructor. This is
-// required so that we can call the base class' constructor with the pixel
-// data.
-BitmapPlatformDeviceWin* BitmapPlatformDeviceWin::create(HDC screen_dc,
-                                                   int width,
-                                                   int height,
-                                                   bool is_opaque,
-                                                   HANDLE shared_section) {
-  SkBitmap bitmap;
-
-  // CreateDIBSection appears to get unhappy if we create an empty bitmap, so
-  // just create a minimal bitmap
-  if ((width == 0) || (height == 0)) {
-    width = 1;
-    height = 1;
-  }
-
-  BITMAPINFOHEADER hdr = {0};
-  CreateBitmapHeader(width, height, &hdr);
-
-  void* data = NULL;
-  HBITMAP hbitmap = CreateDIBSection(screen_dc,
-                                     reinterpret_cast<BITMAPINFO*>(&hdr), 0,
-                                     &data,
-                                     shared_section, 0);
-
-  // If we run out of GDI objects or some other error occurs, we won't get a
-  // bitmap here. This will cause us to crash later because the data pointer is
-  // NULL. To make sure that we can assign blame for those crashes to this code,
-  // we deliberately crash here, even in release mode.
-  if (!hbitmap) {
-    DWORD error = GetLastError();
-    LOG(ERROR) << "CreateDIBSection Failed. Error: " << error << "\n";
-    return NULL;
-  }
-
-  bitmap.setConfig(SkBitmap::kARGB_8888_Config, width, height);
-  bitmap.setPixels(data);
-  bitmap.setIsOpaque(is_opaque);
-
-  if (is_opaque) {
-#ifndef NDEBUG
-    // To aid in finding bugs, we set the background color to something
-    // obviously wrong so it will be noticable when it is not cleared
-    bitmap.eraseARGB(255, 0, 255, 128);  // bright bluish green
-#endif
-  } else {
-    // A transparent layer is requested: fill with our magic "transparent"
-    // color, see the declaration of kMagicTransparencyColor above
-    sk_memset32(static_cast<uint32_t*>(data), kMagicTransparencyColor,
-                width * height);
-  }
-
-  // The device object will take ownership of the HBITMAP.
-  return new BitmapPlatformDeviceWin(new BitmapPlatformDeviceWinData(hbitmap),
-                                     bitmap);
-}
-
-// The device will own the HBITMAP, which corresponds to also owning the pixel
-// data. Therefore, we do not transfer ownership to the SkDevice's bitmap.
-BitmapPlatformDeviceWin::BitmapPlatformDeviceWin(
-    BitmapPlatformDeviceWinData* data,
-    const SkBitmap& bitmap) : PlatformDeviceWin(bitmap), data_(data) {
-}
-
-// The copy constructor just adds another reference to the underlying data.
-// We use a const cast since the default Skia definitions don't define the
-// proper constedness that we expect (accessBitmap should really be const).
-BitmapPlatformDeviceWin::BitmapPlatformDeviceWin(
-    const BitmapPlatformDeviceWin& other)
-    : PlatformDeviceWin(
-          const_cast<BitmapPlatformDeviceWin&>(other).accessBitmap(true)),
-      data_(other.data_) {
-}
-
-BitmapPlatformDeviceWin::~BitmapPlatformDeviceWin() {
-}
-
-BitmapPlatformDeviceWin& BitmapPlatformDeviceWin::operator=(
-    const BitmapPlatformDeviceWin& other) {
-  data_ = other.data_;
-  return *this;
-}
-
-HDC BitmapPlatformDeviceWin::getBitmapDC() {
-  return data_->GetBitmapDC();
-}
-
-void BitmapPlatformDeviceWin::setMatrixClip(const SkMatrix& transform,
-                                         const SkRegion& region) {
-  data_->SetMatrixClip(transform, region);
-}
-
-void BitmapPlatformDeviceWin::drawToHDC(HDC dc, int x, int y,
-                                     const RECT* src_rect) {
-  bool created_dc = !data_->IsBitmapDCCreated();
-  HDC source_dc = getBitmapDC();
-
-  RECT temp_rect;
-  if (!src_rect) {
-    temp_rect.left = 0;
-    temp_rect.right = width();
-    temp_rect.top = 0;
-    temp_rect.bottom = height();
-    src_rect = &temp_rect;
-  }
-
-  int copy_width = src_rect->right - src_rect->left;
-  int copy_height = src_rect->bottom - src_rect->top;
-
-  // We need to reset the translation for our bitmap or (0,0) won't be in the
-  // upper left anymore
-  SkMatrix identity;
-  identity.reset();
-
-  LoadTransformToDC(source_dc, identity);
-  if (isOpaque()) {
-    BitBlt(dc,
-           x,
-           y,
-           copy_width,
-           copy_height,
-           source_dc,
-           src_rect->left,
-           src_rect->top,
-           SRCCOPY);
-  } else {
-    DCHECK(copy_width != 0 && copy_height != 0);
-    BLENDFUNCTION blend_function = {AC_SRC_OVER, 0, 255, AC_SRC_ALPHA};
-    GdiAlphaBlend(dc,
-                  x,
-                  y,
-                  copy_width,
-                  copy_height,
-                  source_dc,
-                  src_rect->left,
-                  src_rect->top,
-                  copy_width,
-                  copy_height,
-                  blend_function);
-  }
-  LoadTransformToDC(source_dc, data_->transform());
-
-  if (created_dc)
-    data_->ReleaseBitmapDC();
-}
-
-void BitmapPlatformDeviceWin::prepareForGDI(int x, int y, int width,
-                                            int height) {
-  processPixels<PrepareAlphaForGDI>(x, y, width, height);
-}
-
-void BitmapPlatformDeviceWin::postProcessGDI(int x, int y, int width,
-                                             int height) {
-  processPixels<PostProcessAlphaForGDI>(x, y, width, height);
-}
-
-void BitmapPlatformDeviceWin::makeOpaque(int x, int y, int width, int height) {
-  processPixels<MakeOpaqueAlphaAdjuster>(x, y, width, height);
-}
-
-void BitmapPlatformDeviceWin::fixupAlphaBeforeCompositing() {
-  const SkBitmap& bitmap = accessBitmap(true);
-  SkAutoLockPixels lock(bitmap);
-  uint32_t* data = bitmap.getAddr32(0, 0);
-
-  size_t words = bitmap.rowBytes() / sizeof(uint32_t) * bitmap.height();
-  for (size_t i = 0; i < words; i++) {
-    if (data[i] == kMagicTransparencyColor)
-      data[i] = 0;
-    else
-      data[i] |= 0xFF000000;
-  }
-}
-
-// Returns the color value at the specified location.
-SkColor BitmapPlatformDeviceWin::getColorAt(int x, int y) {
-  const SkBitmap& bitmap = accessBitmap(false);
-  SkAutoLockPixels lock(bitmap);
-  uint32_t* data = bitmap.getAddr32(0, 0);
-  return static_cast<SkColor>(data[x + y * width()]);
-}
-
-void BitmapPlatformDeviceWin::onAccessBitmap(SkBitmap* bitmap) {
-  // FIXME(brettw) OPTIMIZATION: We should only flush if we know a GDI
-  // operation has occurred on our DC.
-  if (data_->IsBitmapDCCreated())
-    GdiFlush();
-}
-
-template<BitmapPlatformDeviceWin::adjustAlpha adjustor>
-void BitmapPlatformDeviceWin::processPixels(int x,
-                                   int y,
-                                   int width,
-                                   int height) {
-  const SkBitmap& bitmap = accessBitmap(true);
-  DCHECK_EQ(bitmap.config(), SkBitmap::kARGB_8888_Config);
-  const SkMatrix& matrix = data_->transform();
-  int bitmap_start_x = SkScalarRound(matrix.getTranslateX()) + x;
-  int bitmap_start_y = SkScalarRound(matrix.getTranslateY()) + y;
-
-  if (Constrain(bitmap.width(), &bitmap_start_x, &width) &&
-      Constrain(bitmap.height(), &bitmap_start_y, &height)) {
-    SkAutoLockPixels lock(bitmap);
-    DCHECK_EQ(bitmap.rowBytes() % sizeof(uint32_t), 0u);
-    size_t row_words = bitmap.rowBytes() / sizeof(uint32_t);
-    // Set data to the first pixel to be modified.
-    uint32_t* data = bitmap.getAddr32(0, 0) + (bitmap_start_y * row_words) +
-                     bitmap_start_x;
-    for (int i = 0; i < height; i++) {
-      for (int j = 0; j < width; j++) {
-        adjustor(data + j);
-      }
-      data += row_words;
-    }
-  }
-}
-
-}  // namespace gfx
-