blob: 22d9bf4b0e2d6f43a92d1ea5f42cb2ffca9e0444 [file] [log] [blame]
// Copyright (c) 2017 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 <windows.h>
#include <psapi.h>
#include <stddef.h>
#include "base/debug/gdi_debug_util_win.h"
#include "base/memory/ptr_util.h"
#include "base/logging.h"
#include "base/win/win_util.h"
#include "skia/ext/platform_canvas.h"
#include "skia/ext/skia_utils_win.h"
#include "third_party/skia/include/core/SkMatrix.h"
#include "third_party/skia/include/core/SkPath.h"
#include "third_party/skia/include/core/SkRefCnt.h"
#include "third_party/skia/include/core/SkRect.h"
namespace {
static void DeleteHDCCallback(void*, void* context) {
DCHECK_NE(context, nullptr);
HDC hdc = static_cast<HDC>(context);
// We must get this before we call RestoreDC, as that will drop hbitmap and
// reselect the original/default bitmap.
HGDIOBJ hbitmap = GetCurrentObject(hdc, OBJ_BITMAP);
DCHECK_NE(hbitmap, nullptr);
bool success = RestoreDC(hdc, -1); // effectly performs the deselect of hbitmap
// Now we are the only owner, so we can delete our bitmap
success = DeleteObject(hbitmap);
success = DeleteDC(hdc);
// Allocate the layer and fill in the fields for the Rec, or return false
// on error.
static bool Create(int width,
int height,
bool is_opaque,
HANDLE shared_section,
bool do_clear,
SkRasterHandleAllocator::Rec* rec) {
void* pixels;
HBITMAP hbitmap =
skia::CreateHBitmap(width, height, is_opaque, shared_section, &pixels);
if (!hbitmap) {
LOG(ERROR) << "CreateHBitmap failed";
return false;
size_t row_bytes = skia::PlatformCanvasStrideForWidth(width);
if (do_clear)
sk_bzero(pixels, row_bytes * height);
HDC hdc = CreateCompatibleDC(nullptr);
if (!hdc) {
return false;
SetGraphicsMode(hdc, GM_ADVANCED);
int saveIndex = SaveDC(hdc); // so we can Restore in the delete callback
DCHECK_NE(saveIndex, 0);
// Be sure to select *after* we called SaveDC.
// Because we're using save/restore, we don't need to explicitly track the
// returned "previous" value.
SelectObject(hdc, hbitmap);
rec->fReleaseProc = DeleteHDCCallback;
rec->fReleaseCtx = hdc;
rec->fPixels = pixels;
rec->fRowBytes = row_bytes;
rec->fHandle = hdc;
return true;
* Subclass of SkRasterHandleAllocator that returns an HDC as its "handle".
class GDIAllocator : public SkRasterHandleAllocator {
GDIAllocator() {}
bool allocHandle(const SkImageInfo& info, Rec* rec) override {
SkASSERT(info.colorType() == kN32_SkColorType);
return Create(info.width(), info.height(), info.isOpaque(), nullptr,
!info.isOpaque(), rec);
void updateHandle(Handle handle,
const SkMatrix& ctm,
const SkIRect& clip_bounds) override {
HDC hdc = static_cast<HDC>(handle);
skia::LoadTransformToDC(hdc, ctm);
HRGN hrgn = CreateRectRgnIndirect(&skia::SkIRectToRECT(clip_bounds));
int result = SelectClipRgn(hdc, hrgn);
DCHECK(result != ERROR);
result = DeleteObject(hrgn);
DCHECK(result != 0);
void unmap_view_proc(void* pixels, void*) {
} // namespace
namespace skia {
std::unique_ptr<SkCanvas> CreatePlatformCanvasWithSharedSection(
int width,
int height,
bool is_opaque,
HANDLE shared_section,
OnFailureType failure_type) {
SkAlphaType alpha = is_opaque ? kOpaque_SkAlphaType : kPremul_SkAlphaType;
SkImageInfo info = SkImageInfo::MakeN32(width, height, alpha);
size_t row_bytes = PlatformCanvasStrideForWidth(width);
// This function contains an implementation of a Skia platform bitmap for
// drawing and compositing graphics. The original implementation uses Windows
// GDI to create the backing bitmap memory, however it's possible for a
// process to not have access to GDI which will cause this code to fail. It's
// possible to detect when GDI is unavailable and instead directly map the
// shared memory as the bitmap.
if (base::win::IsUser32AndGdi32Available()) {
SkRasterHandleAllocator::Rec rec;
if (Create(width, height, is_opaque, shared_section, false, &rec))
return SkRasterHandleAllocator::MakeCanvas(
base::MakeUnique<GDIAllocator>(), info, &rec);
} else {
DCHECK(shared_section != NULL);
void* pixels =
MapViewOfFile(shared_section, FILE_MAP_WRITE, 0, 0, row_bytes * height);
if (pixels) {
SkBitmap bitmap;
if (bitmap.installPixels(info, pixels, row_bytes, nullptr,
unmap_view_proc, nullptr)) {
return base::MakeUnique<SkCanvas>(bitmap);
if (failure_type == CRASH_ON_FAILURE)
return nullptr;
HDC GetNativeDrawingContext(SkCanvas* canvas) {
return canvas ? static_cast<HDC>(canvas->accessTopRasterHandle()) : nullptr;
} // namespace skia