blob: 1f136bd3598249a30ddff18ff9e7e90e0a984acb [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 {
struct HDCContextRec {
HDC hdc_;
HBITMAP prev_bitmap_;
static void DeleteHDCCallback(void*, void* context) {
DCHECK_NE(context, nullptr);
const HDCContextRec* rec = static_cast<const HDCContextRec*>(context);
// Must select back in the old bitmap before we delete the hdc, and so we can
// recover the new_bitmap that we allocated, so we can delete it.
HBITMAP new_bitmap =
static_cast<HBITMAP>(SelectObject(rec->hdc_, rec->prev_bitmap_));
bool success = DeleteObject(new_bitmap);
success = DeleteDC(rec->hdc_);
delete rec;
// 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 new_bitmap =
skia::CreateHBitmap(width, height, is_opaque, shared_section, &pixels);
if (!new_bitmap) {
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);
HBITMAP prev_bitmap = static_cast<HBITMAP>(SelectObject(hdc, new_bitmap));
rec->fReleaseProc = DeleteHDCCallback;
rec->fReleaseCtx = new HDCContextRec{hdc, prev_bitmap};
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, 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