1 /*
2  * Copyright 2016 Google Inc.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #include "../RasterWindowContext.h"
9 #include "SkAutoMalloc.h"
10 #include "SkSurface.h"
11 #include "WindowContextFactory_win.h"
12 
13 #include <Windows.h>
14 
15 using sk_app::RasterWindowContext;
16 using sk_app::DisplayParams;
17 
18 namespace {
19 
20 class RasterWindowContext_win : public RasterWindowContext {
21 public:
22     RasterWindowContext_win(HWND, const DisplayParams&);
23 
24     sk_sp<SkSurface> getBackbufferSurface() override;
25     void swapBuffers() override;
isValid()26     bool isValid() override { return SkToBool(fWnd); }
27     void resize(int w, int h) override;
28     void setDisplayParams(const DisplayParams& params) override;
29 
30 protected:
31     SkAutoMalloc fSurfaceMemory;
32     sk_sp<SkSurface> fBackbufferSurface;
33     HWND fWnd;
34 };
35 
RasterWindowContext_win(HWND wnd,const DisplayParams & params)36 RasterWindowContext_win::RasterWindowContext_win(HWND wnd, const DisplayParams& params)
37         : fWnd(wnd) {
38     fDisplayParams = params;
39     RECT rect;
40     GetWindowRect(wnd, &rect);
41     this->resize(rect.right - rect.left, rect.bottom - rect.top);
42 }
43 
setDisplayParams(const DisplayParams & params)44 void RasterWindowContext_win::setDisplayParams(const DisplayParams& params) {
45     fDisplayParams = params;
46     RECT rect;
47     GetWindowRect(fWnd, &rect);
48     this->resize(rect.right - rect.left, rect.bottom - rect.top);
49 }
50 
resize(int w,int h)51 void RasterWindowContext_win::resize(int w, int h) {
52     fWidth = w;
53     fHeight = h;
54     fBackbufferSurface.reset();
55     const size_t bmpSize = sizeof(BITMAPINFOHEADER) + w * h * sizeof(uint32_t);
56     fSurfaceMemory.reset(bmpSize);
57     BITMAPINFO* bmpInfo = reinterpret_cast<BITMAPINFO*>(fSurfaceMemory.get());
58     ZeroMemory(bmpInfo, sizeof(BITMAPINFO));
59     bmpInfo->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
60     bmpInfo->bmiHeader.biWidth = w;
61     bmpInfo->bmiHeader.biHeight = -h; // negative means top-down bitmap. Skia draws top-down.
62     bmpInfo->bmiHeader.biPlanes = 1;
63     bmpInfo->bmiHeader.biBitCount = 32;
64     bmpInfo->bmiHeader.biCompression = BI_RGB;
65     void* pixels = bmpInfo->bmiColors;
66 
67     SkImageInfo info = SkImageInfo::Make(w, h, fDisplayParams.fColorType, kPremul_SkAlphaType,
68                                          fDisplayParams.fColorSpace);
69     fBackbufferSurface = SkSurface::MakeRasterDirect(info, pixels, sizeof(uint32_t) * w);
70 }
71 
getBackbufferSurface()72 sk_sp<SkSurface> RasterWindowContext_win::getBackbufferSurface() { return fBackbufferSurface; }
73 
swapBuffers()74 void RasterWindowContext_win::swapBuffers() {
75     BITMAPINFO* bmpInfo = reinterpret_cast<BITMAPINFO*>(fSurfaceMemory.get());
76     HDC dc = GetDC(fWnd);
77     StretchDIBits(dc, 0, 0, fWidth, fHeight, 0, 0, fWidth, fHeight, bmpInfo->bmiColors, bmpInfo,
78                   DIB_RGB_COLORS, SRCCOPY);
79     ReleaseDC(fWnd, dc);
80 }
81 
82 }  // anonymous namespace
83 
84 namespace sk_app {
85 namespace window_context_factory {
86 
NewRasterForWin(HWND wnd,const DisplayParams & params)87 WindowContext* NewRasterForWin(HWND wnd, const DisplayParams& params) {
88     WindowContext* ctx = new RasterWindowContext_win(wnd, params);
89     if (!ctx->isValid()) {
90         delete ctx;
91         ctx = nullptr;
92     }
93     return ctx;
94 }
95 
96 }  // namespace window_context_factory
97 }  // namespace sk_app
98