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      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;
     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 private:
     36     typedef RasterWindowContext INHERITED;
     37 };
     38 
     39 RasterWindowContext_win::RasterWindowContext_win(HWND wnd, const DisplayParams& params)
     40     : INHERITED(params)
     41     , fWnd(wnd) {
     42     RECT rect;
     43     GetWindowRect(wnd, &rect);
     44     this->resize(rect.right - rect.left, rect.bottom - rect.top);
     45 }
     46 
     47 void RasterWindowContext_win::setDisplayParams(const DisplayParams& params) {
     48     fDisplayParams = params;
     49     RECT rect;
     50     GetWindowRect(fWnd, &rect);
     51     this->resize(rect.right - rect.left, rect.bottom - rect.top);
     52 }
     53 
     54 void RasterWindowContext_win::resize(int w, int h) {
     55     fWidth = w;
     56     fHeight = h;
     57     fBackbufferSurface.reset();
     58     const size_t bmpSize = sizeof(BITMAPINFOHEADER) + w * h * sizeof(uint32_t);
     59     fSurfaceMemory.reset(bmpSize);
     60     BITMAPINFO* bmpInfo = reinterpret_cast<BITMAPINFO*>(fSurfaceMemory.get());
     61     ZeroMemory(bmpInfo, sizeof(BITMAPINFO));
     62     bmpInfo->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
     63     bmpInfo->bmiHeader.biWidth = w;
     64     bmpInfo->bmiHeader.biHeight = -h; // negative means top-down bitmap. Skia draws top-down.
     65     bmpInfo->bmiHeader.biPlanes = 1;
     66     bmpInfo->bmiHeader.biBitCount = 32;
     67     bmpInfo->bmiHeader.biCompression = BI_RGB;
     68     void* pixels = bmpInfo->bmiColors;
     69 
     70     SkImageInfo info = SkImageInfo::Make(w, h, fDisplayParams.fColorType, kPremul_SkAlphaType,
     71                                          fDisplayParams.fColorSpace);
     72     fBackbufferSurface = SkSurface::MakeRasterDirect(info, pixels, sizeof(uint32_t) * w);
     73 }
     74 
     75 sk_sp<SkSurface> RasterWindowContext_win::getBackbufferSurface() { return fBackbufferSurface; }
     76 
     77 void RasterWindowContext_win::swapBuffers() {
     78     BITMAPINFO* bmpInfo = reinterpret_cast<BITMAPINFO*>(fSurfaceMemory.get());
     79     HDC dc = GetDC(fWnd);
     80     StretchDIBits(dc, 0, 0, fWidth, fHeight, 0, 0, fWidth, fHeight, bmpInfo->bmiColors, bmpInfo,
     81                   DIB_RGB_COLORS, SRCCOPY);
     82     ReleaseDC(fWnd, dc);
     83 }
     84 
     85 }  // anonymous namespace
     86 
     87 namespace sk_app {
     88 namespace window_context_factory {
     89 
     90 WindowContext* NewRasterForWin(HWND wnd, const DisplayParams& params) {
     91     WindowContext* ctx = new RasterWindowContext_win(wnd, params);
     92     if (!ctx->isValid()) {
     93         delete ctx;
     94         ctx = nullptr;
     95     }
     96     return ctx;
     97 }
     98 
     99 }  // namespace window_context_factory
    100 }  // namespace sk_app
    101