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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 
     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 
     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 
     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 
     72 sk_sp<SkSurface> RasterWindowContext_win::getBackbufferSurface() { return fBackbufferSurface; }
     73 
     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 
     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