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
15using sk_app::RasterWindowContext;
16using sk_app::DisplayParams;
17
18namespace {
19
20class RasterWindowContext_win : public RasterWindowContext {
21public:
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
30protected:
31    SkAutoMalloc fSurfaceMemory;
32    sk_sp<SkSurface> fBackbufferSurface;
33    HWND fWnd;
34
35private:
36    typedef RasterWindowContext INHERITED;
37};
38
39RasterWindowContext_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
47void 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
54void 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
75sk_sp<SkSurface> RasterWindowContext_win::getBackbufferSurface() { return fBackbufferSurface; }
76
77void 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
87namespace sk_app {
88namespace window_context_factory {
89
90WindowContext* 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