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};
35
36RasterWindowContext_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
44void 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
51void 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
72sk_sp<SkSurface> RasterWindowContext_win::getBackbufferSurface() { return fBackbufferSurface; }
73
74void 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
84namespace sk_app {
85namespace window_context_factory {
86
87WindowContext* 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