1
2 /*
3 * Copyright 2016 Google Inc.
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9 #include <OpenGL/gl.h>
10 #include "../GLWindowContext.h"
11 #include "SDL.h"
12 #include "SkCanvas.h"
13 #include "SkColorFilter.h"
14 #include "WindowContextFactory_mac.h"
15 #include "gl/GrGLInterface.h"
16 #include "sk_tool_utils.h"
17
18 using sk_app::DisplayParams;
19 using sk_app::window_context_factory::MacWindowInfo;
20 using sk_app::GLWindowContext;
21
22 namespace {
23
24 // We use SDL to support Mac windowing mainly for convenience's sake. However, it
25 // does not allow us to support a purely raster backend because we have no hooks into
26 // the NSWindow's drawRect: method. Hence we use GL to handle the update. Should we
27 // want to avoid this, we will probably need to write our own windowing backend.
28
29 class RasterWindowContext_mac : public GLWindowContext {
30 public:
31 RasterWindowContext_mac(const MacWindowInfo&, const DisplayParams&);
32
33 ~RasterWindowContext_mac() override;
34
35 sk_sp<SkSurface> getBackbufferSurface() override;
36
37 void onSwapBuffers() override;
38
39 sk_sp<const GrGLInterface> onInitializeContext() override;
40 void onDestroyContext() override;
41
42 private:
43 SDL_Window* fWindow;
44 SDL_GLContext fGLContext;
45 sk_sp<SkSurface> fBackbufferSurface;
46
47 typedef GLWindowContext INHERITED;
48 };
49
RasterWindowContext_mac(const MacWindowInfo & info,const DisplayParams & params)50 RasterWindowContext_mac::RasterWindowContext_mac(const MacWindowInfo& info,
51 const DisplayParams& params)
52 : INHERITED(params)
53 , fWindow(info.fWindow)
54 , fGLContext(nullptr) {
55
56 // any config code here (particularly for msaa)?
57
58 this->initializeContext();
59 }
60
~RasterWindowContext_mac()61 RasterWindowContext_mac::~RasterWindowContext_mac() {
62 this->destroyContext();
63 }
64
onInitializeContext()65 sk_sp<const GrGLInterface> RasterWindowContext_mac::onInitializeContext() {
66 SkASSERT(fWindow);
67
68 fGLContext = SDL_GL_CreateContext(fWindow);
69 if (!fGLContext) {
70 SkDebugf("%s\n", SDL_GetError());
71 return nullptr;
72 }
73
74 if (0 == SDL_GL_MakeCurrent(fWindow, fGLContext)) {
75 glClearStencil(0);
76 glClearColor(0, 0, 0, 0);
77 glStencilMask(0xffffffff);
78 glClear(GL_STENCIL_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
79
80 SDL_GL_GetAttribute(SDL_GL_STENCIL_SIZE, &fStencilBits);
81 SDL_GL_GetAttribute(SDL_GL_MULTISAMPLESAMPLES, &fSampleCount);
82 fSampleCount = SkTMax(fSampleCount, 1);
83
84 SDL_GetWindowSize(fWindow, &fWidth, &fHeight);
85 glViewport(0, 0, fWidth, fHeight);
86 } else {
87 SkDebugf("MakeCurrent failed: %s\n", SDL_GetError());
88 }
89
90 // make the offscreen image
91 SkImageInfo info = SkImageInfo::Make(fWidth, fHeight, fDisplayParams.fColorType,
92 kPremul_SkAlphaType, fDisplayParams.fColorSpace);
93 fBackbufferSurface = SkSurface::MakeRaster(info);
94 return GrGLMakeNativeInterface();
95 }
96
onDestroyContext()97 void RasterWindowContext_mac::onDestroyContext() {
98 if (!fWindow || !fGLContext) {
99 return;
100 }
101 fBackbufferSurface.reset(nullptr);
102 SDL_GL_DeleteContext(fGLContext);
103 fGLContext = nullptr;
104 }
105
getBackbufferSurface()106 sk_sp<SkSurface> RasterWindowContext_mac::getBackbufferSurface() { return fBackbufferSurface; }
107
onSwapBuffers()108 void RasterWindowContext_mac::onSwapBuffers() {
109 if (fWindow && fGLContext) {
110 // We made/have an off-screen surface. Get the contents as an SkImage:
111 sk_sp<SkImage> snapshot = fBackbufferSurface->makeImageSnapshot();
112
113 sk_sp<SkSurface> gpuSurface = INHERITED::getBackbufferSurface();
114 SkCanvas* gpuCanvas = gpuSurface->getCanvas();
115 gpuCanvas->drawImage(snapshot, 0, 0);
116 gpuCanvas->flush();
117
118 SDL_GL_SwapWindow(fWindow);
119 }
120 }
121
122 } // anonymous namespace
123
124 namespace sk_app {
125 namespace window_context_factory {
126
NewRasterForMac(const MacWindowInfo & info,const DisplayParams & params)127 WindowContext* NewRasterForMac(const MacWindowInfo& info, const DisplayParams& params) {
128 WindowContext* ctx = new RasterWindowContext_mac(info, params);
129 if (!ctx->isValid()) {
130 delete ctx;
131 return nullptr;
132 }
133 return ctx;
134 }
135
136 } // namespace window_context_factory
137 } // namespace sk_app
138