1 
2 /*
3  * Copyright 2017 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 <OpenGLES/ES2/gl.h>
10 #include "../GLWindowContext.h"
11 #include "SDL.h"
12 #include "WindowContextFactory_ios.h"
13 #include "gl/GrGLInterface.h"
14 
15 using sk_app::DisplayParams;
16 using sk_app::window_context_factory::IOSWindowInfo;
17 using sk_app::GLWindowContext;
18 
19 namespace {
20 
21 class GLWindowContext_ios : public GLWindowContext {
22 public:
23     GLWindowContext_ios(const IOSWindowInfo&, const DisplayParams&);
24 
25     ~GLWindowContext_ios() override;
26 
27     void onSwapBuffers() override;
28 
29     sk_sp<const GrGLInterface> onInitializeContext() override;
onDestroyContext()30     void onDestroyContext() override {}
31 
32 private:
33     SDL_Window*   fWindow;
34     SDL_GLContext fGLContext;
35 
36     typedef GLWindowContext INHERITED;
37 };
38 
GLWindowContext_ios(const IOSWindowInfo & info,const DisplayParams & params)39 GLWindowContext_ios::GLWindowContext_ios(const IOSWindowInfo& info, const DisplayParams& params)
40     : INHERITED(params)
41     , fWindow(info.fWindow)
42     , fGLContext(info.fGLContext) {
43 
44     // any config code here (particularly for msaa)?
45 
46     this->initializeContext();
47 }
48 
~GLWindowContext_ios()49 GLWindowContext_ios::~GLWindowContext_ios() {
50     this->destroyContext();
51 }
52 
onInitializeContext()53 sk_sp<const GrGLInterface> GLWindowContext_ios::onInitializeContext() {
54     SkASSERT(fWindow);
55     SkASSERT(fGLContext);
56 
57     if (0 == SDL_GL_MakeCurrent(fWindow, fGLContext)) {
58         glClearStencil(0);
59         glClearColor(0, 0, 0, 0);
60         glStencilMask(0xffffffff);
61         glClear(GL_STENCIL_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
62 
63         SDL_GL_GetAttribute(SDL_GL_STENCIL_SIZE, &fStencilBits);
64         SDL_GL_GetAttribute(SDL_GL_MULTISAMPLESAMPLES, &fSampleCount);
65         fSampleCount = SkTMax(fSampleCount, 1);
66 
67         SDL_GL_GetDrawableSize(fWindow, &fWidth, &fHeight);
68         glViewport(0, 0, fWidth, fHeight);
69     } else {
70         SkDebugf("MakeCurrent failed: %s\n", SDL_GetError());
71     }
72     return GrGLMakeNativeInterface();
73 }
74 
onSwapBuffers()75 void GLWindowContext_ios::onSwapBuffers() {
76     if (fWindow && fGLContext) {
77         SDL_GL_SwapWindow(fWindow);
78     }
79 }
80 
81 }  // anonymous namespace
82 
83 namespace sk_app {
84 namespace window_context_factory {
85 
NewGLForIOS(const IOSWindowInfo & info,const DisplayParams & params)86 WindowContext* NewGLForIOS(const IOSWindowInfo& info, const DisplayParams& params) {
87     WindowContext* ctx = new GLWindowContext_ios(info, params);
88     if (!ctx->isValid()) {
89         delete ctx;
90         return nullptr;
91     }
92     return ctx;
93 }
94 
95 }  // namespace window_context_factory
96 }  // namespace sk_app
97