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comparison Applications/Platforms/WebAssembly/WebAssemblyOpenGLContext.cpp @ 1591:5887a4f8594b

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moving platform-specific files out of the "OrthancStone" folder
author Sebastien Jodogne <s.jodogne@gmail.com>
date Fri, 23 Oct 2020 13:15:03 +0200
parents OrthancStone/Sources/OpenGL/WebAssemblyOpenGLContext.cpp@1f812f4c95be
children 4fb8fdf03314
comparison
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1590:7b963bccafef 1591:5887a4f8594b
1 /**
2 * Stone of Orthanc
3 * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
4 * Department, University Hospital of Liege, Belgium
5 * Copyright (C) 2017-2020 Osimis S.A., Belgium
6 *
7 * This program is free software: you can redistribute it and/or
8 * modify it under the terms of the GNU Affero General Public License
9 * as published by the Free Software Foundation, either version 3 of
10 * the License, or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Affero General Public License for more details.
16 *
17 * You should have received a copy of the GNU Affero General Public License
18 * along with this program. If not, see <http://www.gnu.org/licenses/>.
19 **/
20
21
22 #include "WebAssemblyOpenGLContext.h"
23
24 #include "../../../OrthancStone/Sources/StoneException.h"
25
26 #include <OrthancException.h>
27
28 #include <emscripten/html5.h>
29 #include <emscripten/em_asm.h>
30
31 #include <boost/math/special_functions/round.hpp>
32
33 namespace OrthancStone
34 {
35 namespace OpenGL
36 {
37 class WebAssemblyOpenGLContext::PImpl
38 {
39 private:
40 std::string canvasSelector_;
41 EMSCRIPTEN_WEBGL_CONTEXT_HANDLE context_;
42 bool isContextLost_;
43
44 public:
45 explicit PImpl(const std::string& canvasSelector) :
46 canvasSelector_(canvasSelector),
47 isContextLost_(false)
48 {
49 // Context configuration
50 EmscriptenWebGLContextAttributes attr;
51 emscripten_webgl_init_context_attributes(&attr);
52
53 // The next line might be necessary to print using
54 // WebGL. Sometimes, if set to "false" (the default value),
55 // the canvas was rendered as a fully white or black
56 // area. UNCONFIRMED.
57 attr.preserveDrawingBuffer = true;
58
59 context_ = emscripten_webgl_create_context(canvasSelector.c_str(), &attr);
60 if (context_ == 0)
61 {
62 std::string message("Cannot create an OpenGL context for the element with the following CSS selector: \"");
63 message += canvasSelector;
64 message += "\" Please make sure the -s DISABLE_DEPRECATED_FIND_EVENT_TARGET_BEHAVIOR=1 flag has been passed to Emscripten when building.";
65 LOG(ERROR) << message;
66 throw Orthanc::OrthancException(Orthanc::ErrorCode_InternalError, message);
67 }
68 }
69
70 void* DebugGetInternalContext() const
71 {
72 return reinterpret_cast<void*>(context_);
73 }
74
75 bool IsContextLost()
76 {
77 //LOG(TRACE) << "IsContextLost() for context " << std::hex << context_ << std::dec;
78 bool apiFlag = (emscripten_is_webgl_context_lost(context_) != 0);
79 isContextLost_ = apiFlag;
80 return isContextLost_;
81 }
82
83 void SetLostContext()
84 {
85 isContextLost_ = true;
86 }
87
88 ~PImpl()
89 {
90 try
91 {
92 EMSCRIPTEN_RESULT result = emscripten_webgl_destroy_context(context_);
93 if (result != EMSCRIPTEN_RESULT_SUCCESS)
94 {
95 LOG(ERROR) << "emscripten_webgl_destroy_context returned code " << result;
96 }
97 }
98 catch (const Orthanc::OrthancException& e)
99 {
100 if (e.HasDetails())
101 {
102 LOG(ERROR) << "OrthancException in WebAssemblyOpenGLContext::~PImpl: " << e.What() << " Details: " << e.GetDetails();
103 }
104 else
105 {
106 LOG(ERROR) << "OrthancException in WebAssemblyOpenGLContext::~PImpl: " << e.What();
107 }
108 }
109 catch (const std::exception& e)
110 {
111 LOG(ERROR) << "std::exception in WebAssemblyOpenGLContext::~PImpl: " << e.what();
112 }
113 catch (...)
114 {
115 LOG(ERROR) << "Unknown exception in WebAssemblyOpenGLContext::~PImpl";
116 }
117 }
118
119 const std::string& GetCanvasSelector() const
120 {
121 return canvasSelector_;
122 }
123
124 void MakeCurrent()
125 {
126 if (IsContextLost())
127 {
128 LOG(ERROR) << "MakeCurrent() called on lost context " << context_;
129 throw StoneException(ErrorCode_WebGLContextLost);
130 }
131
132 if (emscripten_is_webgl_context_lost(context_))
133 {
134 LOG(ERROR) << "OpenGL context has been lost for canvas selector: " << canvasSelector_;
135 SetLostContext();
136 throw StoneException(ErrorCode_WebGLContextLost);
137 }
138
139 if (emscripten_webgl_make_context_current(context_) != EMSCRIPTEN_RESULT_SUCCESS)
140 {
141 throw Orthanc::OrthancException(Orthanc::ErrorCode_InternalError,
142 "Cannot set the OpenGL context");
143 }
144 }
145
146 void SwapBuffer()
147 {
148 /**
149 * "Rendered WebGL content is implicitly presented (displayed to
150 * the user) on the canvas when the event handler that renders with
151 * WebGL returns back to the browser event loop."
152 * https://emscripten.org/docs/api_reference/html5.h.html#webgl-context
153 *
154 * Could call "emscripten_webgl_commit_frame()" if
155 * "explicitSwapControl" option were set to "true".
156 **/
157 }
158 };
159
160
161 WebAssemblyOpenGLContext::WebAssemblyOpenGLContext(const std::string& canvasSelector) :
162 pimpl_(new PImpl(canvasSelector))
163 {
164 }
165
166 bool WebAssemblyOpenGLContext::IsContextLost()
167 {
168 return pimpl_->IsContextLost();
169 }
170
171 void WebAssemblyOpenGLContext::SetLostContext()
172 {
173 pimpl_->SetLostContext();
174 }
175
176 void* WebAssemblyOpenGLContext::DebugGetInternalContext() const
177 {
178 return pimpl_->DebugGetInternalContext();
179 }
180
181 void WebAssemblyOpenGLContext::MakeCurrent()
182 {
183 assert(pimpl_.get() != NULL);
184 pimpl_->MakeCurrent();
185 }
186
187 void WebAssemblyOpenGLContext::SwapBuffer()
188 {
189 assert(pimpl_.get() != NULL);
190 pimpl_->SwapBuffer();
191 }
192
193 const std::string& WebAssemblyOpenGLContext::GetCanvasSelector() const
194 {
195 assert(pimpl_.get() != NULL);
196 return pimpl_->GetCanvasSelector();
197 }
198 }
199 }