blob: 3dfb201367a9e777ae905d7697417ef9b78692f3 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
|
// Copyright (C) 2018 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
#include "qwasmopenglcontext.h"
#include "qwasmintegration.h"
#include <EGL/egl.h>
#include <emscripten/bind.h>
#include <emscripten/val.h>
namespace {
void qtDoNothing(emscripten::val) { }
} // namespace
EMSCRIPTEN_BINDINGS(qwasmopenglcontext)
{
function("qtDoNothing", &qtDoNothing);
}
QT_BEGIN_NAMESPACE
QWasmOpenGLContext::QWasmOpenGLContext(const QSurfaceFormat &format)
: m_requestedFormat(format)
{
m_requestedFormat.setRenderableType(QSurfaceFormat::OpenGLES);
// if we set one, we need to set the other as well since in webgl, these are tied together
if (format.depthBufferSize() < 0 && format.stencilBufferSize() > 0)
m_requestedFormat.setDepthBufferSize(16);
if (format.stencilBufferSize() < 0 && format.depthBufferSize() > 0)
m_requestedFormat.setStencilBufferSize(8);
}
QWasmOpenGLContext::~QWasmOpenGLContext()
{
if (!m_context)
return;
// Destroy GL context. Work around bug in emscripten_webgl_destroy_context
// which removes all event handlers on the canvas by temporarily replacing the function
// that does the removal with a function that does nothing.
emscripten::val jsEvents = emscripten::val::module_property("JSEvents");
emscripten::val savedRemoveAllHandlersOnTargetFunction =
jsEvents["removeAllHandlersOnTarget"];
jsEvents.set("removeAllHandlersOnTarget", emscripten::val::module_property("qtDoNothing"));
emscripten_webgl_destroy_context(m_context);
jsEvents.set("removeAllHandlersOnTarget", savedRemoveAllHandlersOnTargetFunction);
m_context = 0;
}
bool QWasmOpenGLContext::isOpenGLVersionSupported(QSurfaceFormat format)
{
// Version check: support WebGL 1 and 2:
// (ES) 2.0 -> WebGL 1.0
// (ES) 3.0 -> WebGL 2.0
// [we don't expect that new WebGL versions will be created]
return ((format.majorVersion() == 2 && format.minorVersion() == 0) ||
(format.majorVersion() == 3 && format.minorVersion() == 0));
}
bool QWasmOpenGLContext::maybeCreateEmscriptenContext(QPlatformSurface *surface)
{
if (m_context && m_surface == surface)
return true;
// TODO(mikolajboc): Use OffscreenCanvas if available.
if (surface->surface()->surfaceClass() == QSurface::Offscreen)
return false;
m_surface = surface;
auto *window = static_cast<QWasmWindow *>(surface);
m_context = createEmscriptenContext(window->canvasSelector(), m_requestedFormat);
return true;
}
EMSCRIPTEN_WEBGL_CONTEXT_HANDLE
QWasmOpenGLContext::createEmscriptenContext(const std::string &canvasSelector,
QSurfaceFormat format)
{
EmscriptenWebGLContextAttributes attributes;
emscripten_webgl_init_context_attributes(&attributes); // Populate with default attributes
attributes.powerPreference = EM_WEBGL_POWER_PREFERENCE_HIGH_PERFORMANCE;
attributes.failIfMajorPerformanceCaveat = false;
attributes.antialias = true;
attributes.enableExtensionsByDefault = true;
attributes.majorVersion = format.majorVersion() - 1;
attributes.minorVersion = format.minorVersion();
// WebGL doesn't allow separate attach buffers to STENCIL_ATTACHMENT and DEPTH_ATTACHMENT
// we need both or none
const bool useDepthStencil = (format.depthBufferSize() > 0 || format.stencilBufferSize() > 0);
// WebGL offers enable/disable control but not size control for these
attributes.alpha = format.alphaBufferSize() > 0;
attributes.depth = useDepthStencil;
attributes.stencil = useDepthStencil;
return emscripten_webgl_create_context(canvasSelector.c_str(), &attributes);
}
QSurfaceFormat QWasmOpenGLContext::format() const
{
return m_requestedFormat;
}
GLuint QWasmOpenGLContext::defaultFramebufferObject(QPlatformSurface *surface) const
{
return QPlatformOpenGLContext::defaultFramebufferObject(surface);
}
bool QWasmOpenGLContext::makeCurrent(QPlatformSurface *surface)
{
if (!maybeCreateEmscriptenContext(surface))
return false;
return emscripten_webgl_make_context_current(m_context) == EMSCRIPTEN_RESULT_SUCCESS;
}
void QWasmOpenGLContext::swapBuffers(QPlatformSurface *surface)
{
Q_UNUSED(surface);
// No swapbuffers on WebGl
}
void QWasmOpenGLContext::doneCurrent()
{
// No doneCurrent on WebGl
}
bool QWasmOpenGLContext::isSharing() const
{
return false;
}
bool QWasmOpenGLContext::isValid() const
{
if (!isOpenGLVersionSupported(m_requestedFormat))
return false;
// Note: we get isValid() calls before we see the surface and can
// create a native context, so no context is also a valid state.
return !m_context || !emscripten_is_webgl_context_lost(m_context);
}
QFunctionPointer QWasmOpenGLContext::getProcAddress(const char *procName)
{
return reinterpret_cast<QFunctionPointer>(eglGetProcAddress(procName));
}
QT_END_NAMESPACE
|
