File: qopenglcontextwindow.cpp

package info (click to toggle)
qtbase-opensource-src 5.11.3+dfsg1-1
  • links: PTS, VCS
  • area: main
  • in suites: buster
  • size: 312,420 kB
  • sloc: cpp: 1,831,913; ansic: 318,856; xml: 113,585; python: 9,691; java: 7,209; asm: 4,023; perl: 2,151; sh: 1,790; yacc: 1,733; lex: 1,197; makefile: 301; objc: 70
file content (160 lines) | stat: -rw-r--r-- 5,741 bytes parent folder | download | duplicates (4)
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
154
155
156
157
158
159
160
/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the test suite of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:GPL-EXCEPT$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 as published by the Free Software
** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qopenglcontextwindow.h"
#include <QtGui/QOpenGLFunctions>
#include <QtGui/QOffscreenSurface>
#include <QtGui/QGuiApplication>
#include <QtGui/QMatrix4x4>
#include <qpa/qplatformnativeinterface.h>

#include <QtEglSupport/private/qeglconvenience_p.h>
#include <QtPlatformHeaders/QEGLNativeContext>

QOpenGLContextWindow::QOpenGLContextWindow()
    : m_blitter(0)
{
    setSurfaceType(OpenGLSurface);

    m_context = new QOpenGLContext(this);
    m_context->setFormat(requestedFormat());
    m_context->create();

    m_image = QImage(QStringLiteral("qticon64.png")).convertToFormat(QImage::Format_RGBA8888);
    Q_ASSERT(!m_image.isNull());

    create(); // to make sure format() returns something real
    createForeignContext();
}

QOpenGLContextWindow::~QOpenGLContextWindow()
{
    if (m_blitter) {
        m_blitter->destroy(); // the dtor does not call this for some reason
        delete m_blitter;
    }
}

void QOpenGLContextWindow::render()
{
    if (!m_context->makeCurrent(this))
        qFatal("makeCurrent() failed");

    QOpenGLFunctions *f = m_context->functions();
    f->glViewport(0, 0, dWidth(), dHeight());
    f->glClearColor(0, 0, 0, 1);
    f->glClear(GL_COLOR_BUFFER_BIT);

    if (!m_blitter) {
        m_blitter = new QOpenGLTextureBlitter;
        m_blitter->create();
    }

    // Draw the image. If nothing gets shown, then something went wrong with the context
    // adoption or sharing was not successfully enabled.
    m_blitter->bind();
    QRectF r(0, 0, dWidth(), dHeight());
    QMatrix4x4 target = QOpenGLTextureBlitter::targetTransform(QRectF(100, 100, 100, 100), r.toRect());
    m_blitter->blit(m_textureId, target, QOpenGLTextureBlitter::OriginTopLeft);
    m_blitter->release();

    m_context->swapBuffers(this);
}

void QOpenGLContextWindow::exposeEvent(QExposeEvent *)
{
    if (isExposed())
        render();
}

void QOpenGLContextWindow::createForeignContext()
{
    // Here a context will be created manually. This context will share with m_context's
    // underlying native context.  This way the texture, that belongs to the context
    // created here, will be accessible from m_context too.

    EGLContext shareCtx = m_context->nativeHandle().value<QEGLNativeContext>().context();
    Q_ASSERT(shareCtx != EGL_NO_CONTEXT);

    EGLDisplay dpy = (EGLDisplay) qGuiApp->platformNativeInterface()->nativeResourceForWindow(
        QByteArrayLiteral("egldisplay"), this);
    Q_ASSERT(dpy != EGL_NO_DISPLAY);

    QSurfaceFormat fmt = format();
    EGLConfig config = q_configFromGLFormat(dpy, fmt);

    QVector<EGLint> contextAttrs;
    contextAttrs.append(EGL_CONTEXT_CLIENT_VERSION);
    contextAttrs.append(fmt.majorVersion());
    contextAttrs.append(EGL_NONE);
    switch (fmt.renderableType()) {
#ifdef EGL_VERSION_1_4
    case QSurfaceFormat::OpenGL:
        eglBindAPI(EGL_OPENGL_API);
        break;
#endif // EGL_VERSION_1_4
    default:
        eglBindAPI(EGL_OPENGL_ES_API);
        break;
    }

    EGLContext ctx = eglCreateContext(dpy, config, shareCtx, contextAttrs.constData());
    Q_ASSERT(ctx != EGL_NO_CONTEXT);

    // Wrap ctx into a QOpenGLContext.
    QOpenGLContext *ctxWrap = new QOpenGLContext;
    ctxWrap->setNativeHandle(QVariant::fromValue<QEGLNativeContext>(QEGLNativeContext(ctx, dpy)));
    ctxWrap->setShareContext(m_context); // only needed for correct bookkeeping
    if (!ctxWrap->create())
        qFatal("Failed to created wrapping context");
    Q_ASSERT(ctxWrap->nativeHandle().value<QEGLNativeContext>().context() == ctx);

    QOffscreenSurface surface;
    surface.setFormat(fmt);
    surface.create();

    if (!ctxWrap->makeCurrent(&surface))
        qFatal("Failed to make pbuffer surface current");

    // Create the texture.
    QOpenGLFunctions *f = QOpenGLContext::currentContext()->functions();
    GLuint textureId = 0;
    f->glGenTextures(1, &textureId);
    f->glBindTexture(GL_TEXTURE_2D, textureId);
    f->glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    f->glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, m_image.width(), m_image.height(), 0, GL_RGBA, GL_UNSIGNED_BYTE,
                    m_image.constBits());
    Q_ASSERT(f->glGetError() == GL_NO_ERROR);

    ctxWrap->doneCurrent();
    delete ctxWrap; // ctx is not destroyed
    eglDestroyContext(dpy, ctx); // resources like the texture stay alive until any context on the share list is alive
    Q_ASSERT(eglGetError() == EGL_SUCCESS);

    m_textureId = textureId;
}