summaryrefslogtreecommitdiffstats
path: root/src/platformsupport/glxconvenience/qglxconvenience.cpp
blob: 4225bebf37da60fcdd164e3cbfd94435271bb6ac (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
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the plugins of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** 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 Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or any later version approved by the KDE Free
** Qt Foundation. The licenses are as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
** 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-2.0.html and
** https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

// We have to include this before the X11 headers dragged in by
// qglxconvenience_p.h.
#include <QtCore/QByteArray>
#include <QtCore/QScopedPointer>

#include "qglxconvenience_p.h"

#include <QtCore/QVector>
#include <QtCore/QVarLengthArray>

#ifndef QT_NO_XRENDER
#include <X11/extensions/Xrender.h>
#endif

#include <GL/glxext.h>

enum {
    XFocusOut = FocusOut,
    XFocusIn = FocusIn,
    XKeyPress = KeyPress,
    XKeyRelease = KeyRelease,
    XNone = None,
    XRevertToParent = RevertToParent,
    XGrayScale = GrayScale,
    XCursorShape = CursorShape
};
#undef FocusOut
#undef FocusIn
#undef KeyPress
#undef KeyRelease
#undef None
#undef RevertToParent
#undef GrayScale
#undef CursorShape

#ifdef FontChange
#undef FontChange
#endif

QVector<int> qglx_buildSpec(const QSurfaceFormat &format, int drawableBit)
{
    QVector<int> spec;

    spec << GLX_LEVEL
         << 0

         << GLX_RENDER_TYPE
         << GLX_RGBA_BIT

         << GLX_RED_SIZE
         << qMax(1, format.redBufferSize())

         << GLX_GREEN_SIZE
         << qMax(1, format.greenBufferSize())

         << GLX_BLUE_SIZE
         << qMax(1, format.blueBufferSize())

         << GLX_ALPHA_SIZE
         << qMax(0, format.alphaBufferSize());

    if (format.swapBehavior() != QSurfaceFormat::SingleBuffer)
        spec << GLX_DOUBLEBUFFER
             << True;

    if (format.stereo())
        spec << GLX_STEREO
             << True;

    if (format.depthBufferSize() != -1)
        spec << GLX_DEPTH_SIZE
             << format.depthBufferSize();

    if (format.stencilBufferSize() != -1)
        spec << GLX_STENCIL_SIZE
             << format.stencilBufferSize();

    if (format.samples() > 1)
        spec << GLX_SAMPLE_BUFFERS_ARB
             << 1
             << GLX_SAMPLES_ARB
             << format.samples();

    spec << GLX_DRAWABLE_TYPE
         << drawableBit

         << XNone;

    return spec;
}

namespace  {
struct QXcbSoftwareOpenGLEnforcer {
    QXcbSoftwareOpenGLEnforcer() {
        // Allow forcing LIBGL_ALWAYS_SOFTWARE for Qt 5 applications only.
        // This is most useful with drivers that only support OpenGL 1.
        // We need OpenGL 2, but the user probably doesn't want
        // LIBGL_ALWAYS_SOFTWARE in OpenGL 1 apps.

        if (!checkedForceSoftwareOpenGL) {
            // If LIBGL_ALWAYS_SOFTWARE is already set, don't mess with it.
            // We want to unset LIBGL_ALWAYS_SOFTWARE at the end so it does not
            // get inherited by other processes, of course only if it wasn't
            // already set before.
            if (!qEnvironmentVariableIsEmpty("QT_XCB_FORCE_SOFTWARE_OPENGL")
                && !qEnvironmentVariableIsSet("LIBGL_ALWAYS_SOFTWARE"))
                forceSoftwareOpenGL = true;

            checkedForceSoftwareOpenGL = true;
        }

        if (forceSoftwareOpenGL)
            qputenv("LIBGL_ALWAYS_SOFTWARE", QByteArrayLiteral("1"));
    }

    ~QXcbSoftwareOpenGLEnforcer() {
        // unset LIBGL_ALWAYS_SOFTWARE now so other processes don't inherit it
        if (forceSoftwareOpenGL)
            qunsetenv("LIBGL_ALWAYS_SOFTWARE");
    }

    static bool checkedForceSoftwareOpenGL;
    static bool forceSoftwareOpenGL;
};

bool QXcbSoftwareOpenGLEnforcer::checkedForceSoftwareOpenGL = false;
bool QXcbSoftwareOpenGLEnforcer::forceSoftwareOpenGL = false;

template <class T>
struct QXlibScopedPointerDeleter {
    static inline void cleanup(T *pointer) {
        XFree(pointer);
    }
};

template <class T>
using QXlibPointer = QScopedPointer<T, QXlibScopedPointerDeleter<T>>;

template <class T>
using QXlibArrayPointer = QScopedArrayPointer<T, QXlibScopedPointerDeleter<T>>;
}

GLXFBConfig qglx_findConfig(Display *display, int screen , QSurfaceFormat format, bool highestPixelFormat, int drawableBit)
{
    QXcbSoftwareOpenGLEnforcer softwareOpenGLEnforcer;

    GLXFBConfig config = 0;

    do {
        const QVector<int> spec = qglx_buildSpec(format, drawableBit);

        int confcount = 0;
        QXlibArrayPointer<GLXFBConfig> configs(glXChooseFBConfig(display, screen, spec.constData(), &confcount));

        if (!config && confcount > 0) {
            config = configs[0];
            if (highestPixelFormat && !format.hasAlpha())
                break;
        }

        const int requestedRed = qMax(0, format.redBufferSize());
        const int requestedGreen = qMax(0, format.greenBufferSize());
        const int requestedBlue = qMax(0, format.blueBufferSize());
        const int requestedAlpha = qMax(0, format.alphaBufferSize());

        for (int i = 0; i < confcount; i++) {
            GLXFBConfig candidate = configs[i];

            QXlibPointer<XVisualInfo> visual(glXGetVisualFromFBConfig(display, candidate));

            const int actualRed = qPopulationCount(visual->red_mask);
            const int actualGreen = qPopulationCount(visual->green_mask);
            const int actualBlue = qPopulationCount(visual->blue_mask);
            const int actualAlpha = visual->depth - actualRed - actualGreen - actualBlue;

            if (requestedRed && actualRed != requestedRed)
                continue;
            if (requestedGreen && actualGreen != requestedGreen)
                continue;
            if (requestedBlue && actualBlue != requestedBlue)
                continue;
            if (requestedAlpha && actualAlpha != requestedAlpha)
                continue;

            return candidate;
        }
    } while (qglx_reduceFormat(&format));

    return config;
}

XVisualInfo *qglx_findVisualInfo(Display *display, int screen, QSurfaceFormat *format, int drawableBit)
{
    Q_ASSERT(format);

    XVisualInfo *visualInfo = 0;

    GLXFBConfig config = qglx_findConfig(display, screen, *format, false, drawableBit);
    if (config)
        visualInfo = glXGetVisualFromFBConfig(display, config);

    if (visualInfo) {
        qglx_surfaceFormatFromGLXFBConfig(format, display, config);
        return visualInfo;
    }

    // attempt to fall back to glXChooseVisual
    do {
        QVector<int> attribs = qglx_buildSpec(*format, drawableBit);
        visualInfo = glXChooseVisual(display, screen, attribs.data());

        if (visualInfo) {
            qglx_surfaceFormatFromVisualInfo(format, display, visualInfo);
            return visualInfo;
        }
    } while (qglx_reduceFormat(format));

    return visualInfo;
}

void qglx_surfaceFormatFromGLXFBConfig(QSurfaceFormat *format, Display *display, GLXFBConfig config)
{
    int redSize     = 0;
    int greenSize   = 0;
    int blueSize    = 0;
    int alphaSize   = 0;
    int depthSize   = 0;
    int stencilSize = 0;
    int sampleBuffers = 0;
    int sampleCount = 0;
    int stereo      = 0;

    glXGetFBConfigAttrib(display, config, GLX_RED_SIZE,     &redSize);
    glXGetFBConfigAttrib(display, config, GLX_GREEN_SIZE,   &greenSize);
    glXGetFBConfigAttrib(display, config, GLX_BLUE_SIZE,    &blueSize);
    glXGetFBConfigAttrib(display, config, GLX_ALPHA_SIZE,   &alphaSize);
    glXGetFBConfigAttrib(display, config, GLX_DEPTH_SIZE,   &depthSize);
    glXGetFBConfigAttrib(display, config, GLX_STENCIL_SIZE, &stencilSize);
    glXGetFBConfigAttrib(display, config, GLX_SAMPLES_ARB,  &sampleBuffers);
    glXGetFBConfigAttrib(display, config, GLX_STEREO,       &stereo);

    format->setRedBufferSize(redSize);
    format->setGreenBufferSize(greenSize);
    format->setBlueBufferSize(blueSize);
    format->setAlphaBufferSize(alphaSize);
    format->setDepthBufferSize(depthSize);
    format->setStencilBufferSize(stencilSize);
    if (sampleBuffers) {
        glXGetFBConfigAttrib(display, config, GLX_SAMPLES_ARB, &sampleCount);
        format->setSamples(sampleCount);
    }

    format->setStereo(stereo);
}

void qglx_surfaceFormatFromVisualInfo(QSurfaceFormat *format, Display *display, XVisualInfo *visualInfo)
{
    int redSize     = 0;
    int greenSize   = 0;
    int blueSize    = 0;
    int alphaSize   = 0;
    int depthSize   = 0;
    int stencilSize = 0;
    int sampleBuffers = 0;
    int sampleCount = 0;
    int stereo      = 0;

    glXGetConfig(display, visualInfo, GLX_RED_SIZE,     &redSize);
    glXGetConfig(display, visualInfo, GLX_GREEN_SIZE,   &greenSize);
    glXGetConfig(display, visualInfo, GLX_BLUE_SIZE,    &blueSize);
    glXGetConfig(display, visualInfo, GLX_ALPHA_SIZE,   &alphaSize);
    glXGetConfig(display, visualInfo, GLX_DEPTH_SIZE,   &depthSize);
    glXGetConfig(display, visualInfo, GLX_STENCIL_SIZE, &stencilSize);
    glXGetConfig(display, visualInfo, GLX_SAMPLES_ARB,  &sampleBuffers);
    glXGetConfig(display, visualInfo, GLX_STEREO,       &stereo);

    format->setRedBufferSize(redSize);
    format->setGreenBufferSize(greenSize);
    format->setBlueBufferSize(blueSize);
    format->setAlphaBufferSize(alphaSize);
    format->setDepthBufferSize(depthSize);
    format->setStencilBufferSize(stencilSize);
    if (sampleBuffers) {
        glXGetConfig(display, visualInfo, GLX_SAMPLES_ARB, &sampleCount);
        format->setSamples(sampleCount);
    }

    format->setStereo(stereo);
}

bool qglx_reduceFormat(QSurfaceFormat *format)
{
    Q_ASSERT(format);

    if (format->redBufferSize() > 1) {
        format->setRedBufferSize(1);
        return true;
    }

    if (format->greenBufferSize() > 1) {
        format->setGreenBufferSize(1);
        return true;
    }

    if (format->blueBufferSize() > 1) {
        format->setBlueBufferSize(1);
        return true;
    }

    if (format->swapBehavior() != QSurfaceFormat::SingleBuffer){
        format->setSwapBehavior(QSurfaceFormat::SingleBuffer);
        return true;
    }

    if (format->samples() > 1) {
        format->setSamples(qMin(16, format->samples() / 2));
        return true;
    }

    if (format->depthBufferSize() >= 32) {
        format->setDepthBufferSize(24);
        return true;
    }

    if (format->depthBufferSize() > 1) {
        format->setDepthBufferSize(1);
        return true;
    }

    if (format->depthBufferSize() > 0) {
        format->setDepthBufferSize(0);
        return true;
    }

    if (format->hasAlpha()) {
        format->setAlphaBufferSize(0);
        return true;
    }

    if (format->stencilBufferSize() > 1) {
        format->setStencilBufferSize(1);
        return true;
    }

    if (format->stencilBufferSize() > 0) {
        format->setStencilBufferSize(0);
        return true;
    }

    if (format->stereo()) {
        format->setStereo(false);
        return true;
    }

    return false;
}