/****************************************************************************
**
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** General Public License version 2.1 as published by the Free Software
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** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
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****************************************************************************/

#include <QDebug>

#include <private/qgl_p.h>
#include <private/qegl_p.h>
#include <private/qeglproperties_p.h>

#if !defined(QT_OPENGL_ES_1) && !defined(QT_OPENGL_ES_1_CL)
#include <private/qpaintengineex_opengl2_p.h>
#endif

#ifndef QT_OPENGL_ES_2
#include <private/qpaintengine_opengl_p.h>
#endif

#include "qpixmapdata_x11gl_p.h"

QT_BEGIN_NAMESPACE

extern EGLConfig qt_chooseEGLConfigForPixmap(bool hasAlpha, bool readOnly); // in qgl_x11egl.cpp
extern bool qt_createEGLSurfaceForPixmap(QPixmapData* pmd, bool readOnly); // in qgl_x11egl.cpp

// On 16bpp systems, RGB & ARGB pixmaps are different bit-depths and therefore need
// different contexts:
static EGLContext qPixmapARGBSharedEglContext = EGL_NO_CONTEXT;
static EGLContext qPixmapRGBSharedEglContext = EGL_NO_CONTEXT;

bool QX11GLPixmapData::hasX11GLPixmaps()
{
    static bool checkedForX11Pixmaps = false;
    static bool haveX11Pixmaps = false;

    if (checkedForX11Pixmaps)
        return haveX11Pixmaps;

    checkedForX11Pixmaps = true;

    QX11PixmapData *argbPixmapData = 0;
    QX11PixmapData *rgbPixmapData = 0;
    do {
        if (qgetenv("QT_USE_X11GL_PIXMAPS").isEmpty())
            break;

        // Check we actually have EGL configs which support pixmaps
        EGLConfig argbConfig = qt_chooseEGLConfigForPixmap(true, false);
        EGLConfig rgbConfig = qt_chooseEGLConfigForPixmap(false, false);

        if (argbConfig == 0 || rgbConfig == 0)
            break;

        // Create the shared contexts:
        eglBindAPI(EGL_OPENGL_ES_API);
        EGLint contextAttribs[] = {
#if defined(QT_OPENGL_ES_2)
            EGL_CONTEXT_CLIENT_VERSION, 2,
#endif
            EGL_NONE
        };
        qPixmapARGBSharedEglContext = eglCreateContext(QEglContext::display(),
                                                       argbConfig, 0, contextAttribs);

        if (argbConfig == rgbConfig) {
            // If the configs are the same, we can re-use the same context.
            qPixmapRGBSharedEglContext = qPixmapARGBSharedEglContext;
        } else {
            qPixmapRGBSharedEglContext = eglCreateContext(QEglContext::display(),
                                                           rgbConfig, 0, contextAttribs);
        }

        argbPixmapData = new QX11PixmapData(QPixmapData::PixmapType);
        argbPixmapData->resize(100, 100);
        argbPixmapData->fill(Qt::transparent); // Force ARGB

        if (!qt_createEGLSurfaceForPixmap(argbPixmapData, false))
            break;

        haveX11Pixmaps = eglMakeCurrent(QEglContext::display(),
                                        (EGLSurface)argbPixmapData->gl_surface,
                                        (EGLSurface)argbPixmapData->gl_surface,
                                        qPixmapARGBSharedEglContext);
        if (!haveX11Pixmaps) {
            EGLint err = eglGetError();
            qWarning() << "Unable to make pixmap config current:" << err << QEglContext::errorString(err);
            break;
        }

        // If the ARGB & RGB configs are the same, we don't need to check RGB too
        if (haveX11Pixmaps && (argbConfig != rgbConfig)) {
            rgbPixmapData = new QX11PixmapData(QPixmapData::PixmapType);
            rgbPixmapData->resize(100, 100);
            rgbPixmapData->fill(Qt::red);

            // Try to actually create an EGL pixmap surface
            if (!qt_createEGLSurfaceForPixmap(rgbPixmapData, false))
                break;

            haveX11Pixmaps = eglMakeCurrent(QEglContext::display(),
                                            (EGLSurface)rgbPixmapData->gl_surface,
                                            (EGLSurface)rgbPixmapData->gl_surface,
                                            qPixmapRGBSharedEglContext);
            if (!haveX11Pixmaps) {
                EGLint err = eglGetError();
                qWarning() << "Unable to make pixmap config current:" << err << QEglContext::errorString(err);
                break;
            }
        }
    } while (0);

    if (qPixmapARGBSharedEglContext || qPixmapRGBSharedEglContext) {
        eglMakeCurrent(QEglContext::display(),
                       EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
    }

    if (argbPixmapData) {
        if (argbPixmapData->gl_surface)
            QGLContextPrivate::destroyGlSurfaceForPixmap(argbPixmapData);
        delete argbPixmapData;
        argbPixmapData = 0;
    }
    if (rgbPixmapData) {
        if (rgbPixmapData->gl_surface)
            QGLContextPrivate::destroyGlSurfaceForPixmap(rgbPixmapData);
        delete rgbPixmapData;
        rgbPixmapData = 0;
    }

    if (!haveX11Pixmaps) {
        // Clean up the context(s) if we can't use X11GL pixmaps
        if (qPixmapARGBSharedEglContext != EGL_NO_CONTEXT)
            eglDestroyContext(QEglContext::display(), qPixmapARGBSharedEglContext);

        if (qPixmapRGBSharedEglContext != qPixmapARGBSharedEglContext &&
            qPixmapRGBSharedEglContext != EGL_NO_CONTEXT)
        {
            eglDestroyContext(QEglContext::display(), qPixmapRGBSharedEglContext);
        }
        qPixmapRGBSharedEglContext = EGL_NO_CONTEXT;
        qPixmapARGBSharedEglContext = EGL_NO_CONTEXT;
    }

    if (haveX11Pixmaps)
        qDebug("QX11GLPixmapData is supported");
    else
        qDebug("QX11GLPixmapData is *NOT* being used");

    return haveX11Pixmaps;
}

QX11GLPixmapData::QX11GLPixmapData()
    : QX11PixmapData(QPixmapData::PixmapType),
      ctx(0)
{
}

QX11GLPixmapData::~QX11GLPixmapData()
{
}

#if !defined(QT_OPENGL_ES_1) && !defined(QT_OPENGL_ES_1_CL)
Q_GLOBAL_STATIC(QGL2PaintEngineEx, qt_gl_pixmap_2_engine)
#endif

#ifndef QT_OPENGL_ES_2
Q_GLOBAL_STATIC(QOpenGLPaintEngine, qt_gl_pixmap_engine)
#endif


QPaintEngine* QX11GLPixmapData::paintEngine() const
{
    // We need to create the context before beginPaint - do it here:
    if (!ctx) {
        ctx = new QGLContext(glFormat());
        if (ctx->d_func()->eglContext == 0)
            ctx->d_func()->eglContext = new QEglContext();
        ctx->d_func()->eglContext->setApi(QEgl::OpenGL);
        ctx->d_func()->eglContext->setContext(hasAlphaChannel() ? qPixmapARGBSharedEglContext
                                                                : qPixmapRGBSharedEglContext);
    }

    QPaintEngine* engine;

#if defined(QT_OPENGL_ES_1) || defined(QT_OPENGL_ES_1_CL)
    engine = qt_gl_pixmap_engine();
#elif defined(QT_OPENGL_ES_2)
    engine = qt_gl_pixmap_2_engine();
#else
    if (qt_gl_preferGL2Engine())
        engine = qt_gl_pixmap_2_engine();
    else
        engine = qt_gl_pixmap_engine();
#endif



    // Support multiple painters on multiple pixmaps simultaniously
    if (engine->isActive()) {
        qWarning("Pixmap paint engine already active");

#if defined(QT_OPENGL_ES_1) || defined(QT_OPENGL_ES_1_CL)
        engine = new QOpenGLPaintEngine;
#elif defined(QT_OPENGL_ES_2)
        engine = new QGL2PaintEngineEx;
#else
        if (qt_gl_preferGL2Engine())
            engine = new QGL2PaintEngineEx;
        else
            engine = new QOpenGLPaintEngine;
#endif

        engine->setAutoDestruct(true);
        return engine;
    }

    return engine;
}

void QX11GLPixmapData::beginPaint()
{
//    qDebug("QX11GLPixmapData::beginPaint()");
    if ((EGLSurface)gl_surface == EGL_NO_SURFACE) {
        qt_createEGLSurfaceForPixmap(this, false);
        ctx->d_func()->eglSurface = (EGLSurface)gl_surface;
        ctx->d_func()->valid = true; // ;-)
    }
    QGLPaintDevice::beginPaint();
}

void QX11GLPixmapData::endPaint()
{
    glFinish();
    QGLPaintDevice::endPaint();
}

QGLContext* QX11GLPixmapData::context() const
{
    return ctx;
}

QSize QX11GLPixmapData::size() const
{
    return QSize(w, h);
}


QGLFormat QX11GLPixmapData::glFormat()
{
    return QGLFormat::defaultFormat(); //###
}

QT_END_NAMESPACE