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****************************************************************************/

#define GL_GLEXT_PROTOTYPES

#include "shivavgwindowsurface.h"

#include <QtOpenVG/private/qpaintengine_vg_p.h>

#if defined(Q_WS_X11)

#include "private/qt_x11_p.h"

#include "qx11info_x11.h"

#include <GL/glx.h>

extern QX11Info *qt_x11Info(const QPaintDevice *pd);

#endif

// Define this to use framebuffer objects.

//#define QVG_USE_FBO 1

#include <vg/openvg.h>

QT_BEGIN_NAMESPACE

class QShivaContext

{

public:

    QShivaContext();

    ~QShivaContext();

    bool makeCurrent(ShivaVGWindowSurfacePrivate *surface);

    void doneCurrent();

    bool initialized;

    QSize currentSize;

    ShivaVGWindowSurfacePrivate *currentSurface;

};

Q_GLOBAL_STATIC(QShivaContext, shivaContext);

class ShivaVGWindowSurfacePrivate

{

public:

    ShivaVGWindowSurfacePrivate()

        : isCurrent(false)

        , needsResize(true)

        , engine(0)

#if defined(QVG_USE_FBO)

        , fbo(0)

        , texture(0)

#endif

#if defined(Q_WS_X11)

        , drawable(0)

        , context(0)

#endif

    {

    }

    ~ShivaVGWindowSurfacePrivate();

    void ensureContext(QWidget *widget);

    QSize size;

    bool isCurrent;

    bool needsResize;

    QVGPaintEngine *engine;

#if defined(QVG_USE_FBO)

    GLuint fbo;

    GLuint texture;

#endif

#if defined(Q_WS_X11)

    GLXDrawable drawable;

    GLXContext context;

#endif

};

QShivaContext::QShivaContext()

    : initialized(false)

    , currentSurface(0)

{

}

QShivaContext::~QShivaContext()

{

    if (initialized)

        vgDestroyContextSH();

}

bool QShivaContext::makeCurrent(ShivaVGWindowSurfacePrivate *surface)

{

    if (currentSurface)

        currentSurface->isCurrent = false;

    surface->isCurrent = true;

    currentSurface = surface;

    currentSize = surface->size;

#if defined(Q_WS_X11)

    glXMakeCurrent(X11->display, surface->drawable, surface->context);

#endif

    if (!initialized) {

        if (!vgCreateContextSH(currentSize.width(), currentSize.height())) {

            qWarning("vgCreateContextSH(%d, %d): could not create context", currentSize.width(), currentSize.height());

            return false;

        }

        initialized = true;

    } else {

        vgResizeSurfaceSH(currentSize.width(), currentSize.height());

    }

#if defined(QVG_USE_FBO)

    if (surface->fbo)

        glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, surface->fbo);

    else

        glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);

#endif

    return true;

}

void QShivaContext::doneCurrent()

{

    if (currentSurface) {

        currentSurface->isCurrent = false;

        currentSurface = 0;

    }

#if defined(Q_WS_X11)

    glXMakeCurrent(X11->display, 0, 0);

#endif

}

ShivaVGWindowSurfacePrivate::~ShivaVGWindowSurfacePrivate()

{

#if defined(QVG_USE_FBO)

    if (fbo) {

        glDeleteTextures(1, &texture);

        glDeleteFramebuffersEXT(1, &fbo);

    }

#endif

}

void ShivaVGWindowSurfacePrivate::ensureContext(QWidget *widget)

{

#if defined(Q_WS_X11)

    Window win = widget->winId();

    if (win != drawable) {

        if (context)

            glXDestroyContext(X11->display, context);

        drawable = win;

    }

    if (context == 0) {

        const QX11Info *xinfo = qt_x11Info(widget);

        int spec[64];

        int i = 0;

        spec[i++] = GLX_DOUBLEBUFFER;

        spec[i++] = GLX_DEPTH_SIZE;

        spec[i++] = 1;

        spec[i++] = GLX_STENCIL_SIZE;

        spec[i++] = 1;

        spec[i++] = GLX_RGBA;

        spec[i++] = GLX_RED_SIZE;

        spec[i++] = 1;

        spec[i++] = GLX_GREEN_SIZE;

        spec[i++] = 1;

        spec[i++] = GLX_BLUE_SIZE;

        spec[i++] = 1;

        spec[i++] = GLX_SAMPLE_BUFFERS_ARB;

        spec[i++] = 1;

        spec[i++] = GLX_SAMPLES_ARB;

        spec[i++] = 4;

        spec[i] = XNone;

        XVisualInfo *visual = glXChooseVisual

            (xinfo->display(), xinfo->screen(), spec);

        context = glXCreateContext(X11->display, visual, 0, True);

        if (!context)

            qWarning("glXCreateContext: could not create GL context for VG rendering");

    }

#else

    Q_UNUSED(widget);

#endif

#if defined(QVG_USE_FBO)

    if (needsResize && fbo) {

#if defined(Q_WS_X11)

        glXMakeCurrent(X11->display, drawable, context);

#endif

        glDeleteTextures(1, &texture);

        glDeleteFramebuffersEXT(1, &fbo);

#if defined(Q_WS_X11)

        glXMakeCurrent(X11->display, 0, 0);

#endif

        fbo = 0;

        texture = 0;

    }

    if (!fbo) {

#if defined(Q_WS_X11)

        glXMakeCurrent(X11->display, drawable, context);

#endif

        glGenFramebuffersEXT(1, &fbo);

        glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo);

        glGenTextures(1, &texture);

        glBindTexture(GL_TEXTURE_2D, texture);

        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, size.width(), size.height(), 0,

                     GL_RGBA, GL_UNSIGNED_BYTE, NULL);

        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);

        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

        glFramebufferTexture2DEXT

            (GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D,

             texture, 0);

        glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);

#if defined(Q_WS_X11)

        glXMakeCurrent(X11->display, 0, 0);

#endif

    }

#endif

    needsResize = false;

}

ShivaVGWindowSurface::ShivaVGWindowSurface(QWidget *window)

    : QWindowSurface(window), d_ptr(new ShivaVGWindowSurfacePrivate)

{

}

ShivaVGWindowSurface::~ShivaVGWindowSurface()

{

    if (d_ptr->isCurrent) {

        shivaContext()->doneCurrent();

        glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);

    }

#if defined(Q_WS_X11)

    if (d_ptr->context)

        glXDestroyContext(X11->display, d_ptr->context);

#endif

    delete d_ptr;

}

QPaintDevice *ShivaVGWindowSurface::paintDevice()

{

    d_ptr->ensureContext(window());

    shivaContext()->makeCurrent(d_ptr);

    glClearDepth(0.0f);

    glClear(GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    return this;

}

void ShivaVGWindowSurface::flush(QWidget *widget, const QRegion &region, const QPoint &offset)

{

    Q_UNUSED(region);

    Q_UNUSED(offset);

    QWidget *parent = widget->internalWinId() ? widget : widget->nativeParentWidget();

    d_ptr->ensureContext(parent);

    QShivaContext *context = shivaContext();

    if (!d_ptr->isCurrent)

        context->makeCurrent(d_ptr);

#if defined(QVG_USE_FBO)

    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);

    if (d_ptr->fbo) {

        static GLfloat const vertices[][2] = {

            {-1, -1}, {1, -1}, {1, 1}, {-1, 1}

        };

        static GLfloat const texCoords[][2] = {

            {0, 0}, {1, 0}, {1, 1}, {0, 1}

        };

        glMatrixMode(GL_PROJECTION);

        glLoadIdentity();

        glMatrixMode(GL_MODELVIEW);

        glLoadIdentity();

        glVertexPointer(2, GL_FLOAT, 0, vertices);

        glTexCoordPointer(2, GL_FLOAT, 0, texCoords);

        glBindTexture(GL_TEXTURE_2D, d_ptr->texture);

        glEnable(GL_TEXTURE_2D);

        glEnableClientState(GL_VERTEX_ARRAY);

        glEnableClientState(GL_TEXTURE_COORD_ARRAY);

        glDrawArrays(GL_TRIANGLE_FAN, 0, 4);

        glDisableClientState(GL_TEXTURE_COORD_ARRAY);

        glDisableClientState(GL_VERTEX_ARRAY);

        glDisable(GL_TEXTURE_2D);

        glBindTexture(GL_TEXTURE_2D, 0);

    }

#endif

#if defined(Q_WS_X11)

    glXSwapBuffers(X11->display, d_ptr->drawable);

#endif

    context->doneCurrent();

}

void ShivaVGWindowSurface::setGeometry(const QRect &rect)

{

    QWindowSurface::setGeometry(rect);

    d_ptr->needsResize = true;

    d_ptr->size = rect.size();

}

bool ShivaVGWindowSurface::scroll(const QRegion &area, int dx, int dy)

{

    return QWindowSurface::scroll(area, dx, dy);

}

void ShivaVGWindowSurface::beginPaint(const QRegion &region)

{

    // Nothing to do here.

    Q_UNUSED(region);

}

void ShivaVGWindowSurface::endPaint(const QRegion &region)

{

    // Nothing to do here.

    Q_UNUSED(region);

}

Q_GLOBAL_STATIC(QVGPaintEngine, sharedPaintEngine);

QPaintEngine *ShivaVGWindowSurface::paintEngine() const

{

    if (!d_ptr->engine)

        d_ptr->engine = sharedPaintEngine();

    return d_ptr->engine;

}

int ShivaVGWindowSurface::metric(PaintDeviceMetric met) const

{

    return qt_paint_device_metric(window(), met);

}

QT_END_NAMESPACE