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

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

#include <qdebug.h>

#include "qglpixelbuffer.h"

#include "qglpixelbuffer_p.h"

#include "qgl_egl_p.h"

#include <qimage.h>

#include <private/qgl_p.h>

#ifdef QT_OPENGL_ES_1_CL

#include "qgl_cl_p.h"

#endif

QT_BEGIN_NAMESPACE

#ifdef EGL_BIND_TO_TEXTURE_RGBA

#define QGL_RENDER_TEXTURE 1

#else

#define QGL_RENDER_TEXTURE 0

#endif

bool QGLPixelBufferPrivate::init(const QSize &size, const QGLFormat &f, QGLWidget *shareWidget)

{

    // Create the EGL context.

    ctx = new QEglContext();

    ctx->setApi(QEgl::OpenGL);

    // Find the shared context.

    QEglContext *shareContext = 0;

    if (shareWidget && shareWidget->d_func()->glcx)

        shareContext = shareWidget->d_func()->glcx->d_func()->eglContext;

    // Choose an appropriate configuration.  We use the best format

    // we can find, even if it is greater than the requested format.

    // We try for a pbuffer that is capable of texture rendering if possible.

    textureFormat = EGL_NONE;

    if (shareContext) {

        // Use the same configuration as the widget we are sharing with.

        ctx->setConfig(shareContext->config());

#if QGL_RENDER_TEXTURE

        EGLint value = EGL_FALSE;

        if (ctx->configAttrib(EGL_BIND_TO_TEXTURE_RGBA, &value) && value)

            textureFormat = EGL_TEXTURE_RGBA;

        else if (ctx->configAttrib(EGL_BIND_TO_TEXTURE_RGB, &value) && value)

            textureFormat = EGL_TEXTURE_RGB;

#endif

    } else {

        QEglProperties configProps;

        qt_egl_set_format(configProps, QInternal::Pbuffer, f);

        configProps.setRenderableType(ctx->api());

        bool ok = false;

#if QGL_RENDER_TEXTURE

        textureFormat = EGL_TEXTURE_RGBA;

        configProps.setValue(EGL_BIND_TO_TEXTURE_RGBA, EGL_TRUE);

        ok = ctx->chooseConfig(configProps, QEgl::BestPixelFormat);

        if (!ok) {

            // Try again with RGB texture rendering.

            textureFormat = EGL_TEXTURE_RGB;

            configProps.removeValue(EGL_BIND_TO_TEXTURE_RGBA);

            configProps.setValue(EGL_BIND_TO_TEXTURE_RGB, EGL_TRUE);

            ok = ctx->chooseConfig(configProps, QEgl::BestPixelFormat);

            if (!ok) {

                // One last try for a pbuffer with no texture rendering.

                configProps.removeValue(EGL_BIND_TO_TEXTURE_RGB);

                textureFormat = EGL_NONE;

            }

        }

#endif

        if (!ok) {

            if (!ctx->chooseConfig(configProps, QEgl::BestPixelFormat)) {

                delete ctx;

                ctx = 0;

                return false;

            }

        }

    }

    // Retrieve the actual format properties.

    qt_egl_update_format(*ctx, format);

    // Create the attributes needed for the pbuffer.

    QEglProperties attribs;

    attribs.setValue(EGL_WIDTH, size.width());

    attribs.setValue(EGL_HEIGHT, size.height());

#if QGL_RENDER_TEXTURE

    if (textureFormat != EGL_NONE) {

        attribs.setValue(EGL_TEXTURE_FORMAT, textureFormat);

        attribs.setValue(EGL_TEXTURE_TARGET, EGL_TEXTURE_2D);

    }

#endif

    // Create the pbuffer surface.

    pbuf = eglCreatePbufferSurface(ctx->display(), ctx->config(), attribs.properties());

#if QGL_RENDER_TEXTURE

    if (pbuf == EGL_NO_SURFACE && textureFormat != EGL_NONE) {

        // Try again with texture rendering disabled.

        textureFormat = EGL_NONE;

        attribs.removeValue(EGL_TEXTURE_FORMAT);

        attribs.removeValue(EGL_TEXTURE_TARGET);

        pbuf = eglCreatePbufferSurface(ctx->display(), ctx->config(), attribs.properties());

    }

#endif

    if (pbuf == EGL_NO_SURFACE) {

        qWarning() << "QGLPixelBufferPrivate::init(): Unable to create EGL pbuffer surface:" << QEglContext::errorString(eglGetError());

        return false;

    }

    // Create a new context for the configuration.

    if (!ctx->createContext(shareContext)) {

        delete ctx;

        ctx = 0;

        return false;

    }

    return true;

}

bool QGLPixelBufferPrivate::cleanup()

{

    // No need to destroy "pbuf" here - it is done in QGLContext::reset().

    return true;

}

bool QGLPixelBuffer::bindToDynamicTexture(GLuint texture_id)

{

#if QGL_RENDER_TEXTURE

    Q_D(QGLPixelBuffer);

    if (d->invalid || d->textureFormat == EGL_NONE || !d->ctx)

        return false;

    glBindTexture(GL_TEXTURE_2D, texture_id);

    return eglBindTexImage(d->ctx->display(), d->pbuf, EGL_BACK_BUFFER);

#else

    Q_UNUSED(texture_id);

    return false;

#endif

}

void QGLPixelBuffer::releaseFromDynamicTexture()

{

#if QGL_RENDER_TEXTURE

    Q_D(QGLPixelBuffer);

    if (d->invalid || d->textureFormat == EGL_NONE || !d->ctx)

        return;

    eglReleaseTexImage(d->ctx->display(), d->pbuf, EGL_BACK_BUFFER);

#endif

}

GLuint QGLPixelBuffer::generateDynamicTexture() const

{

#if QGL_RENDER_TEXTURE

    Q_D(const QGLPixelBuffer);

    GLuint texture;

    glGenTextures(1, &texture);

    glBindTexture(GL_TEXTURE_2D, texture);

    if (d->textureFormat == EGL_TEXTURE_RGB)

        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, d->req_size.width(), d->req_size.height(), 0, GL_RGB, GL_UNSIGNED_BYTE, 0);

    else

        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, d->req_size.width(), d->req_size.height(), 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);

    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

    return texture;

#else

    return 0;

#endif

}

bool QGLPixelBuffer::hasOpenGLPbuffers()

{

    // See if we have at least 1 configuration that matches the default format.

    if (dpy == EGL_NO_DISPLAY)

        return false;

    QEglProperties configProps;

    qt_egl_set_format(configProps, QInternal::Pbuffer, QGLFormat::defaultFormat());

    configProps.setRenderableType(QEgl::OpenGL);

    do {

        EGLConfig cfg = 0;

        EGLint matching = 0;

        if (eglChooseConfig(dpy, configProps.properties(),

                            &cfg, 1, &matching) && matching > 0)

            return true;

    } while (configProps.reduceConfiguration());

    return false;

}

QT_END_NAMESPACE