qpaintengine_opengl.cpp

奇趣公司比较新的qt/emd版本

public:
    QGLOffscreen()
        : QObject(),
          offscreen(0),
          ctx(0),
          mask_dim(0),
          activated(false),
          bound(false)
    {
        connect(QGLProxy::signalProxy(),
                SIGNAL(aboutToDestroyContext(const QGLContext *)),
                SLOT(cleanupGLContextRefs(const QGLContext *)));
    }

    inline void setDevice(QPaintDevice *pdev);

    void begin();
    void end();

    inline void bind();
    inline void release();

    inline bool isBound() const;

    inline QSize drawableSize() const;
    inline QSize offscreenSize() const;

    inline GLuint offscreenTexture() const;

    QGLContext *context() const;

    static bool isSupported();

    inline void initialize();

    inline bool isValid() const;

public Q_SLOTS:
    void cleanupGLContextRefs(const QGLContext *context) {
        if (context == ctx)
            ctx = 0;
    }

private:
    QGLDrawable drawable;

    QGLFramebufferObject *offscreen;
    QGLContext *ctx;

    // dimensions of mask texture (square)
    int mask_dim;
    QSize last_failed_size;

    bool drawable_fbo;

    bool activated;
    bool initialized;

    bool bound;
};

inline void QGLOffscreen::setDevice(QPaintDevice *pdev)
{
    drawable.setDevice(pdev);

    drawable_fbo = (pdev->devType() == QInternal::FramebufferObject);
}

void QGLOffscreen::begin()
{
#ifndef Q_WS_QWS
    initialized = false;

    if (activated)
        initialize();
#endif
}

void QGLOffscreen::initialize()
{
#ifndef Q_WS_QWS
    if (initialized)
        return;

    activated = true;
    initialized = true;

    int dim = qMax(2048, static_cast<int>(qt_next_power_of_two(qMax(drawable.size().width(), drawable.size().height()))));

    bool shared_context = qgl_share_reg()->checkSharing(drawable.context(), ctx);
    bool would_fail = last_failed_size.isValid() &&
                      (drawable.size().width() >= last_failed_size.width() ||
                       drawable.size().height() >= last_failed_size.height());
    bool needs_refresh = dim > mask_dim || !shared_context;

    if (needs_refresh && !would_fail) {
        DEBUG_ONCE qDebug() << "QGLOffscreen::initialize(): creating offscreen of size" << dim;
        delete offscreen;
        offscreen = new QGLFramebufferObject(dim, dim);
        mask_dim = dim;

        if (!offscreen->isValid()) {
            qWarning("QGLOffscreen: Invalid offscreen fbo (size %dx%d)", mask_dim, mask_dim);
            delete offscreen;
            offscreen = 0;
            mask_dim = 0;
            last_failed_size = drawable.size();
        }
    }

    qt_mask_texture_cache()->setOffscreenSize(offscreenSize());
    qt_mask_texture_cache()->setDrawableSize(drawable.size());
    ctx = drawable.context();
#endif
}

inline bool QGLOffscreen::isValid() const
{
    return offscreen;
}

void QGLOffscreen::end()
{
    if (bound)
        release();
#ifdef DEBUG_DISPLAY_MASK_TEXTURE
    glDisable(GL_FRAGMENT_PROGRAM_ARB);
    glReadBuffer(GL_BACK);
    glDrawBuffer(GL_BACK);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    glColor4f(1, 1, 1, 1);
    glDisable(GL_DEPTH_TEST);
    glBlendFunc(GL_ONE, GL_ZERO);
    glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
    glEnable(GL_TEXTURE_2D);
    glBindTexture(GL_TEXTURE_2D, offscreen->texture());

    glBegin(GL_QUADS);
    glTexCoord2f(0.0, 1.0); glVertex2f(0.0, 0.0);
    glTexCoord2f(1.0, 1.0); glVertex2f(drawable.size().width(), 0.0);
    glTexCoord2f(1.0, 0.0); glVertex2f(drawable.size().width(), drawable.size().height());
    glTexCoord2f(0.0, 0.0); glVertex2f(0.0, drawable.size().height());
    glEnd();

    glBindTexture(GL_TEXTURE_2D, 0);
    glDisable(GL_TEXTURE_2D);
#endif
}

inline void QGLOffscreen::bind()
{
#ifndef Q_WS_QWS
    Q_ASSERT(initialized);

    if (!offscreen || bound)
        return;

    DEBUG_ONCE qDebug() << "QGLOffscreen: binding offscreen";
    offscreen->bind();

    bound = true;

    glViewport(0, 0, offscreenSize().width(), offscreenSize().height());

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrtho(0, offscreenSize().width(), offscreenSize().height(), 0, -999999, 999999);
    glMatrixMode(GL_MODELVIEW);
#endif
}

inline void QGLOffscreen::release()
{
#ifndef Q_WS_QWS
    if (!offscreen || !bound)
        return;

#ifdef Q_WS_X11
    // workaround for bug in nvidia driver versions 9x.xx
    if (QGLExtensions::nvidiaFboNeedsFinish)
        glFinish();
#endif

    DEBUG_ONCE_STR("QGLOffscreen: releasing offscreen");

    if (drawable_fbo)
        drawable.makeCurrent();
    else
        offscreen->release();

    QSize sz(drawable.size());
    glViewport(0, 0, sz.width(), sz.height());

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrtho(0, sz.width(), sz.height(), 0, -999999, 999999);
    glMatrixMode(GL_MODELVIEW);

    bound = false;
#endif
}

inline bool QGLOffscreen::isBound() const
{
    return bound;
}

inline QSize QGLOffscreen::drawableSize() const
{
    return drawable.size();
}

inline QSize QGLOffscreen::offscreenSize() const
{
    return QSize(mask_dim, mask_dim);
}

inline GLuint QGLOffscreen::offscreenTexture() const
{
    return offscreen ? offscreen->texture() : 0;
}

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

bool QGLOffscreen::isSupported()
{
    return (QGLExtensions::glExtensions & QGLExtensions::FramebufferObject) // for fbo
        && (QGLFormat::openGLVersionFlags() & QGLFormat::OpenGL_Version_2_0); // non-power-of-two textures
}

struct QDrawQueueItem
{
    QDrawQueueItem(qreal _opacity,
                   QBrush _brush,
                   const QPointF &_brush_origion,
                   QPainter::CompositionMode _composition_mode,
                   const QTransform &_matrix,
                   QGLMaskTextureCache::CacheLocation _location)
        : opacity(_opacity),
          brush(_brush),
          brush_origin(_brush_origion),
          composition_mode(_composition_mode),
          matrix(_matrix),
          location(_location) {}
    qreal opacity;
    QBrush brush;
    QPointF brush_origin;
    QPainter::CompositionMode composition_mode;

    QTransform matrix;
    QGLMaskTextureCache::CacheLocation location;
};

class QOpenGLPaintEnginePrivate;
class QGLPrivateCleanup : public QObject
{
    Q_OBJECT
public:
    QGLPrivateCleanup(QOpenGLPaintEnginePrivate *priv)
        : p(priv)
    {
        connect(QGLProxy::signalProxy(),
                SIGNAL(aboutToDestroyContext(const QGLContext *)),
                SLOT(cleanupGLContextRefs(const QGLContext *)));
    }

public Q_SLOTS:
    void cleanupGLContextRefs(const QGLContext *context);

private:
    QOpenGLPaintEnginePrivate *p;
};

class QOpenGLPaintEnginePrivate : public QPaintEnginePrivate
{
    Q_DECLARE_PUBLIC(QOpenGLPaintEngine)
public:
    QOpenGLPaintEnginePrivate()
        : opacity(1)
        , composition_mode(QPainter::CompositionMode_SourceOver)
        , has_fast_pen(false)
        , txop(QTransform::TxNone)
        , inverseScale(1)
        , moveToCount(0)
        , shader_ctx(0)
        , grad_palette(0)
        , use_stencil_method(false)
        , has_stencil_face_ext(false)
        , use_fragment_programs(false)
        , high_quality_antialiasing(false)
        , drawable_texture(0)
        , ref_cleaner(this)
        {}

    inline void setGLPen(const QColor &c) {
        uint alpha = qRound(c.alpha() * opacity);
        pen_color[0] = (c.red() * alpha + 128) >> 8;
        pen_color[1] = (c.green() * alpha + 128) >> 8;
        pen_color[2] = (c.blue() * alpha + 128) >> 8;
        pen_color[3] = alpha;
    }

    inline void setGLBrush(const QColor &c) {
        uint alpha = qRound(c.alpha() * opacity);
        brush_color[0] = (c.red() * alpha + 128) >> 8;
        brush_color[1] = (c.green() * alpha + 128) >> 8;
        brush_color[2] = (c.blue() * alpha + 128) >> 8;
        brush_color[3] = alpha;
    }

    inline void setGradientOps(const QBrush &brush, const QRectF &bounds);
    void createGradientPaletteTexture(const QGradient& g);

    void updateGradient(const QBrush &brush, const QRectF &bounds);

    inline void lineToStencil(qreal x, qreal y);
    inline void curveToStencil(const QPointF &cp1, const QPointF &cp2, const QPointF &ep);
    void pathToVertexArrays(const QPainterPath &path);
    void fillVertexArray(Qt::FillRule fillRule);
    void drawVertexArrays();
    void fillPath(const QPainterPath &path);
    void fillPolygon_dev(const QPointF *polygonPoints, int pointCount,
                         Qt::FillRule fill);

    void drawFastRect(const QRectF &rect);
    void strokePath(const QPainterPath &path, bool use_cache);
    void strokePathFastPen(const QPainterPath &path, bool needsResolving);
    void strokeLines(const QPainterPath &path);

    void cleanupGLContextRefs(const QGLContext *context) {
        if (context == shader_ctx)
            shader_ctx = 0;
    }

    QPen cpen;
    QBrush cbrush;
    QRegion crgn;
    Qt::BrushStyle brush_style;
    QPointF brush_origin;
    Qt::BrushStyle pen_brush_style;
    qreal opacity;
    QPainter::CompositionMode composition_mode;

    Qt::BrushStyle current_style;

    uint has_clipping : 1;
    uint has_pen : 1;
    uint has_brush : 1;
    uint has_fast_pen : 1;

    QTransform matrix;
    GLubyte pen_color[4];
    GLubyte brush_color[4];
    QTransform::TransformationType txop;
    QGLDrawable drawable;
    QGLOffscreen offscreen;

    qreal inverseScale;

    int moveToCount;
    QPointF path_start;

    bool isFastRect(const QRectF &r);

    void drawImageAsPath(const QRectF &r, const QImage &img, const QRectF &sr);
    void drawTiledImageAsPath(const QRectF &r, const QImage &img);

    void drawOffscreenPath(const QPainterPath &path);

    void composite(const QRectF &rect, const QPoint &maskOffset = QPoint());
    void composite(GLuint primitive, const float *vertexArray, int vertexCount, const QPoint &maskOffset = QPoint());

    bool createFragmentPrograms();
    void deleteFragmentPrograms();
    void updateFragmentProgramData(int locations[]);

    void cacheItemErased(int channel, const QRect &rect);

    void addItem(const QGLMaskTextureCache::CacheLocation &location);
    void drawItem(const QDrawQueueItem &item);
    void flushDrawQueue();

    void copyDrawable(const QRectF &rect);

    QGLContext *shader_ctx;
    GLuint grad_palette;

    GLuint painter_fragment_programs[num_fragment_brushes][num_fragment_composition_modes];
    GLuint mask_fragment_programs[num_fragment_masks];

    bool use_stencil_method;
    bool has_stencil_face_ext;
    bool use_fragment_programs;
    bool high_quality_antialiasing;

    float inv_matrix_data[3][4];
    float fmp_data[4];
    float fmp2_m_radius2_data[4];
    float angle_data[4];
    float linear_data[4];

    float porterduff_ab_data[4];
    float porterduff_xyz_data[4];

    float mask_offset_data[4];
    float mask_channel_data[4];

    FragmentBrushType fragment_brush;
    FragmentCompositionModeType fragment_composition_mode;

    bool has_fast_composition_mode;

    void setPorterDuffData(float a, float b, float x, float y, float z);
    void setInvMatrixData(const QTransform &inv_matrix);

    qreal max_x;
    qreal max_y;
    qreal min_x;