qqnxrasterwindow.cpp

// Copyright (C) 2013 - 2014 BlackBerry Limited. All rights reserved.

// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only

// Qt-Security score:significant reason:default

#include "qqnxglobal.h"

#include "qqnxrasterwindow.h"

#include "qqnxscreen.h"

#include <QDebug>

#include <private/qhighdpiscaling_p.h>

#include <errno.h>

QT_BEGIN_NAMESPACE

QQnxRasterWindow::QQnxRasterWindow(QWindow *window, screen_context_t context, bool needRootWindow) :

    QQnxWindow(window, context, needRootWindow),

    m_currentBufferIndex(-1),

    m_previousBufferIndex(-1)

    initWindow();

    const int val = SCREEN_USAGE_NATIVE | SCREEN_USAGE_READ | SCREEN_USAGE_WRITE;

    const int result = screen_set_window_property_iv(nativeHandle(), SCREEN_PROPERTY_USAGE, &val);

    if (Q_UNLIKELY(result != 0))

        qFatal("QQnxRasterWindow: failed to set window alpha usage, errno=%d", errno);

void QQnxRasterWindow::post(const QRegion &dirty)

    // How double-buffering works

    // --------------------------

//

    // The are two buffers, the previous one and the current one.

    // The previous buffer always contains the complete, full image of the whole window when it

    // was last posted.

    // The current buffer starts with the complete, full image of the second to last posting

    // of the window.

//

    // During painting, Qt paints on the current buffer. Thus, when Qt has finished painting, the

    // current buffer contains the second to last image plus the newly painted regions.

    // Since the second to last image is too old, we copy over the image from the previous buffer, but

    // only for those regions that Qt didn't paint (because that would overwrite what Qt has just

    // painted). This is the copyPreviousToCurrent() call below.

//

    // After the call to copyPreviousToCurrent(), the current buffer contains the complete, full image of the

    // whole window in its current state, and we call screen_post_window() to make the new buffer

    // available to libscreen (called "posting"). There, only the regions that Qt painted on are

    // posted, as nothing else has changed.

//

    // After that, the previous and the current buffers are swapped, and the whole cycle starts anew.

    // Check if render buffer exists and something was rendered

    if (m_currentBufferIndex != -1 && !dirty.isEmpty()) {

        qCDebug(lcQpaWindow) << Q_FUNC_INFO << "window = " << window();

        QQnxBuffer &currentBuffer = m_buffers[m_currentBufferIndex];

#if defined(QQNX_INCREMENTAL_RASTER_UPDATE)

        // Copy unmodified region from old render buffer to new render buffer;

        // required to allow partial updates

        QRegion preserve = m_previousDirty - dirty - m_scrolled;

        blitPreviousToCurrent(preserve, 0, 0);

        // Calculate region that changed

        QRegion modified = preserve + dirty + m_scrolled;

        QRect rect = modified.boundingRect();

        int dirtyRect[4] = { rect.x(), rect.y(), rect.x() + rect.width(), rect.y() + rect.height() };

        // Update the display with contents of render buffer

        Q_SCREEN_CHECKERROR(

                screen_post_window(nativeHandle(), currentBuffer.nativeBuffer(), 1, dirtyRect, 0),

                "Failed to post window");

#else

        // Update the display with contents of render buffer

        Q_SCREEN_CHECKERROR(

                screen_post_window(nativeHandle(), currentBuffer.nativeBuffer(), 0, NULL, 0),

                "Failed to post window");

#endif

        // Advance to next nender buffer

        m_previousBufferIndex = m_currentBufferIndex++;

        if (m_currentBufferIndex >= MAX_BUFFER_COUNT)

            m_currentBufferIndex = 0;

        // Save modified region and clear scrolled region

        m_previousDirty = QRect(QPoint(0, 0), QHighDpi::toNativePixels(window()->size(), window()));

        m_scrolled = QRegion();

        windowPosted();

void QQnxRasterWindow::scroll(const QRegion &region, int dx, int dy, bool flush)

    qCDebug(lcQpaWindow) << Q_FUNC_INFO << "window = " << window();

    blitPreviousToCurrent(region, dx, dy, flush);

    m_scrolled += region;

QQnxBuffer &QQnxRasterWindow::renderBuffer()

    qCDebug(lcQpaWindow) << Q_FUNC_INFO << "window = " << window();

    // Check if render buffer is invalid

    if (m_currentBufferIndex == -1) {

        auto platformScreen = static_cast<QQnxScreen *>(screen());

        // Get all buffers available for rendering

        screen_buffer_t buffers[MAX_BUFFER_COUNT];

        const int result = screen_get_window_property_pv(nativeHandle(), SCREEN_PROPERTY_RENDER_BUFFERS,

                                                   (void **)buffers);

        Q_SCREEN_CRITICALERROR(result, "Failed to query window buffers");

        // Wrap each buffer and clear

        for (int i = 0; i < MAX_BUFFER_COUNT; ++i) {

            m_buffers[i] = QQnxBuffer(buffers[i]);

            // Clear Buffer

            int bg[] = { SCREEN_BLIT_COLOR, 0x00000000, SCREEN_BLIT_END };

            Q_SCREEN_CHECKERROR(screen_fill(platformScreen->nativeContext(), buffers[i], bg),

                                "Failed to clear window buffer");

        Q_SCREEN_CHECKERROR(screen_flush_blits(platformScreen->nativeContext(), SCREEN_WAIT_IDLE),

                            "Failed to flush blits");

        // Use the first available render buffer

        m_currentBufferIndex = 0;

        m_previousBufferIndex = -1;

    return m_buffers[m_currentBufferIndex];

void QQnxRasterWindow::setParent(const QPlatformWindow *wnd)

    QQnxWindow::setParent(wnd);

    adjustBufferSize();

void QQnxRasterWindow::adjustBufferSize()

    adjustBufferSize(QHighDpi::toNativePixels(window()->size(), window()));

void QQnxRasterWindow::adjustBufferSize(const QSize &size)

    if (size != bufferSize())

        setBufferSize(size);

int QQnxRasterWindow::pixelFormat() const

    return static_cast<QQnxScreen *>(screen())->nativeFormat();

void QQnxRasterWindow::resetBuffers()

    // Buffers were destroyed; reacquire them

    m_previousBufferIndex = -1;

    m_currentBufferIndex = -1;

    m_previousDirty = QRegion();

    m_scrolled = QRegion();

void QQnxRasterWindow::blitPreviousToCurrent(const QRegion &region, int dx, int dy, bool flush)

    qCDebug(lcQpaWindow) << Q_FUNC_INFO << "window = " << window();

    // Abort if previous buffer is invalid or if nothing to copy

    if (m_previousBufferIndex == -1 || region.isEmpty())

        return;

    QQnxBuffer &currentBuffer = m_buffers[m_currentBufferIndex];

    QQnxBuffer &previousBuffer = m_buffers[m_previousBufferIndex];

    // Break down region into non-overlapping rectangles

    for (auto rit = region.rbegin(), rend = region.rend(); rit != rend; ++rit) {

        // Clip rectangle to bounds of target

        const QRect rect = rit->intersected(currentBuffer.rect());

        if (rect.isEmpty())

            continue;

        // Setup blit operation

        int attribs[] = { SCREEN_BLIT_SOURCE_X, rect.x(),

                          SCREEN_BLIT_SOURCE_Y, rect.y(),

                          SCREEN_BLIT_SOURCE_WIDTH, rect.width(),

                          SCREEN_BLIT_SOURCE_HEIGHT, rect.height(),

                          SCREEN_BLIT_DESTINATION_X, rect.x() + dx,

                          SCREEN_BLIT_DESTINATION_Y, rect.y() + dy,

                          SCREEN_BLIT_DESTINATION_WIDTH, rect.width(),

                          SCREEN_BLIT_DESTINATION_HEIGHT, rect.height(),

                          SCREEN_BLIT_END };

        // Queue blit operation

        Q_SCREEN_CHECKERROR(screen_blit(m_screenContext, currentBuffer.nativeBuffer(),

                                       previousBuffer.nativeBuffer(), attribs),

                            "Failed to blit buffers");

    // Check if flush requested

    if (flush) {

        // Wait for all blits to complete

        Q_SCREEN_CHECKERROR(screen_flush_blits(m_screenContext, SCREEN_WAIT_IDLE),

                            "Failed to flush blits");

        // Buffer was modified outside the CPU

        currentBuffer.invalidateInCache();

QT_END_NAMESPACE

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