qt6-bb10/src/plugins/platforms/xcb/qxcbbackingstore.cpp

363 lines
12 KiB
C++

/****************************************************************************
**
** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the plugins of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
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** use the contact form at http://qt.digia.com/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
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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 "qxcbbackingstore.h"
#include "qxcbconnection.h"
#include "qxcbscreen.h"
#include "qxcbwindow.h"
#include <xcb/shm.h>
#include <xcb/xcb_image.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <stdio.h>
#include <errno.h>
#include <qdebug.h>
#include <qpainter.h>
#include <qscreen.h>
#include <algorithm>
QT_BEGIN_NAMESPACE
class QXcbShmImage : public QXcbObject
{
public:
QXcbShmImage(QXcbScreen *connection, const QSize &size, uint depth, QImage::Format format);
~QXcbShmImage() { destroy(); }
QImage *image() { return &m_qimage; }
QSize size() const { return m_qimage.size(); }
void put(xcb_window_t window, const QPoint &dst, const QRect &source);
void preparePaint(const QRegion &region);
private:
void destroy();
xcb_shm_segment_info_t m_shm_info;
xcb_image_t *m_xcb_image;
QImage m_qimage;
xcb_gcontext_t m_gc;
xcb_window_t m_gc_window;
QRegion m_dirty;
};
QXcbShmImage::QXcbShmImage(QXcbScreen *screen, const QSize &size, uint depth, QImage::Format format)
: QXcbObject(screen->connection())
, m_gc(0)
, m_gc_window(0)
{
Q_XCB_NOOP(connection());
m_xcb_image = xcb_image_create_native(xcb_connection(),
size.width(),
size.height(),
XCB_IMAGE_FORMAT_Z_PIXMAP,
depth,
0,
~0,
0);
const int segmentSize = m_xcb_image->stride * m_xcb_image->height;
if (!segmentSize)
return;
int id = shmget(IPC_PRIVATE, segmentSize, IPC_CREAT | 0600);
if (id == -1)
qWarning("QXcbShmImage: shmget() failed (%d) for size %d (%dx%d)",
errno, segmentSize, size.width(), size.height());
else
m_shm_info.shmid = id;
m_shm_info.shmaddr = m_xcb_image->data = (quint8 *)shmat (m_shm_info.shmid, 0, 0);
m_shm_info.shmseg = xcb_generate_id(xcb_connection());
const xcb_query_extension_reply_t *shm_reply = xcb_get_extension_data(xcb_connection(), &xcb_shm_id);
bool shm_present = shm_reply != NULL && shm_reply->present;
xcb_generic_error_t *error = NULL;
if (shm_present)
error = xcb_request_check(xcb_connection(), xcb_shm_attach_checked(xcb_connection(), m_shm_info.shmseg, m_shm_info.shmid, false));
if (!shm_present || error) {
free(error);
shmdt(m_shm_info.shmaddr);
shmctl(m_shm_info.shmid, IPC_RMID, 0);
m_shm_info.shmaddr = 0;
m_xcb_image->data = (uint8_t *)malloc(segmentSize);
} else {
if (shmctl(m_shm_info.shmid, IPC_RMID, 0) == -1)
qWarning() << "QXcbBackingStore: Error while marking the shared memory segment to be destroyed";
}
m_qimage = QImage( (uchar*) m_xcb_image->data, m_xcb_image->width, m_xcb_image->height, m_xcb_image->stride, format);
}
void QXcbShmImage::destroy()
{
const int segmentSize = m_xcb_image ? (m_xcb_image->stride * m_xcb_image->height) : 0;
if (segmentSize && m_shm_info.shmaddr)
Q_XCB_CALL(xcb_shm_detach(xcb_connection(), m_shm_info.shmseg));
xcb_image_destroy(m_xcb_image);
if (segmentSize) {
if (m_shm_info.shmaddr) {
shmdt(m_shm_info.shmaddr);
shmctl(m_shm_info.shmid, IPC_RMID, 0);
} else {
free(m_xcb_image->data);
}
}
if (m_gc)
Q_XCB_CALL(xcb_free_gc(xcb_connection(), m_gc));
}
void QXcbShmImage::put(xcb_window_t window, const QPoint &target, const QRect &source)
{
Q_XCB_NOOP(connection());
if (m_gc_window != window) {
if (m_gc)
Q_XCB_CALL(xcb_free_gc(xcb_connection(), m_gc));
m_gc = xcb_generate_id(xcb_connection());
Q_XCB_CALL(xcb_create_gc(xcb_connection(), m_gc, window, 0, 0));
m_gc_window = window;
}
Q_XCB_NOOP(connection());
if (m_shm_info.shmaddr) {
xcb_image_shm_put(xcb_connection(),
window,
m_gc,
m_xcb_image,
m_shm_info,
source.x(),
source.y(),
target.x(),
target.y(),
source.width(),
source.height(),
false);
} else {
// If we upload the whole image in a single chunk, the result might be
// larger than the server's maximum request size and stuff breaks.
// To work around that, we upload the image in chunks where each chunk
// is small enough for a single request.
int src_x = source.x();
int src_y = source.y();
int target_x = target.x();
int target_y = target.y();
int width = source.width();
int height = source.height();
// We must make sure that each request is not larger than max_req_size.
// Each request takes req_size + m_xcb_image->stride * height bytes.
uint32_t max_req_size = xcb_get_maximum_request_length(xcb_connection());
uint32_t req_size = sizeof(xcb_put_image_request_t);
int rows_per_put = (max_req_size - req_size) / m_xcb_image->stride;
// This assert could trigger if a single row has more pixels than fit in
// a single PutImage request. However, max_req_size is guaranteed to be
// at least 16384 bytes. That should be enough for quite large images.
Q_ASSERT(rows_per_put > 0);
while (height > 0) {
int rows = std::min(height, rows_per_put);
xcb_image_t *subimage = xcb_image_subimage(m_xcb_image, src_x, src_y, width, rows,
0, 0, 0);
xcb_image_put(xcb_connection(),
window,
m_gc,
subimage,
target_x,
target_y,
0);
xcb_image_destroy(subimage);
src_y += rows;
target_y += rows;
height -= rows;
}
}
Q_XCB_NOOP(connection());
m_dirty = m_dirty | source;
xcb_flush(xcb_connection());
Q_XCB_NOOP(connection());
}
void QXcbShmImage::preparePaint(const QRegion &region)
{
// to prevent X from reading from the image region while we're writing to it
if (m_dirty.intersects(region)) {
connection()->sync();
m_dirty = QRegion();
}
}
QXcbBackingStore::QXcbBackingStore(QWindow *window)
: QPlatformBackingStore(window)
, m_image(0)
, m_syncingResize(false)
{
QXcbScreen *screen = static_cast<QXcbScreen *>(window->screen()->handle());
setConnection(screen->connection());
}
QXcbBackingStore::~QXcbBackingStore()
{
delete m_image;
}
QPaintDevice *QXcbBackingStore::paintDevice()
{
return m_image ? m_image->image() : 0;
}
void QXcbBackingStore::beginPaint(const QRegion &region)
{
if (!m_image)
return;
m_image->preparePaint(region);
if (m_image->image()->hasAlphaChannel()) {
QPainter p(m_image->image());
p.setCompositionMode(QPainter::CompositionMode_Source);
const QVector<QRect> rects = region.rects();
const QColor blank = Qt::transparent;
for (QVector<QRect>::const_iterator it = rects.begin(); it != rects.end(); ++it) {
p.fillRect(*it, blank);
}
}
}
void QXcbBackingStore::flush(QWindow *window, const QRegion &region, const QPoint &offset)
{
if (!m_image || m_image->size().isEmpty())
return;
QSize imageSize = m_image->size();
QRegion clipped = region;
clipped &= QRect(0, 0, window->width(), window->height());
clipped &= QRect(0, 0, imageSize.width(), imageSize.height()).translated(-offset);
QRect bounds = clipped.boundingRect();
if (bounds.isNull())
return;
Q_XCB_NOOP(connection());
QXcbWindow *platformWindow = static_cast<QXcbWindow *>(window->handle());
if (!platformWindow) {
qWarning("QXcbBackingStore::flush: QWindow has no platform window (QTBUG-32681)");
return;
}
QVector<QRect> rects = clipped.rects();
for (int i = 0; i < rects.size(); ++i)
m_image->put(platformWindow->xcb_window(), rects.at(i).topLeft(), rects.at(i).translated(offset));
Q_XCB_NOOP(connection());
if (m_syncingResize) {
xcb_flush(xcb_connection());
connection()->sync();
m_syncingResize = false;
platformWindow->updateSyncRequestCounter();
}
}
void QXcbBackingStore::resize(const QSize &size, const QRegion &)
{
if (m_image && size == m_image->size())
return;
Q_XCB_NOOP(connection());
QXcbScreen *screen = static_cast<QXcbScreen *>(window()->screen()->handle());
QPlatformWindow *pw = window()->handle();
if (!pw) {
window()->create();
pw = window()->handle();
}
QXcbWindow* win = static_cast<QXcbWindow *>(pw);
delete m_image;
m_image = new QXcbShmImage(screen, size, win->depth(), win->imageFormat());
Q_XCB_NOOP(connection());
m_syncingResize = true;
}
extern void qt_scrollRectInImage(QImage &img, const QRect &rect, const QPoint &offset);
bool QXcbBackingStore::scroll(const QRegion &area, int dx, int dy)
{
if (!m_image || m_image->image()->isNull())
return false;
m_image->preparePaint(area);
const QVector<QRect> rects = area.rects();
for (int i = 0; i < rects.size(); ++i)
qt_scrollRectInImage(*m_image->image(), rects.at(i), QPoint(dx, dy));
return true;
}
QT_END_NAMESPACE