Method enqueueScale

YACReader/continuous_page_widget.cpp:322–347

}

void ContinuousPageWidget::enqueueScale(int pageIndex, const QImage *source, const QSize &targetSize, const QSize &targetPixelSize, qreal dpr)
{
    if (!source || source->isNull() || targetPixelSize.isEmpty()) {
        return;
    }

    ScaleRequestKey key;
    key.sourceCacheKey = source->cacheKey();
    key.targetPixelSize = targetPixelSize;
    key.devicePixelRatio = dpr;
    key.generation = cacheGeneration;

    auto it = pendingScaleRequests.constFind(pageIndex);
    if (it != pendingScaleRequests.constEnd() && it.value() == key) {
        return; // identical scale already in flight
    }

    pendingScaleRequests.insert(pageIndex, key);

    // *source copies the QImage (implicitly shared, copy-on-write), so the task
    // reads it on the worker thread without racing the render buffer.
    auto *task = new PageScaleTask(this, pageIndex, cacheGeneration, *source, source->size(),
                                   source->cacheKey(), targetSize, targetPixelSize, dpr,
                                   Configuration::getConfiguration().getScalingMethod());
    scalePool.start(task);
}

void ContinuousPageWidget::deliverScaledImage(int pageIndex, quint64 generation, QImage scaledImage,
                                              qint64 sourceCacheKey, QSize sourceSize, QSize targetSize,