qlibcamera_controls.cpp

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// Copyright (C) 2026 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#include "qlibcamera_controls_p.h"
 
#include <libcamera/control_ids.h>
#include <libcamera/controls.h>
#include <libcamera/geometry.h>
 
QT_BEGIN_NAMESPACE
 
namespace QLibCamera {
 
using namespace libcamera;
 
namespace QLibCameraControls {
 
QCamera::Features detectSupportedFeatures(const ControlInfoMap &controls)
{
    QCamera::Features features;
 
    if (controls.find(&libcamera::controls::ColourTemperature) != controls.end())
        features |= QCamera::Feature::ColorTemperature;
    if (controls.find(&libcamera::controls::ExposureValue) != controls.end())
        features |= QCamera::Feature::ExposureCompensation;
    if (controls.find(&libcamera::controls::AnalogueGain) != controls.end())
        features |= QCamera::Feature::IsoSensitivity;
    if (controls.find(&libcamera::controls::ExposureTime) != controls.end())
        features |= QCamera::Feature::ManualExposureTime;
    if (controls.find(&libcamera::controls::LensPosition) != controls.end())
        features |= QCamera::Feature::FocusDistance;
 
    return features;
}
 
void setAeEnable(ControlList &pending, bool enable)
{
    pending.set(libcamera::controls::AeEnable, enable);
}
 
void setManualExposureTime(ControlList &pending, float seconds)
{
    // libcamera::controls::ExposureTime is in microseconds.
    pending.set(libcamera::controls::AeEnable, false);
    pending.set(libcamera::controls::ExposureTime, int32_t(seconds * 1'000'000.f));
}
 
void setExposureCompensation(ControlList &pending, float stops)
{
    pending.set(libcamera::controls::ExposureValue, stops);
}
 
void setAnalogueGainForIso(ControlList &pending, int iso)
{
    // ISO 100 is conventionally analogue gain 1.0.
    pending.set(libcamera::controls::AeEnable, false);
    pending.set(libcamera::controls::AnalogueGain, float(iso) / 100.f);
}
 
void setAwbEnable(ControlList &pending, bool enable)
{
    pending.set(libcamera::controls::AwbEnable, enable);
}
 
void setColorTemperature(ControlList &pending, int kelvin)
{
    pending.set(libcamera::controls::AwbEnable, false);
    pending.set(libcamera::controls::ColourTemperature, kelvin);
}
 
void setZoomFactor(ControlList &pending, const ControlInfoMap &controls, float zoomFactor)
{
    const auto it = controls.find(&libcamera::controls::ScalerCrop);
    if (it == controls.end())
        return;
 
    const Rectangle maxCrop = it->second.max().get<Rectangle>();
    if (maxCrop.isNull() || zoomFactor <= 1.f)
        return;
 
    const unsigned int width = std::max(1u, static_cast<unsigned int>(maxCrop.width / zoomFactor));
    const unsigned int height =
            std::max(1u, static_cast<unsigned int>(maxCrop.height / zoomFactor));
    const int x = maxCrop.x + int(maxCrop.width - width) / 2;
    const int y = maxCrop.y + int(maxCrop.height - height) / 2;
 
    pending.set(libcamera::controls::ScalerCrop, Rectangle(x, y, width, height));
}
 
} // namespace QLibCameraControls
 
} // namespace QLibCamera
 
QT_END_NAMESPACE