qv4l2: refactor crop size calculation

Improve readability by using QSize members and operators for size calculations

Signed-off-by: Ove Brynestad <ovebryne@cisco.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>

diff --git a/utils/qv4l2/capture-win.cpp b/utils/qv4l2/capture-win.cpp
index 89575d4..7c080e8 100644 (file)
--- a/utils/qv4l2/capture-win.cpp
+++ b/utils/qv4l2/capture-win.cpp
@@ -114,9 +114,23 @@ void CaptureWin::resetSize()
        resize(w, h);
 }
 
-int CaptureWin::cropHeight(int width, int height)
+QSize CaptureWin::cropFrameSize(QSize size)
 {
-       double realWidth = width * m_pixelAspectRatio;
+       // Crop width
+       int validWidth;
+
+       if (m_cropMethod == QV4L2_CROP_P43)
+               validWidth = (size.height() * 4.0 / 3.0) / m_pixelAspectRatio;
+       else
+               validWidth = size.width(); // no width crop
+
+       if (validWidth < MIN_WIN_SIZE_WIDTH || validWidth >= size.width())
+               validWidth = size.width();  // no width crop
+
+       int deltaWidth = (size.width() - validWidth) / 2;
+
+       // Crop height
+       double realWidth = size.width() * m_pixelAspectRatio;
        int validHeight;
 
        switch (m_cropMethod) {
@@ -133,29 +147,18 @@ int CaptureWin::cropHeight(int width, int height)
                validHeight = realWidth / 2.39;
                break;
        case QV4L2_CROP_TB:
-               validHeight = height - 2;
+               validHeight = size.height() - 2;
                break;
        default:
-               return 0;
+               validHeight = size.height();  // No height crop
        }
 
-       if (validHeight < MIN_WIN_SIZE_HEIGHT || validHeight >= height)
-               return 0;
-
-       return (height - validHeight) / 2;
-}
-
-int CaptureWin::cropWidth(int width, int height)
-{
-       if (m_cropMethod != QV4L2_CROP_P43)
-               return 0;
+       if (validHeight < MIN_WIN_SIZE_HEIGHT || validHeight >= size.height())
+               validHeight = size.height();  // No height crop
 
-       int validWidth = (height * 4.0 / 3.0) / m_pixelAspectRatio;
+       int deltaHeight = (size.height() - validHeight) / 2;
 
-       if (validWidth < MIN_WIN_SIZE_WIDTH || validWidth >= width)
-               return 0;
-
-       return (width - validWidth) / 2;
+       return QSize(deltaWidth, deltaHeight);
 }
 
 void CaptureWin::updateSize()
@@ -163,10 +166,8 @@ void CaptureWin::updateSize()
        m_crop.updated = 0;
        if (m_frame.updated) {
                m_scaledSize = scaleFrameSize(m_windowSize, m_frame.size);
-               m_crop.delta.setHeight(cropHeight(m_frame.size.width(), m_frame.size.height()));
-               m_crop.delta.setWidth(cropWidth(m_frame.size.width(), m_frame.size.height()));
-               m_crop.size.setHeight(m_frame.size.height() - (m_crop.delta.height() * 2));
-               m_crop.size.setWidth(m_frame.size.width() - (m_crop.delta.width() * 2));
+               m_crop.delta = cropFrameSize(m_frame.size);
+               m_crop.size = m_frame.size - 2 * m_crop.delta;
                m_crop.updated = 1;
        }
 }
@@ -215,7 +216,7 @@ void CaptureWin::enableScaling(bool enable)
 
 void CaptureWin::resize(int width, int height)
 {
-       int h, w;
+       QSize newSize;
 
        // Dont resize window if the frame size is the same in
        // the event the window has been paused when beeing resized.
@@ -226,12 +227,12 @@ void CaptureWin::resize(int width, int height)
        m_origFrameSize.setHeight(height);
 
        QSize margins = getMargins();
-       QSize aspectedFrameSize = pixelAspectFrameSize(QSize(width, height));
 
-       h = margins.height() - cropHeight(width, height) * 2 + aspectedFrameSize.height();
-       w = margins.width() - cropWidth(width, height) * 2 + aspectedFrameSize.width();
-       height = h;
-       width = w;
+       newSize =  margins + pixelAspectFrameSize(m_origFrameSize)
+               - 2 * cropFrameSize(m_origFrameSize);
+
+       width =  newSize.width();
+       height = newSize.height();
 
        QDesktopWidget *screen = QApplication::desktop();
        QRect resolution = screen->screenGeometry();
@@ -252,8 +253,7 @@ void CaptureWin::resize(int width, int height)
 
 QSize CaptureWin::scaleFrameSize(QSize window, QSize frame)
 {
-       QSize croppedSize = frame - QSize((cropWidth(frame.width(), frame.height()) * 2),
-                                         (cropHeight(frame.width(), frame.height()) * 2));
+       QSize croppedSize = frame - 2 * cropFrameSize(frame);
        QSize actualSize = pixelAspectFrameSize(croppedSize);
 
        if (!m_enableScaling) {

diff --git a/utils/qv4l2/capture-win.h b/utils/qv4l2/capture-win.h
index ccd0196..c1a1c25 100644 (file)
--- a/utils/qv4l2/capture-win.h
+++ b/utils/qv4l2/capture-win.h
@@ -128,15 +128,13 @@ public:
         * remove from top and bottom. To get total multiply the return
         * value by 2.
         *
-        * @param width Frame width
-        * @param height Frame height
-        * @return The pixels to remove when cropping height
+        * @param size Frame size
+        * @return The size (no of height & width pixels) to remove when cropping
         *
         * @note The width and height must be original frame size
         *       to ensure that the cropping is done correctly.
         */
-       static int cropHeight(int width, int height);
-       static int cropWidth(int width, int height);
+       static QSize cropFrameSize(QSize size);
 
        /**
         * @brief Get the frame size when aspect ratio is applied and increases size.