/// <summary>
/// Calculates FrameDouble, CropSource, CropAfter and OutputWidth values.
/// </summary>
/// <param name="force">When false, this call is ignored when AutoCalculateSize is false.</param>
private void CalculateSize(bool force) {
if (!force && !AutoCalculateSize)
return;
if (!SourceWidth.HasValue || !SourceHeight.HasValue || OutputHeight > 10000) {
OutputWidth = null;
return;
}
// Calculate CropSource and CropAfter values.
if (Crop) {
// CropSource must be a factor of 4.
CropSource = new Rect(
CropLeft / 4 * 4,
CropTop / 4 * 4,
CropRight / 4 * 4,
CropBottom / 4 * 4);
} else
CropSource = new Rect();
FrameDouble = 0;
int ScaleFactor = 1;
int FrameDoubleX = 0, FrameDoubleY = 0;
int ScaleFactorX = 1, ScaleFactorY = 1;
// Calculate scale factor based on height
while ((SourceHeight - CropSource.Top - CropSource.Bottom) * ScaleFactorY < OutputHeight) {
FrameDoubleY += 1;
ScaleFactorY *= 2;
}
// Calculate scale factor based on width
while ((SourceWidth - CropSource.Left - CropSource.Right) * ScaleFactorX * SourceAspectRatio < OutputWidth) {
FrameDoubleX += 1;
ScaleFactorX *= 2;
}
// Take highest ratio
FrameDouble = FrameDoubleX > FrameDoubleY ? FrameDoubleX : FrameDoubleY;
ScaleFactor = ScaleFactorX > ScaleFactorY ? ScaleFactorX : ScaleFactorY;
if (Crop) {
CropAfter = new Rect(
(CropLeft - CropSource.Left) * ScaleFactor,
(CropTop - CropSource.Top) * ScaleFactor,
(CropRight - CropSource.Right) * ScaleFactor,
(CropBottom - CropSource.Bottom) * ScaleFactor);
} else
CropAfter = new Rect();
int CropHeight = ((SourceHeight.Value - CropSource.Top - CropSource.Bottom) * ScaleFactor);
int CropWidth = ((SourceWidth.Value - CropSource.Left - CropSource.Right) * ScaleFactor);
if (CropAfter.HasValue) {
CropHeight = CropHeight - CropAfter.Top - CropAfter.Bottom;
CropWidth = CropWidth - CropAfter.Left - CropAfter.Right;
}
// Make width divisible by 4 without distorting pixels
float TotalWidth = (float)CropWidth * SourceAspectRatio / CropHeight * OutputHeight;
OutputWidth = (int)Math.Round(TotalWidth / 4) * 4;
if (TotalWidth >= OutputWidth.Value) {
float WidthAdjust = TotalWidth - OutputWidth.Value;
int WidthAdjustInt = (int)Math.Round(WidthAdjust / 2);
CropAfter.Left += WidthAdjustInt;
CropAfter.Right += WidthAdjustInt;
} else {
float HeightAdjust = (OutputWidth.Value - TotalWidth) / SourceAspectRatio;
int HeightAdjustInt = (int)Math.Round(HeightAdjust / 2);
CropAfter.Top += HeightAdjustInt;
CropAfter.Bottom += HeightAdjustInt;
}
}
