/// <summary>
/// Draws the specified contents to a Gdk window.
/// </summary>
/// <param name="window">The Gdk window to work with.</param>
public void Draw(Gdk.Window window)
{
using (var context = Gdk.CairoHelper.Create(window))
{
using (var surface = context.GetTarget())
{
var renderer = new ScopeRenderer(context);
_currentScopeGraphicsRangeExtents = renderer.GetScopeGraphicsRangeDeviceAreaExtents(window.Width, window.Height);
var currentReadoutsDeviceExtents = renderer.GetReadoutsDeviceAreaExtents(window.Width, window.Height);
var userRange = _currentScopeGraphicsRangeExtents != null
? CreateScopeGraphicsRange(_currentScopeGraphicsRangeExtents,
_xMinimumGraticuleUnits, _yMinimumGraticuleUnits, _userOriginOffset)
: null;
renderer.DrawMainBackground(window.Width, window.Height);
if (userRange != null)
{
renderer.DrawScopeGraphics(userRange, Cursors, Graphs);
}
renderer.DrawReadouts(currentReadoutsDeviceExtents, Readouts);
// There's a bug related to internal reference counting (already fixed on GitHub)
// that causes a memory leak. Thus we use our workaround dispose method here.
//surface.Dispose ();
surface.DisposeHard();
}
context.Dispose();
}
}
/// <summary>
/// Draws the readouts (i.e. some additional information regarding the scope settings and signals).
/// </summary>
/// <param name="extents">The extents of the device area to draw the readouts to.</param>
/// <param name="readouts">The readouts to draw.</param>
public void DrawReadouts(DeviceAreaExtents extents, IEnumerable <ScopeReadout> readouts)
{
readouts = readouts ?? new ScopeReadout[0];
foreach (var readout in readouts)
{
DrawReadout(extents, readout);
}
}
/// <summary>
/// Creates a rectangle range the scope contents are rendered to, according to the specified values.
/// </summary>
/// <returns>The user range.</returns>
/// <param name="extents">The extents of the device area to render to.</param>
/// <param name="xUserMinSpan">The minimum horizontal (X) span requeste, in user-specific units.</param>
/// <param name="yUserMinSpan">The minimum vertical (Y) span requeste, in user-specific units.</param>
/// <param name="originOffset">The offset of the origin to the range center, in user-specific units.</param>
/// <returns>The created rectangle range or <c>null</c> if no range could be created.</returns>
private RectangleRange CreateScopeGraphicsRange(DeviceAreaExtents extents,
double xUserMinSpan, double yUserMinSpan, Distance userOriginOffset)
{
var rangeWidth = extents.Width;
var rangeHeight = extents.Height;
// As this could result in division by zero or infinite values,
// we don't create a range in this case.
if (rangeWidth <= 0 || rangeHeight <= 0)
{
return(null);
}
double aspectRatioFactor;
UserToDeviceStretchMode userToDeviceStretchMode;
if (_stretchMode == ScopeStretchMode.Expand)
{
aspectRatioFactor = new AspectRatioCalculator(rangeWidth, rangeHeight, xUserMinSpan, yUserMinSpan)
.UserToDeviceAspectRatioFactor;
userToDeviceStretchMode = UserToDeviceStretchMode.UniformToAny;
}
else
{
aspectRatioFactor = 1;
userToDeviceStretchMode = UserToDeviceStretchMode.Fill;
}
// Expand the width or height range to utilize any extra space available.
var xUserSpan = xUserMinSpan;
var yUserSpan = yUserMinSpan;
if (aspectRatioFactor > 1)
{
xUserSpan *= aspectRatioFactor;
}
else
{
yUserSpan /= aspectRatioFactor;
}
var userToDeviceMatrix = CreateUserToDeviceTransformationMatrix(rangeWidth, rangeHeight, xUserSpan, yUserSpan, userToDeviceStretchMode);
// Note: "if (matrix != null)" fails. Bug in the equality operator of Matrix?
// Consider the origin offset (in user-specific units).
userToDeviceMatrix.Translate(+userOriginOffset.Dx, +userOriginOffset.Dy);
return(new RectangleRange(rangeWidth, rangeHeight, xUserSpan, yUserSpan, userOriginOffset, userToDeviceMatrix));
}
/// <summary>
/// Draws a scope readout.
/// </summary>
private void DrawReadout(DeviceAreaExtents extents, ScopeReadout readout)
{
var fontHeight = GetFontExtents().Height;
var lineHeight = fontHeight;
var columnWidth = (extents.Width - 2 * _defaultReadoutsAlignmentDistance.Dx) / _numberOfReadoutColumns;
var readoutPosition = new PointD(
extents.MinX + readout.Column * columnWidth,
extents.MinY + readout.Line * lineHeight
);
DrawText(readout.CurrentText, readoutPosition, readout.Color,
ScopeHorizontalAlignment.Left, ScopeVerticalAlignment.Top, _defaultReadoutsAlignmentDistance);
}
