I'm currently trying to create a little plot interactive editor, using WPF. On maximized window the plot dragging with mouse is not responsive enough because of the plot grid.
I got a path for my plot grid lying inside a Canvas control (render transform just shifts it to the bottom of the canvas)
<Path Name="VisualGrid" RenderTransform="{StaticResource PlotTechnicalAdjust}" Style="{DynamicResource ResourceKey=GridStyle}" Panel.ZIndex="1"/>
Here is how grid is created; _curState has actual camera "viewport" metadata
if (_curState.Changes.ScaleStepXChanged)
{
foreach (TextBlock item in _xLabels)
{
DeleteLabel(item);
}
_xLabels.Clear();
double i = _curState.LeftEdgeLine;
_gridGeom.Children[(int)GridGeomIndexes.VerticalLines] = new GeometryGroup { Transform = _verticalLinesShift};
var verticalLines =(GeometryGroup)_gridGeom.Children[(int)GridGeomIndexes.VerticalLines];
while (i <= _curState.RightEdgeLine * (1.001))
{
verticalLines.Children.Add(new LineGeometry(new Point(i * _plotParameters.PixelsPerOneX, 0),
new Point(i * _plotParameters.PixelsPerOneX,
-_wnd.ContainerGeneral.Height)));
_xLabels.Add(CreateLabel(i, Axis.X));
i += _curState.CurrentScaleStepX;
}
_curState.Changes.ScaleStepXChanged = false;
}
if (_curState.Changes.ScaleStepYChanged)
{
foreach (TextBlock item in _yLabels)
{
DeleteLabel(item);
}
_yLabels.Clear();
double i = _curState.BottomEdgeLine;
_gridGeom.Children[(int)GridGeomIndexes.HorizontalLines] = new GeometryGroup { Transform = _horizontalLinesShift};
var horizontalLines = (GeometryGroup)_gridGeom.Children[(int)GridGeomIndexes.HorizontalLines];
while (i <= _curState.TopEdgeLine * (1.001))
{
horizontalLines.Children.Add(new LineGeometry(new Point(0, -i * _plotParameters.PixelsPerOneY),
new Point(_wnd.ContainerGeneral.Width,
-i * _plotParameters.PixelsPerOneY)));
_yLabels.Add(CreateLabel(i, Axis.Y));
i += _curState.CurrentScaleStepY;
}
_curState.Changes.ScaleStepYChanged = false;
}
Where Transforms are composition of TranslateTransform and ScaleTransform (for vertical lines I only use X components and only Y for horizontal lines). After beeing created those GeometryGroups are only edited if a new line apears into camera or an existing line exits viewable space. Grid is only recreated when axis graduations have to be changed after zooming.
I have a dragging option implemented like this:
private Point _cursorOldPos = new Point();
private void OnDragPlotMouseMove(object sender, MouseEventArgs e)
{
if (e.Handled)
return;
Point cursorNewPos = e.GetPosition(ContainerGeneral);
_plotView.TranslateShiftX.X += cursorNewPos.X - _cursorOldPos.X;
_plotView.TranslateShiftY.Y += cursorNewPos.Y - _cursorOldPos.Y;
_cursorOldPos = cursorNewPos;
e.Handled = true;
}
This works perfectly smooth with a small window (1200x400 units) for a large amount of points (like 100+). But for a large window (fullscreen 1920x1080) it happens pretty jittery even without any data-point controls on canvas. The strange moment is that lags don't appear when I order my GridGenerator to keep around 100+ lines for small window and drag performance suffers when I got less than 50 lines on maximezed. It makes me think that it might somehow depend not on a number of elements inside a geometry, but on their linear size. I suppose I should mention that OnSizeChanged I adjust the ContainerGeneral canvas' height and width and simply re-create the grid.
Checked the number of lines stored in runtime to make sure I don't have any extras. Tried using Image with DrawingVisual instead of Path. Nothing helped.
Appearances for clearer understanding
