Is there a simple way to retrieve the X/Y coordinates of ANY point in the chart Area (relative to that chart Axis of course)?
As of now, I just managed to retrieve coordinates when the mouse is on a Series (not outside)
private void chart_GetToolTipText(object sender, ToolTipEventArgs e)
{
if (e.HitTestResult.Series != null)
{
e.Text = e.HitTestResult.Series.Points[e.HitTestResult.PointIndex].YValues[0] + " \n " + DateTime.FromOADate(e.HitTestResult.Series.Points[e.HitTestResult.PointIndex].XValue);
}
}
Anyway, as always with MS Chart Controls, there is no easy way to do things, but a funky workaround to get things done. I am sadly getting used to it...
private void chart1_MouseWhatever(object sender, MouseEventArgs e)
{
chartArea1.CursorX.SetCursorPixelPosition(new Point(e.X, e.Y), true);
chartArea1.CursorY.SetCursorPixelPosition(new Point(e.X, e.Y), true);
double pX = chartArea1.CursorX.Position; //X Axis Coordinate of your mouse cursor
double pY = chartArea1.CursorY.Position; //Y Axis Coordinate of your mouse cursor
}
This works for my purposes and doesn't side effect the cursor.
private Tuple<double,double> GetAxisValuesFromMouse(int x, int y)
{
var chartArea = _chart.ChartAreas[0];
var xValue = chartArea.AxisX.PixelPositionToValue(x);
var yValue = chartArea.AxisY.PixelPositionToValue(y);
return new Tuple<double, double>(xValue, yValue);
}
I tried your answer, but it didn't work for me. It ended up putting the cursor in one spot and never moving. I believe this is because I use decimal/double values along both axes, and the cursor is being rounded to the nearest integer.
After several attempts, I was able to work out a method for determining where the cursor is inside the chart. The hard part was figuring out that all the "positions" for the chart elements are actually percentage values (from 0 to 100).
As per
http://msdn.microsoft.com/en-us/library/system.windows.forms.datavisualization.charting.elementposition.aspx:
"Defines the position of the chart element in relative coordinates, which range from (0,0) to (100,100)."
I hope you don't mind, I am posting this answer here just for posterity, in case anyone else comes across this problem, and your method also does not work for them. Its not pretty or elegant in any way, but so far it works for me.
private struct PointD
{
public double X;
public double Y;
public PointD(double X, double Y)
{
this.X = X;
this.Y = Y;
}
}
private void chart1_MouseMove(object sender, MouseEventArgs e)
{
var pos = LocationInChart(e.X, e.Y);
lblCoords.Text = string.Format("({0}, {1}) ... ({2}, {3})", e.X, e.Y, pos.X, pos.Y);
}
private PointD LocationInChart(double xMouse, double yMouse)
{
var ca = chart1.ChartAreas[0];
//Position inside the control, from 0 to 100
var relPosInControl = new PointD
(
((double)xMouse / (double)execDetailsChart.Width) * 100,
((double)yMouse / (double)execDetailsChart.Height) * 100
);
//Verify we are inside the Chart Area
if (relPosInControl.X < ca.Position.X || relPosInControl.X > ca.Position.Right
|| relPosInControl.Y < ca.Position.Y || relPosInControl.Y > ca.Position.Bottom) return new PointD(double.NaN, double.NaN);
//Position inside the Chart Area, from 0 to 100
var relPosInChartArea = new PointD
(
((relPosInControl.X - ca.Position.X) / ca.Position.Width) * 100,
((relPosInControl.Y - ca.Position.Y) / ca.Position.Height) * 100
);
//Verify we are inside the Plot Area
if (relPosInChartArea.X < ca.InnerPlotPosition.X || relPosInChartArea.X > ca.InnerPlotPosition.Right
|| relPosInChartArea.Y < ca.InnerPlotPosition.Y || relPosInChartArea.Y > ca.InnerPlotPosition.Bottom) return new PointD(double.NaN, double.NaN);
//Position inside the Plot Area, 0 to 1
var relPosInPlotArea = new PointD
(
((relPosInChartArea.X - ca.InnerPlotPosition.X) / ca.InnerPlotPosition.Width),
((relPosInChartArea.Y - ca.InnerPlotPosition.Y) / ca.InnerPlotPosition.Height)
);
var X = relPosInPlotArea.X * (ca.AxisX.Maximum - ca.AxisX.Minimum) + ca.AxisX.Minimum;
var Y = (1 - relPosInPlotArea.Y) * (ca.AxisY.Maximum - ca.AxisY.Minimum) + ca.AxisY.Minimum;
return new PointD(X, Y);
}
private void OnChartMouseMove(object sender, MouseEventArgs e)
{
var sourceChart = sender as Chart;
HitTestResult result = sourceChart.HitTest(e.X, e.Y);
ChartArea chartAreas = sourceChart.ChartAreas[0];
if (result.ChartElementType == ChartElementType.DataPoint)
{
chartAreas.CursorX.Position = chartAreas.AxisX.PixelPositionToValue(e.X);
chartAreas.CursorY.Position = chartAreas.AxisY.PixelPositionToValue(e.Y);
}
}
This works
private void chart1_MouseWhatever(object sender, MouseEventArgs e)
{
Point chartLocationOnForm = chart1.FindForm().PointToClient(chart1.Parent.PointToScreen(chart1.Location));
double x = chart1.ChartAreas[0].AxisX.PixelPositionToValue(e.X - chartLocationOnForm.X);
double y = chart1.ChartAreas[0].AxisY.PixelPositionToValue(e.Y - chartLocationOnForm.Y);
}
And this works
private void chart1_MouseWhatever(object sender, MouseEventArgs e)
{
Point chartLocationOnForm = chart1.FindForm().PointToClient(chart1.Parent.PointToScreen(chart1.Location));
chart1.ChartAreas[0].CursorX.SetCursorPixelPosition(new PointF(e.X - chartLocationOnForm.X, e.Y - chartLocationOnForm.Y), true);
chart1.ChartAreas[0].CursorY.SetCursorPixelPosition(new PointF(e.X - chartLocationOnForm.X, e.Y - chartLocationOnForm.Y), true);
double x = chart1.ChartAreas[0].CursorX.Position;
double y = chart1.ChartAreas[0].CursorY.Position;
}
This is what I got, I think many of us are along the same lines but with different interpretations of what it is you're looking for.
This will give you the coordinates at any location in the plotting area. I found the HitTest gives a clean and simple solution, but there are a few checks to make, whether the cursor is on a data point, a gridline, or in the plotting area (which seem to take precedence in that order). I assume you'll be interested in the coordinate regardless of which of those objects the mouse is over.
private void chart_GetToolTipText(object sender, ToolTipEventArgs e)
{
// If the mouse isn't on the plotting area, a datapoint, or gridline then exit
HitTestResult htr = chart.HitTest(e.X, e.Y);
if (htr.ChartElementType != ChartElementType.PlottingArea && htr.ChartElementType != ChartElementType.DataPoint && htr.ChartElementType != ChartElementType.Gridlines)
return;
ChartArea ca = chart.ChartAreas[0]; // Assuming you only have 1 chart area on the chart
double xCoord = ca.AxisX.PixelPositionToValue(e.X);
double yCoord = ca.AxisY.PixelPositionToValue(e.Y);
e.Text = "X = " + Math.Round(xCoord, 2).ToString() + "\nY = " + Math.Round(yCoord, 2).ToString();
}
VB.net version, with zoom correction:
Private Function LocationInChart(xMouse, yMouse) As PointF
Dim ca = Chart1.ChartAreas(0)
'Position inside the control, from 0 to 100
Dim relPosInControl = New PointF((xMouse / Chart1.Width) * 100, (yMouse / Chart1.Height) * 100)
'Verify we are inside the Chart Area
If (relPosInControl.X < ca.Position.X Or relPosInControl.X > ca.Position.Right Or relPosInControl.Y < ca.Position.Y Or relPosInControl.Y > ca.Position.Bottom) Then Return New PointF(Double.NaN, Double.NaN)
'Position inside the Chart Area, from 0 to 100
Dim relPosInChartArea = New PointF(((relPosInControl.X - ca.Position.X) / ca.Position.Width) * 100, ((relPosInControl.Y - ca.Position.Y) / ca.Position.Height) * 100)
'Verify we are inside the Plot Area
If (relPosInChartArea.X < ca.InnerPlotPosition.X Or relPosInChartArea.X > ca.InnerPlotPosition.Right Or relPosInChartArea.Y < ca.InnerPlotPosition.Y Or relPosInChartArea.Y > ca.InnerPlotPosition.Bottom) Then Return New PointF(Double.NaN, Double.NaN)
'Position inside the Plot Area, 0 to 1
Dim relPosInPlotArea = New PointF(((relPosInChartArea.X - ca.InnerPlotPosition.X) / ca.InnerPlotPosition.Width), ((relPosInChartArea.Y - ca.InnerPlotPosition.Y) / ca.InnerPlotPosition.Height))
Dim X = relPosInPlotArea.X * (ca.AxisX.Maximum - ca.AxisX.Minimum) + ca.AxisX.Minimum
Dim Y = (1 - relPosInPlotArea.Y) * (ca.AxisY.Maximum - ca.AxisY.Minimum) + ca.AxisY.Minimum
' zoomo korekcija
Dim zoomx = (ca.AxisX.ScaleView.ViewMaximum - ca.AxisX.ScaleView.ViewMinimum) / (ca.AxisX.Maximum - ca.AxisX.Minimum)
Dim zoomy = (ca.AxisY.ScaleView.ViewMaximum - ca.AxisY.ScaleView.ViewMinimum) / (ca.AxisY.Maximum - ca.AxisY.Minimum)
Dim xx = ca.AxisX.ScaleView.ViewMinimum + X * zoomx
Dim yy = ca.AxisY.ScaleView.ViewMinimum + Y * zoomy
Return New PointF(xx, yy)
End Function
Related
I'm working on a connect 4 game and I've got the following part done:
I've made the board which is able to display tiles of the board in 3 colors (white, red and yellow). I've also written some code to display a box around the column on which the user is hovering such that he can see where he is placing a dish.
I've also created the code which allows a dish to be added to the board. Both of these processes use the following code:
//Calculate the size of a single cell
int cellX = this.Size.Width / this.Columns;
//calculate the cell which was clicked
int nColumn = (int)Math.Floor((Double)x / cellX);
x is the value of MouseEventArgs.X of the pannel on which this is called. For drawing a boundry box this code works perfectly but for dropping a dish it doesn't. sometimes it drops 1 left of where I want it sometimes one right.
Here is the code for both events:
//draws the bounding box around the column for a given x value.
public void drawBoundingBox(int x)
{
//Calculate the size of a single cell
int cellX = this.Size.Width / this.Columns;
//calculate the cell which was clicked
int nColumn = (int)Math.Floor((Double)x / cellX);
if (nColumn != this.lastColumn)
{
this.Refresh();
Graphics g = CreateGraphics();
Pen pRed = new Pen(Color.Red, 3);
if (nColumn < this.Columns)
{
Rectangle rect = new Rectangle(new Point(nColumn * cellX, 0),
new Size(cellX, this.Size.Height));
g.DrawRectangle(pRed, rect);
}
}
this.lastColumn = nColumn;
}
public Boolean move(int mousePosition) {
int cellX = this.Size.Width / this.Columns;
int nColumn = (int)Math.Floor((Double)mousePosition / cellX);
return board.Move(nColumn);
}
Here is the code for board.move():
public bool Move(int x)
{
bool found = false;
for (int i = Rows - 1; i >= 0 && !found; i--)
{
Console.WriteLine("X equals: " + x + " i equals: " + i);
if (States[i,x] == 0) {
found = true;
States[i, x] = (byte)(((moves++) % 2) + 1);
}
}
return found;
}
Here is a gif showing what I mean:
To me it seams like a rounding error but it's wierd to me that the bounding box works well with the mouse but the clicking action doesn't...
I have a chart (myChart) and more ChartArea in MyArea that is the ChartAreasCollection. I have to determinate if a double click is made in a certain ChartArea of the collection for select it. With the code written below every ChartArea has the same values for limits (x,y) so the if-condition is always true, even if the click was done on the first area.
Every chartarea can be visible or not so for use this function I have to check with the counter ActiveAreas if are visible more then one.
private void chartInForm_DoubleClick(object sender, EventArgs e)
{
if (ActiveAreas > 1)
{
Point mouse = ((MouseEventArgs)e).Location;
foreach (ChartArea ca in MyArea)
{
if (mouse.X > ca.Position.X &&
mouse.X < ca.Position.X + ca.Position.Width * myChart.Width / 100 &&
mouse.Y > ca.Position.Y &&
mouse.Y < ca.Position.Y + ca.Position.Height * myChart.Height / 100)
MessageBox.Show(ca.Name);
}
}
}
This should help:
private void chartInForm_MouseDoubleClick(object sender, MouseEventArgs e)
{
foreach(ChartArea ca in chartInForm.ChartAreas)
{
if (ChartAreaClientRectangle(chartInForm, ca).Contains(e.Location))
{
Console.WriteLine(" You have double-clicked on chartarea " + ca.Name;
break;
}
}
}
The key is using Position.ToRectangleF when calculating the pixel positions of the CAs; it will bring back the result even when the ChartArea is positioned automatically..:
RectangleF ChartAreaClientRectangle(Chart chart, ChartArea CA)
{
RectangleF CAR = CA.Position.ToRectangleF();
float pw = chart.ClientSize.Width / 100f;
float ph = chart.ClientSize.Height / 100f;
return new RectangleF(pw * CAR.X, ph * CAR.Y, pw * CAR.Width, ph * CAR.Height);
}
Note that invisible ChartAreas by default will not be clicked nor will they take up space and the others will move to their place. But if you set fixed positions this may change and you may indeed need to add a check for ca.Visible ...
I am using the Charts component in Windows Forms.
I create a straight line using
chart1.Series["Grenzwert"].Points.Add(new DataPoint(0, y));
chart1.Series["Grenzwert"].Points.Add(new DataPoint(maxwidth, y));
Also I plot a a series of points connected by a line, let's call it curve.
How do I show everything over straight line and under curve filled?
Column fills the whole area, not just above straight line.
Example:
This is late and not really short but imo it is the best way to color areas in a chart.
The Lines and also the Spline charttypes can be very precisely colored by coding the Paint event with the right data. The necessary pixel values can be obtained by the axis function ValueToPixelPosition. See here for another example!
The following code is a little longer because we need to add certain points at the start and end of both the chart and each colored area. Other than that it is very straight forward: Create GraphicsPaths by adding the pixel coordinates with AddLines and fill the GraphicsPaths in the Paint event.
For testing and for fun I have added a movable HorizontalLineAnnotation, so I can see how the areas vary when I drag it up and down..:
The Paint event is rather simple; it refers to a HorizontalLineAnnotation hl :
private void chart1_Paint(object sender, PaintEventArgs e)
{
double limit = hl.Y; // get the limit value
hl.X = 0; // reset the x value of the annotation
List<GraphicsPath> paths = getPaths(chart1.ChartAreas[0], chart1.Series[0], limit);
using (SolidBrush brush = new SolidBrush(Color.FromArgb(127, Color.Red)))
foreach (GraphicsPath gp in paths)
{ e.Graphics.FillPath(brush, gp); gp.Dispose(); }
}
The code to get the paths is obviously way too long for comfort..:
List<GraphicsPath> getPaths(ChartArea ca, Series ser, double limit)
{
List<GraphicsPath> paths = new List<GraphicsPath>();
List<PointF> points = new List<PointF>();
int first = 0;
float limitPix = (float)ca.AxisY.ValueToPixelPosition(limit);
for (int i = 0; i < ser.Points.Count; i++)
{
if ((ser.Points[i].YValues[0] > limit) && (i < ser.Points.Count - 1))
{
if (points.Count == 0) first = i; // remember group start
// insert very first point:
if (i == 0) points.Insert(0, new PointF(
(float)ca.AxisX.ValueToPixelPosition(ser.Points[0].XValue), limitPix));
points.Add( pointfFromDataPoint(ser.Points[i], ca)); // the regular points
}
else
{
if (points.Count > 0)
{
if (first > 0) points.Insert(0, median(
pointfFromDataPoint(ser.Points[first - 1], ca),
pointfFromDataPoint(ser.Points[first], ca), limitPix));
if (i == ser.Points.Count - 1)
{
if ((ser.Points[i].YValues[0] > limit))
points.Add(pointfFromDataPoint(ser.Points[i], ca));
points.Add(new PointF(
(float)ca.AxisX.ValueToPixelPosition(ser.Points[i].XValue), limitPix));
}
else
points.Add(median(pointfFromDataPoint(ser.Points[i - 1], ca),
pointfFromDataPoint(ser.Points[i], ca), limitPix));
GraphicsPath gp = new GraphicsPath();
gp.FillMode = FillMode.Winding;
gp.AddLines(points.ToArray());
gp.CloseFigure();
paths.Add(gp);
points.Clear();
}
}
}
return paths;
}
It uses two helper functions:
PointF pointfFromDataPoint(DataPoint dp, ChartArea ca)
{
return new PointF( (float)ca.AxisX.ValueToPixelPosition(dp.XValue),
(float)ca.AxisY.ValueToPixelPosition(dp.YValues[0]));
}
PointF median(PointF p1, PointF p2, float y0)
{
float x0 = p2.X - (p2.X - p1.X) * (p2.Y - y0) / (p2.Y - p1.Y);
return new PointF(x0, y0);
}
The HorizontalLineAnnotation is set up like this:
hl = new HorizontalLineAnnotation();
hl.AllowMoving = true;
hl.LineColor = Color.OrangeRed;
hl.LineWidth = 1;
hl.AnchorDataPoint = S1.Points[1];
hl.X = 0;
hl.Y = 0; // or some other starting value..
hl.Width = 100; // percent of chart..
hl.ClipToChartArea = chart1.ChartAreas[0].Name; // ..but clipped
chart1.Annotations.Add(hl);
I have an idea that use SeriesChartType.Range as follow.
private void UpdateChart(float straight_line, List<DataPoint> curve)
{
float y = straight_line; // YValue of the straight line
var list = curve.ToList(); // Clone the curve
int count = list.Count - 2;
for (int i = 0; i < count; i++) // Calculate intersection point between the straight line and a line between (x0,y0) and (x1,y1)
{
double x0 = list[i + 0].XValue;
double y0 = list[i + 0].YValues[0];
double x1 = list[i + 1].XValue;
double y1 = list[i + 1].YValues[0];
if ((y0 > y && y1 < y) || (y0 < y && y1 > y))
{
double x = (y - y0) * (x1 - x0) / (y1 - y0) + x0;
list.Add(new DataPoint(x, y));
}
}
list.Sort((a, b) => Math.Sign(a.XValue - b.XValue));
chart1.Series[0].Points.Clear();
chart1.Series[0].ChartType = SeriesChartType.Range;
chart1.Series[0].Color = Color.Red;
chart1.Series[0].BorderColor = Color.Cyan;
chart1.ChartAreas[0].AxisX.Minimum = 0;
chart1.ChartAreas[0].AxisX.Interval = 1;
for (int i = 0; i < list.Count; i++)
{
double xx = list[i].XValue;
double yy = list[i].YValues[0];
if (yy > y)
{
chart1.Series[0].Points.AddXY(xx, y, yy);
}
else
{
chart1.Series[0].Points.AddXY(xx, yy, yy);
}
}
chart1.ChartAreas[0].AxisY.StripLines.Add(new StripLine { IntervalOffset = y, Interval = 0, BorderColor = Color.Orange, BorderWidth = 2 });
}
As in the below drawing to judge whether the straight line and a line between (x0,y0) and (x1,y1) intersect, case 1 is (y0 < y && y1 > y) and case 2 is (y0 > y && y1 < y) . In case 1 and case 2, they intersect each other. In case 3 and case 4, they don't intersect each other.
You can do this as follows.
Set the column fill like you did before. Everything will be red.
Create a new column graph on the same chart.
Set its values to the same as your jagged line, but capped at the y value of the straight line you already have.
Set the fill colour for the columns to white. This will block out the red fill for any areas not between the lines.
I'm trying to create a resizable image overlay (for cropping purposes). It seems pretty easy to resize the overlay if I ignore the aspect ratio, but I can't figure out how to perform a constrained resize that respects the AR. I figure that I obviously can't obey the overlay's "grip" positions (or even borders) unless I force the mouse to follow it, but that seems unnatural, so I'll just have to rely on the mouse gesture (which I don't mind doing).
I can also easily resize the overlay and then force it into the proper dimensions afterwards (like every other question about this topic on this site is about), but it's not very intuitive when using a mouse.
This is sort of what I'm going for:
http://deepliquid.com/projects/Jcrop/demos.php?demo=live_crop
I've written an application like this before but it was browser-based so I used a javascript library. This is a desktop application and I haven't found a suitable library for this.
I've left a lot of details out of this code snippet and simplified some conditions with booleans.
private void pbImage_Paint(object sender, PaintEventArgs e)
{
//Overlay
e.Graphics.FillRectangle(brushRect, overlayRect);
// Grips
e.Graphics.FillRectangle(gripRect, leftTopGrip);
e.Graphics.FillRectangle(gripRect, rightTopGrip);
e.Graphics.FillRectangle(gripRect, leftBottomGrip);
e.Graphics.FillRectangle(gripRect, rightBottomGrip);
AdjustGrips();
base.OnPaint(e);
}
public void AdjustGrips()
{
// The next section only causes the grips to partly obey
// the AR - the rest of the overlay ignores it
if (overlayRect.Height * arWidth <= overlayRect.Width)
overlayRect.Width = overlayRect.Height * arWidth;
else if (overlayRect.Width * arHeight <= overlayRect.Height)
overlayRect.Height = overlayRect.Width * arHeight;
leftTopGrip.X = overlayRect.Left;
leftTopGrip.Y = overlayRect.Top;
rightTopGrip.X = overlayRect.Right - rightTopGrip.Width;
rightTopGrip.Y = overlayRect.Top;
leftBottomGrip.Y = overlayRect.Bottom - leftBottomGrip.Height;
leftBottomGrip.X = overlayRect.Left;
rightBottomGrip.X = overlayRect.Right - rightBottomGrip.Width;
rightBottomGrip.Y = overlayRect.Bottom - rightBottomGrip.Height;
}
private void pbImage_MouseMove(object sender, MouseEventArgs e)
{
Point pt = new Point(e.X, e.Y);
// Details elided
if (e.Button == MouseButtons.Left && mouseinGrip)
{
if (bottomRightIsGripped)
{
newOverlayRect.X = overlayRect.X;
newOverlayRect.Y = overlayRect.Y;
newOverlayRect.Width = pt.X - newOverlayRect.Left;
newOverlayRect.Height = pt.Y - newOverlayRect.Top;
if (newOverlayRect.X > newOverlayRect.Right)
{
newOverlayRect.Offset(-width, 0);
if (newOverlayRect.X < 0)
newOverlayRect.X = 0;
}
if (newOverlayRect.Y > newOverlayRect.Bottom)
{
newOverlayRect.Offset(0, -height);
if (newOverlayRect.Y < 0)
newOverlayRect.Y = 0;
}
pbImage.Invalidate();
oldOverlayRect = overlayRect = newOverlayRect;
Cursor = Cursors.SizeNWSE;
}
// Code for other grips elided
}
AdjustGrips();
pbImage.Update();
base.OnMouseMove(e);
}
// Mouse up and down elided
You have complete control over the new size for the overlay as it drags.
The example link that you've given, is simply selecting a starting point based on the click down, then selecting Max(Abs(pt.x - start.x), Abs(pt.y - start.y)), and basing the crop square off of that.
To use a non square ratio, normalize the distances first.
// given known data
//
// Point start;
// The starting location of the mouse down for the drag,
// or the top left / bottom right of the crop based on if the mouse is
// left/above the starting point
//
// Size ratio;
// The ratio of the result crop
//
// pt = (20)x(-20)
// start = (0),(0)
// ratio = (1)x(2)
var dist = new Point(pt.X - start.X, pt.Y - start.Y);
// "normalize" the vector from the ratio
// normalized vector is the distances with respect to the ratio
// ratio is (1)x(2). A (20)x(-20) is normalized as (20),(-10)
var normalized = new Point(dist.X / ratio.Width, dist.Y / ratio.Height);
// In our (20),(-10) example, we choose the ratio's height 20 as the larger normal.
// we will base our new size on the height
var largestNormal = (Math.Abs(normalized.X) > Math.Abs(normalized.Y)
? Math.Abs(normalized.X) : Math.Abs(normalized.Y);
// The calcedX will be 20, calcedY will be 40
var calcedOffset = (largestNormal * ratio.Width, largestNormal * ratio.Height);
// reflect the calculation back to the correct quarter
// final size is (20)x(-40)
if (distX < 0) calcedOffset.X *= -1;
if (distY < 0) calcedOffset.Y *= -1;
var newPt = new Point(start.X + calcedOffset.X, start.Y + calcedOffset.Y);
Notice that one of the lengths can grow greater than the mouse location, but it will never be less. This will have the effect of the mouse traveling along the edge of the new crop box, and the box maintaining ratio.
I've figured out what was causing the original problems in my code. Unlike a static image resize, the aspect ratio code depends on which grip you're "holding", so putting it in a common location for all cases (eg. when the grip positions are set) will not work. You can easily calculate the size of the what the rect should be on the next update, but the position should be set depending on which grip is being held.
If, for example, you're resizing by holding the top left grip, then the bottom and right sides of the cropping rectangle should remain stationary. If you leave the code the same, then the rectangle resizes correctly, but it moves around the canvas and/or the grips go out of sync with the corners of the rect. There is probably a better way to do this but here's some crude code that works. I've only included code for the bottom right and top left grips to illustrate the differences. Extraneous things like setting the mouse pointer and error checking omitted.
private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
Point mousePosition = new Point(e.X, e.Y);
if (e.Button == MouseButtons.Left)
{
// This resizeMode, moveMode and other booleans
// are set in the MouseUp event
if (resizeBottomLeft)
{
// Top and Right should remain static!
newCropRect.X = mousePosition.X;
newCropRect.Y = currentCropRect.Y;
newCropRect.Width = currentCropRect.Right - mousePosition.X;
newCropRect.Height = mousePosition.Y - newCropRect.Top;
if (newCropRect.X > newCropRect.Right)
{
newCropRect.Offset(cropBoxWidth, 0);
if (newCropRect.Right > ClientRectangle.Width)
newCropRect.Width = ClientRectangle.Width - newCropRect.X;
}
if (newCropRect.Y > newCropRect.Bottom)
{
newCropRect.Offset(0, -cropBoxHeight);
if (newCropRect.Y < 0)
newCropRect.Y = 0;
}
// Aspect Ratio + Positioning
if (newCropRect.Width > newCropRect.Height)
{
newCropRect.Height = (int)(newCropRect.Width / ASPECT_RATIO);
}
else
{
int newWidth = (int)(newCropRect.Height * ASPECT_RATIO);
newCropRect.X = newCropRect.Right - newWidth;
newCropRect.Width = newWidth;
}
}
else if (resizeTopRight)
{
// Bottom and Left should remain static!
newCropRect.X = oldCropRect.X;
newCropRect.Y = mousePosition.Y;
newCropRect.Width = mousePosition.X - newCropRect.Left;
newCropRect.Height = oldCropRect.Bottom - mousePosition.Y;
if (newCropRect.X > newCropRect.Right)
{
newCropRect.Offset(-cropBoxWidth, 0);
if (newCropRect.X < 0)
newCropRect.X = 0;
}
if (newCropRect.Y > newCropRect.Bottom)
{
newCropRect.Offset(0, cropBoxHeight);
if (newCropRect.Bottom > ClientRectangle.Height)
newCropRect.Y = ClientRectangle.Height - newCropRect.Height;
}
// Aspect Ratio + Positioning
if (newCropRect.Width > newCropRect.Height)
{
int newHeight = (int)(newCropRect.Width / ASPECT_RATIO);
newCropRect.Y = newCropRect.Bottom - newHeight;
newCropRect.Height = newHeight;
}
else
{
int newWidth = (int)(newCropRect.Height * ASPECT_RATIO);
newCropRect.Width = newWidth;
}
}
else if (moveMode) //Moving the rectangle
{
newMousePosition = mousePosition;
int dx = newMousePosition.X - oldMousePosition.X;
int dy = newMousePosition.Y - oldMousePosition.Y;
currentCropRect.Offset(dx, dy);
newCropRect = currentCropRect;
oldMousePosition = newMousePosition;
}
if (resizeMode || moveMode)
{
oldCropRect = currentCropRect = newCropRect;
// Set the new position of the grips
AdjustGrips();
pictureBox1.Invalidate();
pictureBox1.Update();
}
}
}
Currently my software uses the HitTest() method of a chart object in MSCharts but as I scale this up to more and more data points on my chart combined with other factors this can have a massive performance hit.
I was wondering if there any alternatives that you know of to provide the same functionality ( get the X Coordinate on the chart for the cursor position ) but without the performance hit as hit testing seems to be a very brute force way of obtaining my answer.
My chart is created from the class System.Windows.Forms.DataVisualization.Charting.Chart
Edit for clarity: I need to find the position of a line on my chart to use it for other calculations.
Had the same performance issue with a mousewheel event.
Here is my solution:
To get the axes values of the current mouse position:
double posX = Math.Round(currentArea.AxisX.PixelPositionToValue(e.X));
double posY = Math.Round(currentArea.AxisY.PixelPositionToValue(e.Y));
Taken from Showing Mouse Axis Coordinates on Chart Control with a little change to get it more accurate.
But you should check before, that the mouse is in a ChartArea, else it will throw you an Exception.
To get the ChatElement on which the mouse points:
// Gets the ChartArea that the mouse points
private ChartArea mouseinChartArea(Chart source, Point e)
{
double relativeX = (double)e.X * 100 / source.Width;
double relativeY = (double)e.Y * 100 / source.Height;
foreach (ChartArea ca in source.ChartAreas)
{
if (relativeX > ca.Position.X && relativeX < ca.Position.Right &&
relativeY > ca.Position.Y && relativeY < ca.Position.Bottom)
return ca;
}
return null;
}
// for my purpose, returns an axis. But you can return anything
private Axis findAxisforZooming(Chart source, Point e)
{
ChartArea currentArea = mouseinChartArea(source, new Point(e.X, e.Y)); // Check if inside
if (currentArea == null)
return null;
double axisXfontSize = currentArea.AxisX.LabelAutoFitMinFontSize + ((double)source.Width / SystemInformation.PrimaryMonitorSize.Width)
* (currentArea.AxisX.LabelAutoFitMaxFontSize - currentArea.AxisX.LabelAutoFitMinFontSize);
double axisYfontSize = currentArea.AxisY.LabelAutoFitMinFontSize + ((double)source.Height / SystemInformation.PrimaryMonitorSize.Height)
* (currentArea.AxisY.LabelAutoFitMaxFontSize - currentArea.AxisY.LabelAutoFitMinFontSize);
double axisYfontHeightSize = (axisYfontSize - currentArea.AxisY.LabelStyle.Font.Size) + currentArea.AxisY.LabelStyle.Font.Height;
Graphics g = this.CreateGraphics();
if (currentArea.AxisX.LabelStyle.Font.Unit == GraphicsUnit.Point)
axisXfontSize = axisXfontSize * g.DpiX / 72;
if (currentArea.AxisY.LabelStyle.Font.Unit == GraphicsUnit.Point)
axisYfontHeightSize = axisYfontHeightSize * g.DpiX / 72;
g.Dispose();
// Replacing the SystemInformation.PrimaryMonitorSize with the source.Width / Height will give the accurate TickMarks size.
// But it doens't count for the gab between the tickMarks and the axis lables (so by replacing, it give a good proximity with the gab)
int axisYTickMarks = (int)Math.Round(currentArea.AxisY.MajorTickMark.Size / 100 * SystemInformation.PrimaryMonitorSize.Width); // source.Width;
int axisXTickMarks = (int)Math.Round(currentArea.AxisX.MajorTickMark.Size / 100 * SystemInformation.PrimaryMonitorSize.Height); // source.Height;
int leftInnerPlot = (int)Math.Round(currentArea.Position.X / 100 * source.Width +
currentArea.InnerPlotPosition.X / 100 * currentArea.Position.Width / 100 * source.Width);
int rightInnerPlot = (int)Math.Round(currentArea.Position.X / 100 * this.chart1.Width +
currentArea.InnerPlotPosition.Right / 100 * currentArea.Position.Width / 100 * source.Width);
int topInnerPlot = (int)Math.Round(currentArea.Position.Y / 100 * this.chart1.Height +
currentArea.InnerPlotPosition.Y / 100 * currentArea.Position.Height / 100 * source.Height);
int bottomInnerPlot = (int)Math.Round(currentArea.Position.Y / 100 * source.Height +
currentArea.InnerPlotPosition.Bottom / 100 * currentArea.Position.Height / 100 * source.Height);
// Now you got the boundaries of every important ChartElement.
// Only left to check if the mouse is within your desire ChartElement,
// like the following:
bottomInnerPlot += axisXTickMarks + (int)Math.Round(axisXfontSize); // Include AxisX
if (e.X > leftInnerPlot && e.X < rightInnerPlot &&
e.Y > topInnerPlot && e.Y < bottomInnerPlot) // return AxisX if inside the InnerPlot area or on AxisX
return currentArea.AxisX;
else if (e.X > (leftInnerPlot - axisYTickMarks - (int)Math.Round(axisYfontHeightSize)) && e.X < rightInnerPlot &&
e.Y > topInnerPlot && e.Y < bottomInnerPlot) // return AxisY if on AxisY only
return currentArea.AxisY;
return null;
}
As it can be seen, the code is longer than HitTest(). But the run time is shorter.