I have this little code to use AddArc() method in a label, but when I execute the code the label disappears. I believe it is the numbers I have used, I followed instructions from the Windows documentation and it had these parameters there too.
GraphicsPath gp = new GraphicsPath();
Rectangle rec = new Rectangle(20, 20, 50, 100);
gp.AddArc(rec, 0 , 180);
label2.Region = new Region(gp);
label2.Invalidate();
I used another code to make the correct way or curve in a text
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
var center = new Point(Width / 2, Height / 2);
var radius = Math.Min(Width, Height) / 3;
var text = "Hello";//txtUp.Text;
var font = new Font(FontFamily.GenericSansSerif, 24, FontStyle.Bold);
for (var i = 0; i < text.Length; ++i)
{
var c = new String(text[i], 1);
var size = e.Graphics.MeasureString(c, font);
var charRadius = radius + size.Height;
var angle = (((float)i / text.Length) - 2);
var x = (int)(center.X + Math.Cos(angle) * charRadius);
var y = (int)(center.Y + Math.Sin(angle) * charRadius);
e.Graphics.TranslateTransform(x, y);
e.Graphics.RotateTransform((float)(90 + 360 * angle / (2 * Math.PI)));
e.Graphics.DrawString(c, font, Brushes.Red, 0, 0);
e.Graphics.ResetTransform();
e.Graphics.DrawArc(new Pen(Brushes.Transparent, 2.0f), center.X - radius, center.Y - radius, radius * 2, radius * 2, 0, 360);
}
}
but it wont show in front of a panel is it possible.
This is what it looks like:
Is it possible to move that text in front of the green circle?
Related
How to I rotate an image without it showing like this?
Here's my Rotation Method:
public static Bitmap RotateImageN(Bitmap bmp, float angle)
{
Bitmap rotatedImage = new Bitmap(bmp.Width, bmp.Height);
using (Graphics g = Graphics.FromImage(rotatedImage))
{
// Set the rotation point to the center in the matrix
g.TranslateTransform(bmp.Width / 2, bmp.Height / 2);
// Rotate
g.RotateTransform(angle);
// Restore rotation point in the matrix
g.TranslateTransform(-bmp.Width / 2, -bmp.Height / 2);
// Draw the image on the bitmap
g.DrawImage(bmp, new Point(0, 0));
}
return rotatedImage;
}
Edit: After trying Loocid's Code
Your rotatedImage Bitmap needs to be big enough to accommodate the rotated image.
Say you rotated your original image by 30° you need to get the size of the bounding box like so:
Using some basic trig:
x = L*cos(30 * π / 180) + w*cos(60 * π / 180)
y = L*sin(30 * π / 180) + w*sin(60 * π / 180)
Therefore change the start of your code to:
var x = bmp.Width * Math.Cos(angle * Math.PI / 180) + bmp.Height * Math.Cos((90-angle) * Math.PI / 180)
var y = bmp.Width * Math.Sin(angle * Math.PI / 180) + bmp.Height * Math.Sin((90-angle) * Math.PI / 180)
Bitmap rotatedImage = new Bitmap(x, y);
The issue occurs in the rotating is related to the bounding box. It is clipping the edge because of the image you provided does not fit into the area that you have given.
I also faced this issue. So I tried a solution from here.
Adding the code that works for me.
public static Bitmap RotateImageN(Bitmap bitmap, float angle)
{
Matrix matrix = new Matrix();
matrix.Translate(bitmap.Width / -2, bitmap.Height / -2, MatrixOrder.Append);
matrix.RotateAt(angle, new System.Drawing.Point(0, 0), MatrixOrder.Append);
using (GraphicsPath graphicsPath = new GraphicsPath())
{
graphicsPath.AddPolygon(new System.Drawing.Point[] { new System.Drawing.Point(0, 0), new System.Drawing.Point(bitmap.Width, 0), new System.Drawing.Point(0, bitmap.Height) });
graphicsPath.Transform(matrix);
System.Drawing.PointF[] points = graphicsPath.PathPoints;
Rectangle rectangle = boundingBox(bitmap, matrix);
Bitmap resultBitmap = new Bitmap(rectangle.Width, rectangle.Height);
using (Graphics gDest = Graphics.FromImage(resultBitmap))
{
Matrix mDest = new Matrix();
mDest.Translate(resultBitmap.Width / 2, resultBitmap.Height / 2, MatrixOrder.Append);
gDest.Transform = mDest;
gDest.DrawImage(bitmap, points);
return resultBitmap;
}
}
}
private static Rectangle boundingBox(Image image, Matrix matrix)
{
GraphicsUnit graphicsUnit = new GraphicsUnit();
Rectangle boundingRectangle = Rectangle.Round(image.GetBounds(ref graphicsUnit));
Point topLeft = new Point(boundingRectangle.Left, boundingRectangle.Top);
Point topRight = new Point(boundingRectangle.Right, boundingRectangle.Top);
Point bottomRight = new Point(boundingRectangle.Right, boundingRectangle.Bottom);
Point bottomLeft = new Point(boundingRectangle.Left, boundingRectangle.Bottom);
Point[] points = new Point[] { topLeft, topRight, bottomRight, bottomLeft };
GraphicsPath graphicsPath = new GraphicsPath(points, new byte[] { (byte)PathPointType.Start, (byte)PathPointType.Line, (byte)PathPointType.Line, (byte)PathPointType.Line });
graphicsPath.Transform(matrix);
return Rectangle.Round(graphicsPath.GetBounds());
}
I want to draw ellipse excluding cross inside of it. I have a suspision that I need to use opacity mask. Here is how I am trying to do it.
Color grey = Color.FromArgb(128, Colors.Gray.R, Colors.Gray.G, Colors.Gray.B);
double radius = Math.Min(ActualWidth, ActualHeight) / 2;
Brush ellipse_brush = new SolidColorBrush(grey);
CombinedGeometry cg = new CombinedGeometry();
Drawing maskDrawing = new GeometryDrawing(Brushes.Lime, null, cg);
DrawingBrush mask = new DrawingBrush(maskDrawing);
dc.PushOpacityMask(mask);
dc.DrawEllipse(ellipse_brush, new Pen(ellipse_brush, 0), new Point(radius, radius), radius, radius);
dc.Pop();
Thing is that I don't understand how to create CombinedGeometry for ellipse and two lines. Or maybe I am on the wrong path?
You do not need an opacity mask in conjunction with a CombinedGeometry.
Create the cross outline geometry from a GeometryGroup with two lines and an appropriate Pen, then combine it Xor with an EllipseGeometry and draw the result:
var radius = Math.Min(ActualWidth, ActualHeight) / 2;
var crossSize = 0.8 * radius;
var crossThickness = 0.3 * radius;
var centerPoint = new Point(radius, radius);
var ellipseGeometry = new EllipseGeometry(centerPoint, radius, radius);
var crossGeometry = new GeometryGroup();
crossGeometry.Children.Add(new LineGeometry(
new Point(centerPoint.X - crossSize / 2, centerPoint.Y - crossSize / 2),
new Point(centerPoint.X + crossSize / 2, centerPoint.Y + crossSize / 2)));
crossGeometry.Children.Add(new LineGeometry(
new Point(centerPoint.X - crossSize / 2, centerPoint.Y + crossSize / 2),
new Point(centerPoint.X + crossSize / 2, centerPoint.Y - crossSize / 2)));
var crossPen = new Pen
{
Thickness = crossThickness,
StartLineCap = PenLineCap.Round,
EndLineCap = PenLineCap.Round
};
var crossOutlineGeometry = crossGeometry.GetWidenedPathGeometry(crossPen);
var combinedGeometry = new CombinedGeometry(GeometryCombineMode.Xor,
ellipseGeometry, crossOutlineGeometry);
dc.DrawGeometry(Brushes.Gray, null, combinedGeometry);
I have UserControl of Size 300*200.
and rectangle of size 300*200.
graphics.DrawRectangle(Pens.Black, 0, 0, 300, 200);
When I rotate rectangle in userControl by 30 degree, I get rotated rectangle but it is outsized.
PointF center = new PointF(150,100);
graphics.FillRectangle(Brushes.Black, center.X, center.Y, 2, 2); // draw center point.
using (Matrix matrix = new Matrix())
{
matrix.RotateAt(30, center);
graphics.Transform = matrix;
graphics.DrawRectangle(Pens.Black, 0, 0, 300, 200);
graphics.ResetTransform();
}
I want to fit rectangle like actual result.Check Image here
Can anyone have solution about this.
Thanks.
It's more of a math question than programming one.
Calculate bouning box of any rectangle rotated by any angle in radians.
var newWidth= Math.Abs(height*Math.Sin(angle)) + Math.Abs(width*Math.Cos(angle))
var newHeight= Math.Abs(width*Math.Sin(angle)) + Math.Abs(height*Math.Cos(angle))
Calculate scale for x and y:
scaleX = width/newWidth;
scaleY = height/newHeight;
Apply it to your rectangle.
EDIT:
Applied to your example:
PointF center = new PointF(150, 100);
graphics.FillRectangle(Brushes.Black, center.X, center.Y, 2, 2); // draw center point.
var height = 200;
var width = 300;
var angle = 30;
var radians = angle * Math.PI / 180;
var boundingWidth = Math.Abs(height * Math.Sin(radians)) + Math.Abs(width * Math.Cos(radians));
var boundingHeight = Math.Abs(width * Math.Sin(radians)) + Math.Abs(height * Math.Cos(radians));
var scaleX = (float)(width / boundingWidth);
var scaleY = (float)(height / boundingHeight);
using (Matrix matrix = new Matrix())
{
matrix.Scale(scaleX, scaleY, MatrixOrder.Append);
matrix.Translate(((float)boundingWidth - width) / 2, ((float)boundingHeight - height) / 2);
matrix.RotateAt(angle, center);
graphics.Transform = matrix;
graphics.DrawRectangle(Pens.Black, 0, 0, width, height);
graphics.ResetTransform();
}
How can i draw a polygon according to the input coordinates which are given in C#.
You didn't show any code because based on those coordinate, you are applying some form of scaling to the image.
Using the Paint event of a PictureBox, here is an example using those coordinates on the screen. It fills in the polygon, then draws the border, then it loops through all the points to draw the red circle:
void pictureBox1_Paint(object sender, PaintEventArgs e) {
e.Graphics.SmoothingMode = SmoothingMode.AntiAlias;
e.Graphics.Clear(Color.White);
// draw the shading background:
List<Point> shadePoints = new List<Point>();
shadePoints.Add(new Point(0, pictureBox1.ClientSize.Height));
shadePoints.Add(new Point(pictureBox1.ClientSize.Width, 0));
shadePoints.Add(new Point(pictureBox1.ClientSize.Width,
pictureBox1.ClientSize.Height));
e.Graphics.FillPolygon(Brushes.LightGray, shadePoints.ToArray());
// scale the drawing larger:
using (Matrix m = new Matrix()) {
m.Scale(4, 4);
e.Graphics.Transform = m;
List<Point> polyPoints = new List<Point>();
polyPoints.Add(new Point(10, 10));
polyPoints.Add(new Point(12, 35));
polyPoints.Add(new Point(22, 35));
polyPoints.Add(new Point(24, 22));
// use a semi-transparent background brush:
using (SolidBrush br = new SolidBrush(Color.FromArgb(100, Color.Yellow))) {
e.Graphics.FillPolygon(br, polyPoints.ToArray());
}
e.Graphics.DrawPolygon(Pens.DarkBlue, polyPoints.ToArray());
foreach (Point p in polyPoints) {
e.Graphics.FillEllipse(Brushes.Red,
new Rectangle(p.X - 2, p.Y - 2, 4, 4));
}
}
}
You may use Graphics.DrawPolygon. You can store the coordinates in an array of Point and then you can pass that to DrawPolygon method. You may wanna see:
Drawing with Graphics in WinForms using C#
private System.Drawing.Graphics g;
System.Drawing.Point[] p = new System.Drawing.Point[6];
p[0].X = 0;
p[0].Y = 0;
p[1].X = 53;
p[1].Y = 111;
p[2].X = 114;
p[2].Y = 86;
p[3].X = 34;
p[3].Y = 34;
p[4].X = 165;
p[4].Y = 7;
g = PictureBox1.CreateGraphics();
g.DrawPolygon(pen1, p);
This simple function is able to generate an array of PointF equal to the vertices of the regular polygon to be drawn, where "center" is the center of the polygon, "sides" is its number of sides, "sideLength" is the size of each side in pixels and "offset" is its slope.
public PointF[] GetRegularPolygonScreenVertex(Point center, int sides, int sideLength, float offset)
{
var points = new PointF[sides];
for (int i = 0; i < sides; i++)
{
points[i] = new PointF(
(float)(center.X + sideLength * Math.Cos((i * 360 / sides + offset) * Math.PI / 180f)),
(float)(center.Y + sideLength * Math.Sin((i * 360 / sides + offset) * Math.PI / 180f))
);
}
return points;
}
The result obtained can be used to draw a polygon, e.g. with the function:
GraphicsObject.DrawPolygon(new Pen(Brushes.Black, GetRegularPolygonScreenVertex(new Point(X, Y), 6, 30, 60f));
Which will generate a regular hexagon with a side of 30 pixels inclined by 30°.
hex
I am scratching my head to figure out a way to scale a signal on a 2D graphic pane. The story is: I connect my application to a microcontroller and on fixed intervals I read a data value (A voltage point). Now I want to draw this on my graphic pane. Example:
So up in the picture you see at time 0, the voltage is also 0 and this goes on and after 6 data points I will clear the pane and redo the whole stuff.
The question is, how can I translate this voltage into pixel values, having in mind I want the middle of the graphic pane to be my signals 0, just like a normal cartesian graph. Can someone please help me to figure out the scaling algorithm in this case?
Seems like simple math: just add the width/2 to all X coordinates which you are passing into drawing functions. Suppose you have an array of 6 points you can do the following:
var g = this.CreateGraphics();
var points = new Point[6]{new Point(0, 0), new Point(10, 10), new Point(30, 0), new Point(40,20), new Point(50, 0), new Point(60,30)};
for (int i = 0; i < points.Length-1; i++)
{
g.DrawLine(Pens.Black, points[i].X + Width / 2, Height / 2 - points[i].Y, points[i + 1].X + Width / 2, Height / 2 - points[i + 1].Y);
}
Alternatively you can invoke TranslateTransform function to move all further drawing to some amount by X and Y axes. Example:
var g = this.CreateGraphics();
var points = new Point[6]{new Point(0, 0), new Point(10, 10), new Point(30, 0), new Point(40,20), new Point(50, 0), new Point(60,30)};
g.TranslateTransform(Width / 2, 0, System.Drawing.Drawing2D.MatrixOrder.Append);
for (int i = 0; i < points.Length-1; i++)
{
g.DrawLine(Pens.Black, points[i].X, Height / 2 - points[i].Y, points[i + 1].X, Height / 2 - points[i + 1].Y);
}
Maybe this will be useful (remember that scale and translate functions are changing points in array):
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
var points = new PointF[6] { new PointF(0, 0), new PointF(30, 3), new PointF(90, 0), new PointF(190, 3.1f), new PointF(270, -0.5f), new PointF(360, 3.5f) };
float maxX = (from p in points select p).Max(t => t.X);
float maxY = (from p in points select p).Max(t => t.Y);
float xSizeToFit = pictureBox1.Width;
float ySizeToFit = pictureBox1.Height/2;
float scaleX = xSizeToFit / maxX;
float scaleY = ySizeToFit / maxY;
// scale to fit to given size
ScalePoints(points, scaleX, scaleY);
// translate to center
TranslatePoints(points, this.pictureBox1.Width / 2 - 0.5f * xSizeToFit, this.pictureBox1.Height / 2 + 0.5f * ySizeToFit);
DrawAxis(e.Graphics, this.pictureBox1.Size);
e.Graphics.DrawLines(Pens.Black, points);
}
private void TranslatePoints(PointF[] points, float transX, float transY)
{
for (int i = 0; i < points.Length; i++)
{
points[i].X += transX;
points[i].Y = transY - points[i].Y;
}
}
private void ScalePoints(PointF[] points, float scaleX, float scaleY)
{
for (int i = 0; i < points.Length; i++)
{
points[i].X *= scaleX;
points[i].Y *= scaleY;
}
}
public void DrawAxis(Graphics g, Size size)
{
//x
g.DrawLine(Pens.Black, 0, size.Height / 2, size.Width, size.Height / 2);
//y
g.DrawLine(Pens.Black, size.Width / 2, size.Height, size.Width / 2, 0);
}
private void pictureBox1_Resize(object sender, EventArgs e)
{
pictureBox1.Invalidate();
}