Basically i have a windows form that user will be able to draw different shapes(e.g square, circle and triangle), user will be able to highlight any of these shapes after drawing and then control that highlighted shape by moving or rotating it, i don't know how to rotate the shape. any one can help, this is my code (only to draw a square)
PS: user need to click twice on the form to draw the shape between those 2 points as shown below also i know i should be using onPaint method but this is the requirements of the task
Thanks
public Square(Point keyPt, Point oppPt) // constructor
{
this.keyPt = keyPt;
this.oppPt = oppPt;
}
// You will need a different draw method for each kind of shape. Note the square is drawn
// from first principles. All other shapes should similarly be drawn from first principles.
// Ideally no C# standard library class or method should be used to create, draw or transform a shape
// and instead should utilse user-developed code.
public void draw(Graphics g, Pen blackPen)
{
// This method draws the square by calculating the positions of the other 2 corners
double xDiff, yDiff, xMid, yMid; // range and mid points of x & y
// calculate ranges and mid points
xDiff = oppPt.X - keyPt.X;
yDiff = oppPt.Y - keyPt.Y;
xMid = (oppPt.X + keyPt.X) / 2;
yMid = (oppPt.Y + keyPt.Y) / 2;
// draw square
g.DrawLine(blackPen, (int)keyPt.X, (int)keyPt.Y, (int)(xMid + yDiff / 2), (int)(yMid - xDiff / 2));
g.DrawLine(blackPen, (int)(xMid + yDiff / 2), (int)(yMid - xDiff / 2), (int)oppPt.X, (int)oppPt.Y);
g.DrawLine(blackPen, (int)oppPt.X, (int)oppPt.Y, (int)(xMid - yDiff / 2), (int)(yMid + xDiff / 2));
g.DrawLine(blackPen, (int)(xMid - yDiff / 2), (int)(yMid + xDiff / 2), (int)keyPt.X, (int)keyPt.Y);
}
public void fillSquare(Graphics g, Brush redBrush)
{
float xDiff = oppPt.X - keyPt.X;
float yDiff = oppPt.Y - keyPt.Y;
float xMid = (oppPt.X + keyPt.X) / 2;
float yMid = (oppPt.Y + keyPt.Y) / 2;
var path = new GraphicsPath();
path.AddLines(new PointF[] {
keyPt,
new PointF(xMid + yDiff/2, yMid-xDiff/2),
oppPt
});
path.AddLines(new PointF[] {
keyPt,
new PointF(xMid - yDiff/2, yMid + xDiff/2),
oppPt
});
path.CloseFigure();
// Fill Triangle
g.FillPath(redBrush, path);
}
}
}
i have tried this method but something is missing i don't know what is it
private void itemRotation(PaintEventArgs e)
{
Pen blackpen = new Pen(Color.Black);
Graphics g = e.Graphics;
Font myFont = new System.Drawing.Font("Helvetica", 9);
Brush blackwriter = new SolidBrush(System.Drawing.Color.Black);
if (rotateItem)
{
for (int i = 0; i < shapes.Count; i++)
{
if (shapes[i].Selected)
{
if (shapes[i].ShapeType == (int)ShapeTypes.Square)
{
PointF center = new PointF(shapes[i].keyPt.X + (shapes[i].oppPt.X / 2.0F), shapes[i].keyPt.Y + (shapes[i].oppPt.Y / 2.0F));
shapes[i].keyPt = new Point(shapes[i].keyPt.X, shapes[i].keyPt.Y);
shapes[i].oppPt = new Point(shapes[i].oppPt.X, shapes[i].oppPt.Y);
Matrix myMatrix = new Matrix();
myMatrix.Rotate(30);
g.Transform = myMatrix;
((Square)shapes[i]).draw(g, blackpen);
g.DrawString("2nd pos", myFont, blackwriter, shapes[i].keyPt.X, shapes[i].oppPt.X);
}
}
}
}
}
Below is an example of how to draw the same shape (a GraphicsPath) into various locations and rotations.
The key here is the following two commands
e.Graphics.TranslateTransform(x, y);
e.Graphics.RotateTransform(-angle);
See results below:
and the code used to generate it:
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
// This code defines a graphics shape using a GraphicsPath
// and draws multiple copies along a grid and with various
// rotation angle angles.
e.Graphics.SmoothingMode=SmoothingMode.AntiAlias;
var target = sender as PictureBox;
// Step 1 - Define a rectangle 20 by 12 pixels, center at origin.
var gp = new GraphicsPath();
gp.AddLines(new PointF[] {
new PointF(-10, -6),
new PointF( 10, -6),
new PointF( 10, 6),
new PointF(-10, 6) });
gp.CloseFigure();
// Step 2 - Define a 10×9 grid with two loops
float angle = 0;
for (int i = 0; i<9; i++)
{
// divide the control height into 10 divisions
float y = (i+1)*target.Height/10;
for (int j = 0; j<10; j++)
{
// divide the control width into 11 divisions
float x = (j+1)*target.Width/11;
// Save the default transformation state
var state = e.Graphics.Save();
// Traslate the origin to (x,y), each grid point
e.Graphics.TranslateTransform(x, y);
// Rotate shape by an angle (negative = CCW)
e.Graphics.RotateTransform(-angle);
// Draw the shape
e.Graphics.FillPath(Brushes.LightSeaGreen, gp);
e.Graphics.DrawPath(Pens.Black, gp);
// Restore the default transformation state
e.Graphics.Restore(state);
// Increment the angle by one degree.
// The idea is to show all 90 degrees of rotation in a 10×9 grid.
angle++;
}
}
}
Related
At the moment I develope a ChartControl and it works just pretty well in my opinion,
but now I'm at a point where it would be nice to have the ability to zoom the drawed signal for better analyzing.
At the moment I calculate the needed points like this:
for (int i = 0; i < PointsCount; i++){
xAxisPoint = xAxisOP.X + i * (xAxisWidth / PointsCount);
yAxisPoint = yAxisHeight * data[i].Point / Divisor;
if(yAxisPoint > yAxisHeight){
yAxisPoint = yAxisHeight;
}
if(yAxisPoint < -yAxisHeight){
yAxisPoint = -yAxisHeight;
}
Points[i] = new PointF(xAxisPoint, yAxisOP.Y + yAxisPoint);
}
if(zoom){
graphics.ScaleTransform(0.2f*ZoomFactor, 0.2f*ZoomFactor);
}
using (Pen plotPen = new Pen(plotColor, 1)){
graphics.DrawLines(plotPen, Points);
}
But the problem is: When it zooms in, the zoom is way too big and is drawn outside the bounds of my control.
Is there a way to specify an area in which it should be Scaled (zoomed)?
For the final question: Is there a way to specify an area in which it should be scaled/zoomed? you need a combination of SetClip, TranslateTransform and ScaleTransform.
Here is an example.
It uses a
target rectangle zoomTgtArea where the zoomed graphics are displayed,
a mouse location zoomOrigin where the zoom origin is,
a float zoomFactor, a positive float.
Initial values:
Rectangle zoomTgtArea = new Rectangle(300, 500, 200, 200);
Point zoomOrigin = Point.Empty; // updated in MouseMove when button is pressed
float zoomFactor = 2f;
The trick to zoom in on only a part of the graphics is to display the graphics twice, once normally and once with the transformations of the Graphics object.
Let's try:
private void pictureBox_Paint(object sender, PaintEventArgs e)
{
// normal drawing
DrawStuff(e.Graphics);
// for the movable zoom we want a small correction
Rectangle cr = pictureBox.ClientRectangle;
float pcw = cr.Width / (cr.Width - ZoomTgtArea.Width / 2f) ;
float pch = cr.Height / (cr.Height - ZoomTgtArea.Height / 2f) ;
// now we prepare the graphics object; note: order matters!
e.Graphics.SetClip(zoomTgtArea );
// we can either follow the mouse or keep the output area fixed:
if (cbx_fixed.Checked)
e.Graphics.TranslateTransform( ZoomTgtArea.X - zoomCenter.X * zoomFactor,
ZoomTgtArea.Y - zoomCenter.Y * zoomFactor);
else
e.Graphics.TranslateTransform( - zoomCenter.X * zoomFactor * pcw,
- zoomCenter.Y * zoomFactor * pch);
// finally zoom
e.Graphics.ScaleTransform(zoomFactor, zoomFactor);
// and display zoomed
DrawStuff(e.Graphics);
}
The DrawStuff I used is simple:
void DrawStuff(Graphics g)
{
bool isZoomed = g.Transform.Elements[0]!= 1
|| g.Transform.OffsetX != 0 | g.Transform.OffsetY != 0;
if (isZoomed) g.Clear(Color.Gainsboro); // pick your back color
// all your drawing here!
Rectangle r = new Rectangle(10, 10, 500, 800); // some size
using (Font f = new Font("Tahoma", 11f))
g.DrawString(text, f, Brushes.DarkSlateBlue, r);
}
Its only extra is clearing the background so the normal drawing won't shine through the zoomed version..
Let's see:
I have a user control and I'm using ScaleTransform() to implement zoom.
However, in order to keep the center content in the center after the zoom, it is also necessary to scroll. For example, if I zoom in (make things bigger), the X and Y origin should increase so that most of the content does not move down and to the right. (That is, as I zoom in, some of the content should disappear to the left and top.)
Has anyone worked out the calculations of how much to scroll in the X and Y direction in response to a zoom?
For example:
e.Graphics.ScaleTransform(2.0F, 2.0F);
e.Graphics.TranslateTransform(?, ?);
What would be my arguments to TranslateTransform() be so that the center part of the content remains at the center?
Note: I am not displaying an image. I am drawing the graphic content to the surface of my user control.
Or perhaps there's an even easier way?
This should work and I can't imagine any easier way; it assumes you have decided on the center of the zooming. I have chosen to draw centered on the panel:
float zoom = 1f;
private void drawPanel1_Paint(object sender, PaintEventArgs e)
{
Point c = new Point(drawPanel1.ClientSize.Width / 2, drawPanel1.ClientSize.Height / 2);
// a blue sanity check for testing
e.Graphics.FillEllipse(Brushes.DodgerBlue, c.X - 3, c.Y - 3, 6, 6);
// the offsets you were looking for:
float ox = c.X * ( zoom - 1f);
float oy = c.Y * ( zoom - 1f);
// first move and then scale
e.Graphics.TranslateTransform(-ox, -oy);
e.Graphics.ScaleTransform(zoom, zoom);
// now we can draw centered around our point c
Size sz = new Size(300, 400);
int count = 10;
int wx = sz.Width / count;
int wy = sz.Height / count;
for (int i = 0; i < count; i++)
{
Rectangle r = new Rectangle(c.X - i * wx / 2 , c.Y - i * wy / 2, i * wx, i * wy );
e.Graphics.DrawRectangle(Pens.Red, r );
}
}
Note the order of moving and scaling!
I guess you are using some differet interface, but in my case, that's what got the job done (for leaving the mouse in it's original location on the draw after the mouse wheel event):
private void DrawPb_MouseWheel(object sender, MouseEventArgs e)
{
// e contains current mouse location and the wheel direction
int wheelDirection = e.Delta / Math.Abs(e.Delta); // is 'in' or 'out' (1 or -1).
double factor = Math.Exp(wheelDirection * Constants.ZoomFactor); // divide or multiply
double newX = e.X - e.X / factor; // what used to be x is now newX
double newY = e.Y - e.Y / factor; // same for y
Point offset = new Point((int)(-newX), (int)(-newY)); // the offset of the old point to it's new location
Graph.AddOffset(offset); // apply offset
}
I'm stuck here. I want to have the eyes drawn while 'looking' at (the angle of) the cursor. Also, it should be contained within the bigger circle/quadrant (just like an eyeball). Sadly, it just won't draw the eye for me at the right position/angle and at every mouse movement. The only thing it will do is initially draw an ellipse at (0,0), but that's not what I want.
My idea is to calculate the ratio of the triangles with pythagorean theorem. Then apply the right coordinates (With the correct ratio) in the drawEllipse(); method. This should be repeated everytime you move the cursor.
You can check my image for the mathematical reasoning.
Here is my code, note that the panel is made in the designer mode which isn't included in this code, but shouldn't be a big deal:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace oogjes2
{
public partial class Form1 : Form
{
public int mousex;
public int mousey;
public Form1()
{
InitializeComponent();
panel1.Paint += paintpanel;
panel1.MouseMove += panel1_MouseMove;
}
//panel1 cover the screen from (0.0) and onwards,
void panel1_MouseMove(object sender, MouseEventArgs mea)
{
int mousex = mea.X;
int mousey = mea.Y;
}
void paintpanel(object obj, PaintEventArgs pea)
{
Pen blackpen = new Pen(Color.Black, 3);
// the black outer circle which doesnt move
pea.Graphics.DrawEllipse(blackpen, -125, -125, 250, 250);
// e = 63. Diagonal distance from (0,0) to starting point drawEllipse
// factor = multiplication from mea.x and mea.y to the respective ex and ey of the small circle.
// ey = factor * mousex (mea.X). Same for ex.
float e = (float)Math.Sqrt(45 * 45 + 45 * 45); //=63
float factor = (e / (float)Math.Sqrt(mousex * mousex + mousey * mousey));
int ex = mousex * (int)factor;
int ey = mousey * (int)factor;
// the eye that should be redrawn at every mousemovement
pea.Graphics.DrawEllipse(blackpen, ex, ey, 50, 50);
this.Invalidate();
}
}
}
Try this out:
public partial class Form1 : Form
{
private Timer tmr;
private int PupilRadius = 20;
private int EyeBallRadius = 50;
private int DistanceBetweenEyes = 20;
public Form1()
{
InitializeComponent();
this.panel1.Paint += panel1_Paint;
tmr = new Timer();
tmr.Interval = 100;
tmr.Tick += tmr_Tick;
tmr.Start();
}
void tmr_Tick(object sender, EventArgs e)
{
panel1.Invalidate();
}
void panel1_Paint(object sender, PaintEventArgs e)
{
Point center = new Point(panel1.ClientSize.Width / 2, panel1.ClientSize.Height / 2);
Point LeftEyeCenter = new Point(center.X - EyeBallRadius - (DistanceBetweenEyes / 2), center.Y);
Point RightEyeCenter = new Point(center.X + EyeBallRadius + (DistanceBetweenEyes / 2), center.Y);
Rectangle rc = new Rectangle(LeftEyeCenter, new Size(1, 1));
rc.Inflate(EyeBallRadius, EyeBallRadius);
e.Graphics.DrawEllipse(Pens.Black, rc);
rc = new Rectangle(RightEyeCenter, new Size(1, 1));
rc.Inflate(EyeBallRadius, EyeBallRadius);
e.Graphics.DrawEllipse(Pens.Black, rc);
Point curPos = panel1.PointToClient(Cursor.Position);
Double DistanceFromLeftEyeToCursor = getDistance(LeftEyeCenter.X, LeftEyeCenter.Y, curPos.X, curPos.Y);
Double DistanceFromRightEyeToCursor = getDistance(RightEyeCenter.X, RightEyeCenter.Y, curPos.X, curPos.Y);
double angleLeft = getAngleInDegrees(LeftEyeCenter.X, LeftEyeCenter.Y, curPos.X, curPos.Y);
double angleRight = getAngleInDegrees(RightEyeCenter.X, RightEyeCenter.Y, curPos.X, curPos.Y);
rc = new Rectangle(new Point(Math.Min((int)DistanceFromLeftEyeToCursor, EyeBallRadius - PupilRadius), 0), new Size(1, 1));
rc.Inflate(PupilRadius, PupilRadius);
e.Graphics.TranslateTransform(LeftEyeCenter.X, LeftEyeCenter.Y);
e.Graphics.RotateTransform((float)angleLeft);
e.Graphics.FillEllipse(Brushes.Blue, rc);
rc = new Rectangle(new Point(Math.Min((int)DistanceFromRightEyeToCursor, EyeBallRadius - PupilRadius), 0), new Size(1, 1));
rc.Inflate(PupilRadius, PupilRadius);
e.Graphics.ResetTransform();
e.Graphics.TranslateTransform(RightEyeCenter.X, RightEyeCenter.Y);
e.Graphics.RotateTransform((float)angleRight);
e.Graphics.FillEllipse(Brushes.Blue, rc);
}
private Double getDistance(int Ax, int Ay, int Bx, int By)
{
return Math.Sqrt(Math.Pow((Double)Ax - Bx, 2) + Math.Pow((Double)Ay - By, 2));
}
private Double getAngleInDegrees(int cx, int cy, int X, int Y)
{
// draw a line from the center of the circle
// to the where the cursor is...
// If the line points:
// up = 0 degrees
// right = 90 degrees
// down = 180 degrees
// left = 270 degrees
Double angle;
int dy = Y - cy;
int dx = X - cx;
if (dx == 0) // Straight up and down | avoid divide by zero error!
{
if (dy <= 0)
{
angle = 0;
}
else
{
angle = 180;
}
}
else
{
angle = Math.Atan((Double)dy / (Double)dx);
angle = angle * ((Double)180 / Math.PI);
if (X <= cx)
{
angle = 180 + angle;
}
}
return angle;
}
}
If you want to have an eye following the cursor, you'll need to calculate the angle from the eye to the cursor.
You'll need to know just three things:
the position of the eye, the position of the mouse, and how far the center of the pupil is from the center of the eye (I'm calling your inner circle the pupil and outer circle the eye).
Since the eye never moves (only rotates around it's center) you already know it's position.
void direction_to_cursor(){
float p = Math.sqrt((45 + r)*(45 + r)*2); // Distance from outer circle center to inner circle center
// assuming you want the top left corner 63 away from 0, 0
// r is radius of inner circle
int x = mouseX - EyeX; // In your picture it looks like your eye is at 0,0
int y = -(mouseY - EyeY); // inverted y axis (0 is at top)
float dir = Math.atan2(x, y);
int px = p * Math.cos(dir); // x Center of inner circle
int py = p * Math.cos(dir); // y Center of inner circle
px -= r; // Get left x coordinate of circle
py -= r; // get right x coordinate of circle
pea.Graphics.DrawEllipse(blackpen, px, py, 50, 50);
}
step1: Calculate distance from center of Eye to center of pupil
step2: Calculate x and y difference between the Mouse and Eye
step3: Calculate direction from eye to mouse.
step4: Calculate position of pupil from direction and distance from center of eye
you could use the following
void paintpanel(object obj, PaintEventArgs pea)
{
Pen blackpen = new Pen(Color.Black, 3);
pea.Graphics.DrawEllipse(blackpen, -125, -125, 250, 250);
float p = Math.sqrt(2*70*70); // (45+25)*(45+25)+(45+25)*(45+25)
float dir = Math.atan(y, x);
int ex = Math.cos(dir) * p - 25;
int ey = Math.sin(dir) * p - 25;
// the eye that should be redrawn at every mousemovement
pea.Graphics.DrawEllipse(blackpen, ex, ey, 50, 50);
this.Invalidate();
}
I want to increase the height of the curve but its left and right position should remain same. Just want to lift up from center to give it a shape like curve as height changes.
Pen blackPen = new Pen(Color.Black, 3);
// Create coordinates of rectangle to bound ellipse.
int x = 93;
int y = 136;
int width = 320;
int height = 50;
// Create start and sweep angles on ellipse.
int startAngle = 0;
int sweepAngle = -180;
// Draw arc to screen.
e.Graphics.DrawArc(blackPen, x, y, width, height, startAngle, sweepAngle);
In the most direct way your problem can be solved like this:
int change = 0;
e.Graphics.DrawArc(blackPen, x, y-change, width, height+change, startAngle, sweepAngle);
By increasing the variable change the ellipse will curve up more and more:
private void button1_Click(object sender, EventArgs e)
{
change += 10;
panel1.Invalidate();
}
But maybe you want more control over the shape? Let's have a look at the options:
Here are examples of the three 'curve' drawing methods:
Curves, Beziers & Ellipses
And here is the code to draw that image.
Please ignore the Graphics.xxxTransform calls! They only are meant to shift the curves a little bit upwards so they don't overlap too much to see them properly.
Also note that the curves in the first image are not completely convex. See the last part of the answer to see a DrawCurve call that avoids the concave segments!
The important part are the Points! And just as the comments suggest, in the third part the ellipses are being changed by making the height larger and moving the top of the Rectangle up by the same amount.
The complexity DrawArc of and DrawCurve is pretty much equal; both are controlled by four integers with a rather clear meaning: They either make one rectangle or the corners of a symmetrical triangle. (Plus one counterpoint for the convex call.)
DrawBezier is more complex, especially since the controls point(s) are not actually on the resulting curve. They can be thought of force vectors that pull the line into a curved shape and are harder to calculate.
private void panel1_Paint(object sender, PaintEventArgs e)
{
Point a = new Point(0, 200);
Point c = new Point(200, 200);
for (int i = 0; i< 10; i++)
{
e.Graphics.TranslateTransform(0, -5);
Point b = new Point(100, 50 + i * 10);
e.Graphics.DrawCurve(Pens.Maroon, new[] { a, b, c }, 0.7f);
}
e.Graphics.ResetTransform();
Point pa = new Point(250, 200);
Point pb = new Point(450, 200);
for (int i = 0; i < 10; i++)
{
e.Graphics.TranslateTransform(0, -5);
Point pc = new Point(350, 200 - i * 10);
e.Graphics.DrawBezier(Pens.ForestGreen, pa, pc, pc, pb);
}
e.Graphics.ResetTransform();
int x = 500;
int y0 = 200;
int w = 200;
for (int i = 0; i < 10; i++)
{
e.Graphics.TranslateTransform(0, -5);
Rectangle rect = new Rectangle(x, y0 - i * 10, w, 10 + i * 10);
e.Graphics.DrawArc(Pens.DarkBlue, rect, -0, -180);
}
e.Graphics.ResetTransform();
}
Notes:
The Curve (1st image) can be further controlled by the Tension parameter. The lower the tension the more pointed it gets, approaching 1f it makes the curve broader..
The Bezier curve (2nd image) is using only one control point. (Twice.) The curve gets a little pointed this way. You can make it broader and broader by using two different points the move apart little by little..
The Ellipse can't be controlled; it will always fill the bounding Rectangle.
Here is an example of varying the Curves and the Beziers:
The Curves are drawn with varying Tensions. Also I have used an overload that helps to get rid of the concave part at the start and end of the curve. The trick is to add a suitable extra point to the start and end and to tell the DrawCurve to leave out these 1st and last segments.
The simplest point to use (for both ends actually) is the counterpoint of the one at the top.
The Beziers are drawn using two control points, moving out and up a little.
Here is the code for the variations:
Point a = new Point(0, 200);
Point c = new Point(200, 200);
for (int i = 1; i < 10; i++)
{
e.Graphics.TranslateTransform(0, -5);
Point b = new Point(100, 50);
Point b0 = new Point(b.X, a.Y + (a.Y - b.Y));
e.Graphics.DrawCurve(Pens.Maroon, new[] { b0, a, b, c, b0 }, 1, 2, 0.1f * i);
}
e.Graphics.ResetTransform();
Point pa = new Point(250, 200);
Point pb = new Point(450, 200);
for (int i = 0; i < 10; i++)
{
e.Graphics.TranslateTransform(0, -5);
Point ca = new Point(350 - i * 9, 100 - i * 5);
Point cb = new Point(350 + i * 9, 100 - i * 5);
e.Graphics.DrawBezier(Pens.ForestGreen, pa, ca, cb, pb);
}
e.Graphics.ResetTransform();
here was the solution just increase value of y0 as u increase the value of
y0-i here i=20
int x = 96;
int y0 = 260;
int w = 320;
e.Graphics.TranslateTransform(0, -5);
Rectangle rect = new Rectangle(x, y0 - 20 * 10, w, 10 + 20 * 10);
e.Graphics.DrawArc(Pens.DarkBlue, rect, -0, -180);
e.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