I am creating a document based application and i want to draw a horizontal line underlying the text. But, line should not be straight. i want to draw a line like this.
Currently i am using System.Graphics object to draw any object.
private void DrawLine(Graphics g, Point Location, int iWidth)
{
iWidth = Convert.ToInt16(iWidth / 2);
iWidth = iWidth * 2;
Point[] pArray = new Point[Convert.ToInt16(iWidth / 2)];
int iNag = 2;
for (int i = 0; i < iWidth; i+=2)
{
pArray[(i / 2)] = new Point(Location.X + i , Location.Y + iNag);
if (iNag == 0)
iNag = 2;
else
iNag = 0;
}
g.DrawLines(Pens.Black, pArray);
}
UPDATED:
Above code is working fine and line draws perfectly but, this code effects on application performance. Is there another way to do this thing.
If you want fast drawing just make a png image of the line you want, with width larger than you need and then draw the image:
private void DrawLine(Graphics g, Point Location, int iWidth)
{
Rectangle srcRect = new Rectangle(0, 0, iWidth, zigzagLine.Height);
Rectangle dstRect = new Rectangle(Location.X, Location.Y, iWidth, zigzagLine.Height);
g.DrawImage(zigzagLine, dstRect, srcRect, GraphicsUnit.Pixel);
}
zigzagLine is the bitmap.
valter
Related
I want to draw Arc in Vieport3D using MeshGeometry3D.I have searched for it a lot but not found anything ,what I found is using PathGeometry.I am new to WPF so don't know much about 3D graphics.How can I do this?
thanks
here is the code which I wrote to create mesh-geometry for Arc.I hope this will help someone.
private GeometryModel3D GetModel(double radius, Vector3D normal, Point3D center, int resolution, double StartAngle, double EndAngle)
{
var mod = new GeometryModel3D();
var geo = new MeshGeometry3D();
// Generate the circle in the XZ-plane
// Add the center first
geo.Positions.Add(new Point3D(0, 0, 0));
// Iterate from angle 0 to 2*PI
double dev = (2 * Math.PI) / resolution;
double thik = 0.02;
//float spaceangle = StartAngle + 1;
if (StartAngle != EndAngle)
{
for (double i = StartAngle; i < EndAngle; i += dev)
{
geo.Positions.Add(new Point3D(radius * Math.Cos(i), 0, -radius * Math.Sin(i)));
geo.Positions.Add(new Point3D((radius-thik) * Math.Cos(i), 0, (-(radius-thik)) * Math.Sin(i)));
}
for (int i = 3; i < geo.Positions.Count; i += 1)
{
geo.TriangleIndices.Add(i - 3);
geo.TriangleIndices.Add(i - 1);
geo.TriangleIndices.Add(i - 2);
geo.TriangleIndices.Add(i - 1);
geo.TriangleIndices.Add(i);
geo.TriangleIndices.Add(i - 2);
}
}
mod.Geometry = geo;
// Create transforms
var trn = new Transform3DGroup();
// Up Vector (normal for XZ-plane)
var up = new Vector3D(0, 1, 0);
// Set normal length to 1
normal.Normalize();
var axis = Vector3D.CrossProduct(up, normal); // Cross product is rotation axis
var angle = Vector3D.AngleBetween(up, normal); // Angle to rotate
trn.Children.Add(new RotateTransform3D(new AxisAngleRotation3D(axis, angle)));
trn.Children.Add(new TranslateTransform3D(new Vector3D(center.X, center.Y, center.Z)));
mod.Transform = trn;
return mod;
}
Need to divide a UserControl with a background picture into multiple small clickable areas. Clicking them should simply raise an event, allowing to determine which particular area of the picture was clicked.
The obvious solution is using transparent labels. However, they are heavily flickering. So it looks like labels are not designed for this purpose, they take too much time to load.
So I'm thinking if any lighter option exists? To logically "slice up" the surface.
I also need a border around the areas, though.
on the user control do:
MouseClick += new System.Windows.Forms.MouseEventHandler(this.UserControl1_MouseClick);
and now in the UserControl1_MouseClick event do:
private void UserControl1_MouseClick(object sender, MouseEventArgs e)
{
int x = e.X;
int y = e.Y;
}
now let's divide the user control to a 10x10 area:
int xIdx = x / (Width / 10);
int yIdx = y / (Height / 10);
ClickOnArea(xIdx, yIdx);
in ClickOnArea method you just need to decide what to do in each area. maybe using a 2d array of Action
as for the border do this:
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
Graphics g = e.Graphics;
Pen p = new Pen(Color.Black);
float xIdx = (float)(Width / 10.0);
float yIdx = (float)(Height / 10.0);
for (int i = 0; i < 10; i++)
{
float currVal = yIdx*i;
g.DrawLine(p, 0, currVal, Width, currVal);
}
g.DrawLine(p, 0, Height - 1, Width, Height - 1);
for (int j = 0; j < 10; j++)
{
float currVal = xIdx * j;
g.DrawLine(p, currVal, 0, currVal, Height);
}
g.DrawLine(p, Width - 1, 0, Width - 1, Height);
}
In C#, WPF I've created a rectangle:
Rectangle myRgbRectangle = new Rectangle();
myRgbRectangle.Width = 1;
myRgbRectangle.Height = 1;
SolidColorBrush mySolidColorBrush = new SolidColorBrush();
Yes, I really just want it to be 1 pixel by 1 pixel. And I want to change the color based on the variable height like so:
mySolidColorBrush.Color = Color.FromArgb(255, 0, 0, (byte)height);
myRgbRectangle.Fill = mySolidColorBrush;
Now, how do I draw at a specific x,y location on the screen? I do have a grid (myGrid) on my MainWindow.xaml.
Thanks!
Here's the pertinent code:
myRgbRectangle.Width = 1;
myRgbRectangle.Height = 1;
SolidColorBrush mySolidColorBrush = new SolidColorBrush();
int height;
for (int i = 0; i < ElevationManager.Instance.heightData.GetLength(0); i++)
for (int j = 0; j < ElevationManager.Instance.heightData.GetLength(1); j++)
{
height = ElevationManager.Instance.heightData[i, j] / 100;
// Describes the brush's color using RGB values.
// Each value has a range of 0-255.
mySolidColorBrush.Color = Color.FromArgb(255, 0, 0, (byte)height);
myRgbRectangle.Fill = mySolidColorBrush;
myCanvas.Children.Add(myRgbRectangle);
Canvas.SetTop(myRgbRectangle, j);
Canvas.SetLeft(myRgbRectangle, i);
And it's throwing this error: Specified Visual is already a child of another Visual or the root of a CompositionTarget.
You need to use a Canvas istead of a Grid. You use coordinates to position elements in a Canvas versus Column and Row in a Grid.
Definition of a Canvas:
Defines an area within which you can explicitly position child elements by using coordinates that are relative to the Canvas area.
You would then use Canvas.SetTop and Canvas.SetLeft Properties like this (assuming that your canvas is named myCanvas):
myCanvas.Children.Add(myRgbRectangle);
Canvas.SetTop(myRgbRectangle, 50);
Canvas.SetLeft(myRgbRectangle, 50);
Edit
Based on your edit, it is like I said you are adding the same rectangle more than once. You need to be creating it in your For Loop each time you add it. Something like this.
for (int i = 0; i < ElevationManager.Instance.heightData.GetLength(0); i++)
for (int j = 0; j < ElevationManager.Instance.heightData.GetLength(1); j++)
{
Rectangle rect = new Rectangle();
rect.Width = 1;
rect.Height = 1;
height = ElevationManager.Instance.heightData[i, j] / 100;
// Describes the brush's color using RGB values.
// Each value has a range of 0-255.
mySolidColorBrush.Color = Color.FromArgb(255, 0, 0, (byte)height);
rect.Fill = mySolidColorBrush;
myCanvas.Children.Add(rect);
Canvas.SetTop(rect, j);
Canvas.SetLeft(rect, i);
}
I have some WriteableBitmap object.
Lets say that the image that is actully on the WriteableBitmap object is 600x400.
I want to copy part of the image - some Rectangle ( for example Rectangle of 100x100 in the middle of the WriteableBitmap ) and paste the copy to some other image control.
How can i do it ?
I suspect you've got this fixed now, but I had the same problem and I found the answer so I thought I'd post it. The code at http://writeablebitmapex.codeplex.com/ has a "Crop" routine that does pretty much what you're after. Once you have a SizeOfArgb constant set to 4, you can use this:
public static WriteableBitmap Crop(this WriteableBitmap bmp, int x, int y, int width, int height)
{
var srcWidth = bmp.PixelWidth;
var srcHeight = bmp.PixelHeight;
// If the rectangle is completly out of the bitmap
if (x > srcWidth || y > srcHeight)
{
return new WriteableBitmap(0, 0);
}
// Clamp to boundaries
if (x < 0) x = 0;
if (x + width > srcWidth) width = srcWidth - x;
if (y < 0) y = 0;
if (y + height > srcHeight) height = srcHeight - y;
// Copy the pixels line by line using fast BlockCopy
var result = new WriteableBitmap(width, height);
for (var line = 0; line < height; line++)
{
var srcOff = ((y + line) * srcWidth + x) * SizeOfArgb;
var dstOff = line * width * SizeOfArgb;
Buffer.BlockCopy(bmp.Pixels, srcOff, result.Pixels, dstOff, width * SizeOfArgb);
}
return result;
}
public static BitmapSource Crop(this BitmapSource bmp, Int32Rect rect)
{
return new CroppedBitmap(bmp, rect);
}
I have a BitmapImage instance in Silverlight, and I am trying to find a way to read the color information of each pixel in the image. How can I do this? I see that there is a CopyPixels() method on this class that writes pixel information into the array that you pass it, but I don't know how to read color information out of that array.
How can I do this?
Look for the WriteableBitmap class in Silverlight 3. This class has a member Pixels which returns the bitmap's pixel data in an array of int's.
An example with a transform. bi is an BitmapImage object.
Image img = new Image();
img.source = bi;
img.Measure(new Size(100, 100));
img.Arrange(new Rect(0, 0, 100, 100));
ScaleTransform scaleTrans = new ScaleTransform();
double scale = (double)500 / (double)Math.Max(bi.PixelHeight, bi.PixelWidth);
scaleTrans.CenterX = 0;
scaleTrans.CenterY = 0;
scaleTrans.ScaleX = scale;
scaleTrans.ScaleY = scale;
WriteableBitmap writeableBitmap = new WriteableBitmap(500, 500);
writeableBitmap.Render(img, scaleTrans);
int[] pixelData = writeableBitmap.Pixels;
This is not possible with the current Bitmap API in the currently released Silverlight 3 beta.
The Silverlight BitmapImage file does not have a CopyPixels method. Please see the MSDN documentation here.
First, you should use WritableBitmap to get pixels collection: WriteableBitmap bmp = new WriteableBitmap(bitmapImageObj);. Each pixel is represented as 32-bit integer. I have made structure, which just helps to splits integer into a four bytes (ARGB).
struct BitmapPixel
{
public byte A;
public byte R;
public byte G;
public byte B;
public BitmapPixel(int pixel)
: this(BitConverter.GetBytes(pixel))
{
}
public BitmapPixel(byte[] pixel)
: this(pixel[3], pixel[2], pixel[1], pixel[0])
{
}
public BitmapPixel(byte a, byte r, byte g, byte b)
{
this.A = a;
this.R = r;
this.G = g;
this.B = b;
}
public int ToInt32()
{
byte[] pixel = new byte[4] { this.B, this.G, this.R, this.A };
return BitConverter.ToInt32(pixel, 0);
}
}
Here is an example of how it could be used to change red value:
BitmapPixel pixel = new BitmapPixel(bmp.Pixels[0]);
pixel.R = 255;
bmp.Pixels[0] = pixel.ToInt32();
Also I would like to mention that WriteableBitmap.Pixels are in Premultiplied RGB format. This article will explain what it means. And here is how compensation done by using BitmapPixel structure:
public static void CompensateRGB(int[] pixels)
{
for (int i = 0; i < pixels.Length; i++)
{
BitmapPixel pixel = new BitmapPixel(pixels[i]);
if (pixel.A == 255 || pixel.A == 0)
continue;
if (pixel.R == 0 && pixel.G == 0 && pixel.B == 0)
{
// color is unrecoverable, get rid of this
// pixel by making it transparent
pixel.A = 0;
}
else
{
double factor = 255.0 / pixel.A;
pixel.A = 255;
pixel.R = (byte)(pixel.R * factor);
pixel.G = (byte)(pixel.G * factor);
pixel.B = (byte)(pixel.B * factor);
}
pixels[i] = pixel.ToInt32();
}
}