Drawing Triangles, Pentagons, Stars, etc. Plugin: 2007-02-09

[BoltBait]

I needed to draw a pentagon, but Paint.NET didn't have a tool to do that. I don't have a way to create tools, so I did the next best thing--I wrote a Codelab script.

Here are some examples of what you can create with this filter:

If you like it, you can download the precompiled effect here: BoltBait's Plugin Pack

Visit this site to see step-by-step instructions how to actually use the script: http://boltbait.googlepages.com/shapes

Here is the updated Codelab script: (For you script writers... it is one of the weirdest scripts you'll ever see. Why? Because the rendering loop doesn't seem to do anything!):

void Render(Surface dst, Surface src, Rectangle rect) 
{ 
    int rpercent = 95;        // percent of radius (1-100), default 100, slider 
    int verticies = 5;        // number of points (3-10?), default 5, slider 
    int rotation = 15;        // degrees to rotate the shape (0-359), default 0, slider 
    int stars = 1;            // 1=normal, 2=stars (integer, range 1 to less than verticies/2)

    PdnRegion selectionRegion = EnvironmentParameters.GetSelection(src.Bounds); 
    Rectangle selection = this.EnvironmentParameters.GetSelection(src.Bounds).GetBoundsInt(); 

    // Because I have to reset the destination every time 
    // this is reeeeeaaaaallllly slow 
    for(int y = rect.Top; y < rect.Bottom; y++) 
    { 
        for (int x = rect.Left; x < rect.Right; x++) 
        { 
            if (selectionRegion.IsVisible(x, y)) 
            { 
                dst[x,y] = src[x,y]; 
            } 
        } 
    } 

    // If this was a tool, this is where the starting nub is located 
    long CenterX = (long)(((selection.Right - selection.Left) / 2)+selection.Left); 
    long CenterY = (long)(((selection.Bottom - selection.Top) / 2)+selection.Top); 

    // calculate actual radius 
    // If this was a tool, you should calculate this from the second nub location 
    double r = (double)(Math.Min(CenterX-selection.Left,CenterY-selection.Top)/100.0*rpercent); 

    ColorBgra PrimaryColor = (ColorBgra)EnvironmentParameters.PrimaryColor; // for 2.72 use  .ForeColor;

    ColorBgra CurrentPixel; 
    double th = 360.0/verticies; 
    double X1 = 0, Y1 = 0, X2 = 0, Y2 = 0; 
    double angle = 0; 

    for (int P = 0; P<=verticies; P++) 
    { 
        // Find the starting point (X1,Y1) 
        angle = Math.PI * ((th * P) + rotation) / 180.0; 
        X1 = (r * Math.Cos(angle)) + CenterX; 
        Y1 = (r * Math.Sin(angle)) + CenterY;
        // Find next end point (X2,Y2) 
        angle = Math.PI * ((th * (P+stars)) + rotation) / 180.0; 
        X2 = (r * Math.Cos(angle)) + CenterX; 
        Y2 = (r * Math.Sin(angle)) + CenterY; 
        // Draw line from (X1,Y1) to (X2,Y2) 
        DrawLine((int)X1,(int)Y1,(int)X2,(int)Y2, dst, PrimaryColor, selectionRegion); 
    } 
} 

void DrawLine(int x1, int y1, int x2, int y2, Surface dst, ColorBgra LineColor, PdnRegion selectionRegion) 
{ 
   int i,gd,gm; 
   double roundx,roundy,xi,yi,dx,dy,x,y,l; 

   dx=x2-x1; 
   dy=y2-y1; 

   if(Math.Abs(dx)>Math.Abs(dy)) 
   { 
      l=dx; 
   } 
   else 
   { 
      l=dy; 
   } 

   if (l<0) 
   { 
      DrawLine(x2,y2,x1,y1,dst,LineColor,selectionRegion); 
   } 
   else 
   { 
      xi=dx/l; 
      yi=dy/l; 

      x=x1; 
      y=y1; 

      if (selectionRegion.IsVisible((int)x, (int)y)) 
      { 
         dst[(int)x, (int)y] = LineColor; 
      } 

      for(i=1;i<=l;i++) 
      { 
         x=x+xi; 
         y=y+yi; 

         roundx=x+0.5; 
         roundy=y+0.5; 
         if (selectionRegion.IsVisible((int)roundx, (int)roundy)) 
         { 
            dst[(int)roundx, (int)roundy] = LineColor; 
         } 
      } 
   } 
} 

Here are some examples of stars you can create:

Now I want to see what you can do with it!

Source Code

Since you asked, here is the VS2005 souce code: PolygonSRC.zip (Ignore the fact that I misspelled the project name. )
This should serve as a good example of how to use GDI+ drawing commands on the canvas.
This should also serve as a good example of how to use this template.

[Picc84]

Awesome! I'am going to creat 190371905717509 side figures! Thanks, no, realy though, awesome idea!

[BoltBait]

Thanks, but after 360 sides or so it just becomes a circle.

[MadJik]

Hi

I have got an error line 43:

 ColorBgra PrimaryColor = (ColorBgra)EnvironmentParameters.PrimaryColor; 

PrimaryColor isn't recognize (paint 2.72!)

I change it to

ColorBgra PrimaryColor = (ColorBgra) 0;

for the tests.

Try this code to have stars:

void Render(Surface dst, Surface src, Rectangle rect) 
{
   int rpercent = 95;        // percent of radius (1-100), default 100, slider 
   int verticies = 5;        // number of points (3-10?), default 5, slider 
   int rotation = 0;        // degrees to rotate the shape (0-359), default 0, slider 
   double angfact = 2;          // angle factor to draw crossing lines, default 1, slider 

   PdnRegion selectionRegion = EnvironmentParameters.GetSelection(src.Bounds); 
   Rectangle selection = this.EnvironmentParameters.GetSelection(src.Bounds).GetBoundsInt(); 

   // Because I have to reset the destination every time 
   // this is reeeeeaaaaallllly slow 
   for(int y = rect.Top; y < rect.Bottom; y++) 
   { 
       for (int x = rect.Left; x < rect.Right; x++) 
       { 
           if (selectionRegion.IsVisible(x, y)) 
           { 
               dst[x,y] = src[x,y]; 
           } 
       } 
   } 

   // If this was a tool, this is where the starting nub is located 
   long CenterX = (long)(((selection.Right - selection.Left) / 2)+selection.Left); 
   long CenterY = (long)(((selection.Bottom - selection.Top) / 2)+selection.Top); 

   // calculate actual radius 
   // If this was a tool, you should calculate this from the second nub location 
   double r = (double)(Math.Min(CenterX-selection.Left,CenterY-selection.Top)/100.0*rpercent); 

   ColorBgra PrimaryColor = (ColorBgra) 0; 

   ColorBgra CurrentPixel; 
   double th = 360.0/verticies; 
   double X1 = 0, Y1 = 0, X2 = 0, Y2 = 0; 
   double angle = 0; 

   // Find the first vertex 
   angle = Math.PI * ((th ) + rotation) / 180.0; 
   X1 = (r * Math.Cos(angle*angfact)) + CenterX; 
   Y1 = (r * Math.Sin(angle*angfact)) + CenterY; 

   for (int P = 0; P<=verticies; P++) 
   { 
       // Find next end point (X2,Y2) 
       angle = Math.PI * ((th * P) + rotation) / 180.0; 
       X2 = (r * Math.Cos(angle*angfact)) + CenterX; 
       Y2 = (r * Math.Sin(angle*angfact)) + CenterY; 

       // Draw line from (X1,Y1) to (X2,Y2) 
       DrawLine((int)X1,(int)Y1,(int)X2,(int)Y2, dst, PrimaryColor, selectionRegion); 

       // Get ready for the next line 
       X1 = X2; 
       Y1 = Y2; 
   } 
} 

void DrawLine(int x1, int y1, int x2, int y2, Surface dst, ColorBgra LineColor, PdnRegion selectionRegion) 
{ 
  int i; 
  double roundx,roundy,xi,yi,dx,dy,x,y,l; 

  dx=x2-x1; 
  dy=y2-y1; 

  if(Math.Abs(dx)>Math.Abs(dy)) 
  { 
     l=dx; 
  } 
  else 
  { 
     l=dy; 
  } 

  if (l<0) 
  { 
     DrawLine(x2,y2,x1,y1,dst,LineColor,selectionRegion); 
  } 
  else 
  { 
     xi=dx/l; 
     yi=dy/l; 

     x=x1; 
     y=y1; 

     if (selectionRegion.IsVisible((int)x, (int)y)) 
     { 
        dst[(int)x, (int)y] = LineColor; 
     } 

     for(i=1;i<=l;i++) 
     { 
        x=x+xi; 
        y=y+yi; 

        roundx=x+0.5; 
        roundy=y+0.5; 
        if (selectionRegion.IsVisible((int)roundx, (int)roundy)) 
        { 
           dst[(int)roundx, (int)roundy] = LineColor; 
        } 
     } 
  } 
} 

[MadJik]

Test also with other values :

int verticies =9; // number of points (3-10?), default 5, slider

double angfact = 4; // angle factor to draw

[trickman]

needs a UI... xP

[BoltBait]

Hi

I have got an error line 43:

 ColorBgra PrimaryColor = (ColorBgra)EnvironmentParameters.PrimaryColor; 

PrimaryColor isn't recognize (paint 2.72!)

I change it to

ColorBgra PrimaryColor = (ColorBgra) 0;

for the tests.

That's correct. Primary color is a 3.0 thing.

For 2.72, change the line to:

ColorBgra PrimaryColor = (ColorBgra)EnvironmentParameters.ForeColor;

Hey! Nice idea for creating stars. I noticed some problems with your code--it doesn't work when you choose a figure with an even number of sides and for some reason, the lines don't come out solid. I'm going to steal that idea and put it on my page. (Well, I won't steal it, per se--I'll credit you.)

[MadJik]

No problem! I'm also sharing ideas :wink:

I'm not c# users. But I know differents other programming languages so I can manage to adapt some code lab.

I was just trying to make your code working and add some ideas but I didn't test every cases to find out bugs (if any).

[BoltBait]

OK, so, taking Madjik's idea (then fixing it)...

Here is the updated Codelab script:

void Render(Surface dst, Surface src, Rectangle rect) 
{ 
   int rpercent = 95;        // percent of radius (1-100), default 100, slider 
   int verticies = 5;        // number of points (3-10?), default 5, slider 
   int rotation = 15;        // degrees to rotate the shape (0-359), default 0, slider 
   int stars = 1;            // 1=normal, 2=stars (integer, range 1 to less than verticies/2)

   PdnRegion selectionRegion = EnvironmentParameters.GetSelection(src.Bounds); 
   Rectangle selection = this.EnvironmentParameters.GetSelection(src.Bounds).GetBoundsInt(); 

   // Because I have to reset the destination every time 
   // this is reeeeeaaaaallllly slow 
   for(int y = rect.Top; y     { 
       for (int x = rect.Left; x         { 
           if (selectionRegion.IsVisible(x, y)) 
           { 
               dst[x,y] = src[x,y]; 
           } 
       } 
   } 

   // If this was a tool, this is where the starting nub is located 
   long CenterX = (long)(((selection.Right - selection.Left) / 2)+selection.Left); 
   long CenterY = (long)(((selection.Bottom - selection.Top) / 2)+selection.Top); 

   // calculate actual radius 
   // If this was a tool, you should calculate this from the second nub location 
   double r = (double)(Math.Min(CenterX-selection.Left,CenterY-selection.Top)/100.0*rpercent); 

   ColorBgra PrimaryColor = (ColorBgra)EnvironmentParameters.PrimaryColor; // for 2.72 use  .ForeColor;

   ColorBgra CurrentPixel; 
   double th = 360.0/verticies; 
   double X1 = 0, Y1 = 0, X2 = 0, Y2 = 0; 
   double angle = 0; 

   for (int P = 0; P    { 
    // Find the starting point (X1,Y1) 
       angle = Math.PI * ((th * P) + rotation) / 180.0; 
       X1 = (r * Math.Cos(angle)) + CenterX; 
       Y1 = (r * Math.Sin(angle)) + CenterY;
       // Find next end point (X2,Y2) 
       angle = Math.PI * ((th * (P+stars)) + rotation) / 180.0; 
       X2 = (r * Math.Cos(angle)) + CenterX; 
       Y2 = (r * Math.Sin(angle)) + CenterY; 
       // Draw line from (X1,Y1) to (X2,Y2) 
       DrawLine((int)X1,(int)Y1,(int)X2,(int)Y2, dst, PrimaryColor, selectionRegion); 
   } 
} 

void DrawLine(int x1, int y1, int x2, int y2, Surface dst, ColorBgra LineColor, PdnRegion selectionRegion) 
{ 
  int i,gd,gm; 
  double roundx,roundy,xi,yi,dx,dy,x,y,l; 

  dx=x2-x1; 
  dy=y2-y1; 

  if(Math.Abs(dx)>Math.Abs(dy)) 
  { 
     l=dx; 
  } 
  else 
  { 
     l=dy; 
  } 

  if (l   { 
     DrawLine(x2,y2,x1,y1,dst,LineColor,selectionRegion); 
  } 
  else 
  { 
     xi=dx/l; 
     yi=dy/l; 

     x=x1; 
     y=y1; 

     if (selectionRegion.IsVisible((int)x, (int)y)) 
     { 
        dst[(int)x, (int)y] = LineColor; 
     } 

     for(i=1;i      { 
        x=x+xi; 
        y=y+yi; 

        roundx=x+0.5; 
        roundy=y+0.5; 
        if (selectionRegion.IsVisible((int)roundx, (int)roundy)) 
        { 
           dst[(int)roundx, (int)roundy] = LineColor; 
        } 
     } 
  } 
}

Here are some examples of stars you can create:

Now, who will put a UI on this?

[jansie]

whatever happened to 'put this dll in the appropriate folder, and start using the plug-in'. all this code wearies me.

[MadJik]

whatever happened to 'put this dll in the appropriate folder, and start using the plug-in'. all this code wearies me.

So what is your question or request ? :?:

[trickman]

Madjik, you could put a dropdown box with the options "star" and "poligon". It's kinda stupid to have a 1-255 slider instead if sometimes nothing appears or appears a star or appears a poligon.

A brush width slider would also be nice.

[BoltBait]

A brush width slider would also be nice.

Problem with that^ is that the script does not support brush widths.

[MadJik]

@ Trickman:

I asked for help for GUI : result near none !

I tried to adapt sources, I found standard GUI with one, two or three sliders. That's what I used for Polygones. I could give my source as well if you want to adapt it, I will look forward to see what you'll change to make it "less stupid" !

@ boilbait:

Thanks for your answer!

[MadJik]

Some more explanation about "starisation" with the Polygone Effect:

Let's start with a simple one : Vertice = 7 / Stars = 1.

When drawing the polygone the line simply goes from point 0 (not shown, sorry) to point 1 to point 2 etc...

If then we change stars to 2:

The line will skip one point. The line goes from point 0 to point 2 to point 4 etc...

Then we have crossing lines that are drawing a star.

If then we change stars to 3:

The line will skip two points. The line goes from point 0 to point 3 to point 6 etc...

Then the star looks fine.

If then we change stars to 4:

The line will skip three points. The line goes from point 0 to point 4 to point 1 etc...

Then the star looks exactly as the previous one (stars=3) but it is drawn the other way.

If then we change stars to 5 then the star should look as stars=2 but it is drawn the other way.

If then we change stars to 6 then the star should look as stars=1 but it is drawn the other way.

And finaly if we set stars to 7 then all lines are going from point 0 to point 0 so we have a spot.

To have some kind of stickers you should draw a star with a lot of vertices like this example (vertice=29 stars=9)

With the magic wand select outside the star and invert the selection by Ctrl+I then use the gradient effect to fill it.

[TinSoldier]

That looks cool! I'll have to download it.

[Doctor]

Wow, this is a pretty cool plug-in. I was just messing around, and I got this:

Image host by http://imageshack.us

[BoltBait]

==> to BoltBait :

Could you change the topic title (Codelab + Plugin...)?

Sorry, this is not possible. The subject line has a limited length. This would make it too long.

[mastermind7373]

You could call it "Polygon and Theta Curves Plugin(Codelab)".

[Illnab1024]

Theta Curves isn't a term known by the "general population"

Imagine:

wtf are theta curves?!?!

[Picc84]

I can see it. Yea, people will be drawn away by the "technical" name, (well, the people that dont understand it)

[MadJik]

Could I call it Madjik's curves plugins?

[Rick Brewster]

Yes but when people think "Curves" w.r.t. image editing software, they think of this: http://www.getpaint.net/doc/3.0/en/Curves.html . Maybe replace the word "curves" with "shapes."

[frantastic]

Lol, i wish i knew how to use the

codelab.!

[BoltBait]

MadJik, could you send me the source code to the Polygon effect? I would like to look at it.

Also, I've been thinking a lot about effect submenus. I think that anything that creates something new (like drawing shapes) should be in a submenu called "Render".

Here is how I group the effects that I have written:

http://boltbait.googlepages.com/