Rainbow Plugin (09-12-2007)

[spongey437]

Still playing around with the Codelab and thought I would try to create a rainbow effect. Here is what I came up with. Run on just a blank page it will create something like this:

But my use for it was to do something like this.

Right now it just creates the rainbow as you see it here with the colors stretching vertically down the page. It works for selections as well, but only rectangular ones. It still creates something with weird shaped selections, but it is all screwed up and I cant seem to wrap my hands around how to program around it. Also, if I had more programming experience I would have liked to have set this up like a gradient tool, but at least for now it just does the rainbow.

I have set up three selection bars for Red, Green and Blue starting colors. You can create different rainbow effects by playing with the starting colors, but the default settings will give you your standard rainbow (though for some reason the size of the image can affect how far down the color scale it gets. For example on an 800x600 image it seems to stop at light blue, but for a smaller images reaches purple and even sometimes makes it back to red - which was the intent when programming it).

Here is the code in case anyone is interested.

int Amount1=255;	//[0,255]Red Start
int Amount2=0;	//[0,255]Green Start
int Amount3=0;	//[0,255]Blue Start

void Render(Surface dst, Surface src, Rectangle rect)
{
   PdnRegion selectionRegion = EnvironmentParameters.GetSelection(src.Bounds);

   // Delete any of these lines you don't need
   Rectangle selection = this.EnvironmentParameters.GetSelection(src.Bounds).GetBoundsInt();

   long CenterX = (long)(((selection.Right - selection.Left) / 2)+selection.Left);
   long CenterY = (long)(((selection.Bottom - selection.Top) / 2)+selection.Top);
   ColorBgra PrimaryColor = (ColorBgra)EnvironmentParameters.PrimaryColor;
   ColorBgra SecondaryColor = (ColorBgra)EnvironmentParameters.SecondaryColor;
   int BrushWidth = (int)EnvironmentParameters.BrushWidth;

   int l = 1;
   int p = 1530 / rect.Right;
   int r = Amount1;
   int g = Amount2;
   int b = Amount3;

   ColorBgra CurrentPixel;
   for(int y = rect.Top; y < rect.Bottom; y++)
   {
       for (int x = rect.Left; x < rect.Right; x++)
       {
           if (selectionRegion.IsVisible(x, y))
           {
               CurrentPixel = src[x,y];
               // TODO: Add pixel processing code here
               if (x == rect.Left)
               {
                   r = Amount1;
                   g = Amount2;
                   b = Amount3;
               }

               switch(l)
               {
               case 1:

                   g = g + p;
                   if (g > 255)
                   	{
                       g = 255;
                       l = 2;
                       }
                   break;                

               case 2:

                   r = r - p;
                   if (r < 0)
                   	{
                       r = 0;
                       l = 3;
                       }
                   break;                

               case 3:

                   b = b + p;
                   if (b > 255)
                   	{
                       b = 255;
                       l = 4;
                       }
                   break;

               case 4:

                   g = g - p;
                   if (g < 0)
                   	{
                       g = 0;
                       l = 5;
                       }
                   break;                

               case 5:

                   r = r + p;
                   if (r > 255)
                   	{
                       r = 255;
                       l = 6;
                       }
                   break;                

               case 6:

                   b = b - p;
                   if (b < 0)
                   	{
                       b = 0;
                       l = 1;
                       }
                   break;
               }



               // Access RGBA values this way, for example:
                  CurrentPixel.R = (byte)r;
                  CurrentPixel.G = (byte)g;
                  CurrentPixel.B = (byte)b;
               // CurrentPixel.A = (byte)PrimaryColor.A;
               dst[x,y] = CurrentPixel;
           }
       }
   }
}

Thanks to Miguel for showing me the 'switch' routine to use (which apparently runs faster than a bunch of if statements). I incorporated it into this and remembered to add an icon this time.

Let me know what you think. here is the link to the plugin http://Spongey437.googlepages.com/rainbow3.dll

[BoltBait]

This effect can already be done with this plugin:

http://boltbait.googlepages.com/Gradient.dll

Choose the ending colors for primary and secondary, then run the effect and choose the Long HSV method.

Description of this effect can be found here: viewtopic.php?t=2294

[spongey437]

This effect can already be done with this plugin:

http://boltbait.googlepages.com/Gradient.dll

Choose the ending colors for primary and secondary, then run the effect and choose the Long HSV method.

Description of this effect can be found here: viewtopic.php?t=2294

My bad. I didnt have that one and I really had thought I had downloaded all the plugins.

[barkbark00]

What we really need is a gradient plugin where we can load a PdN palette file (or xml like Curves+ and Shape 3D) which would specify the colors and the order that we want the colors blended...like a custom rainbow with all of the options from BB's gradient plugin!

Edit:

^^that's a long sentence!

[Fisherman's Friend]

My bad. I didnt have that one and I really had thought I had downloaded all the plugins.

Well, your plugin can be moved to "color" (via source). So it's useful for me as it doesn't blow up my effects menu. Thank you.

Also I don't see that another plugin which can do the same is a reason to stop sharing your work. Some people like this one, some that one. I prefer yours.

[BuzzKill]

What we really need is a gradient plugin where we can load a PdN palette file (or xml like Curves+ and Shape 3D) which would specify the colors and the order that we want the colors blended...like a custom rainbow with all of the options from BB's gradient plugin!

I second that.

[barkbark00]

I third it!

...Wait, can I even do that?

[usedHONDA]

I fourth it (if BB00 is allowed to third)!

[Mr Frojo]

I agree, but who'll code it?

[MiguelPereira]

well this one wont render in a image with high res. I'm working on a pic with 2048x1536 it wont render the rainbow

[PythonPower]

YAAAAAAAAY!! Now I can make rainbows! *huggles creator*

*glances around at other comments* You can make those arc rainbows with Gradient? How?

[Bob]

This effect can already be done with [my] plugin

Does Spongey's code looks good, dear C# Master?

[MiguelPereira]

You can make those arc rainbows with Gradient? How?

Use RectToPolar plugin

[BoltBait]

You can make those arc rainbows with Gradient? How?

Use RectToPolar plugin

...and if that doesn't work

try Effects > Distort > Polar Inversion

[Blooper]

Or tube oblique. I like BB's plug-in better, but it's no reason to not publish your work indeed.