Merge pull request #1 from bergmeister/improvment_endcolumn_andvariablecolumnheight

Improvement: finite column length and make column length variable

README.md

@@ -1,27 +1,25 @@
 # cmatrix Effect
 
-The matrix effect on windows through windows power shell
+The matrix effect on Windows through `PowerShell`
 
-![Mareix](https://github.com/matriex/cmatrix/blob/master/cmatrix.PNG "Matrix effect")
+![Matrix](demo.gif "Matrix effect")
 
 ## How to
 
-1) Open Windows Powershell with Admin Privillege
+1) Open `Windows Powershell` (in some cases Admin privilege might be needed)
 
-2) Download and save cmatrix.psm1 to desktop
+2) Either download and save [cmatrix.psm1](https://raw.githubusercontent.com/matriex/cmatrix/master/cmatrix.psm1) or just clonethis repo using `git clone https://github.com/matriex/cmatrix`
 
-3) Create a folder cmatrix on "C:\Windows\System32\WindowsPowerShell\v1.0\Modules\"
+3) Import the module, set the timeout and enable it:
+````powershell
+Set-Executionpolicy remotesigned
+Import-Module .\cmatrix
+Set-ScreenSaverTimeout -Seconds 5
+Enable-ScreenSaver
+````
 
-4) Copy cmatrix.psm1 to "C:\Windows\System32\WindowsPowerShell\v1.0\Modules\cmatrix\cmatrix.psm1"
+If you are happy with it, then you can put it also in one of your module folders that you can get via `$env:PSModulePath`. Just create a folder named `cmatrix` and put `cmatrix.psm1` in it and then the next time you can just import it as `Import-Module cmatrix` without having to specify the full path.
-
-5) Type the commands on terminal
-  
-   **set-executionpolicy remotesigned**
-   
-   **import-module cmatrix**
-   
-   **Set-screenSaverTimeout -Seconds 5**
-   
-   **Enable-ScreenSaver**
 
 _Author: Oisin Grehan_
+
+_Contributor: Christoph Bergmeister_

cmatrix.psm1

@@ -197,7 +197,8 @@ function New-Column {
  
         [int]$script:head = 1
         [int]$script:fade = 0
-        [int]$script:fadelen = [math]::Abs($ylimit / 3)
+		$randomLengthVariation = (1 + (get-random -min -30 -max 50)/100)
+        [int]$script:fadelen = [math]::Abs($ylimit / 3 * $randomLengthVariation)
        
         $script:fadelen += (get-random -min 0 -max $fadelen)
        
@@ -224,14 +225,30 @@ function New-Column {
                     & $parentModule New-BufferCell -Character `
                         ([char](get-random -min 65 -max 122)) -Fore darkgreen) > $null
 
+                # tail end
+                $tail = $fade-1
+                if ($tail -lt $ylimit) {
+                    & $parentModule Set-BufferCell $xpos ($fade-1) (
+                        & $parentModule New-BufferCell -Character `
+                        ([char](get-random -min 65 -max 122)) -Fore black) > $null
+                    }
+
                 $script:fade++
             }
 
+
             # are we done animating?
             if ($fade -lt $ylimit) {
                 return $true
             }
 
+            # remove last row from tail end
+            if (($fade - 1) -lt $ylimit) {
+                & $parentModule Set-BufferCell $xpos ($fade - 1) (
+                    & $parentModule New-BufferCell -Character `
+                    ([char]' ') -Fore black) > $null
+            }
+                       
             $false            
         }
                
@@ -243,9 +260,9 @@ function New-Column {
 function Start-ScreenSaver {
    
     # feel free to tweak maxcolumns and frame delay
-    # currently 8 columns with 50ms wait
+    # currently 20 columns with 30ms wait
    
-    Start-CMatrix -max 8 -frame 50
+    Start-CMatrix -max 20 -frame 30
 }
  
 function Register-Timer {