Merge pull request #447 from cx20/add_powershell_console_triangle_sample

Added Console Triangle by PowerShell

Author: cx20

powershell/console/triangle/Hello.ps1

@@ -0,0 +1,81 @@
+# Define a function to determine the nearest approximate ConsoleColor based on RGB values.
+function Get-NearestConsoleColor {
+    param (
+        [int]$r,
+        [int]$g,
+        [int]$b
+    )
+
+    # Define approximate RGB values for each ConsoleColor.
+    $colors = @{
+        'Black'       = @{ r = 0;   g = 0;   b = 0 }
+        'DarkBlue'    = @{ r = 0;   g = 0;   b = 128 }
+        'DarkGreen'   = @{ r = 0;   g = 128; b = 0 }
+        'DarkCyan'    = @{ r = 0;   g = 128; b = 128 }
+        'DarkRed'     = @{ r = 128; g = 0;   b = 0 }
+        'DarkMagenta' = @{ r = 128; g = 0;   b = 128 }
+        'DarkYellow'  = @{ r = 128; g = 128; b = 0 }
+        'Gray'        = @{ r = 192; g = 192; b = 192 }
+        'DarkGray'    = @{ r = 128; g = 128; b = 128 }
+        'Blue'        = @{ r = 0;   g = 0;   b = 255 }
+        'Green'       = @{ r = 0;   g = 255; b = 0 }
+        'Cyan'        = @{ r = 0;   g = 255; b = 255 }
+        'Red'         = @{ r = 255; g = 0;   b = 0 }
+        'Magenta'     = @{ r = 255; g = 0;   b = 255 }
+        'Yellow'      = @{ r = 255; g = 255; b = 0 }
+        'White'       = @{ r = 255; g = 255; b = 255 }
+    }
+
+    $bestColor = $null
+    $bestDistance = [double]::MaxValue
+
+    # Loop through each color to find the nearest match using Euclidean distance in RGB space.
+    foreach ($color in $colors.Keys) {
+        $cr = $colors[$color].r
+        $cg = $colors[$color].g
+        $cb = $colors[$color].b
+        # Calculate the Euclidean distance in RGB space.
+        $distance = [math]::Sqrt( ($r - $cr) * ($r - $cr) + ($g - $cg) * ($g - $cg) + ($b - $cb) * ($b - $cb) )
+        if ($distance -lt $bestDistance) {
+            $bestDistance = $distance
+            $bestColor = $color
+        }
+    }
+    return $bestColor
+}
+
+# Define the height of the triangle (number of rows).
+$height = 10
+
+# Output each row of the triangle.
+for ($i = 0; $i -lt $height; $i++) {
+    # Add left padding spaces to center-align the triangle.
+    $padding = " " * ($height - $i)
+    Write-Host -NoNewline $padding
+
+    # Each row will have (2*$i + 1) characters.
+    for ($j = 0; $j -lt (2 * $i + 1); $j++) {
+        # Calculate the horizontal ratio 's' for the current cell (range: 0 to 1).
+        if ($i -eq 0) {
+            $s = 0.5  # The first row has only one character, so set s to 0.5.
+        } else {
+            $s = $j / (2 * $i)
+        }
+        # Calculate the vertical ratio 't' (0 at the top, 1 at the bottom).
+        $t = $i / ($height - 1)
+
+        # Calculate each color component using simple linear interpolation:
+        # Top vertex (t=0) is Red: (255, 0, 0).
+        # Bottom-left vertex (s=0, t=1) is Blue: (0, 0, 255).
+        # Bottom-right vertex (s=1, t=1) is Green: (0, 255, 0).
+        $R = [int](255 * (1 - $t))
+        $B = [int](255 * $t * (1 - $s))
+        $G = [int](255 * $t * $s)
+
+        # Determine the nearest ConsoleColor for the calculated RGB value.
+        $consoleColor = Get-NearestConsoleColor -r $R -g $G -b $B
+
+        Write-Host "*" -ForegroundColor $consoleColor -NoNewline
+    }
+    Write-Host ""
+}

powershell/console/triangle/readme.md

@@ -0,0 +1,22 @@
+run:
+```
+C:\> PowerShell -File hello.ps1
+```
+Result:
+```
++------------------------------------------+
+|Command Prompt                   [_][~][X]|
++------------------------------------------+
+|C:\hello\powershell\console\hello> run.bat|
+|          *                               |
+|         ***                              |
+|        *****                             |
+|       *******                            |
+|      *********                           |
+|     ***********                          |
+|    *************                         |
+|   ***************                        |
+|  *****************                       |
+| *******************                      |
++------------------------------------------+
+ ```

powershell/console/triangle/run.bat

@@ -0,0 +1 @@
+powershell -file Hello.ps1