Use PowerShell instead of ImageMagick for AppVeyor build

appveyor.yml

@@ -41,7 +41,6 @@ for:
       choco install ActivePerl
       choco install nasm
       choco install jom
-      choco install imagemagick.tool --version 7.0.11.13
       choco install wixtoolset --version 3.11.2
 
       Remove-Item -Path (Join-Path $Env:SystemDrive OpenSSL-Win32) -Recurse

dist/msi/ConvertTo-Icon.ps1

@@ -0,0 +1,73 @@
+$ErrorActionPreference = 'Stop'
+
+# Adapted from: https://gist.github.com/darkfall/1656050
+
+Add-Type -AssemblyName System.Drawing
+
+$outputFileName = $args[0]
+$inputFileNames = $args[1..$args.Count]
+
+$inputImages = [System.Collections.ArrayList]@()
+
+foreach ($inputFileName in $inputFileNames) {
+    $resolvedInputFileName = $ExecutionContext.SessionState.Path.GetResolvedPSPathFromPSPath($inputFileName)
+    Write-Output "Input[$($inputImages.Count)]: $inputFileName ($resolvedInputFileName)"
+
+    $inputBitmap = New-Object System.Drawing.Bitmap "$resolvedInputFileName"
+    if ($inputBitmap.Width -ne $inputBitmap.Height) {
+        throw "Input image is not square ($($inputBitmap.Width) != $($inputBitmap.Height))"
+    }
+
+    $inputStream = New-Object System.IO.MemoryStream
+    $inputBitmap.Save($inputStream, [System.Drawing.Imaging.ImageFormat]::Png)
+
+    $inputImage = @{
+        Size = $inputBitmap.Width
+        Bytes = $inputStream.ToArray()
+    }
+    Write-Output "  Size = $($inputImage.Size), Bytes = $($inputImage.Bytes.Count)"
+
+    [void]$inputImages.Add($inputImage)
+
+    $inputBitmap.Dispose()
+    $inputStream.Dispose()
+}
+
+$resolvedOutputFileName = $ExecutionContext.SessionState.Path.GetUnresolvedProviderPathFromPSPath($outputFileName)
+Write-Output "Output: $outputFileName ($resolvedOutputFileName)"
+
+$outputFile = [System.IO.File]::Create($resolvedOutputFileName)
+
+$outputFileWriter = New-Object System.IO.BinaryWriter($outputFile)
+$outputFileWriter.Write([short]0) # 0-1 reserved, 0
+$outputFileWriter.Write([short]1) # 2-3 image type, 1 = icon, 2 = cursor
+$outputFileWriter.Write([short]$inputImages.Count) # 4-5 number of images
+
+$offset = 6 + (16 * $inputImages.Count)
+
+for ($i = 0; $i -lt $inputImages.Count; ++$i) {
+    $size = $inputImages[$i].Size
+    if ($size -eq 256) {
+        $size = 0
+    }
+
+    $outputFileWriter.Write([byte]$size) # 0 image width
+    $outputFileWriter.Write([byte]$size) # 1 image height
+    $outputFileWriter.Write([byte]0) # 2 number of colors
+    $outputFileWriter.Write([byte]0) # 3 reserved
+    $outputFileWriter.Write([short]0) # 4-5 color planes
+    $outputFileWriter.Write([short]32) # 6-7 bits per pixel
+    $outputFileWriter.Write([int]$inputImages[$i].Bytes.Count) # 8-11 size of image data
+    $outputFileWriter.Write([int]$offset) # 12-15 offset of image data
+
+    $offset += $inputImages[$i].Bytes.Count
+}
+
+for ($i = 0; $i -lt $inputImages.Count; ++$i) {
+    # write image data
+    # png data must contain the whole png data file
+    $outputFileWriter.Write($inputImages[$i].Bytes)
+}
+
+$outputFileWriter.Flush()
+$outputFile.Close()

dist/msi/UtilityFunctions.cmake

@@ -44,10 +44,22 @@ function(png2ico OUTPUT_FILE)
         set(OUTPUT_FILE "${CMAKE_CURRENT_BINARY_DIR}/${OUTPUT_FILE}")
     endif()
 
-    add_custom_command(
-        OUTPUT "${OUTPUT_FILE}"
-        COMMAND magick convert ${ARGN} "${OUTPUT_FILE}"
-        DEPENDS ${ARGN})
+    find_program(MAGICK_PROGRAM magick)
+    find_program(PWSH_PROGRAM pwsh powershell)
+
+    if(MAGICK_PROGRAM)
+        add_custom_command(
+            OUTPUT "${OUTPUT_FILE}"
+            COMMAND "${MAGICK_PROGRAM}" convert ${ARGN} "${OUTPUT_FILE}"
+            DEPENDS ${ARGN})
+    elseif(PWSH_PROGRAM)
+        add_custom_command(
+            OUTPUT "${OUTPUT_FILE}"
+            COMMAND "${PWSH_PROGRAM}" -Command "${CMAKE_CURRENT_LIST_DIR}/ConvertTo-Icon.ps1" "${OUTPUT_FILE}" ${ARGN}
+            DEPENDS ${ARGN})
+    else()
+        message(FATAL_ERROR "Unable to convert PNGs to ICO (no suitable program found)")
+    endif()
 
     list(APPEND ${OUTPUT_VAR} "${OUTPUT_FILE}")
     set(${OUTPUT_VAR} "${${OUTPUT_VAR}}" PARENT_SCOPE)