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Git diff for Kicad PCB layouts
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| #!/bin/bash | |
| # | |
| # kicad-diff-pcb -- Git diff for Kicad PCB layouts | |
| # 22 Jul 2025 - @todbot / Tod Kurt | |
| # | |
| # Install steps: | |
| # 1. Make sure `kicad-cli` is in your PATH | |
| # 2. Save this file somewhere in your PATH, I prefer "~/bin" | |
| # 3. Make this script executable: "chmod +x kicad-diff-pcb" | |
| # 4. Add the following to your ~/.gitconfig | |
| # | |
| # [difftool "diff-kicad-pcb"] | |
| # cmd = ~/bin/diff-kicad-pcb $LOCAL $REMOTE | |
| # [alias] | |
| # diff-kicad-pcb = "difftool -t diff-kicad-pcb" | |
| # | |
| # Usage: | |
| # git diff-kicad-pcb <git-commit-hash> mypcb.kicad_pcb | |
| # | |
| # | |
| # Takes ideas from: | |
| # from: https://forum.kicad.info/t/pcb-diff-with-custom-tool-and-kicad-cli/46664 | |
| # | |
| set -euo pipefail | |
| TEMPDIR=$(mktemp -d) | |
| TEMPSVG1="$TEMPDIR/pcb1.svg" | |
| TEMPSVG2="$TEMPDIR/pcb2.svg" | |
| TEMPHTML="$TEMPDIR/diff-kicad-pcb-viewer.html" | |
| # command used to a URL | |
| OPENCMD="open" # MacOS to open an HTML file in a web browser | |
| # try to autoconfigure what other OSes do | |
| unameS="$(uname -s)" | |
| if [[ "$unameS" == "Linux" ]]; then | |
| OPENCMD="xdg-open" | |
| elif [[ "$unameS" == "Windows" ]]; then | |
| OPENCMD="explorer.exe" | |
| fi | |
| generate_svg() { | |
| INPUT=$1 | |
| OUTPUT=$2 | |
| kicad-cli pcb export svg --mode-single --exclude-drawing-sheet --page-size-mode 0 \ | |
| -l "B.Cu,F.Cu,B.Silkscreen,F.Silkscreen,Edge.Cuts,B.Mask,F.Mask" \ | |
| -o $OUTPUT $INPUT | |
| } | |
| generate_html() { | |
| cat <<EOF | |
| <!doctype html> | |
| <html> | |
| <head> | |
| <style> | |
| body { | |
| font-family: Arial; | |
| } | |
| .svg-container { | |
| position: relative; | |
| width: 1000px; | |
| height: 1000px; | |
| } | |
| .svg-container div { | |
| position: absolute; | |
| inset: 0; | |
| object-fit: cover; /* to maintain aspect ratio */ | |
| } | |
| #img1 { | |
| z-index: 1; | |
| } | |
| #img2 { | |
| z-index: 2; | |
| background: white; | |
| -webkit-mask-image: linear-gradient(to right,transparent 50%,#fff 0%); | |
| -webkit-mask-size: 210%; | |
| -webkit-mask-position: 0; | |
| animation: slideIn 2s ease-in-out infinite alternate; | |
| } | |
| @keyframes slideIn { | |
| to { | |
| -webkit-mask-position: 100%;; | |
| } | |
| } | |
| </style> | |
| </head> | |
| <body> | |
| <h1>PCB diff</h1> | |
| <div class="svg-container" id="container"> | |
| <div id="img1"><b>old:</b><img id="svg1" src="$1" /></div> | |
| <div id="img2"><b>new:</b><img id="svg2" src="$2" /></div> | |
| </div> | |
| </body> | |
| </html> | |
| EOF | |
| } | |
| generate_svg $1 $TEMPSVG1 | |
| generate_svg $2 $TEMPSVG2 | |
| html=$(generate_html $TEMPSVG1 $TEMPSVG2) | |
| echo $html > $TEMPHTML | |
| echo "opening viewer page '$TEMPHTML'" | |
| $OPENCMD "$TEMPHTML" |
Note: updated to use CSS animations and not need mouse clicks. It now auto-animates.
Can also use this without editing .gitconfig with something like:
git difftool b5fe1a3c1f32584b7e0cd15fd699b884e30ec378 eight_by_qtpy.kicad_pcb --extcmd 'diff-kicad-pcb'
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Demo of the script above:
diff-kicad-pcb-demo-23Jul2025.mp4