From 84f4a381780b2b1e20eb619e85a64b94ade126dc Mon Sep 17 00:00:00 2001
From: Christopher Monsanto <chris@monsan.to>
Date: Tue, 16 Jun 2020 01:23:50 -0400
Subject: [PATCH] add tools/trim

---
 pnpm-lock.yaml          |  5 +++++
 pnpm-workspace.yaml     |  1 +
 tools/trim/image.js     | 37 +++++++++++++++++++++++++++++++++++++
 tools/trim/index.js     | 41 +++++++++++++++++++++++++++++++++++++++++
 tools/trim/package.json |  6 ++++++
 5 files changed, 90 insertions(+)
 create mode 100644 tools/trim/image.js
 create mode 100644 tools/trim/index.js
 create mode 100644 tools/trim/package.json

diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index dd307a28..286cafc6 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -17,6 +17,11 @@ importers:
       commander: ^5.0.0
       make-promises-safe: ^5.1.0
       spritesmith: ^3.4.0
+  tools/trim:
+    dependencies:
+      commander: 5.1.0
+    specifiers:
+      commander: ^5.1.0
   tools/tupctime:
     dependencies:
       better-sqlite3: 7.0.1
diff --git a/pnpm-workspace.yaml b/pnpm-workspace.yaml
index 4d5f284e..ac9570f0 100644
--- a/pnpm-workspace.yaml
+++ b/pnpm-workspace.yaml
@@ -3,3 +3,4 @@ packages:
     - 'tools/tupctime'
     - 'tools/deploy'
     - 'tools/deflopt'
+    - 'tools/trim'
diff --git a/tools/trim/image.js b/tools/trim/image.js
new file mode 100644
index 00000000..372634dd
--- /dev/null
+++ b/tools/trim/image.js
@@ -0,0 +1,37 @@
+
+import cp from 'child_process';
+
+export function getDims(input) {
+    const info = cp.execFileSync('convert', [input, '-format', "%w+%h+%@", 'info:'],
+                                 {encoding:'utf8'});
+
+    const [imageWidth, imageHeight, width, height, left, top] =
+          info.split(/x|\+/g).map(dim => parseInt(dim));
+
+    const right = imageWidth - (left + width);
+    const bottom = imageHeight - (top + height);
+
+    return {
+        width,
+        height,
+        left,
+        top,
+        right,
+        bottom
+    }
+}
+
+export function crop(input, {width, height, left, top}, output) {
+    cp.execFileSync('convert', [input, '+repage', '-crop', `${width}x${height}+${left}+${top}`, output]);
+}
+
+// Trim, preserving displacement from center
+// Returns crop coords
+export function losslessTrim(dims) {
+    return {
+        left: Math.min(dims.left, dims.right),
+        width: dims.width + Math.abs(dims.left - dims.right),
+        top: Math.min(dims.top, dims.bottom),
+        height: dims.height + Math.abs(dims.top - dims.bottom),
+    }
+}
diff --git a/tools/trim/index.js b/tools/trim/index.js
new file mode 100644
index 00000000..28997fbb
--- /dev/null
+++ b/tools/trim/index.js
@@ -0,0 +1,41 @@
+
+import program from 'commander';
+import * as image from './image.js';
+
+program
+    .option('-c, --check', 'Check only')
+    .option('-v, --verbose', 'Print info')
+    .option('-f, --force', 'Force write even when already cropped')
+    .parse(process.argv);
+
+let retVal = 0;
+
+for (const file of program.args) {
+    const dims = image.getDims(file);
+    const alreadyCropped = (dims.left === 0 || dims.right === 0) &&
+          (dims.top === 0 || dims.bottom === 0);
+
+    if (program.verbose) {
+        let msg = `${file}: ${dims.width}x${dims.height}, `;
+        if (alreadyCropped) {
+            msg += `displacement horiz ${dims.left - dims.right}, vert ${dims.top - dims.bottom}`;
+        } else {
+            msg += `padding left ${dims.left}, top ${dims.top}, right ${dims.right}, bottom ${dims.bottom}`;
+        }
+        console.log(msg);
+    }
+
+    if (program.check && !alreadyCropped) {
+        retVal = 1;
+        if (!program.verbose) {
+            break;
+        }
+    }
+        
+    if (!program.check && (!alreadyCropped || program.force)) {
+        const trimDims = image.losslessTrim(dims);
+        image.crop(file, trimDims, file);
+    }
+}
+
+process.exit(retVal);
diff --git a/tools/trim/package.json b/tools/trim/package.json
new file mode 100644
index 00000000..c47d6951
--- /dev/null
+++ b/tools/trim/package.json
@@ -0,0 +1,6 @@
+{
+    "dependencies": {
+        "commander": "^5.1.0"
+    },
+    "type": "module"
+}