From d23bd71b7ad53ef8c19947986a63b77993ff99d7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A1n=20D=C3=A9nes?= <mr@zealot.hu>
Date: Sun, 27 Feb 2022 13:44:24 +0100
Subject: [PATCH] Support orient/rotate towards other points

---
 roadmap.md          | 11 ++++++-----
 src/anchor.js       | 27 +++++++++++++++++----------
 src/point.js        |  6 ++++++
 test/unit/anchor.js | 10 ++++++++++
 4 files changed, 39 insertions(+), 15 deletions(-)

diff --git a/roadmap.md b/roadmap.md
index e2fa5a9..547f0ad 100644
--- a/roadmap.md
+++ b/roadmap.md
@@ -6,20 +6,20 @@
 
 ### Major
 
-- Anchor overhaul
-    - Recursive-ize anchors
-        - This will potentially cause `ref` to be ambiguous, so maybe introduce a separate `refs` plural?
-    - Add `orient`/`rotate` **towards** other anchors (again, recursively)
 - Restructure pcb point/footprint filtering
     - Use the same `what`/`where` infrastructure as outlines
     - Collapse params/nets/anchors into a single hierarchy from the user's POV
     - Add per-footprint mirror support
     - Add some way for footprints to be able to "resist" the mirroring-related special treatment of negative X shift, rotation, etc.
 - Add auto-bind
-- Merge, generalize, and uniform-ize footprints
+- Merge, generalize, uniform-ize and externalize footprints!
+    - Separate npm package for dependency, onnx-like incremental opset versioning
     - Template for creating them, built-in variables they can use, documentation, external links, etc.
     - Also considering how (or, on which layer) they define their silks, universal mirroring behaviour, etc.
     - Rename class to designator in this context (https://en.wikipedia.org/wiki/Reference_designator#Designators)
+    - Include raw kicad footprint integrations
+        - pull torik's script to be able to convert raw kicad footprints into positionable ergogen ones
+        - have a `dummy` footprint which can just be updated from schematic
 
 ### Minor
 
@@ -49,6 +49,7 @@
 
 ### Patch
 
+- Prevent double mirroring (see discord "mirror_mirror_")
 - Check unexpected keys at top level, too
 - Better error handling for the fillet option?
 - Integration and end2end tests to get coverage to 100%
diff --git a/src/anchor.js b/src/anchor.js
index 031b50b..0d5ae4d 100644
--- a/src/anchor.js
+++ b/src/anchor.js
@@ -91,12 +91,23 @@ const anchor = exports.parse = (raw, name, points={}, default_point=new Point(),
     // Actual orient/shift/rotate/affect handling
     //
 
+    const rotator = (config, name, point) => {
+        // simple case: number gets added to point rotation
+        if (a.type(config)(units) == 'number') {
+            let angle = a.sane(config, name, 'number')(units)
+            if (point.meta.mirrored) {
+                angle = -angle
+            }
+            point.r += angle
+        // recursive case: points turns "towards" target anchor
+        } else {
+            const target = anchor(config, name, points, default_point, mirror)(units)
+            point.r = point.angle(target)
+        }
+    }
+
     if (raw.orient !== undefined) {
-        let angle = a.sane(raw.orient, `${name}.orient`, 'number')(units)
-        if (point.meta.mirrored) {
-            angle = -angle
-        } 
-        point.r += angle
+        rotator(raw.orient, `${name}.orient`, point)
     }
     if (raw.shift !== undefined) {
         let xyval = a.wh(raw.shift, `${name}.shift`)(units)
@@ -106,11 +117,7 @@ const anchor = exports.parse = (raw, name, points={}, default_point=new Point(),
         point.shift(xyval, true)
     }
     if (raw.rotate !== undefined) {
-        let angle = a.sane(raw.rotate, `${name}.rotate`, 'number')(units)
-        if (point.meta.mirrored) {
-            angle = -angle
-        } 
-        point.r += angle
+        rotator(raw.rotate, `${name}.rotate`, point)
     }
     if (raw.affect !== undefined) {
         const candidate = point.clone()
diff --git a/src/point.js b/src/point.js
index b86d48d..9e32b7c 100644
--- a/src/point.js
+++ b/src/point.js
@@ -66,4 +66,10 @@ module.exports = class Point {
         let rect = u.rect(size, size, [-size/2, -size/2])
         return this.position(rect)
     }
+
+    angle(other) {
+        const dx = other.x - this.x
+        const dy = other.y - this.y
+        return -Math.atan2(dx, dy) * (180 / Math.PI)
+    }
 }
diff --git a/test/unit/anchor.js b/test/unit/anchor.js
index 0cde3ee..135ad2a 100644
--- a/test/unit/anchor.js
+++ b/test/unit/anchor.js
@@ -83,6 +83,11 @@ describe('Anchor', function() {
             parse({orient: -90, shift: [0, 1]}, 'name')(),
             [1, 0, -90, {}]
         )
+        // orient towards another point (and then move a diagonal to get to [1, 1])
+        check(
+            parse({orient: 'ten', shift: [0, Math.SQRT2]}, 'name', points)(),
+            [1, 1, -45, {}]
+        )
     })
 
     it('rotate', function() {
@@ -97,6 +102,11 @@ describe('Anchor', function() {
             parse({shift: [0, 1], rotate: -90}, 'name')(),
             [0, 1, -90, {}]
         )
+        // rotate towards another point
+        check(
+            parse({rotate: {shift: [-1, -1]}}, 'name')(),
+            [0, 0, 135, {}]
+        )
     })
 
     it('affect', function() {