From 4eedfa8b258d7f5eda684ad4335ab8c54e55f578 Mon Sep 17 00:00:00 2001
From: Quincy Morgan <quincy.morgan@icloud.com>
Date: Mon, 13 May 2019 16:28:08 -0400
Subject: [PATCH] Don't allow autofixing unsquare buildings unless they are
 already very close to square Allow autofixing buildings with tags

---
 modules/geo/index.js                |  1 +
 modules/geo/ortho.js                | 27 +++++++++++++++++++++++++++
 modules/validations/unsquare_way.js | 11 +++++++----
 3 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/modules/geo/index.js b/modules/geo/index.js
index 4d62211aa..88402d97a 100644
--- a/modules/geo/index.js
+++ b/modules/geo/index.js
@@ -45,4 +45,5 @@ export { geoVecScale } from './vector.js';
 
 export { geoOrthoNormalizedDotProduct } from './ortho.js';
 export { geoOrthoCalcScore } from './ortho.js';
+export { geoOrthoMaxOffsetAngle } from './ortho.js';
 export { geoOrthoCanOrthogonalize } from './ortho.js';
diff --git a/modules/geo/ortho.js b/modules/geo/ortho.js
index 3f6a14eca..31626d98b 100644
--- a/modules/geo/ortho.js
+++ b/modules/geo/ortho.js
@@ -45,6 +45,33 @@ export function geoOrthoCalcScore(points, isClosed, epsilon, threshold) {
     return score;
 }
 
+// returns the maximum angle less than `lessThan` between the actual corner and a 0° or 90° corner
+export function geoOrthoMaxOffsetAngle(coords, isClosed, lessThan) {
+    var max = -Infinity;
+
+    var first = isClosed ? 0 : 1;
+    var last = isClosed ? coords.length : coords.length - 1;
+
+    for (var i = first; i < last; i++) {
+        var a = coords[(i - 1 + coords.length) % coords.length];
+        var origin = coords[i];
+        var b = coords[(i + 1) % coords.length];
+        var normalizedDotP = geoOrthoNormalizedDotProduct(a, b, origin);
+
+        var angle = Math.acos(Math.abs(normalizedDotP)) * 180 / Math.PI;
+
+        if (angle > 45) angle = 90 - angle;
+
+        if (angle >= lessThan) continue;
+
+        if (angle > max) max = angle;
+    }
+
+    if (max === -Infinity) return null;
+
+    return max;
+}
+
 
 // similar to geoOrthoCalcScore, but returns quickly if there is something to do
 export function geoOrthoCanOrthogonalize(coords, isClosed, epsilon, threshold, allowStraightAngles) {
diff --git a/modules/validations/unsquare_way.js b/modules/validations/unsquare_way.js
index 1db257ae8..1450e1ce4 100644
--- a/modules/validations/unsquare_way.js
+++ b/modules/validations/unsquare_way.js
@@ -1,7 +1,7 @@
 import { t } from '../util/locale';
 import { actionChangeTags } from '../actions/change_tags';
 import { actionOrthogonalize } from '../actions/orthogonalize';
-import { geoOrthoCanOrthogonalize } from '../geo';
+import { geoOrthoCanOrthogonalize, geoOrthoMaxOffsetAngle } from '../geo/ortho';
 import { utilDisplayLabel } from '../util';
 import { validationIssue, validationIssueFix } from '../core/validation';
 
@@ -9,9 +9,10 @@ import { validationIssue, validationIssueFix } from '../core/validation';
 export function validationUnsquareWay() {
     var type = 'unsquare_way';
 
-    // use looser epsilon for detection to reduce false positives if nearly orthogonal
+    // use looser epsilon for detection to reduce warnings of buildings that are essentially square already
     var epsilon = 0.05;
     var degreeThreshold = 13;
+    var autofixDegreeThreshold = 6.5;
     var nodeThreshold = 10;
 
     function isBuilding(entity, graph) {
@@ -57,9 +58,10 @@ export function validationUnsquareWay() {
         var points = nodes.map(function(node) { return context.projection(node.loc); });
         if (!geoOrthoCanOrthogonalize(points, isClosed, epsilon, degreeThreshold, true)) return [];
 
-        // only allow autofix if there are no extra tags on the building (e.g. source) - #6288
         var autoArgs;
-        if (Object.keys(entity.tags).length === 1) {
+        // only allow autofixing features that are very close to square already
+        var maxOffsetAngle = geoOrthoMaxOffsetAngle(points, isClosed, degreeThreshold);
+        if (maxOffsetAngle && maxOffsetAngle < autofixDegreeThreshold) {
             // note: use default params for actionOrthogonalize, not relaxed epsilon
             var autoAction = actionOrthogonalize(entity.id, context.projection);
             autoAction.transitionable = false;  // when autofixing, do it instantly
@@ -75,6 +77,7 @@ export function validationUnsquareWay() {
             },
             reference: showReference,
             entityIds: [entity.id],
+            hash: JSON.stringify(autoArgs !== undefined),
             fixes: [
                 new validationIssueFix({
                     icon: 'iD-operation-orthogonalize',