From 49c2cb985cc7148f956cd38860bf0dc6082bb551 Mon Sep 17 00:00:00 2001
From: "alonso.torres" <alonso.torres@kaleidos.net>
Date: Tue, 28 Sep 2021 15:55:28 +0200
Subject: [PATCH] :bug: Fix problems with imported svgs

---
 common/src/app/common/path/bool.cljc      | 65 ++++++++++++++---------
 common/src/app/common/path/subpaths.cljc  | 24 +++++++++
 frontend/src/app/main/ui/shapes/bool.cljs |  9 ++--
 3 files changed, 69 insertions(+), 29 deletions(-)

diff --git a/common/src/app/common/path/bool.cljc b/common/src/app/common/path/bool.cljc
index 37aef3402..649e17282 100644
--- a/common/src/app/common/path/bool.cljc
+++ b/common/src/app/common/path/bool.cljc
@@ -13,23 +13,6 @@
    [app.common.path.commands :as upc]
    [app.common.path.subpaths :as ups]))
 
-(defn- reverse-command
-  "Reverses a single command"
-  [command]
-
-  (let [{old-x :x old-y :y} (:params command)
-        {:keys [x y]} (:prev command)
-        {:keys [c1x c1y c2x c2y]} (:params command)]
-
-    (-> command
-        (assoc :prev (gpt/point old-x old-y))
-        (update :params assoc :x x :y y)
-
-        (cond-> (= :curve-to (:command command))
-          (update :params assoc
-                  :c1x c2x :c1y c2y
-                  :c2x c1x :c2y c1y)))))
-
 (defn add-previous
   ([content]
    (add-previous content nil))
@@ -43,6 +26,37 @@
                   (some? prev)
                   (assoc :prev (gsp/command->point prev))))))))
 
+(defn close-paths
+  "Removes the :close-path commands and replace them for line-to so we can calculate
+  the intersections"
+  [content]
+
+  (loop [head (first content)
+         content (rest content)
+         result []
+         last-move nil]
+
+    (if (nil? head)
+      result
+      (let [head-p (gsp/command->point head)
+            head (cond
+                   (and (= :close-path (:command head))
+                        (< (gpt/distance head-p last-move) 0.01))
+                   nil
+
+                   (= :close-path (:command head))
+                   (upc/make-line-to last-move)
+
+                   :else
+                   head)]
+
+        (recur (first content)
+               (rest content)
+               (cond-> result (some? head) (conj head))
+               (if (= :move-to (:command head))
+                 head-p
+                 last-move))))))
+
 (defn- split-command
   [cmd values]
   (case (:command cmd)
@@ -192,8 +206,6 @@
 
    ;; Reverse second content so we can have holes inside other shapes
    (->> content-b-split
-        (reverse)
-        (mapv reverse-command)
         (filter #(and (contains-segment? % content-a)
                       (not (overlap-segment? % content-a-split)))))))
 
@@ -207,10 +219,8 @@
 
 
 (defn create-exclusion [content-a content-b]
-  ;; Pick all segments but reverse content-b (so it makes an exclusion)
-  (let [content-b' (->> (reverse content-b)
-                        (mapv reverse-command))]
-    (d/concat [] content-a content-b')))
+  ;; Pick all segments
+  (d/concat [] content-a content-b))
 
 
 (defn fix-move-to
@@ -237,8 +247,13 @@
 (defn content-bool-pair
   [bool-type content-a content-b]
 
-  (let [content-a (add-previous content-a)
-        content-b (add-previous content-b)
+  (let [content-a (-> content-a (close-paths) (add-previous))
+
+        content-b (-> content-b
+                      (close-paths)
+                      (cond-> (ups/clockwise? content-b)
+                        (ups/reverse-content))
+                      (add-previous))
 
         ;; Split content in new segments in the intersection with the other path
         [content-a-split content-b-split] (content-intersect-split content-a content-b)
diff --git a/common/src/app/common/path/subpaths.cljc b/common/src/app/common/path/subpaths.cljc
index 3c4d90c68..ca92a6c30 100644
--- a/common/src/app/common/path/subpaths.cljc
+++ b/common/src/app/common/path/subpaths.cljc
@@ -158,3 +158,27 @@
        (reverse)
        (mapcat :data)
        (into [])))
+
+;; https://mathworld.wolfram.com/PolygonArea.html
+(defn clockwise?
+  "Check whether the first subpath is clockwise or counter-clock wise"
+  [content]
+  (let [subpath (->> content get-subpaths first :data)]
+    (loop [current (first subpath)
+           subpath (rest subpath)
+           first-point nil
+           signed-area 0]
+
+      (if (nil? current)
+        (> signed-area 0)
+
+        (let [{x1 :x y1 :y :as p} (upc/command->point current)
+              last? (nil? (first subpath))
+              first-point (if (nil? first-point) p first-point)
+              {x2 :x y2 :y} (if last? first-point (upc/command->point (first subpath)))
+              signed-area (+ signed-area (- (* x1 y2) (* x2 y1)))]
+
+          (recur (first subpath)
+                 (rest subpath)
+                 first-point
+                 signed-area))))))
diff --git a/frontend/src/app/main/ui/shapes/bool.cljs b/frontend/src/app/main/ui/shapes/bool.cljs
index faa3b3f99..fd9b58f94 100644
--- a/frontend/src/app/main/ui/shapes/bool.cljs
+++ b/frontend/src/app/main/ui/shapes/bool.cljs
@@ -35,8 +35,9 @@
                       (map #(get childs %))
                       (filter #(not (:hidden %)))
                       (map #(stp/convert-to-path % childs))
-                      (mapv :content)
-                      (mapv pb/add-previous))]
+                      (map :content)
+                      (map pb/close-paths)
+                      (map pb/add-previous))]
              (pb/content-intersect-split content-a content-b))))]
     [:g.debug-bool
      [:g.shape-a
@@ -49,7 +50,7 @@
                                  (dissoc :fill-color :fill-opacity)
                                  (assoc :content content-b))
                       :frame frame}]
-      (for [{:keys [x y]} (gsp/content->points content-b)]
+      (for [{:keys [x y]} (gsp/content->points (pb/close-paths content-b))]
         [:circle {:cx x
                   :cy y
                   :r 2.5
@@ -65,7 +66,7 @@
                                  (dissoc :fill-color :fill-opacity)
                                  (assoc :content content-a))
                       :frame frame}]
-      (for [{:keys [x y]} (gsp/content->points content-a)]
+      (for [{:keys [x y]} (gsp/content->points (pb/close-paths content-a))]
         [:circle {:cx x
                   :cy y
                   :r 1.25