From 46fc472a40fdcda56edef7a858a0d6a9fb4418f2 Mon Sep 17 00:00:00 2001
From: heyarne <hi@arnes.space>
Date: Thu, 3 Jun 2021 19:27:18 +0200
Subject: [PATCH] Copy over all line-us plotting code from
 https://github.com/heyarne/line-us/tree/fa9dbf212049cbc0bef1aca868f9e329bf18a592

There was a problem with origami which should probably be solved by narrowing the focus of the git Line-us git repository
---
 src/heyarne/line_us/connection.clj     | 73 ++++++++++++++++++++++++
 src/heyarne/line_us/edge_detection.clj | 79 ++++++++++++++++++++++++++
 src/heyarne/line_us/gcode.clj          | 48 ++++++++++++++++
 src/heyarne/line_us/helpers.clj        | 34 +++++++++++
 4 files changed, 234 insertions(+)
 create mode 100644 src/heyarne/line_us/connection.clj
 create mode 100644 src/heyarne/line_us/edge_detection.clj
 create mode 100644 src/heyarne/line_us/gcode.clj
 create mode 100644 src/heyarne/line_us/helpers.clj

diff --git a/src/heyarne/line_us/connection.clj b/src/heyarne/line_us/connection.clj
new file mode 100644
index 0000000..30cb65f
--- /dev/null
+++ b/src/heyarne/line_us/connection.clj
@@ -0,0 +1,73 @@
+(ns heyarne.line-us.connection
+  (:require [clojure.java.io :as io])
+  (:import [java.net Socket]))
+
+;; https://github.com/Line-us/Line-us-Programming/blob/master/Documentation/LineUsDrawingArea.pdf
+(def drawing-area
+  {:x [800 1700]
+   :y [-900 900]
+   :z [0 1000]})
+
+(defn connect
+  [url port]
+  (Socket. url port))
+
+(defn disconnect [^Socket line-us]
+  (.close line-us))
+
+(defn read-response [^Socket line-us]
+  (let [stream (io/input-stream line-us)]
+    (loop [line []]
+      (let [c (.read stream)]
+        (case c
+          0 (when-not (empty? line)
+              (apply str (map char line)))
+          -1 (recur line)
+          (recur (conj line c)))))))
+
+(defmacro validate-coord
+  "Throws an exception when a coordinate is outside of the drawable area"
+  [coord]
+  (let [[min-v# max-v#] (get drawing-area (keyword (name coord)))]
+    `(when-not (< ~(dec min-v#) ~coord ~(inc max-v#))
+       (throw (IllegalArgumentException.
+               (str ~(name coord) " should be in range [" ~min-v# ", " ~max-v# "] but is " ~coord))))))
+
+(defn- send-command! [^Socket line-us ^String raw-cmd]
+  ;; this is basically taken from the Processing example code and the processing
+  ;; "Client" class
+  (doto (io/output-stream line-us)
+    (.write (.getBytes (str raw-cmd "\0")))
+    (.flush))
+  ;; wait for the response
+  (let [res (read-response line-us)]
+    (if-not (re-find #"^(ok|hello)" res)
+      (throw (Exception. res))
+      res)))
+
+(defn send-movement!
+  "Moves the arm to the [x y z] vector that is coord. Coordinates are validated
+  to be inside the valid drawing area."
+  [^Socket line-us [x y z :as coords]]
+  (validate-coord x)
+  (validate-coord y)
+  (validate-coord z)
+  (send-command! line-us (str "G01 X" x " Y" y " Z" z))
+  coords)
+
+(defn move-home! [^Socket line-us]
+  (send-movement! line-us [1000 1000 1000]))
+
+(defn- parse-coords [^String raw-coords]
+  (->>
+   (re-find #"X:(-?\d+) Y:(\d+) Z:(\d+)" raw-coords)
+   (rest)
+   (mapv #(Integer/parseInt % 10))))
+
+(defn move-up! [^Socket line-us]
+  (let [[x y _] (parse-coords (send-command! line-us "M114"))]
+    (send-movement! line-us [x y 1000])))
+
+(defn move-down! [^Socket line-us]
+  (let [[x y _] (parse-coords (send-command! line-us "M114"))]
+    (send-movement! line-us [x y 200])))
diff --git a/src/heyarne/line_us/edge_detection.clj b/src/heyarne/line_us/edge_detection.clj
new file mode 100644
index 0000000..54657a3
--- /dev/null
+++ b/src/heyarne/line_us/edge_detection.clj
@@ -0,0 +1,79 @@
+(ns heyarne.line-us.edge-detection
+  (:require [clojure.set :as set]
+            [opencv4.core :as cv]
+            [opencv4.colors.rgb :as rgb]
+            [opencv4.utils :as u])
+  (:import [org.opencv.core Point Rect]))
+
+(def img (-> (u/mat-from-url "https://raw.githubusercontent.com/hellonico/origami/master/doc/cat_in_bowl.jpeg")
+             (cv/cvt-color! cv/COLOR_RGB2GRAY)
+             (u/resize-by 0.2)
+             (cv/canny! 300.0 100.0 3 true)
+             (cv/bitwise-not!))) ;; NOTE: The bitwise-not! here is not actually needed
+
+(defn pixels
+  "Returns a vector of
+   - all pixels in an org.opencv.core.Mat as a byte-array
+   - width
+   - height"
+  [mat]
+  (let [out (byte-array (* (.total mat) (.channels mat)))]
+    (.get mat 0 0 out)
+    [out (.cols mat) (.rows mat)]))
+
+(defn neighborhood [pixels width height x y]
+  (for [y-off [-1 0 1]
+        x-off [-1 0 1]
+        :let [y' (+ y y-off)
+              x' (+ x x-off)]
+        :when (and (< -1 x' width)
+                   (< -1 y' height)
+                   (not= y-off x-off 0))]
+    [[x' y'] (nth pixels (+ x' (* y' width)))]))
+
+(def shape? zero?)
+
+(defn next-connection
+  "Returns the first neighbor of a pixel that's part of the same shape"
+  [pixels width height contour coord]
+  (let [neighbors (apply neighborhood pixels width height coord)]
+    (reduce (fn [_ [neighbor-coord v]]
+              (when (and (shape? v)
+                         (not (contour neighbor-coord)))
+                (reduced neighbor-coord))) neighbors)))
+
+(defn next-start [contour-pixels found-contours]
+  (first (remove (apply set/union found-contours) contour-pixels)))
+
+(defn radial-sweep
+  "Returns a seq of sets, where each set represents one stroke / contour"
+  [mat]
+  (let [[pixels width height] (pixels mat)
+        contour-pixels (for [idx (range (.total mat))
+                             :when (shape? (nth pixels idx))]
+                         [(rem idx width) (quot idx width)])
+        start (first contour-pixels)]
+    (loop [coord start
+           contour #{start}
+           found-contours []]
+      (let [next (next-connection pixels width height contour coord)]
+        (if (nil? next)
+          contour
+          ;; we're continuing with our current contour
+          (recur next (conj contour next) found-contours))))))
+
+(defn draw-coords! [mat [x y]]
+  (cv/circle mat (cv/new-point x y) 1 rgb/green 0 cv/LINE_AA)
+  mat)
+
+
+(comment
+  (u/show img)
+
+  (radial-sweep img)
+
+  (let [out (-> (cv/clone img)
+                (cv/cvt-color! cv/COLOR_GRAY2RGB))]
+    (doseq [xy (radial-sweep img)]
+      (draw-coords! out xy))
+    (u/show out {:frame {:width (.cols out) :height (.rows out)}})))
diff --git a/src/heyarne/line_us/gcode.clj b/src/heyarne/line_us/gcode.clj
new file mode 100644
index 0000000..413a35e
--- /dev/null
+++ b/src/heyarne/line_us/gcode.clj
@@ -0,0 +1,48 @@
+(ns heyarne.line-us.gcode
+  "Provides functions to move from geometry types provided by thi.ng to gcode
+  so you can plot them."
+  (:require [thi.ng.geom.core :as g])
+  (:import [thi.ng.geom.types Line2 LineStrip2 Circle2]))
+
+(defprotocol GCode
+  "Convert thi.ng.geom types into sequences of GCode to plot them. The GCode
+  instructions are given as a sequence of vectors, where each vector is given
+  as [x y z]."
+  (->gcode [_] [_ r]
+    "Returns G01 movements on the x, y, and z axis. Z is constantly 1000 in the
+     current implementation, but this might change in the future. The optional
+     parameter `r` can be used to adjust the resolution."))
+
+(defn- point-seq->gcode [pts]
+  (let [vertices pts
+        [l-x l-y] (last vertices)]
+    (conj (mapv (fn [[x y]]
+                  [x y 0]) vertices)
+          [l-x l-y 1000])))
+
+(defn gcode-seq->str [gcode-seq]
+  (map (fn [[x y z]]
+         (str "G01 X" x " Y" y " Z" z)) gcode-seq))
+
+(extend-protocol GCode
+  Line2
+  (->gcode
+    ([_] (point-seq->gcode (:points _)))
+    ([_ r] (->gcode _)))
+
+  LineStrip2
+  (->gcode
+    ([_] (point-seq->gcode (:points _)))
+    ([_ r] (->gcode _)))
+
+  Circle2
+  (->gcode
+    ([_] (point-seq->gcode (:points (g/as-polygon _))))
+    ([_ r] (point-seq->gcode (:points (g/as-polygon _))))))
+
+(comment
+  (require '[thi.ng.geom.circle :as c])
+
+  (->
+   (->gcode (c/circle))
+   (gcode-seq->str)))
diff --git a/src/heyarne/line_us/helpers.clj b/src/heyarne/line_us/helpers.clj
new file mode 100644
index 0000000..0ad2376
--- /dev/null
+++ b/src/heyarne/line_us/helpers.clj
@@ -0,0 +1,34 @@
+(ns heyarne.line-us.helpers
+  (:require [thi.ng.geom.rect :as rect]
+            [thi.ng.math.core :as m]))
+
+(defn g01-bounds
+  "Returns a rect representing the drawing bounds of a sequence of g01 coords"
+  [g01]
+  (let [bounds [Double/MAX_VALUE Double/MIN_VALUE Double/MIN_VALUE Double/MAX_VALUE]
+        [top right bottom left] (reduce (fn [[top right bottom left] [x y _]]
+                                          [(min top y) (max right x)
+                                           (max bottom y) (min left x)])
+                                        bounds
+                                        g01)]
+    (rect/rect [left bottom] [right top])))
+
+(defn rescale
+  "Returns a new g01 sequence that is proportionally scaled to fit into the
+  bounding box passed in as the second argument. Assumes that the top left
+  in g01-seq is at [0 0]."
+  [g01-seq [top right bottom left]]
+  (let [s-bounds (g01-bounds g01-seq)
+        t-bounds (rect/rect [left bottom] [right top])
+        ;; we need to translate the bounding box
+        [translate-x translate-y] (m/+ (:p s-bounds) (:p t-bounds))
+        ;; and scale it
+        [s-x s-y] (:p s-bounds)
+        [t-x t-y] (:p t-bounds)
+        [s-width s-height] (:size s-bounds)
+        [t-width t-height] (:size t-bounds)
+        factor (min (/ (+ t-x t-width) (+ s-x s-width)) (/ (+ t-y t-height) (+ s-y s-height)))]
+    (map (fn [coord]
+           (-> (update coord 0 #(+ translate-x (* % factor)))
+               (update 1 #(+ translate-y (* % factor)))))
+         g01-seq)))