From aed1b8cd26ffe7875b8961bbf2469fe4741d5a86 Mon Sep 17 00:00:00 2001
From: Andrey Antukh <niwi@niwi.nz>
Date: Tue, 20 Dec 2016 17:03:40 +0100
Subject: [PATCH] Improve matrix transformation helpers.

---
 frontend/src/uxbox/util/geom/matrix.cljs | 154 ++++++++++++++---------
 1 file changed, 96 insertions(+), 58 deletions(-)

diff --git a/frontend/src/uxbox/util/geom/matrix.cljs b/frontend/src/uxbox/util/geom/matrix.cljs
index 9306d19b21..c3586db331 100644
--- a/frontend/src/uxbox/util/geom/matrix.cljs
+++ b/frontend/src/uxbox/util/geom/matrix.cljs
@@ -44,63 +44,7 @@
     (let [[a b c d tx ty] v]
       (Matrix. a b c d tx ty))))
 
-(defn ^boolean matrix?
-  "Return true if `v` is Matrix instance."
-  [v]
-  (instance? Matrix v))
-
-(defn matrix
-  "Create a new matrix instance."
-  ([]
-   (Matrix. 1 0 0 1 0 0))
-  ([v]
-   (-matrix v))
-  ([a b c d tx ty]
-   (Matrix. a b c d tx ty)))
-
-(defn rotate
-  "Apply rotation transformation to the matrix."
-  ([m angle]
-   (let [center (gpt/point 0 0)]
-     (rotate m angle center)))
-  ([m angle center]
-   (let [angle (mth/radians angle)
-         x (:x center)
-         y (:y center)
-         cos (mth/cos angle)
-         sin (mth/sin angle)
-         nsin (- sin)
-         tx (- x (+ (* x cos)) (* y sin))
-         ty (- y (- (* x sin)) (* y cos))
-         a (+ (* cos (:a m)) (* sin (:b m)))
-         b (+ (* nsin (:a m)) (* cos (:b m)))
-         c (+ (* cos (:c m)) (* sin (:d m)))
-         d (+ (* nsin (:c m)) (* cos (:d m)))
-         tx' (+ (:tx m) (* tx (:a m)) (* ty (:b m)))
-         ty' (+ (:ty m) (* tx (:c m)) (* ty (:d m)))]
-     (Matrix. a b c d tx' ty'))))
-
-(defn scale
-  "Apply scale transformation to the matrix."
-  ([m v] (scale m v v))
-  ([m x y]
-   (assoc m
-          :a (* (:a m) x)
-          :c (* (:c m) x)
-          :b (* (:b m) y)
-          :d (* (:d m) y))))
-
-(defn translate
-  "Apply translate transformation to the matrix."
-  ([m pt]
-   (let [pt (gpt/-point pt)]
-     (assoc m
-            :tx (+ (:tx m) (* (:x pt) (:a m)) (* (:y pt) (:b m)))
-            :ty (+ (:ty m) (* (:x pt) (:c m)) (* (:y pt) (:d m))))))
-  ([m x y]
-   (translate m (gpt/point x y))))
-
-(defn append
+(defn multiply
   ([m om]
    (let [a1 (:a m)
          b1 (:b m)
@@ -122,7 +66,101 @@
       (+ tx1 (* tx2 a1) (* ty2 b1))
       (+ ty1 (* tx2 c1) (* ty2 d1)))))
   ([m om & others]
-   (reduce append (append m om) others)))
+   (reduce multiply (multiply m om) others)))
+
+(defn ^boolean matrix?
+  "Return true if `v` is Matrix instance."
+  [v]
+  (instance? Matrix v))
+
+(defn matrix
+  "Create a new matrix instance."
+  ([]
+   (Matrix. 1 0 0 1 0 0))
+  ([v]
+   (-matrix v))
+  ([a b c d tx ty]
+   (Matrix. a b c d tx ty)))
+
+(defn translate-matrix
+  ([pt]
+   (let [pt (gpt/-point pt)]
+     (Matrix. 1 0 0 1 (:x pt) (:y pt))))
+  ([x y]
+   (translate-matrix (gpt/point x y))))
+
+(defn scale-matrix
+  ([s]
+   (Matrix. s 0 0 s 0 0))
+  ([sx sy]
+   (Matrix. sx 0 0 sy 0 0)))
+
+(defn rotate-matrix
+  [a]
+  (let [a (mth/radians a)]
+    (Matrix. (mth/cos a)
+             (mth/sin a)
+             (- (mth/sin a))
+             (mth/cos a)
+             0 0)))
+
+(defn rotate
+  "Apply rotation transformation to the matrix."
+  ([m angle]
+   (multiply m (rotate-matrix angle)))
+  ([m angle center]
+   (multiply m
+           (translate-matrix center)
+           (rotate-matrix angle)
+           (translate-matrix (gpt/negate center)))))
+
+  ;; ([m angle]
+  ;;  (let [center (gpt/point 0 0)]
+  ;;    (rotate m angle center)))
+  ;; ([m angle center]
+  ;;  (let [angle (mth/radians angle)
+  ;;        x (:x center)
+  ;;        y (:y center)
+  ;;        cos (mth/cos angle)
+  ;;        sin (mth/sin angle)
+  ;;        nsin (- sin)
+  ;;        tx (- x (+ (* x cos)) (* y sin))
+  ;;        ty (- y (- (* x sin)) (* y cos))
+  ;;        a (+ (* cos (:a m)) (* sin (:b m)))
+  ;;        b (+ (* nsin (:a m)) (* cos (:b m)))
+  ;;        c (+ (* cos (:c m)) (* sin (:d m)))
+  ;;        d (+ (* nsin (:c m)) (* cos (:d m)))
+  ;;        tx' (+ (:tx m) (* tx (:a m)) (* ty (:b m)))
+  ;;        ty' (+ (:ty m) (* tx (:c m)) (* ty (:d m)))]
+  ;;    (Matrix. a b c d tx' ty'))))
+
+(defn scale
+  "Apply scale transformation to the matrix."
+  ([m v] (scale m v v))
+  ([m vx vy] (multiply m (scale-matrix vx vy))))
+
+  ;; ([m v] (scale m v v))
+  ;; ([m x y]
+  ;;  (assoc m
+  ;;         :a (* (:a m) x)
+  ;;         :c (* (:c m) x)
+  ;;         :b (* (:b m) y)
+  ;;         :d (* (:d m) y))))
+
+(defn translate
+  "Apply translate transformation to the matrix."
+  ([m pt]
+   (multiply m (translate-matrix pt)))
+  ([m x y]
+   (translate m (gpt/point x y))))
+
+  ;; ([m pt]
+  ;;  (let [pt (gpt/-point pt)]
+  ;;    (assoc m
+  ;;           :tx (+ (:tx m) (* (:x pt) (:a m)) (* (:y pt) (:b m)))
+  ;;           :ty (+ (:ty m) (* (:x pt) (:c m)) (* (:y pt) (:d m))))))
+  ;; ([m x y]
+  ;;  (translate m (gpt/point x y))))
 
 (defn ^boolean invertible?
   [{:keys [a b c d tx ty] :as m}]