New suggestion for arrow drawing in Paint

activity.olpc4170

In the paint activity's shape tool we were able to make only horizontal arrows,
so now we have modified the arrow tool which will now make arrows in all
directions.

1 files changed, 22 insertions, 9 deletions

diff --git a/Desenho.py b/Desenho.py
index 17525e5..ec464af 100644
--- a/Desenho.py
+++ b/Desenho.py
@@ -294,18 +294,31 @@ class Desenho:
 
         x = coords[0] - widget.oldx
         y = coords[1] - widget.oldy
-        points = [(widget.oldx, widget.oldy),\
-            (widget.oldx + int(x / 6), widget.oldy + y), \
-            (widget.oldx + int(x / 6), widget.oldy + int(y / 3)), \
-            (widget.oldx + x, widget.oldy + int(y / 3)), \
-            (widget.oldx + x, widget.oldy - int(y / 3)), \
-            (widget.oldx + int(x / 6), widget.oldy - int(y / 3)),\
-            (widget.oldx + int(x / 6), widget.oldy - y)]
+        A = math.atan2(y, x)
+        dA = 2 * math.pi / 2
+        r = math.hypot(y, x)
+        m = math.sin(A)
+        p = [(widget.oldx, widget.oldy)]
+        p.append((widget.oldx + int(r * math.cos(A)),\
+                  widget.oldy + int(r * math.sin(A))))
+        p.append((widget.oldx + int(0.74 * r * math.cos(A + dA / 6)),\
+                  widget.oldy + int(0.74 * r * math.sin(A + dA / 6))))
+        p.append((widget.oldx + int(2 * r * math.cos(A + dA / 6 + dA / 20)),\
+                  widget.oldy + int(2 * r * math.sin(A + dA / 6 + dA / 20))))
+        p.append((widget.oldx +\
+                  int(2 * r * math.cos(A + dA / 6 - dA / 20 + dA / 6)),\
+                  widget.oldy +\
+                  int(2 * r * math.sin(A + dA / 6 - dA / 20 + dA / 6))))
+        p.append((widget.oldx + int(0.74 * r * math.cos(A + dA / 6 + dA / 6)),\
+                  widget.oldy + int(0.74 * r * math.sin(A + dA / 6 + dA / 6))))
+        p.append((widget.oldx + int(r * math.cos(A + dA / 2)),\
+                  widget.oldy + int(r * math.sin(A + dA / 2))))
         pixmap.draw_drawable(widget.gc, widget.pixmap, 0, 0, 0, 0,
             width, height)
+        tp = tuple(p)
         if fill == True:
-            pixmap.draw_polygon(widget.gc, True, points)
-        pixmap.draw_polygon(widget.gc_line, False, points)
+            pixmap.draw_polygon(widget.gc, True, tp)
+        pixmap.draw_polygon(widget.gc_line, False, tp)
         widget.queue_draw()
 
     def parallelogram(self, widget, coords, temp, fill):