Gesture Shapes Detection

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:bust_in_silhouette: Asked By pelvichan

Greetings,

I’m really stuck on this. How would you go about detecting shapes (like triangles or squares) as touch input?

I tried using arypbatista/godot-swipe-detector from the asset lib. But i really don’t know what i’m doing or even where to start.

any advice will be greatly appreciated. Thanks in advance for your time!

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:bust_in_silhouette: Reply From: SuperDIMMaX 
   if start_point.distance_to( touch_point ) > 50:  # min distance
        if start_point.angle_to( touch_point ) > rad2deg( 30 ) and < rad2deg( 90 ):
              # this is example how detect line with angle i.e. triangle

if you need fixed shapes (triangle):

triangle = 0

   if start_point.distance_to( touch_point ) > 100 and < 200:
       var angle = start_point.angle_to( touch_point )
       if triangle == 0:  # stage of triangle
           if angle  > rad2deg( 30 ) and angle < rad2deg( 70 ):
                triangle = 1
                start_point = touch_point    # this is basic mechanics
       elif triangle == 1:
           # next angle

hard to explain all variants, but, you need aprox this code.
and upgrade:
start_point = touch_point ---- in best case need: touch_points = [] and touch_points.append(touch_point)
if touch_points.back().distance_to( touch_point ) > 100:
then you need line between last 2 poins (create vector) and if angle between this vector and current touch point > 30deg. (determination error), then touch_points.append(touch_point)
Finale, when user unpress touch, need just …

if touch_points.size() == 3: # triangle
    for i in touch_points:
       #check angles

Thank you so much for answering.
I will give this a try when I get home!

pelvichan | 2019-12-21 14:24

Or another variant:
Collect all points if if touch_points.back().distanceto( touch_point ) > 50 (precision), and add to array.
then analize array points if points[“angle”].max < ~30 (max angle bitween each) - it seems to be circle…
if have 3 angles = ~60 - triangle
if 4 angles > 80 and < 100 - square
or if you need pentagram… you need have 5 angles ~36 deg each.

P.S. and check angle direction… if you have 2 angles clockwise and 2 conter and start and end point in some place - this is not square… )
and remember - check distance bitween start and and point (in some case not i.e. line or “Z”))

SuperDIMMaX | 2019-12-21 15:24

small addon: you can make check lotal length of vectors for come reason…
if shape need some size, or use for more powerfull magick cast - small triangle - typical fireball - big - more powerfull…

SuperDIMMaX | 2019-12-21 15:50

variant for curves (circle):
find in array min/max x and y point - you get square - find center, check distance bitween each point and center if min and max distance ~ equal - this is circle…
in “infinity” - need intersection in center…

SuperDIMMaX | 2019-12-21 16:01

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