Dot Animation Issue

iris87 · **Posted:** Thu Jun 01, 2023 2:04 pm

What is it you are trying to achieve?
A simple moving dots animation

What is the problem you are having?
Sometimes the dots sort of "stick" to a wall, because I'm just reversing the direction of the dots on collision it will always stick to walls.

Describe what you have tried to solve this problem
I attempted to add a randomness to the reversed angle, this works but not great, it still takes quite a few collisions while stuck on a wall to bounce away.

Post any relevant code (You may choose to attach the file instead of posting the code if it is too long)

(ignore the repel from mouse related things, not implemented yet)

Turing:

setscreen ("graphics:max;max;nobuttonbar;offscreenonly;title:Connecting Dots")
colorback (black)
const AmountOfDots := 100
const RepelFromMouse := true

var DebugChar : string (1)

var ColourArray : array 1 .. 100 of int

for Colour : 1 .. 100
ColourArray (Colour) := RGB.AddColour (Colour / 100, Colour / 100, Colour / 100)
end for

type Dot :
record
X : int
Y : int
Speed : real
Direction : int
end record

var DotArray : array 1 .. AmountOfDots of Dot

for DotIndex : 1 .. AmountOfDots
DotArray (DotIndex).X := Rand.Int (1, maxx - 1)
DotArray (DotIndex).Y := Rand.Int (1, maxy - 1)

DotArray (DotIndex).Speed := Rand.Int (20, 40) / 10

DotArray (DotIndex).Direction := Rand.Int (1, 360)
end for

function DegreeToRadian (degree : int) : real
result degree * (Math.PI / 180)
end DegreeToRadian

% Render loop

var lastFrameTime : int := Time.Elapsed
var MouseX : int
var MouseY : int
var MouseDown : int
var DistanceBetweenPoints : real
var LineColour : int
color(brightgreen)
loop
cls
Mouse.Where (MouseX, MouseY, MouseDown)
put "FPS: ", round (1000 / (Time.Elapsed - lastFrameTime))
put "X:Y ", MouseX, ":", MouseY
lastFrameTime := Time.Elapsed
Time.DelaySinceLast (17)

for DotIndex : 1 .. AmountOfDots

if DotArray (DotIndex).X >= maxx then
DotArray (DotIndex).X := maxx - 1
DotArray (DotIndex).Speed := Rand.Int (20, 40) / 10
DotArray (DotIndex).Direction := 180 - DotArray (DotIndex).Direction + Rand.Int(-20, 20)
end if

if DotArray (DotIndex).Y >= maxy then
DotArray (DotIndex).Y := maxy - 1
DotArray (DotIndex).Speed := Rand.Int (20, 40) / 10
DotArray (DotIndex).Direction := -1 * DotArray (DotIndex).Direction + Rand.Int(-20, 20)
end if

if DotArray (DotIndex).X < 0 then
DotArray (DotIndex).X := 1
DotArray (DotIndex).Speed := Rand.Int (20, 40) / 10
DotArray (DotIndex).Direction := 180 - DotArray (DotIndex).Direction + Rand.Int(-20, 20)
end if

if DotArray (DotIndex).Y < 0 then
DotArray (DotIndex).Y := 1
DotArray (DotIndex).Speed := Rand.Int (20, 40) / 10
DotArray (DotIndex).Direction := -1 * DotArray (DotIndex).Direction + Rand.Int(-20, 20)
end if

DotArray (DotIndex).X += round (Math.cos (DegreeToRadian (DotArray (DotIndex).Direction)) * DotArray (DotIndex).Speed)
DotArray (DotIndex).Y += round (Math.sin (DegreeToRadian (DotArray (DotIndex).Direction)) * DotArray (DotIndex).Speed)
end for
for DotIndex : 1 .. AmountOfDots
for OtherDot : 1 .. AmountOfDots
if OtherDot = DotIndex then
exit
end if
DistanceBetweenPoints := sqrt ((DotArray (OtherDot).X - DotArray (DotIndex).X) ** 2 + (DotArray (OtherDot).Y -
DotArray (DotIndex).Y) ** 2)
if DistanceBetweenPoints < 150 then
LineColour := ColourArray (100 - floor (DistanceBetweenPoints / 1.5))
drawline (DotArray (DotIndex).X, DotArray (DotIndex).Y, DotArray (OtherDot).X, DotArray (OtherDot).Y, LineColour)
end if
end for
end for
for DotIndex : 1 .. AmountOfDots
drawfilloval (DotArray (DotIndex).X, DotArray (DotIndex).Y, 4, 4, white)
end for
View.Update
end loop

Please specify what version of Turing you are using
4.1

scholarlytutor · **Posted:** Sat Jun 03, 2023 8:13 am

Hmm did you try just reversing the direction when a dot bumps the wall? One simple way to do that would be to add 180 degrees. That would just make it go in the exact opposite direction.

Of course, if you wanted it to be more realistic based on the laws of physics, you'd have to consider what angle the dot is bumping the wall at. For example, if it bumps the wall at a 30 degree angle, then it should move away from the wall at 150 degrees (180-30).

A couple of unrelated tips:
You can make the mouse into a type as well. That way it doesn't need 3 separate variables.

There are degree versions of the trig functions. For example, sind and cosd. That saves you the trouble of converting from degrees to radians.

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