bouncing a ball... PLEASE HELP

[coolgirl97]

I need to make a ball bounce within a box...
i got the box done and the bouncing boundaries for the x and y.... NOW I NEED TO ADD A Z.. so the ball can bounce front and back as well..
PLEASE HELP ME!!

This is what i have so far....
drawline (510,360,510,40, black)
drawline (510,360,190,360,black)
drawline (190,360,190,40, black)
drawline (190,40,510,40, black)

drawline (450,300,450,100, black)
drawline (450,300,250,300,black)
drawline (250,300,250,100, black)
drawline (250,100,450,100, black)


drawline (190,360,250,300, black)
drawline (450,300,510,360,black)
drawline (190,40,250,100, black)
drawline (510,40,450,100, black)


%Ball bouncing

const RADIUS := 15
const DELTA_TIME := 0.10
const TIME_DELAY := 10
const x_right_boundary := 480
const x_left_boundary := 220
const y_top_boundary := 330
const y_bottom_boundary := 70
var x, y, x0, y0, v0x, v0y, t : real


x0 := 100
y0 := 100

v0x := 30
v0y := 10

t := 0

loop

x := x0 + v0x * t
y := y0 + v0y * t

drawfilloval (round (x), round (y), round (RADIUS), round (RADIUS),black)
delay (TIME_DELAY)
drawfilloval (round (x), round (y), round (RADIUS), round (RADIUS), white)

if x > x_right_boundary then
x0 := 2 * x_right_boundary - x
y0 := y
v0x := -v0x
t := 0
end if



if x < x_left_boundary then
x0 := 2 * x_left_boundary - x
v0x := -v0x
y0 := y
t := 0
end if

if y > y_top_boundary then
y0 := 2 * y_top_boundary - y
v0y := -v0y
x0 := x
t := 0
end if

if y < y_bottom_boundary then
y0 := 2 * y_bottom_boundary - y
v0y := -v0y
x0 := x
t := 0
end if
t := t + DELTA_TIME
cls
drawline (510,360,510,40, black)
drawline (510,360,190,360,black)
drawline (190,360,190,40, black)
drawline (190,40,510,40, black)

drawline (450,300,450,100, black)
drawline (450,300,250,300,black)
drawline (250,300,250,100, black)
drawline (250,100,450,100, black)


drawline (190,360,250,300, black)
drawline (450,300,510,360,black)
drawline (190,40,250,100, black)
drawline (510,40,450,100, black)
end loop

[Nathan4102]

Your z coord would reflect how close the ball is to the user. When the z is bigger(or smaller), the ball would get bigger. So you could change the radius by some amount based on the z coord.

[coolgirl97]

Thanks,

but the thing is i'm really new to comp sci.. (have no idea y i took the course), and my teacher does not know how to teach :S
so...

how exactly do i add the z coord???

Thank you so much!!

[Nathan4102]

Well "z" would be another variable, just like x and y, and you'd increase it the same way you increase your other variables. Then when you draw the ball, just have the radius relative in some way to z, instead of the constant RADIUS.

E: You'd have to remember to make the ball "bounce" in the z plane as well, just like your x and y's.

[coolgirl97]

so would i do something like this??.. (sorry for all the questions btw)...

drawline (510,360,510,40, black)
drawline (510,360,190,360,black)
drawline (190,360,190,40, black)
drawline (190,40,510,40, black)

drawline (450,300,450,100, black)
drawline (450,300,250,300,black)
drawline (250,300,250,100, black)
drawline (250,100,450,100, black)


drawline (190,360,250,300, black)
drawline (450,300,510,360,black)
drawline (190,40,250,100, black)
drawline (510,40,450,100, black)


%Ball bouncing

const RADIUS := 15
const DELTA_TIME := 0.10
const TIME_DELAY := 10
const x_right_boundary := 480
const x_left_boundary := 220
const y_top_boundary := 330
const y_bottom_boundary := 70
[color=red]const z_front_boundary :=
const z_back_boundary :=[/color]
var x, y, [color=red]z[/color] , x0, y0[color=red], z0,[/color] v0x, v0y,[color=red] v0z[/color] ,t : real


x0 := 100
y0 := 100
[color=red]z0 := [/color]

v0x := 30
v0y := 10
[color=red]v0z :=[/color]

t := 0

loop

x := x0 + v0x * t
y := y0 + v0y * t
[color=red]z:= z0 + v0z * t[/color]
drawfilloval (round (x), round (y), round (RADIUS), round (RADIUS),black)
delay (TIME_DELAY)
drawfilloval (round (x), round (y), round (RADIUS), round (RADIUS), white)
[color=red]drawfilloval (round(z), round (x), round (RADIUS), round (RADIUS), black)
delay (TIME_DELAY)
drawfilloval (round(z), round (x), round (RADIUS), round (RADIUS), white)
delay (TIME_DELAY)
drawfilloval (round(z), round (y), round (RADIUS), round (RADIUS), black)
delay (TIME_DELAY)
drawfilloval (round (z), round (y), round (RADIUS), round (RADIUS), white)
[/color]
if x > x_right_boundary then
x0 := 2 * x_right_boundary - x
y0 := y
v0x := -v0x
t := 0
end if



if x < x_left_boundary then
x0 := 2 * x_left_boundary - x
v0x := -v0x
y0 := y
t := 0
end if

if y > y_top_boundary then
y0 := 2 * y_top_boundary - y
v0y := -v0y
x0 := x
t := 0
end if

if y < y_bottom_boundary then
y0 := 2 * y_bottom_boundary - y
v0y := -v0y
x0 := x
t := 0
end if


[color=red]if z > z_front_boundary then
z0 := 2 * z_front _boundary - z
v0z := -v0z
x0 := x
t := 0

end if

if z < z_back_boundary then
z0 := 2 * z_back_boundary - z
v0z := -v0z
x0 := x
t := 0
end if[/color]

t := t + DELTA_TIME
cls
drawline (510,360,510,40, black)
drawline (510,360,190,360,black)
drawline (190,360,190,40, black)
drawline (190,40,510,40, black)

drawline (450,300,450,100, black)
drawline (450,300,250,300,black)
drawline (250,300,250,100, black)
drawline (250,100,450,100, black)


drawline (190,360,250,300, black)
drawline (450,300,510,360,black)
drawline (190,40,250,100, black)
drawline (510,40,450,100, black)
end loop

[coolgirl97]

ignore.. the colour red thing...

i did it to show what i added.. but it is html coding, so you won't see the difference right away , anyways...

Thanks!

[Nathan4102]

No problem, and that should work, except you need to draw your circle based on your z coord aswell.

[onedirectionlover]

i did... didn't i ??

drawfilloval (round (x), round (y), round (RADIUS), round (RADIUS), black)
delay (TIME_DELAY)
drawfilloval (round (x), round (y), round (RADIUS), round (RADIUS), white)

drawfilloval (round(z), round (x), round (RADIUS), round (RADIUS), black)
delay (TIME_DELAY)
drawfilloval (round(z), round (x), round (RADIUS), round (RADIUS), white)

drawfilloval (round(z), round (y), round (RADIUS), round (RADIUS), black)
delay (TIME_DELAY)
drawfilloval (round (z), round (y), round (RADIUS), round (RADIUS), white)

[Nathan4102]

Youre only changing the x and y parameters of "drawfilloval". round(x) and round(y) should stay as the x and y parameters. The thing you need to change is the x and y radius(3'rd and 4'th parameter). Assuming we're looking at this ball straight down the z plane, as z increases, the ball would appear bigger, correct? Thus, as z increases, we need to draw the ball larger.

[coolgirl97]

Okay... i kinda get what u r saying.. thank you!

but.. just one more question...

so instead of this:
if
z > z_front_boundary then
z0 := 2 * z_front _boundary - z
v0z := -v0z
x0 := x
t := 0

end if

if
z < z_back_boundary then
z0 := 2 * z_back_boundary - z
v0z := -v0z
x0 := x
t := 0

end if


will it be something like this?? :


if
z > z_front_boundary then
RADIUS := 20
v0z := -v0z
x0 := x
t := 0

end if

if
z < z_back_boundary then
RADIUS := 10
v0z := -v0z
x0 := x
t := 0
end if

THANK U SO MUCH !! <3

[jr5000pwp]

I wouldn't do it like that personally. I would take more of an approach of

code:

drawfilloval (round (x), round (y), round (RADIUS+-z*DEPTH_SCALE), round (RADIUS+-z*DEPTH_SCALE), black)

This allows for more logical update code, and better control over different scale/time/distance factors. Note that I used +- to note that both have their advantages and you should decide for yourself if your RADIUS constant should represent the highest radius of the lowest radius.

[coolgirl97]

so... would depth_scale be a const???
and will i need to use it anywhere else other than drawfilloval?

ty!

[coolgirl97]

okay, so this is what i have so far..

its prob all messed up, but can u tell me what i have to do to make it work??

Thank you so much.

drawline (510,360,510,40, black)
drawline (510,360,190,360,black)
drawline (190,360,190,40, black)
drawline (190,40,510,40, black)

drawline (450,300,450,100, black)
drawline (450,300,250,300,black)
drawline (250,300,250,100, black)
drawline (250,100,450,100, black)


drawline (190,360,250,300, black)
drawline (450,300,510,360,black)
drawline (190,40,250,100, black)
drawline (510,40,450,100, black)


%Ball bouncing

const RADIUS := 15
const DELTA_TIME := 0.10
const TIME_DELAY := 10
const x_right_boundary := 480
const x_left_boundary := 220
const y_top_boundary := 330
const y_bottom_boundary := 70
const z_front_boundary :=
const z_back_boundary :=
var x, y, z , x0, y0, z0, v0x, v0y, v0z ,t : real


x0 := 100
y0 := 100
z0 := 100

v0x := 30
v0y := 10
v0z := 20

t := 0

loop

x := x0 + v0x * t
y := y0 + v0y * t
z := z0 + v0z * t

drawfilloval (round (x), round (y), round (RADIUS+-z*DEPTH_SCALE), round (RADIUS+-z*DEPTH_SCALE), black)

delay (TIME_DELAY)

drawfilloval (round (x), round (y), round (RADIUS+-z*DEPTH_SCALE), round (RADIUS+-z*DEPTH_SCALE), white)


if x > x_right_boundary then
x0 := 2 * x_right_boundary - x
y0 := y
v0x := -v0x
t := 0
end if



if x < x_left_boundary then
x0 := 2 * x_left_boundary - x
v0x := -v0x
y0 := y
t := 0
end if

if y > y_top_boundary then
y0 := 2 * y_top_boundary - y
v0y := -v0y
x0 := x
t := 0
end if

if y < y_bottom_boundary then
y0 := 2 * y_bottom_boundary - y
v0y := -v0y
x0 := x
t := 0
end if


t := t + DELTA_TIME

cls

drawline (510,360,510,40, black)
drawline (510,360,190,360,black)
drawline (190,360,190,40, black)
drawline (190,40,510,40, black)

drawline (450,300,450,100, black)
drawline (450,300,250,300,black)
drawline (250,300,250,100, black)
drawline (250,100,450,100, black)


drawline (190,360,250,300, black)
drawline (450,300,510,360,black)
drawline (190,40,250,100, black)
drawline (510,40,450,100, black)
end loop

[jr5000pwp]

Firstly, your z boundaries aren't set.
Secondly, you'd want to declare a DEPTH_SCALE constant. This should probably be a real and you'll just need to play with it until it feels right.
Thirdly, you aren't doing checking for your z co-ordinate. You can probably just copy the x or y code you have and substitute z in, making sure to use the appropriate variables such as z_front_boundary.

[coolgirl97]

Thank you so much!!

I've kinda fixed up everything u told me...

is this correct?? :

drawline (510,360,510,40, black)
drawline (510,360,190,360,black)
drawline (190,360,190,40, black)
drawline (190,40,510,40, black)

drawline (450,300,450,100, black)
drawline (450,300,250,300,black)
drawline (250,300,250,100, black)
drawline (250,100,450,100, black)


drawline (190,360,250,300, black)
drawline (450,300,510,360,black)
drawline (190,40,250,100, black)
drawline (510,40,450,100, black)


%Ball bouncing

const RADIUS := 15
const DELTA_TIME := 0.10
const TIME_DELAY := 10
const x_right_boundary := 480
const x_left_boundary := 220
const y_top_boundary := 330
const y_bottom_boundary := 70
const z_front_boundary := 200
const z_back_boundary := 100
var x, y, z , x0, y0, z0, v0x, v0y, v0z ,t, DEPTH_SCALE : real

DEPTH_SCALE := 18

x0 := 100
y0 := 100
z0 := 100

v0x := 30
v0y := 10
v0z := 20

t := 0

loop

x := x0 + v0x * t
y := y0 + v0y * t
z := z0 + v0z * t

drawfilloval (round (x), round (y), round (RADIUS+-z*DEPTH_SCALE), round (RADIUS+-z*DEPTH_SCALE), black)

delay (TIME_DELAY)

drawfilloval (round (x), round (y), round (RADIUS+-z*DEPTH_SCALE), round (RADIUS+-z*DEPTH_SCALE), white)


if x > x_right_boundary then
x0 := 2 * x_right_boundary - x
y0 := y
v0x := -v0x
t := 0
end if



if x < x_left_boundary then
x0 := 2 * x_left_boundary - x
v0x := -v0x
y0 := y
t := 0
end if

if y > y_top_boundary then
y0 := 2 * y_top_boundary - y
v0y := -v0y
x0 := x
t := 0
end if

if y < y_bottom_boundary then
y0 := 2 * y_bottom_boundary - y
v0y := -v0y
x0 := x
t := 0
end if

if
z > z_front_boundary then
z0 := 2 * z_front _boundary - z
v0z := -v0z
x0 := x
t := 0

end if

if
z < z_back_boundary then
z0 := 2 * z_back_boundary - z
v0z := -v0z
x0 := x
t := 0

end if


t := t + DELTA_TIME

cls

drawline (510,360,510,40, black)
drawline (510,360,190,360,black)
drawline (190,360,190,40, black)
drawline (190,40,510,40, black)

drawline (450,300,450,100, black)
drawline (450,300,250,300,black)
drawline (250,300,250,100, black)
drawline (250,100,450,100, black)


drawline (190,360,250,300, black)
drawline (450,300,510,360,black)
drawline (190,40,250,100, black)
drawline (510,40,450,100, black)
end loop