12 replies to this topic

[metrogdor22]

• Title: 8-directional movement Example
• Description: A super easy tutorial/example on how to do 8-directional movement.
• GM Version: GM 7
• Registered: NO!
• File Type: .gmk
• File Size: 0.02 mb
• File Link:

I wipped this up in about 5 minutes, comments and all; so it should take less than that to understand it. Basicly just shows adding and subtracting of the x and the y to create 8-directional movement. Only uses 8 lines of actual code(really only 4).

[Davve]

x+=keyboard_check(vk_right)*4-keyboard_check(vk_left)*4
y+=keyboard_check(vk_down)*4-keyboard_check(vk_up)*4

From 8 lines of code to 2 lines of code (4 is the speed)

or...

x+=keyboard_check(vk_right)*4
x-=keyboard_check(vk_left)*4
y+=keyboard_check(vk_down)*4
y-=keyboard_check(vk_up)*4

and with collision checking...

x+=(keyboard_check(vk_right)*4)*place_free(x+4,y)
x-=(keyboard_check(vk_left)*4)*place_free(x-4,y)
y+=(keyboard_check(vk_down)*4)*place_free(x,y+4)
y-=(keyboard_check(vk_up)*4)*place_free(x,y-4)

Edited by davve941018, 22 September 2009 - 07:40 PM.

[metrogdor22]

x+=keyboard_check(vk_right)*4-keyboard_check(vk_left)*4
y+=keyboard_check(vk_down)*4-keyboard_check(vk_up)*4

From 8 lines of code to 2 lines of code (4 is the speed)

or...

x+=keyboard_check(vk_right)*4
x-=keyboard_check(vk_left)*4
y+=keyboard_check(vk_down)*4
y-=keyboard_check(vk_up)*4

and with collision checking...

x+=(keyboard_check(vk_right)*4)*place_free(x+4,y)
x-=(keyboard_check(vk_left)*4)*place_free(x-4,y)
y+=(keyboard_check(vk_down)*4)*place_free(x,y+4)
y-=(keyboard_check(vk_up)*4)*place_free(x,y-4)

ok, my tutorial, not yours.

[daman123125]

He's just suggesting ways to make your tut better.
Not bad, but I'm sure it has been done before. Good for people with trouble with 8-direction movement.

[icuurd12b42]

The problem with

x+= (keyboard_check(right) - keyboard_check(left))*4
y+= (keyboard_check(down) - keyboard_check(up))*4

...simplified the math here...

I use that all the time...

is the diagonal movement is faster than straight movement; you move 1.4 units (*4 in the example ) diagonally as oppose to 1 unit (*4 in the example). Which is fine when you want to move exactly from x,y 1,1 to 5,5 for example. Dead on the grid.


But for "truer" even movement, you need to add another step

//get deviation
dx = (keyboard_check(right) - keyboard_check(left));
dy = (keyboard_check(down) - keyboard_check(up));
//translate to direction
dir = point_direction(0,0,dx,dy);
//move evenly diagonally or straight, speed 4
x+=lengthdir_x(4,dir);
y+=lengthdir_y(4,dir);
or
hspeed=lengthdir_x(4,dir);
vspeed=lengthdir_y(4,dir);
or
speed = 4
direction = dir
or
motion_set(dir,4)

Edited by icuurd12b42, 24 September 2009 - 07:40 AM.

[metrogdor22]

The problem with

x+= (keyboard_check(right) - keyboard_check(left))*4
y+= (keyboard_check(down) - keyboard_check(up))*4

...simplified the math here...

I use that all the time...

is the diagonal movement is faster than straight movement; you move 1.4 units (*4 in the example ) diagonally as oppose to 1 unit (*4 in the example). Which is fine when you want to move exactly from x,y 1,1 to 5,5 for example. Dead on the grid.


But for "truer" even movement, you need to add another step

//get deviation
dx = (keyboard_check(right) - keyboard_check(left));
dy = (keyboard_check(down) - keyboard_check(up));
//translate to direction
dir = point_direction(0,0,dx,dy);
//move evenly diagonally or straight, speed 4
x+=lengthdir_x(4,dir);
y+=lengthdir_y(4,dir);
or
hspeed=lengthdir_x(4,dir);
vspeed=lengthdir_y(4,dir);
or
speed = 4
direction = dir
or
motion_set(dir,4)

well, this was supposed to be a simple tutorial.

[CaptainLepidus]

well, this was supposed to be a simple tutorial.

very true. people, his tutorial works just fine.

[synkarius]

But for "truer" even movement, you need to add another step

//get deviation
dx = (keyboard_check(right) - keyboard_check(left));
dy = (keyboard_check(down) - keyboard_check(up));
//translate to direction
dir = point_direction(0,0,dx,dy);
//move evenly diagonally or straight, speed 4
x+=lengthdir_x(4,dir);
y+=lengthdir_y(4,dir);

That's really well done, but you need one more thing. As is, the default is to move to the right.

//move evenly diagonally or straight, speed 4
if !((dir=0)and!(keyboard_check(vk_right))){
x+=lengthdir_x(4,dir);
y+=lengthdir_y(4,dir);}

[icuurd12b42]

That true...
better
if(dx!=0 or dy!=0)
{
x+=lengthdir_x(4,dir);
y+=lengthdir_y(4,dir);
}

Edited by icuurd12b42, 01 October 2009 - 09:04 PM.

[synkarius]

That true...
better
if(dx!=0 and dy!=0)
{
x+=lengthdir_x(4,dir);
y+=lengthdir_y(4,dir);
}

Er, actually, that'd only allow diagonal movement...

[icuurd12b42]

Ooops

if(dx!=0 or dy!=0)
{
x+=lengthdir_x(4,dir);
y+=lengthdir_y(4,dir);
}

[synkarius]

Ooops

if(dx!=0 or dy!=0)
{
x+=lengthdir_x(4,dir);
y+=lengthdir_y(4,dir);
}

Yep. That's correct. And more efficient than mine.

[Dan1]

useful by all means but some basic wall features would have been nice, I added them myself but you'd think a movement example would deal with this