' Run and Jump Demo
' By Allan Crossman

' A demo of reasonable looking acceleration / deceleration / falling.

' I've made negative vertical speed rise
' and positive fall (for simplicity).

waitlength = 0.02

width = 400
depth = 200

left = screen width / 2 - (width / 2)
top = screen height / 2 - (depth / 2)
right = screen width / 2 + (width / 2)
bottom = screen height / 2 + (depth / 2)

resize console left, top, right, bottom

cls

virtue = init screen(0, 0, width, depth)
set screen to virtue

hardedge = 10

posx = width / 2
posy = depth / 2
speedx = 0
speedy = 0


MainLoop:

cls

forecolor 65535, 0, 0
text 10, 20, "A / S to run, SPACE to jump, Q to end."

if posy < depth - hardedge then speedy = speedy + 0.3

keymap scan

if keymap key ("s") then              ' Key S pressed?
   speedx = speedx + 0.2
end if
if keymap key ("a") then              ' Key A pressed?
   speedx = speedx - 0.2
end if

if posy = depth - hardedge then
   if keymap key (" ") then           ' Space pressed?
      speedy = speedy - 8
   end if
end if

if keymap key ("q") then disable done : end

posx = posx + speedx
posy = posy + speedy

if posy > depth - hardedge then   ' If we've gone through the floor
   posy = depth - hardedge
   speedy = 0
end if

if posx < hardedge then           ' If we've gone through the wall
   posx = hardedge
   speedx = (speedx * -1) / 2
end if

if posx > width - hardedge then   ' If we've gone through the wall
   posx = width - hardedge
   speedx = (speedx * -1) / 2
end if

forecolor 65535, 65535, 0
fcircle posx, posy, 8

copyrect 0, 0, width, depth, 0, 0, width, depth, 0, virtue, 0

wait waitlength
goto MainLoop