Need Help with Gravity...

[RedRogueXIII]

Just for a little side project i decided to start on a side scroller.
Ive got a decent amount of gameplay done but I can't seem to get the gravity right for a platform.

up -> Jump
left/right -> move
down -> dash
shift -> high jump (was supposed to be double jump but had problems with that also...)
ctrl -> Lazy shooting code.

* you have to go right in order to see the scrolling background.
When you jump on a platform it changes the height variable- "groundy" but when you walk off the platform the guy is supposed to fall to the ground "layery". I can't see what I messed up on...

code:

View.Set ("graphics:max,max") var x, y, groundy, layery, jumpup, jumpheight, shotx, shoty, scrollm : int var jumpFlag, dblJumpFlag, dashFlag, shootFlag : boolean := false var direction : boolean := true shotx := 0 shoty := 0 scrollm := 0 x := 200 y := 54 jumpup := 20 jumpheight := jumpup groundy := 50 layery := groundy View.Set ("offscreenonly") var chars : array char of boolean proc ground     %drawfill (1, groundy + 1, blue, black)     drawline (0, layery, maxx, layery, black)     Draw.DashedLine (50, 0, 50, maxy, drawDot, red)     Draw.DashedLine (maxx - 50, 0, maxx - 50, maxy, drawDot, red)     Draw.DashedLine (100, 0, 100, maxy, drawDot, red)     Draw.DashedLine (maxx - 100, 0, maxx - 100, maxy, drawDot, red) end ground proc scroll     if x >= maxx - 100 then         scrollm := scrollm + 10     elsif             x <= 100 then         scrollm := scrollm - 10     end if     if x >= maxx - 50 then         scrollm := scrollm + 30     elsif             x <= 50 then         scrollm := scrollm - 30     end if     %Draws a Background     drawline (1300 - scrollm, layery, 1325 - scrollm, 100, black)     drawline (1325 - scrollm, 100, 1350 - scrollm, layery, black)     drawoval (1400 - scrollm, layery + 500, 50, 50, black)     drawfill (1401 - scrollm, layery + 501, yellow, black)     % Platform Test     drawbox (500 - scrollm, 30 + layery, 600 - scrollm, 40 + layery, black)     if x >= 500 - scrollm and x <= 600 - scrollm and y > 40 + layery then         groundy := layery + 40     elsif x <= 500 - scrollm +5 and x >= 600 - scrollm +5 and y > layery then %and y-4 < groundy then         y := layery         groundy := layery         % locate (3, 1)         % put "OMG NOOB PLATFORM"         % groundy := layery         % if y <= 30 + layery then         %     y -= 1         %     y := groundy         % end if     end if end scroll proc jump     if jumpFlag = true then         y += jumpup         jumpup -= 1         if y <= jumpheight then             jumpFlag := false             y := groundy + 4             jumpup := 20         end if     end if end jump proc dblJump     if dblJumpFlag = true then         y += jumpup * 2         jumpup -= 1         if y <= jumpheight then             dblJumpFlag := false             y := groundy + 4             jumpup := 20         end if     end if end dblJump proc dash     if dashFlag = true then         if direction = true then             x += 20         elsif direction = false then             x -= 20         end if     end if     dashFlag := false end dash proc shoot     if shootFlag = true then         shotx := x         shoty := y         if direction = true then             shotx += 10             drawfilloval (shotx, shoty, 4, 2, yellow)             %drawline(shotx, shoty,maxx,shoty,yellow)             Draw.DashedLine (shotx, shoty, maxx, shoty, drawDot, red)             shootFlag := false         elsif direction = false then             shotx -= 10             drawfilloval (shotx, shoty, 4, 2, yellow)             %drawline(shotx, shoty,0,shoty,yellow)             Draw.DashedLine (shotx, shoty, 0, shoty, drawDot, red)             shootFlag := false         end if         if shotx >= maxx and shotx <= 0 then             shootFlag := false         end if     end if     %shootFlag := false end shoot proc move     Input.KeyDown (chars)     if chars (KEY_UP_ARROW) and jumpFlag = false then         jumpFlag := true     end if     if chars (KEY_RIGHT_ARROW) then         x := x + 5         direction := true     end if     if chars (KEY_LEFT_ARROW) then         x := x - 5         direction := false     end if     if chars (KEY_DOWN_ARROW) then     %and y >= groundy + 9 then         %y := y - 5         dashFlag := true     end if     if chars (KEY_CTRL) then         shootFlag := true     end if     if chars (KEY_SHIFT) then         dblJumpFlag := true     end if end move loop     scroll     ground     move     dash     dblJump     jump     shoot     drawoval (x, y, 4, 4, red)     delay (10)     View.Update     cls     locate (1, 1)     put jumpFlag, " ", dblJumpFlag, " ", direction, " ", scrollm ..     locate (2, 1)     put x, " x", y, " y", "layery", layery, "groundy", groundy .. end loop

[iker]

View.WhatDotColor

all you need to know, just set the ordered pairs at the x and y values just below the guy, and if its not black, then fall.

[RedRogueXIII]

Got the solution - turns out i need 2 sensors on each side of the platform so that it works left and right, thanks anyways iker.

code:

% Platform Test     drawbox (500 - scrollm, 30 + layery, 600 - scrollm, 40 + layery, black)     Draw.Text (intstr (500 - scrollm), 500 - scrollm, 30 + layery, test, black)     Draw.Text (intstr (600 - scrollm), 600 - scrollm, 30 + layery, test, black)     if x > 500 - scrollm + 5 and x > 600 - scrollm + 5 then %and y > layery then %and y-4 < groundy then         groundy := layery         y := layery     elsif x < 500 - scrollm + 5 and x < 600 - scrollm + 5 then      %and y > layery then %and y-4 < groundy then         groundy := layery         y := layery     elsif x > 500 - scrollm and x < 600 - scrollm then     %and y > 40 + layery then         groundy := layery + 40     end if

I still wouldnt mind any suggestions on how to handle a double jump...

[MysticVegeta]

Where is constant 9.81m/s^2 pull of gravity here in the code?