Tuto tiny-ecs 2d platformer Part 10 Collision System
From GiderosMobile
The Collision System
This System is where all the fun happens: collisions. Here we deal with cBump for the collisions, cBump is the physics engine we use. We also implement gravity, coyote timer, input buffering, ...
The list of collisions:
-- physics flags
ent.isstepcontacts = false
ent.isfloorcontacts = false
ent.isladdercontacts = false
ent.isptpfcontacts = false -- pass through platform
ent.ismvpfcontacts = false -- moving platform
ent.iswallcontacts = false
ent.isspringcontacts = false
Let's go!
sCollision.lua
The cBump physics engine is a Gideros plugin. I cannot explain in details how it works but I will do my best!
- when we create an Entity, we add it to tiny-ecs world, Gideros stage and also cBump world. This is done when we load the Tiled.lua file. For example, here we add a moving platform:
--EMvpf:init(xid, xspritelayer, xpos, xtexpath, xcolor, w, h, dx, dy, xdir, xspeed, xbgfxlayer)
local e = EMvpf.new(
xid, xlayers["actors"], vpos, xtexpath, xcolor, o.width, o.height,
dx, dy, xdir, vspeed, nil, xlayers["bgfx"]
)
xtiny.tworld:addEntity(e)
xbworld:add(e, e.pos.x, e.pos.y, e.collbox.w, e.collbox.h) -- cBump world
e.sprite:setPosition(e.pos + vector(e.collbox.w/2, -e.h/2+e.collbox.h))
- once an Entity exists in cBump world we can code how it collides in the physics world
- the player1 Entity is moved by the player using the keyboard. An enemy Entity is moved using the AI System (isup, isdown, isleft, isright, ...)
- cBump uses a collisionfilter to process collisions between entities in the physics world. That is what entity collides with what
- then cBump resolves the Entity collision ("touch", "cross", "slide" or "bounce")
The cBump move function:
-- _____ ____ _ _ __ __ _____
-- / ____| _ \| | | | \/ | __ \
--| | | |_) | | | | \ / | |__) |
--| | | _ <| | | | |\/| | ___/
--| |____| |_) | |__| | | | | |
-- \_____|____/ \____/|_| |_|_|
local goalx = ent.pos.x + ent.body.vx * dt
local goaly = ent.pos.y + ent.body.vy * dt
local nextx, nexty, collisions, len = self.bworld:move(ent, goalx, goaly, collisionfilter)
Please create a file "sCollision.lua" in the "_S" folder and the code:
SCollision = Core.class()
function SCollision:init(xtiny, xbworld, xplayer1) -- tiny function
xtiny.processingSystem(self) -- called once on init and every update
self.tiny = xtiny
self.bworld = xbworld
self.player1 = xplayer1
end
function SCollision:filter(ent) -- tiny function
return ent.collbox and ent.body and
not (ent.isprojectile or ent.ismvpf or ent.isdoor)
end
function SCollision:onAdd(ent) -- tiny function
end
function SCollision:onRemove(ent) -- tiny function
end
local p1rangetoofarx = myappwidth*2 -- disable systems to save some CPU, magik XXX
local p1rangetoofary = myappheight*2 -- disable systems to save some CPU, magik XXX
function SCollision:process(ent, dt) -- tiny function
-- OUTSIDE VISIBLE RANGE
if ent.isnme then
if (ent.pos.x > self.player1.pos.x + p1rangetoofarx or
ent.pos.x < self.player1.pos.x - p1rangetoofarx) or
(ent.pos.y > self.player1.pos.y + p1rangetoofary or
ent.pos.y < self.player1.pos.y - p1rangetoofary) then
ent.doanimate = false
return
end
end
-- physics flags
ent.isstepcontacts = false
ent.isfloorcontacts = false
ent.isladdercontacts = false
ent.isptpfcontacts = false
ent.ismvpfcontacts = false
ent.iswallcontacts = false
ent.isspringcontacts = false
-- _____ ____ _ _ _____ _____ _____ ____ _ _
-- / ____/ __ \| | | | |_ _|/ ____|_ _/ __ \| \ | |
--| | | | | | | | | | | | (___ | || | | | \| |
--| | | | | | | | | | | \___ \ | || | | | . ` |
--| |___| |__| | |____| |____ _| |_ ____) |_| || |__| | |\ |
-- \_____\____/|______|______|_____|_____/|_____\____/|_| \_|
-- ______ _____ _ _______ ______ _____
--| ____|_ _| | |__ __| ____| __ \
--| |__ | | | | | | | |__ | |__) |
--| __| | | | | | | | __| | _ /
--| | _| |_| |____| | | |____| | \ \
--|_| |_____|______|_| |______|_| \_\
local function collisionfilter(item, other) -- "touch", "cross", "slide", "bounce"
if other.isnpc then return "cross"
elseif other.isdoor then return "slide" -- needed 20250720
elseif other.iswall then return "slide" -- "touch"
elseif other.isfloor then return "slide"
elseif other.isptpf then
if item.isdown and item.isup then -- prevents ptpf while holding both up and down keys
item.wasdown = true
item.wasup = true
end
if item.isdown and not item.wasdown then
return "cross"
end
if item.body.vy > 0 then -- actor going down
local itembottom = item.pos.y + item.collbox.h
local otherbottom = other.pos.y -- don't add margin here!
if itembottom <= otherbottom then return "slide" end
end
if item.iswalkingnme and item.breed == "C" then
return "slide"
end
elseif other.ismvpf then
if item.isdown and item.isup then -- prevents pt mvpf while holding both up and down keys
item.wasdown = true
item.wasup = true
end
if item.isdown and not item.wasdown then
if other.isptmvpf then return "cross" end -- passthrough moving pf
end
if item.body.vy > 0 then -- actor going down
local itembottom = item.pos.y + item.collbox.h
local otherbottom = other.pos.y + 1
if other.body.vy < 0 then -- mvpf going up
otherbottom += 1 -- margin prevents player from falling when the pf is going up
end
if itembottom <= otherbottom then return "slide" end
end
elseif other.isspring then return "slide"
elseif other.isspike then return "slide"
else return "cross"
end
end
-- _____ ____ _ _ __ __ _____
-- / ____| _ \| | | | \/ | __ \
--| | | |_) | | | | \ / | |__) |
--| | | _ <| | | | |\/| | ___/
--| |____| |_) | |__| | | | | |
-- \_____|____/ \____/|_| |_|_|
local goalx = ent.pos.x + ent.body.vx * dt
local goaly = ent.pos.y + ent.body.vy * dt
local nextx, nexty, collisions, len = self.bworld:move(ent, goalx, goaly, collisionfilter)
-- _____ ____ _ _ _____ _____ _____ ____ _ _ _____
-- / ____/ __ \| | | | |_ _|/ ____|_ _/ __ \| \ | |/ ____|
--| | | | | | | | | | | | (___ | || | | | \| | (___
--| | | | | | | | | | | \___ \ | || | | | . ` |\___ \
--| |___| |__| | |____| |____ _| |_ ____) |_| || |__| | |\ |____) |
-- \_____\____/|______|______|_____|_____/|_____\____/|_| \_|_____/
-- COLLISION FROM ANY SIDES
for i = 1, len do
local item = collisions[i].item
local other = collisions[i].other
local normal = collisions[i].normal
--
if other.isvoid then
if item.isplayer1 then
item.restart = true -- load lose scene?
else
item.currlives = 0
item.readytoremove = true
end
elseif item.isplayer1 and other.isexit then
g_currlevel += 1
item.restart = true
elseif other.isladder then
item.body.currcoyotetimer = item.body.coyotetimer
item.isladdercontacts = true
if item.currlives <= 0 then
item.readytoremove = true -- only remove actor when 'grounded'
end
elseif other.isptpf then
item.isptpfcontacts = true
elseif other.isstep then -- CBump stairs effect ;-)
item.isstepcontacts = true
elseif other.ismvpf then
if item.body.vy > 0 then -- actor going down
local itembottom = item.pos.y + item.collbox.h
local otherbottom = other.pos.y + 1 -- some margin prevent player from sliding/falling
if itembottom <= otherbottom then -- actor above mvpf
item.ismvpfcontacts = true
item.body.currjumpcount = item.body.jumpcount
item.body.currcoyotetimer = item.body.coyotetimer
-- item.body.vy = 0 -- don't reset velocity y here because prevents ptpf!
end
if item.currlives <= 0 then
item.readytoremove = true -- only remove actor when 'grounded'
end
end
if item.isleft and not item.isright and other.body.vx < 0 then
item.body.vx = -item.body.currspeed*0.9 -- slow down speed on mvpf, you choose!
elseif item.isright and not item.isleft and other.body.vx < 0 then
item.body.vx = item.body.currspeed*0.9 -- slow down speed on mvpf, you choose!
elseif (item.isleft and item.isright) and other.body.vx < 0 then
item.body.vx = other.body.vx
elseif not(item.isleft and item.isright) and other.body.vx < 0 then
item.body.vx = other.body.vx
elseif item.isleft and not item.isright and other.body.vx > 0 then
item.body.vx = -item.body.currspeed*0.9 -- slow down speed on mvpf, you choose!
elseif item.isright and not item.isleft and other.body.vx > 0 then
item.body.vx = item.body.currspeed*0.9 -- slow down speed on mvpf, you choose!
elseif (item.isleft and item.isright) and other.body.vx > 0 then
item.body.vx = other.body.vx
elseif not (item.isleft and item.isright) and other.body.vx > 0 then
item.body.vx = other.body.vx
elseif item.isleft and not item.isright and other.body.vx == 0 then
item.body.vx = -item.body.currspeed*0.9 -- slow down speed on mvpf, you choose!
elseif item.isright and not item.isleft and other.body.vx == 0 then
item.body.vx = item.body.currspeed*0.9 -- slow down speed on mvpf, you choose!
elseif (item.isleft and item.isright) and other.body.vx == 0 then
item.body.vx = 0
elseif not (item.isleft and item.isright) and other.body.vx == 0 then
item.body.vx = 0
end
elseif other.iswall then
item.body.currjumpcount = item.body.jumpcount
item.body.currcoyotetimer = item.body.coyotetimer + 1*8 -- increase timer for fun, magik XXX
item.iswallcontacts = true
item.wasonwall = true
-- item.wasup = false -- you can uncomment this line, GAMEPLAY: walls jumping too permissive
elseif other.isspring then
item.body.vy = -other.vy -- reset velocity y (don't accumulate gravity)
item.isspringcontacts = true
if item.currlives <= 0 then
item.readytoremove = true -- only remove actor when 'grounded'
end
elseif other.isspike then
item.body.vx = item.body.currspeed*5*-item.flip -- 3, magik XXX
item.body.vy = -item.body.currupspeed*0.7 -- magik XXX
if item.isplayer1 then
item.isdirty = true
item.damage = 1
end
if item.currlives <= 0 then
item.readytoremove = true -- only remove actor when 'grounded'
end
item.wasup = false
end
-- COLLISION FROM TOP
if normal.y == -1 then
if other.isfloor then
item.body.vy = 0 -- reset velocity y (don't accumulate gravity)
item.isfloorcontacts = true
item.body.currjumpcount = item.body.jumpcount
item.body.currcoyotetimer = item.body.coyotetimer
if item.currlives <= 0 then
item.readytoremove = true -- only remove actor when 'grounded'
end
elseif other.isptpf then
item.body.vy = 0 -- reset velocity y (don't accumulate gravity)
item.isptpfcontacts = true
item.body.currjumpcount = item.body.jumpcount
item.body.currcoyotetimer = item.body.coyotetimer
if item.currlives <= 0 then
item.readytoremove = true -- only remove actor when 'grounded'
end
elseif other.isnme and item.isplayer1 then -- player1 on top of nme
other.isdirty = true
other.damage = 1
item.body.currjumpcount = item.body.jumpcount
if item.isup then
item.body.vy = -ent.body.currupspeed*1.1
else
item.body.vy = -item.body.currupspeed*0.7 -- magik XXX, linked to 'stomp'
end
elseif other.isnme and item.isnme then -- nme on top of nme
item.body.currjumpcount = item.body.jumpcount
if item.isup then
item.body.vy = -ent.body.currupspeed*1.1
else
item.body.vy = -item.body.currupspeed*0.7 -- magik XXX, linked to 'stomp'
end
if item.currlives <= 0 then
item.readytoremove = true -- only remove actor when 'grounded'
end
elseif other.isplayer1 and item.isnme then -- nme on top of player1
other.isdirty = true
other.damage = 1
item.wasup = false -- ??? XXX
item.body.currjumpcount = item.body.jumpcount
item.body.currinputbuffer = item.body.inputbuffer
item.body.currcoyotetimer = item.body.coyotetimer
end
-- COLLISION FROM BOTTOM
elseif normal.y == 1 then
if other.isfloor then -- cancel body gravity when hitting from below (can adjust)
item.body.vy *= 0.5 -- = 0
end
end
-- COLLISION FROM SIDES, -1 collision from item right, 1 collision from item left
if normal.x == -1 or normal.x == 1 then
if item.isplayer1 and other.isfloor then
item.body.vx = -item.flip
elseif item.isnme and other.isdoor then
item.isleft, item.isright = not item.isleft, not item.isright
elseif item.isnme and other.isfloor then
if normal.x == -1 and not item.isleftofplayer then
item.isleft, item.isright = true, false
elseif normal.x == 1 and item.isleftofplayer then
item.isleft, item.isright = false, true
end
end
end
-- PLAYER1
if item.isplayer1 and other.iscollectible then
other.isdirty = true
if other.eid:find("key") then -- add key to inventory
self.tiny.player1inventory[other.eid:sub(4)] = true -- eid with "key" truncated
-- print("key", other.eid, dt)
end
end
end
-- _____ _____ __ _______ _________ __
-- / ____| __ \ /\ \ / /_ _|__ __\ \ / /
--| | __| |__) | / \ \ / / | | | | \ \_/ /
--| | |_ | _ / / /\ \ \/ / | | | | \ /
--| |__| | | \ \ / ____ \ / _| |_ | | | |
-- \_____|_| \_\/_/ \_\/ |_____| |_| |_|
-- gravity after collisions because ptpfs may modify actor body vy
if ent.body.vy < 0 then -- going up
ent.body.vy += 3*8 * ent.body.currmass -- gravity, magik XXX
else -- going down
ent.body.vy += 3*8 * ent.body.currmass -- 3*8, gravity, magik XXX
if ent.body.vy > 500 then -- 500, cap falling speed
ent.body.vy = 500
end
if ent.wasonmvpf then -- prevent fast fall when going off pf
ent.body.vy = ent.body.currupspeed*0.25 -- *0.5, ent going down mvpf, magik XXX
ent.wasonmvpf = false
elseif ent.wasonwall then -- ent wall sliding
ent.body.vy = ent.body.currupspeed*0.01 -- *0.25, magik XXX
ent.wasonwall = false
end
end
-- _____ _ ___ _______ _____ _____ _____
-- | __ \| | | \ \ / / ____|_ _/ ____|/ ____|
-- | |__) | |__| |\ \_/ / (___ | || | | (___
-- | ___/| __ | \ / \___ \ | || | \___ \
-- | | | | | | | | ____) |_| || |____ ____) |
-- |_| |_| |_| |_| |_____/|_____\_____|_____/
if ent.body.currinputbuffer > 0 then -- floor input buffer
ent.body.currinputbuffer -= 1
end
if ent.body.currcoyotetimer > 0 then -- coyote time
ent.body.currcoyotetimer -= 1
end
if ent.body.currdashtimer > 0 then -- dash
ent.body.currdashtimer -= 1
end
if ent.body.currdashcooldown > 0 then -- dash cooldown
ent.body.currdashcooldown -= 1
end
-- IS ON STEP
if ent.isstepcontacts then
-- if ent.isplayer1 then print("isstepcontacts", dt) end
if ent.isleft and not ent.isright then -- LEFT
ent.animation.curranim = g_ANIM_RUN_R
ent.flip = -1
ent.body.vx = -ent.body.currspeed
ent.body.vy = -ent.body.currupspeed*0.4 -- 0.5, step climb speed here XXX
elseif ent.isright and not ent.isleft then -- RIGHT
ent.animation.curranim = g_ANIM_RUN_R
ent.flip = 1
ent.body.vx = ent.body.currspeed
ent.body.vy = -ent.body.currupspeed*0.4 -- 0.5, step climb speed here XXX
else
ent.animation.curranim = g_ANIM_IDLE_R
ent.body.vx *= 0.75 -- 0.8, 0.9, = 0
if (-ent.body.vx<>ent.body.vx) < 0.001 then ent.body.vx = 0 end
end
-- IS ON FLOOR
elseif (ent.isfloorcontacts or
(ent.isfloorcontacts and ent.isladdercontacts)) and
not ent.isptpfcontacts and
not ent.ismvpfcontacts and
not ent.iswallcontacts
then
-- if ent.isplayer1 then print("isonfloor", dt) end
if ent.isleft and not ent.isright then -- LEFT
if ent.washurt > 0 or ent.wasbadlyhurt > 0 then -- animations in ent system
else ent.animation.curranim = g_ANIM_RUN_R
end
if ent.wasbadlyhurt > 0 then
ent.body.vx *= 0.1 -- cancel move! magik XXX
else
ent.flip = -1
if ent.body.currdashtimer > 0 then
ent.body.vx -= ent.body.currspeed*ent.body.dashmultiplier
else
ent.body.vx = -ent.body.currspeed
end
end
elseif ent.isright and not ent.isleft then -- RIGHT
if ent.washurt > 0 or ent.wasbadlyhurt > 0 then -- animations in ent system
else ent.animation.curranim = g_ANIM_RUN_R
end
if ent.wasbadlyhurt > 0 then
ent.body.vx *= 0.1 -- cancel move! magik XXX
else
ent.flip = 1
if ent.body.currdashtimer > 0 then
ent.body.vx += ent.body.currspeed*ent.body.dashmultiplier
else
ent.body.vx = ent.body.currspeed
end
end
else
if ent.washurt > 0 or ent.wasbadlyhurt > 0 then -- animations in ent system
else ent.animation.curranim = g_ANIM_IDLE_R
end
if ent.wasbadlyhurt > 0 then
ent.body.vx *= 0.1 -- cancel move! magik XXX
else
ent.body.vx *= 0.75 -- 0.8, 0.9, = 0
end
if (-ent.body.vx<>ent.body.vx) < 0.001 then ent.body.vx = 0 end
end
if ent.body.currinputbuffer > 0 and not ent.isdown and not ent.wasup then -- UP
if ent.wasbadlyhurt > 0 then
-- cannot jump
else
ent.body.vy = -ent.body.currupspeed
ent.wasup = true
ent.body.currjumpcount = ent.body.jumpcount
ent.body.currinputbuffer = 0 -- prevents double jump when releasing up key
end
-- elseif ent.isdown and not ent.isup then -- DOWN
end
-- IS ON LADDER
elseif not ent.isfloorcontacts and
ent.isladdercontacts and
not ent.isptpfcontacts and
not ent.ismvpfcontacts and
not ent.iswallcontacts
then
-- if ent.isplayer1 then print("isladdercontacts", dt) end
if ent.isflyingnme then return end -- flying nmes don't collide with ladders
if ent.isleft and not ent.isright then -- LEFT
if ent.washurt > 0 or ent.wasbadlyhurt > 0 then -- animations in ent system
else ent.animation.curranim = g_ANIM_RUN_R
end
if ent.wasbadlyhurt > 0 then
ent.body.vx *= 0.1 -- cancel move! magik XXX
else
ent.flip = -1
ent.body.vx = -ent.body.currspeed*0.5
end
elseif ent.isright and not ent.isleft then -- RIGHT
if ent.washurt > 0 or ent.wasbadlyhurt > 0 then -- animations in ent system
else ent.animation.curranim = g_ANIM_RUN_R
end
if ent.wasbadlyhurt > 0 then
ent.body.vx *= 0.1 -- cancel move! magik XXX
else
ent.flip = 1
ent.body.vx = ent.body.currspeed*0.5
end
else
if ent.washurt > 0 or ent.wasbadlyhurt > 0 then -- animations in ent system
else ent.animation.curranim = g_ANIM_IDLE_R
end
if ent.wasbadlyhurt > 0 then
ent.body.vx *= 0.1 -- cancel move! magik XXX
else
ent.body.vx *= 0.75 -- 0.8, 0.9, = 0
end
if (-ent.body.vx<>ent.body.vx) < 0.001 then ent.body.vx = 0 end
end
if ent.isup and not ent.isdown then -- UP
if ent.washurt > 0 or ent.wasbadlyhurt > 0 or ent.currlives <= 0 then -- animations in ent system
else ent.animation.curranim = g_ANIM_RUN_R
end
if ent.wasbadlyhurt > 0 or ent.currlives <= 0 then
-- cannot move
else
ent.body.vy = -ent.body.currupspeed*0.2 -- magik XXX
ent.wasup = false -- allows jumping up off ladder
end
elseif ent.isdown and not ent.isup then -- DOWN
if ent.washurt > 0 or ent.wasbadlyhurt > 0 or ent.currlives <= 0 then -- animations in ent system
else ent.animation.curranim = g_ANIM_RUN_R
end
if ent.wasbadlyhurt > 0 or ent.currlives <= 0 then
-- cannot move
else
ent.body.vy = ent.body.currupspeed*0.2 -- magik XXX
end
else
if ent.wasbadlyhurt > 0 or ent.currlives <= 0 then
ent.body.vy = ent.body.currupspeed -- fall off ladder
else
ent.body.vy = 0
end
end
ent.wasonladder = true
-- IS ON PTPF
elseif not ent.isfloorcontacts and
not ent.isladdercontacts and
ent.isptpfcontacts and
not ent.ismvpfcontacts and
not ent.iswallcontacts
then
-- if ent.isplayer1 then print("isptpfcontacts", dt) end
if ent.isleft and not ent.isright then -- LEFT
if ent.washurt > 0 or ent.wasbadlyhurt > 0 then -- animations in ent system
else ent.animation.curranim = g_ANIM_RUN_R
end
if ent.wasbadlyhurt > 0 then
ent.body.vx *= 0.1 -- cancel move! magik XXX
else
ent.flip = -1
if ent.body.currdashtimer > 0 then
ent.body.vx -= ent.body.currspeed*ent.body.dashmultiplier
else
ent.body.vx = -ent.body.currspeed
end
end
elseif ent.isright and not ent.isleft then -- RIGHT
if ent.washurt > 0 or ent.wasbadlyhurt > 0 then -- animations in ent system
else ent.animation.curranim = g_ANIM_RUN_R
end
if ent.wasbadlyhurt > 0 then
ent.body.vx *= 0.1 -- cancel move! magik XXX
else
ent.flip = 1
if ent.body.currdashtimer > 0 then
ent.body.vx += ent.body.currspeed*ent.body.dashmultiplier
else
ent.body.vx = ent.body.currspeed
end
end
else
if ent.washurt > 0 or ent.wasbadlyhurt > 0 then -- animations in ent system
else ent.animation.curranim = g_ANIM_IDLE_R
end
if ent.wasbadlyhurt > 0 then
ent.body.vx *= 0.1 -- cancel move! magik XXX
else
ent.body.vx *= 0.75 -- 0.8, 0.9, = 0
end
if (-ent.body.vx<>ent.body.vx) < 0.001 then ent.body.vx = 0 end
end
if ent.body.currinputbuffer > 0 and not ent.isdown and not ent.wasup then -- UP
if ent.wasbadlyhurt > 0 then
-- cannot jump
else
ent.body.vy = -ent.body.currupspeed
ent.wasup = true
ent.body.currinputbuffer = 0 -- prevents double jump when releasing up key
end
elseif ent.isdown and not ent.isup and not ent.wasdown then -- DOWN
if ent.wasbadlyhurt > 0 then
-- cannot jump down
else
ent.body.vy = ent.body.currupspeed*0.1
ent.wasdown = true
end
end
-- IS ON MVPF
elseif not ent.isfloorcontacts and
not ent.isladdercontacts and
not ent.isptpfcontacts and
ent.ismvpfcontacts and
not ent.iswallcontacts
then -- also controlled in collisions
-- if ent.isplayer1 then print("ismvpfcontacts", dt) end
if ent.isleft and not ent.isright then -- LEFT
if ent.washurt > 0 or ent.wasbadlyhurt > 0 then -- animations in ent system
else ent.animation.curranim = g_ANIM_RUN_R
end
if ent.wasbadlyhurt > 0 then
ent.body.vx *= 0.1 -- cancel move! magik XXX
else
ent.flip = -1
end
elseif ent.isright and not ent.isleft then -- RIGHT
if ent.washurt > 0 or ent.wasbadlyhurt > 0 then -- animations in ent system
else ent.animation.curranim = g_ANIM_RUN_R
end
if ent.wasbadlyhurt > 0 then
ent.body.vx *= 0.1 -- cancel move! magik XXX
else
ent.flip = 1
end
else
if ent.washurt > 0 or ent.wasbadlyhurt > 0 then -- animations in ent system
else ent.animation.curranim = g_ANIM_IDLE_R
end
end
if ent.body.currinputbuffer > 0 and not ent.isdown and not ent.wasup then -- UP
if ent.wasbadlyhurt > 0 then
-- cannot jump
else
ent.body.vy = -ent.body.currupspeed
ent.wasup = true -- if set to true cannot jump!
ent.body.currinputbuffer = 0 -- prevents double jump when releasing up key
end
elseif ent.isdown and not ent.isup and not ent.wasdown then -- DOWN
if ent.wasbadlyhurt > 0 then
-- cannot jump down
else
ent.body.vy = ent.body.currupspeed*0.1
ent.wasdown = true
end
end
ent.wasonmvpf = true
-- IS ON WALL
elseif not ent.isfloorcontacts and
not ent.isladdercontacts and
not ent.isptpfcontacts and
not ent.ismvpfcontacts and
ent.iswallcontacts
then
-- if ent.isplayer1 then print("isonwall", dt) end
if ent.isleft and not ent.isright then -- LEFT
if ent.washurt > 0 or ent.wasbadlyhurt > 0 then -- animations in ent system
else ent.animation.curranim = g_ANIM_WALL_IDLE_R
end
ent.flip = -1
ent.body.vx = -ent.body.currspeed
elseif ent.isright and not ent.isleft then -- RIGHT
if ent.washurt > 0 or ent.wasbadlyhurt > 0 then -- animations in ent system
else ent.animation.curranim = g_ANIM_WALL_IDLE_R
end
ent.flip = 1
ent.body.vx = ent.body.currspeed
else
if ent.washurt > 0 or ent.wasbadlyhurt > 0 then -- animations in ent system
else ent.animation.curranim = g_ANIM_WALL_DOWN_R
end
ent.body.vy = ent.body.currupspeed*0.25
end
if ent.isup and not ent.isdown then -- UP
if ent.washurt > 0 or ent.wasbadlyhurt > 0 then -- animations in ent system
else ent.animation.curranim = g_ANIM_WALL_UP_R
end
ent.body.vy = -ent.body.currupspeed*0.01
elseif ent.isdown and not ent.isup then -- DOWN
if ent.washurt > 0 or ent.wasbadlyhurt > 0 then -- animations in ent system
else ent.animation.curranim = g_ANIM_WALL_DOWN_R
end
ent.body.vy = ent.body.currupspeed*0.05
end
ent.wasonwall = true
-- IS ON SPRING
elseif ent.isspringcontacts then
-- if ent.isplayer1 then print("isspringcontacts", dt) end
-- IS IN THE AIR
else
-- if ent.isplayer1 then print("isintheair", dt) end
-- anims
if ent.isplayer1 and ent.currlives > 0 then
if ent.washurt > 0 or ent.wasbadlyhurt > 0 then -- animations in ent system
elseif ent.body.vy < 0 then ent.animation.curranim = g_ANIM_JUMPUP_R -- going UP
else ent.animation.curranim = g_ANIM_JUMPDOWN_R -- going DOWN
end
end
-- movements
if ent.isleft and not ent.isright then -- LEFT
ent.flip = -1
if ent.body.currdashtimer > 0 then
ent.body.vx -= ent.body.currspeed*ent.body.dashmultiplier
else
if ent.wasonwall then -- vx acceleration
ent.body.vx = -ent.body.currspeed*1.5 -- 2, magik XXX
else
ent.body.vx = -ent.body.currspeed
end
end
elseif ent.isright and not ent.isleft then -- RIGHT
ent.flip = 1
if ent.body.currdashtimer > 0 then
ent.body.vx += ent.body.currspeed*ent.body.dashmultiplier
else
if ent.wasonwall then -- vx acceleration
ent.body.vx = ent.body.currspeed*1.5 -- 2, magik XXX
else
ent.body.vx = ent.body.currspeed
end
end
else
ent.body.vx *= 0.9 -- 0.99, [0, 1], GAMEPLAY, some air friction, you choose!
end
if ent.isup and not ent.isdown and not ent.wasup
and ent.body.currcoyotetimer > 0 and ent.body.currjumpcount > 0 then -- UP
ent.wasup = true -- you can comment this line, GAMEPLAY WALLS JUMPING
ent.body.currcoyotetimer = 0
ent.body.currjumpcount -= 1
if ent.body.vy >= 0 then -- prevent double jump when fast pressing up!
ent.body.vy = -ent.body.currupspeed
end
if ent.wasonladder then -- attenuate ent jumping off on top of ladder
ent.body.vy *= 0.5
ent.wasonladder = false
end
elseif ent.isdown and not ent.isup and not ent.wasdown then -- DOWN
ent.wasdown = true -- ok
end
end
-- move & flip
ent.pos = vector(nextx, nexty)
ent.sprite:setPosition(ent.pos + vector(ent.collbox.w/2, -ent.h/2+ent.collbox.h))
-- if ent.animation then
ent.animation.bmp:setScale(ent.sx*ent.flip, ent.sy)
-- end
end
What it does:
- runs only once when it is called
- affects only entities which have a spritelayer variable (id) and a sprite variable (id)
- when an Entity is added to tiny-ecs World, the System adds the Entity to its Sprite layer
- when an Entity is removed from tiny-ecs World, the System removes the Entity from its Sprite layer unless it has a ispersistent id
Next?
That was a big one, the last systems will be much smaller 😊 Systems are fairly straight forward and fairly short for what they achieve.
We have covered the first set of systems, the next System is the heart of the game: the collision System.
Prev.: Tuto tiny-ecs 2d platformer Part 9 Systems
Next: Tuto tiny-ecs 2d platformer Part 11 Systems 3
Tutorial - tiny-ecs 2d platformer
