Files
Techmino/parts/backgrounds/quarks.lua
2022-10-29 02:22:52 +08:00

146 lines
3.9 KiB
Lua

local gc=love.graphics
local hsv=COLOR.hsv
local circle,push,pop,rot,translate,setColor=gc.circle,gc.push,gc.pop,gc.rotate,gc.translate,gc.setColor
local rnd,sin,cos,log,ceil=math.random,math.sin,math.cos,math.log,math.ceil
local back={}
local qX,qY,qdX,qdY={},{},{},{} -- quark data in SoA [size, X, Y, dx, dy, color]
local ptcclr={{1,0,0},{0,1,0},{0,0,1}}
local apcclr={{0,1,1},{1,0,1},{1,1,0}}
local blasts={} -- data about annihilation blasts from particles and antiparticles colliding
local ptc={} -- particle-antiparticle data (antiparticle is a mirror of particle)
local nextpair
local W,H,size
local quarkCount=400
local function spawnQuarkRandom(i)
qX[i]=rnd(W)-10 -- X
qY[i]=rnd(H)-10 -- Y
local theta=rnd()*MATH.tau
qdX[i]=cos(theta)*300 -- dx
qdY[i]=sin(theta)*300 -- dy
end
local function spawnQuarkEdge(i)
local side=rnd(4)
if side==1 then -- Up edge of screen
qX[i]=rnd(SCR.x-10,SCR.ex+10)
qY[i]=SCR.y-10
elseif side==2 then -- Right edge of screen
qX[i]=SCR.ex+10
qY[i]=rnd(SCR.y-10,SCR.ey+10)
elseif side==3 then -- Down edge of screen
qX[i]=rnd(SCR.x-10,SCR.ex+10)
qY[i]=SCR.ey+10
elseif side==4 then -- Left edge of screen
qX[i]=SCR.x-10
qY[i]=rnd(SCR.y-10,SCR.ey+10)
end
local theta=rnd()*MATH.tau
qdX[i]=cos(theta)*300 -- dx
qdY[i]=sin(theta)*300 -- dy
end
local function spawnParticlePair()
ptc[#ptc+1]={
x=rnd(W)-10,
y=rnd(H)-10,
dist=0,
theta=rnd()*MATH.tau,
v=500,
c=rnd(3),
}
end
local function spawnBlast(_x,_y)
blasts[#blasts+1]={x=_x,y=_y,t=0}
end
function back.init()
qX,qY,qdX,qdY={},{},{},{}
blasts={}
ptc={}
nextpair=0
BG.resize(SCR.w,SCR.h)
end
function back.resize(w,h)
W,H=w+20,h+20
for i=1,quarkCount do spawnQuarkRandom(i) end
size=2.6*SCR.k
end
function back.update(dt)
-- Move far-away quarks
for i=1,quarkCount do
qX[i]=qX[i]+qdX[i]*dt
qY[i]=qY[i]+qdY[i]*dt
if qX[i]<SCR.x-26 or qX[i]>SCR.ex+26 or qY[i]<SCR.y-26 or qY[i]>SCR.ey+26 then
spawnQuarkEdge(i)
end
end
-- Particle pair attraction & destruction
for i=#ptc,1,-1 do
local p=ptc[i]
if p then
p.dist=p.dist+p.v*dt
p.v=p.v-p.dist^2*dt
-- Destroy colliding particle pairs
if p.dist<=10 and p.v<=0 then
spawnBlast(p.x,p.y)
table.remove(ptc,i)
end
end
end
-- Age blasts, delete old blasts
for i=#blasts,1,-1 do
if blasts[i] then
blasts[i].t=blasts[i].t+dt
if blasts[i].t>=1 then
table.remove(blasts,i)
end
end
end
-- Spawn particle pairs
nextpair=nextpair-dt
if nextpair<=0 then
spawnParticlePair()
nextpair=rnd()*4
end
end
function back.draw()
gc.clear(.08,.04,.01)
translate(-10,-10)
-- Draw quarks in R/G/B
setColor(1,0,0,.8) for i=1, math.floor(quarkCount/3) do circle('fill',qX[i],qY[i],size) end
setColor(0,1,0,.8) for i=math.floor(quarkCount/3)+1, math.floor(quarkCount*2/3) do circle('fill',qX[i],qY[i],size) end
setColor(0,0,1,.8) for i=math.floor(quarkCount*2/3)+1,quarkCount do circle('fill',qX[i],qY[i],size) end
for i=1,#ptc do
local p=ptc[i]
push()
translate(p.x,p.y)
rot(p.theta)
setColor(ptcclr[p.c])
circle('fill', p.dist,0,4*size)
setColor(apcclr[p.c])
circle('fill',-p.dist,0,4*size)
pop()
end
for i=1,#blasts do
local t=blasts[i].t
setColor(hsv(-80*t,1-1.7*log(5*t,10),1,1-t))
circle('fill',blasts[i].x,blasts[i].y,62*t^.3)
end
end
function back.discard()
qX,qY,qdX,qdY,qC=nil
ptc,blasts=nil
collectgarbage()
end
return back