adding particles

particles.lua

@@ -0,0 +1,150 @@
+-- title:  simple particle system
+-- author: pixelbath
+-- desc:   basic particle system, first used in Alter Ego by Kyuchumimo
+-- script: lua
+
+t=0
+x=96
+y=24
+
+particles = {}
+particletype = 'stars'
+local starcolors = { 1, 2, 13, 15}
+-- numparticles = number of particles to show
+-- particletype = rain|snow|stars
+function particleinit(numparticles, type)
+	-- initialize
+	particles = {}
+	particletype = type
+	for i = 0, numparticles do
+		table.insert(particles, {
+			x = math.random() * 240,
+			y = math.random() * 136,
+			lastx = 0,
+			lasty = 0,
+			color = 2,
+			t = 0,
+			vel = 0,
+		})
+	end
+	if particletype == 'stars' then
+		for i = 1, #particles do
+			particles[i].twinkle = math.random() > 0.49 -- randomly pick true/false
+			particles[i].color = starcolors[math.random(#starcolors)]
+		end
+	end
+	if particletype == 'rain' then
+		for i = 1, #particles do
+			particles[i].vel = math.random(3) + 1
+			if particles[i].vel > 2.5 then
+				particles[i].color = 8
+			end
+		end
+	end
+	if particletype == 'snow' then
+		for i = 1, #particles do
+			particles[i].color = 15
+			particles[i].vel = math.random() + 0.2
+		end
+	end
+end
+
+function particleupdate()
+	if particletype == 'stars' then
+		for i = 1,#particles do
+			local p = particles[i]
+			if not p.twinkle then goto continueTwinkle end
+			::continueTwinkle::
+			if t % 15 == 0 and math.random() > 0.1 then
+				p.color = starcolors[math.random(#starcolors)]
+			end
+		end
+	end
+	if particletype == 'rain' then
+		for i = 1,#particles do
+			local p = particles[i]
+			if p.lasty and p.lasty > 136 then
+				p.y = 0
+				p.lasty = 0
+				p.x = math.random() * 240
+			end
+			p.lasty = p.y
+			p.lastx = p.x
+			p.x = p.x - p.vel / 5
+			p.y = p.y + p.vel * 1.5
+		end
+	end
+	if particletype == 'snow' then
+		for i = 1,#particles do
+			local p = particles[i]
+			if p.y and p.y > 136 then
+				p.y = 0
+				p.lasty = 0
+				p.x = math.random() * 240
+			end
+			p.x = p.x - (math.random() - 0.4)
+			p.y = p.y + p.vel
+		end
+	end
+end
+
+function particledraw()
+	if (particletype == 'rain') then
+		for i = 1,#particles do
+			local p = particles[i]
+			line(p.x, p.y, p.lastx, p.lasty, p.color)
+		end
+		return
+	end
+	for i = 1,#particles do
+		local p = particles[i]
+		pix(p.x, p.y, p.color)
+	end
+end
+
+-- init here for title screen
+particleinit(150, 'snow')
+
+
+function TIC()
+
+	if btn(0) then y=y-1 end
+	if btn(1) then y=y+1 end
+	if btn(2) then x=x-1 end
+	if btn(3) then x=x+1 end
+
+	cls(13)
+	spr(1+t%60//30*2,x,y,14,3,0,0,2,2)
+	print("HELLO WORLD!",84,84)
+
+	particleupdate()
+	particledraw()
+	
+	t=t+1
+end
+
+-- <TILES>
+-- 001:eccccccccc888888caaaaaaaca888888cacccccccacc0ccccacc0ccccacc0ccc
+-- 002:ccccceee8888cceeaaaa0cee888a0ceeccca0ccc0cca0c0c0cca0c0c0cca0c0c
+-- 003:eccccccccc888888caaaaaaaca888888cacccccccacccccccacc0ccccacc0ccc
+-- 004:ccccceee8888cceeaaaa0cee888a0ceeccca0cccccca0c0c0cca0c0c0cca0c0c
+-- 017:cacccccccaaaaaaacaaacaaacaaaaccccaaaaaaac8888888cc000cccecccccec
+-- 018:ccca00ccaaaa0ccecaaa0ceeaaaa0ceeaaaa0cee8888ccee000cceeecccceeee
+-- 019:cacccccccaaaaaaacaaacaaacaaaaccccaaaaaaac8888888cc000cccecccccec
+-- 020:ccca00ccaaaa0ccecaaa0ceeaaaa0ceeaaaa0cee8888ccee000cceeecccceeee
+-- </TILES>
+
+-- <WAVES>
+-- 000:00000000ffffffff00000000ffffffff
+-- 001:0123456789abcdeffedcba9876543210
+-- 002:0123456789abcdef0123456789abcdef
+-- </WAVES>
+
+-- <SFX>
+-- 000:000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000304000000000
+-- </SFX>
+
+-- <PALETTE>
+-- 000:1a1c2c5d275db13e53ef7d57ffcd75a7f07038b76425717929366f3b5dc941a6f673eff7f4f4f494b0c2566c86333c57
+-- </PALETTE>
+