needed more particles

fireworks.lua

@@ -14,13 +14,39 @@ colors = {
 
 seeds = {}
 
-function add_firework_seed(xpos)
-	table.insert(seeds, {
-		vel_y = -1 + (math.random() * -1),
-		startx = math.random(240),
-		color = math.random(3)+1,
-		x = xpos, y = 136,
-	})
+-- basic todo:
+
+--	seed
+--		spark trail
+--		timed fuse
+--		velocity x/y
+--		explosion shape
+--		children (stars):
+--			x, y, vel_x, vel_y, color, has_trails, life,
+
+-- types:
+--		willow - each star trails particles with low inertia
+--		grains of wheat / candles - shooting upward, possibly at angles
+--		rainbow chrysanthemums - red/white/blue spherical burst, ends with trail of sparks
+--		orange peony - similar to mums, but no trail of sparks
+--		peacock feather / dragonfly - lots of blue/orange with long tails
+--		green bees - spherical burst, curving trajectories with long green tails
+--		crossette - multiple large stars that burst into smaller stars with a loud crackling
+--		falling leaves - stars twinkle and flutter down
+
+function create_star(xpos, ypos, xvel, yvel, color)
+	local star_color = color or math.random(3)+1
+	local new_star = {
+		vel_x = xvel,
+		vel_y = yvel,
+		color = star_color,
+		x = xpos, y = ypos,
+		num_children = 0,
+		t = 0, det = 200,
+		shape = nil,
+		is_seed = false,
+	}
+	return new_star
 end
 
 function fireworks_update()
@@ -28,36 +54,61 @@ function fireworks_update()
 	for i = 1, #seeds do
 		local this_seed = seeds[i]
 		
+		-- friction and gravity
 		this_seed.vel_y = this_seed.vel_y + 0.012
-		this_seed.y = this_seed.y + this_seed.vel_y
+		this_seed.x = this_seed.x + (this_seed.vel_x * 0.9)
+		this_seed.y = this_seed.y + (this_seed.vel_y * 0.9)
 
 		pix(this_seed.x, this_seed.y, this_seed.color)
+		-- print(this_seed.t..','..this_seed.det, this_seed.x + 2, this_seed.y, this_seed.color, false, 1, true)
 
-		-- reaching the apex
-		if this_seed.vel_y > -0.1 then
-			if math.random() > 10 * math.abs(this_seed.vel_y) then
-				spawn_explosion(this_seed.x, this_seed.y, this_seed.color)
+		-- ways to remove particles
+		if this_seed.y > 136 then
+			table.insert(delete_seeds, i)
+		end
+		if this_seed.det > 0 and this_seed.t > this_seed.det then
+			spawn_explosion(this_seed)
+			table.insert(delete_seeds, i)
+		end
+		if this_seed.is_seed then
+			if this_seed.vel_y > -0.1 and math.random() > 10 * math.abs(this_seed.vel_y) then
+				spawn_explosion(this_seed)
 				table.insert(delete_seeds, i)
 			end
 		end
+
+		this_seed.t = this_seed.t + 1
 	end
 	for i = #delete_seeds, 1, -1 do
 		table.remove(seeds, delete_seeds[i])
 	end
 end
 
-function spawn_explosion(xpos, ypos, color)
-
+function spawn_explosion(star)
+	if star.num_children == 0 then return end
+	if star.shape == nil then star.shape = 'peony' end
+	
+	if star.shape == 'peony' then
+		local angle = 2 * math.pi / star.num_children
+		for i = 1, star.num_children do
+			local xvel = math.cos(angle * i) * ((math.random() * 0.5) + 0.3)
+			local yvel = math.sin(angle * i) * ((math.random() * 0.5) + 0.3)
+			local child_star = create_star(star.x, star.y, xvel, yvel, star.color)
+			child_star.det = math.random() * 30 + 50
+			table.insert(seeds, child_star)
+		end
+	end
 end
 
-add_firework_seed(50)
-
 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
+	if btnp(4) then
+		local seed_yvel = -1 + (math.random() * -1)
+		local seed = create_star(math.random(240), 136, 0, seed_yvel)
+		seed.shape = 'peony'
+		seed.num_children = 100
+		seed.is_seed = true
+		table.insert(seeds, seed)
+	end
 
 	cls(0)
 	fireworks_update()