From dd34ad0a373106191b0b1831ecd48521a6aae997 Mon Sep 17 00:00:00 2001
From: Kistaro Windrider <kistaro@gmail.com>
Date: Thu, 29 Feb 2024 21:19:26 -0800
Subject: [PATCH] by Pyrex: cloud animation prototype

---
 clouds3.p8 | 124 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 124 insertions(+)
 create mode 100644 clouds3.p8

diff --git a/clouds3.p8 b/clouds3.p8
new file mode 100644
index 0000000..d69c74e
--- /dev/null
+++ b/clouds3.p8
@@ -0,0 +1,124 @@
+pico-8 cartridge // http://www.pico-8.com
+version 42
+__lua__
+
+function _init()
+	cmgr0=cloud_manager:new(15,51,5,1,5,13)
+	cmgr1=cloud_manager:new(12,51-8,7,4,13,6)
+	cmgr2=cloud_manager:new(6,51-14,9,3,15,7)
+	cmgr0.step=5
+	cmgr1.step=4
+	cmgr2.step=3
+ last_x=0
+ x=0
+ dx=0
+end
+
+
+function _update60()
+ if (btn(4)) dx+=1.0
+ dx*=0.75
+ x+=dx
+ while last_x<x do
+		cmgr0:update()
+		cmgr1:update()
+		cmgr2:update()
+		last_x+=1
+	end
+end
+
+function _draw()
+ cls(12)
+	cmgr0:draw()
+	cmgr1:draw()
+	cmgr2:draw()
+end
+
+cloud_manager={}
+function cloud_manager:new(sparseness,y,h,oval_h,c0,c1)
+ local c={
+		frame=0,
+		clouds={},
+		bitplanes=split"241,242,244,248",
+		step=1,
+		sparseness=sparseness,
+		y=y,
+		c0=c0,
+		c1=c1,
+		h=h,
+		oval_h=oval_h
+	}
+	setmetatable(c,{__index=cloud_manager})
+	return c
+end
+
+function cloud_manager:update()
+ self.frame+=1
+	if self.frame%(self.step*self.sparseness) == 0 then
+	 local bp=deli(self.bitplanes,1)
+		add(self.clouds,{x=127,y=rnd()*self.h,w=flr(rnd()*16)+16,plane=bp})
+		add(self.bitplanes,bp)
+	end
+	 
+	if self.frame%self.step==0 then
+	 local clouds2={}
+	 for c in all(self.clouds) do
+	  c.x-=1
+	  if (c.x+c.w>0) add(clouds2,c)
+	 end
+	 self.clouds=clouds2
+	end
+end
+
+function cloud_manager:draw()
+	local r0=96
+	local r1=96+16
+	local h=self.h+self.oval_h+1
+	assert(h<=16)
+
+	-- render to spritesheet
+	poke(0x5f55,0x00)
+	rectfill(0,r0,127,r0+h,0)
+	
+	-- use bitplanes
+	for c in all(self.clouds) do
+		poke(0x5f5e,c.plane)
+		ovalfill(c.x,r0+c.y,c.x+c.w,r0+c.y+self.oval_h,15)
+	end
+	poke(0x5f5e,255)
+	
+	-- render from high memory
+	-- to higher memory
+	rectfill(0,r1,127,r1+h,0)
+	
+	for i in all(split"0,1,2,4,8") do
+		palt(i,true)
+	end
+	for i=0,15 do
+		pal(i,7)
+	end
+	
+	poke(0x5f5e,0xf1)
+	sspr(0,r0,128,h,0,r1) 
+	poke(0x5f5e,0xf2)
+	sspr(0,r0,128,h,1,r1+1) 
+	sspr(0,r0,128,h,5,r1+1) 
+	poke(0x5f5e,255)
+	
+	-- render to screen
+	poke(0x5f55,0x60)
+	pal()
+	pal(1,self.c1)
+	pal(2,self.c0)
+	pal(3,self.c1)
+	sspr(0,r1,128,h,0,self.y)
+	pal()
+end
+
+__gfx__
+00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00700700000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00077000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00077000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00700700000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000