From 820efb5b1e9e68781482470778053ac47282c4b7 Mon Sep 17 00:00:00 2001
From: John Tsiombikas <nuclear@member.fsf.org>
Date: Wed, 16 Dec 2020 03:56:20 +0200
Subject: [PATCH] attempt to blur up

---
 Makefile       |    4 ++++
 bootsplash.asm |   21 +++++++++++++++++++--
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 2ae07cf..11d9094 100644
--- a/Makefile
+++ b/Makefile
@@ -11,6 +11,10 @@ $(bin): bootsplash.asm nuclear.rle
 nuclear.rle: nuclear.img
 	cat $< | rle/rle >$@ 2>rle.log
 
+.PHONY: clean
+clean:
+	rm -f $(bin)
+
 .PHONY: run
 run: $(img)
 	qemu-system-i386 -fda $<
diff --git a/bootsplash.asm b/bootsplash.asm
index 03e3a50..130073d 100644
--- a/bootsplash.asm
+++ b/bootsplash.asm
@@ -137,15 +137,32 @@ splash:
 
 	; effect main loop
 .mainloop:
-	mov cx, spawn_rate	; spawn 10 points per frame
+	mov cx, spawn_rate
 .spawn:	call rand
 	xor edx, edx
 	div dword [num_spawn_pos]	; edx <- rand % num_spawn_pos
 	mov bx, [es:edx * 2]		; grab one of the spawn positions
-	mov byte [fs:bx], 1		; plot a pixel there
+	mov byte [fs:bx], 0xff		; plot a pixel there
 	dec cx
 	jnz .spawn
 
+	; blur the screen upwards
+	mov ax, fs
+	mov ds, ax	; let's use ds for this to avoid long instructions
+	xor bx, bx	; use: pointer
+	xor ax, ax	; use: pixel accum
+	xor dx, dx	; use: second pixel
+.blurloop:
+	mov al, [bx]
+	mov dl, [bx + 320]
+	add ax, dx
+	shr ax, 1
+	mov [bx], al
+	inc bx
+	cmp bx, 64000 - 320
+	jnz .blurloop
+
+
 	; wait until the start of vblank
 .waitvblank:
 	mov dx, 3dah
-- 
1.7.10.4