attempt to blur up

[bootsplash] / bootsplash.asm

diff --git a/bootsplash.asm b/bootsplash.asm
index 03e3a50..130073d 100644 (file)
--- 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