X-Git-Url: https://eleni.mutantstargoat.com/git/?p=bootboot;a=blobdiff_plain;f=bb.asm;h=743dc9fce94ee2ffe6f08da2924f0cb48cc89f48;hp=4eb536e154e258f9672441d4b194c6e996b1f8f5;hb=5d0f7f94295e7a09e23dbf5b69ca965af0da3e8e;hpb=f950c9758ede9c9a2cb2889e4863cee546565a7b

diff --git a/bb.asm b/bb.asm
index 4eb536e..743dc9f 100644
--- a/bb.asm
+++ b/bb.asm
@@ -175,16 +175,33 @@ main_loop:
 	jnz .static_loop
 
 	; draw lovebug
-	mov di, 32000
+	mov di, (200 - 32) * 320 + 160 - 16
+	mov ax, [num_frames]
+	shr ax, 2		; /4
+	cmp ax, 200 - 32
+	jz .end
+	mov bx, ax
+	shl ax, 8
+	shl bx, 6
+	add ax, bx
+	sub di, ax
+	call rand
+	and ax, 3		; random value in 0, 15
+	sub ax, 1		; random value in -3, 12
+	add di, ax
 	mov si, lovebug
 	call blit32
 
 ; wait for vblank
-.vsync:
+.vsync_blank:
 	mov dx, 3dah
 	in al, dx
+	and al, 8
+	jnz	.vsync_blank
+.vsync_visible:
+	in al, dx
 	and al, 8 		; the 4th bit is 1 when we are in the vertical blanking period
-	jnz	.vsync
+	jz .vsync_visible
 
 ; copy backbuffer to video memory
 	push es
@@ -201,12 +218,16 @@ main_loop:
 	pop es
 
 	inc word [num_frames]
+;   moved above:
+;	cmp word [num_frames], 200 - 32
+;	jz .end
 
 	in al, 64h		; 60h = keyb data port, 64h = keyb status port
 	and al, 1		; 1 = OUTBUF_FULL = the keyb controller out buf is full
 	jz main_loop	; no key pressed, loop back
 	in al, 60h		; reads the keyb that was pressed to reset the flag
 
+.end:
 ; re-enable all interrupts
 	sti