add time step modifiers

1 files changed, 18 insertions, 6 deletions

diff --git a/main.s b/main.s
index a548e94..14b10a2 100644
--- a/main.s
+++ b/main.s
@@ -824,21 +824,30 @@ poll_loop:
 	movb $EV_EXIT, (event)
 	jmp exit
 
-	1:
-	cmpb $'r, %al
+	1: cmpb $'r, %al
 	jne 1f
 	movb $EV_RESTART, (event)
 
-	1:
-	cmpb $' ', %al
+	1: cmpb $' ', %al
 	jne 1f
 	notl (pause)
 
-	1:
-	cmpb $'p', %al
+	1: cmpb $'p', %al
 	jne 1f
 	movb $EV_PRINT, (event)
 
+	1: cmpb $'-', %al
+	jne 1f
+	cmpl $TIMESTEP, (timespec + 4)
+	jle 1f
+	subl $TIMESTEP, (timespec + 4)
+
+	1: cmpb $'=', %al
+	jne 1f
+	cmpl $TIMEUPTO, (timespec + 4)
+	jge 1f
+	addl $TIMESTEP, (timespec + 4)
+
 	1:
 	jmp poll_loop
 
@@ -1029,6 +1038,9 @@ str_fcntl:	.asciz "fcntl"
 sig_die_set:
 	.byte SIGINT, SIGQUIT, SIGILL, SIGABRT, SIGBUS, SIGTERM, SIGSEGV, 0
 
+.equ TIMEUPTO, 500000000
+.equ TIMESTEP, 25000000
+
 timespec:
 	.int 0
 	.int 100000000