From 3d6abe38d72347d6b254070edb50cf56f236f5d7 Mon Sep 17 00:00:00 2001
From: "B. Watson" <urchlay@slackware.uk>
Date: Tue, 8 Nov 2022 03:07:04 -0500
Subject: Add/fix comments, profiling for initscreen and render. Runtime ~3:05
 now.

---
 dla.s | 30 ++++++++++++++++++++++++++++--
 1 file changed, 28 insertions(+), 2 deletions(-)

(limited to 'dla.s')

diff --git a/dla.s b/dla.s
index bae1b39..4bc8559 100644
--- a/dla.s
+++ b/dla.s
@@ -355,7 +355,10 @@ jsaveimage:
  jmp saveimage
 
 ;;; Subroutine: set_limits
-;;; Sets the X/Y min/max limits based on circlesize
+;;; Sets the X/Y min/max limits based on circlesize.
+;;; Preserves Y register, trashes everything else.
+; The selfmod_* addresses are operands to compare instructions,
+; found in drunkwalk.s.
 set_limits:
  ldx circlesize
  lda xmin,x
@@ -369,9 +372,20 @@ set_limits:
  rts
 
 ;;; Subroutine: initscreen
-;;; clear screen memory and point ANTIC to our display list.
+;;; Clear screen and pixarray memory, point ANTIC to our display list.
 ;;; no arguments. trashes all registers.
+; Take 18 jiffies (0.3 sec). Probably not worth optimizing.
+; Uncomment next line to see how long it takes (check locations
+; $0600-$0603 in atari800 debugger).
+; INITSCR_PROFILE = 1
 initscreen:
+.ifdef INITSCR_PROFILE
+ lda RTCLOK+1
+ sta $0600
+ lda RTCLOK+2
+ sta $0601
+.endif
+
  lda #<screen
  sta pixptr
  lda #>screen
@@ -405,6 +419,9 @@ isloop:
  lda #>dlist
  sta SDLSTH
 
+ ; sneaky: tell the E: driver that screen RAM starts in our buffer,
+ ; so we can use printchr and printchrx to print to the bottom text
+ ; line in graphics mode.
  lda #<textbuf
  sta SAVMSC
  lda #>textbuf
@@ -413,10 +430,19 @@ isloop:
  sta ROWCRS
  sta COLCRS
  sta COLCRS+1
+.ifdef INITSCR_PROFILE
+ lda RTCLOK+1
+ sta $0602
+ lda RTCLOK+2
+ sta $0603
+.endif
  rts
 
  .include "render.s"
 
+;;; Subroutine: plot
+;;; Turns on the pixel at (cursor_x, cursor_y), in pixarray.
+;;; Trashes all registers (and pixptr).
 plot:
  ldx cursor_y
  lda lineaddrs_l,x
-- 
cgit v1.2.3