[src/trunk]: src/sys/dev/ic Don't need a separate bit expansion table for the...

[uwe <uwe%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/76d5a5af1b72
branches:  trunk
changeset: 546989:76d5a5af1b72
user:      uwe <uwe%NetBSD.org@localhost>
date:      Sat May 10 16:20:23 2003 +0000

description:
Don't need a separate bit expansion table for the cursor mask.

diffstat:

 sys/dev/ic/igsfb.c    |  52 ++++++++++++++++++++++----------------------------
 sys/dev/ic/igsfbvar.h |  16 ++------------
 2 files changed, 26 insertions(+), 42 deletions(-)

diffs (162 lines):

diff -r 91a189adb9b8 -r 76d5a5af1b72 sys/dev/ic/igsfb.c
--- a/sys/dev/ic/igsfb.c        Sat May 10 16:12:02 2003 +0000
+++ b/sys/dev/ic/igsfb.c        Sat May 10 16:20:23 2003 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: igsfb.c,v 1.9 2003/05/10 15:25:19 uwe Exp $ */
+/*     $NetBSD: igsfb.c,v 1.10 2003/05/10 16:20:23 uwe Exp $ */
 
 /*
  * Copyright (c) 2002, 2003 Valeriy E. Ushakov
@@ -31,7 +31,7 @@
  * Integraphics Systems IGA 168x and CyberPro series.
  */
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: igsfb.c,v 1.9 2003/05/10 15:25:19 uwe Exp $");
+__KERNEL_RCSID(0, "$NetBSD: igsfb.c,v 1.10 2003/05/10 16:20:23 uwe Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -107,7 +107,7 @@
 static int     igsfb_init_video(struct igsfb_devconfig *);
 static void    igsfb_init_cmap(struct igsfb_devconfig *);
 static u_int16_t igsfb_spread_bits_8(u_int8_t);
-static void    igsfb_init_bit_tables(struct igsfb_devconfig *);
+static void    igsfb_init_bit_table(struct igsfb_devconfig *);
 static void    igsfb_init_wsdisplay(struct igsfb_devconfig *);
 
 static void    igsfb_blank_screen(struct igsfb_devconfig *, int);
@@ -303,8 +303,8 @@
        igs_ext_write(dc->dc_iot, dc->dc_ioh,
                      IGS_EXT_SPRITE_DATA_HI, (croffset >> 8) & 0xf);
 
-       /* init bit expanders for cursor sprite data */
-       igsfb_init_bit_tables(dc);
+       /* init the bit expansion table for cursor sprite data conversion */
+       igsfb_init_bit_table(dc);
 
        /* XXX: fill dc_cursor and use igsfb_update_cursor() instead? */
        memset(&dc->dc_cursor, 0, sizeof(struct igs_hwcursor));
@@ -416,7 +416,7 @@
 
 /*
  * Spread a byte (abcd.efgh) into two (0a0b.0c0d 0e0f.0g0h).
- * Helper function for igsfb_init_bit_tables().
+ * Helper function for igsfb_init_bit_table().
  */
 static u_int16_t
 igsfb_spread_bits_8(b)
@@ -433,24 +433,20 @@
 
 /*
  * Cursor sprite data are in 2bpp.  Incoming image/mask are in 1bpp.
- * Prebuild tables to expand 1bpp->2bpp, with bswapping if neccessary.
+ * Prebuild the table to expand 1bpp->2bpp, with bswapping if neccessary.
  */
 static void
-igsfb_init_bit_tables(dc)
+igsfb_init_bit_table(dc)
        struct igsfb_devconfig *dc;
 {
-       struct igs_bittab *tab = &dc->dc_bittab;
+       u_int16_t *expand = dc->dc_bexpand;
        int need_bswap = IGSFB_HW_SOFT_BSWAP(dc);
+       u_int16_t s;
        u_int i;
 
        for (i = 0; i < 256; ++i) {
-               u_int16_t s = igsfb_spread_bits_8(i);
-
-               if (need_bswap)
-                       s = bswap16(s);
-
-               tab->iexpand[i] = s;
-               tab->mexpand[i] = (s << 1) | s; /* invariant over bswap16(s) */
+               s = igsfb_spread_bits_8(i);
+               expand[i] = need_bswap ? bswap16(s) : s;
        }
 }
 
@@ -847,14 +843,14 @@
  * Convert incoming 1bpp cursor image/mask into native 2bpp format.
  */
 static void
-igsfb_convert_cursor_data(dc, w, h)
+igsfb_convert_cursor_data(dc, width, height)
        struct igsfb_devconfig *dc;
-       u_int w, h;
+       u_int width, height;
 {
        struct igs_hwcursor *cc = &dc->dc_cursor;
-       struct igs_bittab *btab = &dc->dc_bittab;
+       u_int16_t *expand = dc->dc_bexpand;
        u_int8_t *ip, *mp;
-       u_int16_t *dp;
+       u_int16_t is, ms, *dp;
        u_int line, i;
 
        /* init sprite to be all transparent */
@@ -865,20 +861,18 @@
        mp = cc->cc_mask;
        dp = cc->cc_sprite;
 
-       for (line = 0; line < h; ++line) {
-               for (i = 0; i < w; ++i) {
-                       /* NB: tables are pre-bswapped if needed */
-                       u_int16_t is = btab->iexpand[ip[i]];
-                       u_int16_t ms = btab->iexpand[mp[i]]; /* NB: _I_ */
-
+       for (line = 0; line < height; ++line) {
+               for (i = 0; i < width; ++i) {
+                       is = expand[ip[i]]; /* image: 0 -> 00, 1 -> 01 */
+                       ms = expand[mp[i]]; /*  mask: 0 -> 00, 1 -> 11 */
                        ms |= (ms << 1);
                        dp[i] = (0xaaaa & ~ms) | (is & ms);
                }
 
                /* next scanline */
-               ip += w;
-               mp += w;
-               dp += 8;        /* 2bpp, 8 pixels per short = 8 shorts */
+               ip += width;
+               mp += width;
+               dp += 8; /* 64 pixels, 2bpp, 8 pixels per short = 8 shorts */
        }
 }
 
diff -r 91a189adb9b8 -r 76d5a5af1b72 sys/dev/ic/igsfbvar.h
--- a/sys/dev/ic/igsfbvar.h     Sat May 10 16:12:02 2003 +0000
+++ b/sys/dev/ic/igsfbvar.h     Sat May 10 16:20:23 2003 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: igsfbvar.h,v 1.5 2003/05/10 01:51:56 uwe Exp $ */
+/*     $NetBSD: igsfbvar.h,v 1.6 2003/05/10 16:20:23 uwe Exp $ */
 
 /*
  * Copyright (c) 2002, 2003 Valeriy E. Ushakov
@@ -53,16 +53,6 @@
 };
 
 
-/*
- * Precomputed bit tables to convert 1bpp image/mask to 2bpp hw cursor
- * sprite.  For IGSFB_HW_BSWAP attachments they are pre-bswapped as well.
- */
-struct igs_bittab {
-       u_int16_t iexpand[256]; /* image: 0 -> 00, 1 -> 01 */
-       u_int16_t mexpand[256]; /* mask:  0 -> 00, 1 -> 11 */
-};
-
-
 struct igsfb_devconfig {
        /* io space, may be memory mapped */
        bus_space_tag_t dc_iot;
@@ -116,8 +106,8 @@
        struct igs_hwcmap dc_cmap;      /* software copy of colormap */
        struct igs_hwcursor dc_cursor;  /* software copy of cursor sprite */
 
-       /* precomputed bit tables for cursor sprite 1bpp -> 2bpp conversion */
-       struct igs_bittab dc_bittab;
+       /* precomputed bit table for cursor sprite 1bpp -> 2bpp conversion */
+       u_int16_t dc_bexpand[256];
 
        int dc_nscreens;                /* can do only a single screen */