git.y1.nz

commit fbd765331322fd54f9e9117ea8ac2cb3df7460c3
parent d009bfeeda801a44bea741c794be463782b81956
Author: Michel Iwaniec <46843052+michel-iwaniec@users.noreply.github.com>
Date:   Sun, 20 Oct 2024 00:59:54 +0100

NES: Fix bugs with non-multiple-of-2 (/4) map width in set_bkg_submap_attributes (#722)

* Add +1 before shift in inline function set_bkg_submap_attributes
* Add-with carry after right-shift of width in set_bkg_submap_attributes_nes16x16
Diffstat:
M
gbdk-lib/include/nes/nes.h
2
+-
M
gbdk-lib/libc/targets/mos6502/nes/set_tile_submap_attributes.s
1
+

2 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/gbdk-lib/include/nes/nes.h b/gbdk-lib/include/nes/nes.h
@@ -765,7 +765,7 @@ void set_bkg_submap_attributes_nes16x16(uint8_t x, uint8_t y, uint8_t w, uint8_t
 */
 inline void set_bkg_submap_attributes(uint8_t x, uint8_t y, uint8_t w, uint8_t h, const uint8_t *attributes, uint8_t map_w)
 {
-    set_bkg_submap_attributes_nes16x16(x >> 1, y >> 1, (w + 1) >> 1, (h + 1) >> 1, attributes, map_w >> 1);
+    set_bkg_submap_attributes_nes16x16(x >> 1, y >> 1, (w + 1) >> 1, (h + 1) >> 1, attributes, (map_w + 1) >> 1);
 }
 
 
diff --git a/gbdk-lib/libc/targets/mos6502/nes/set_tile_submap_attributes.s b/gbdk-lib/libc/targets/mos6502/nes/set_tile_submap_attributes.s
@@ -101,6 +101,7 @@ _set_bkg_submap_attributes_nes16x16::
     sta *.src_tiles+1
     lda *.map_width
     lsr
+    adc #0 ; Fix problem with skewed offset when original tilemap is not a multiple-of-two
     sta *.map_width
     ldx *.ypos
     jsr __muluchar

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