From 62ce62777d6c64c38ed292cd3ac7bfeee8f7182d Mon Sep 17 00:00:00 2001
From: lif <>
Date: Thu, 4 Jan 2024 22:52:18 -0800
Subject: [PATCH] fix screen edge partial sprite tile drawing in bigend

---
 video.cc | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/video.cc b/video.cc
index 1bbc6af..0d404b1 100644
--- a/video.cc
+++ b/video.cc
@@ -245,6 +245,7 @@ static inline void rend_part_tile_Nbpp(u32 bg_comb, u32 px_comb,
     u16 pxflg = px_comb | tilepal;
     const u16 *subpal = &paltbl[tilepal];
     // Read packed pixel data, skip start pixels
+    // TODO: account for big-endian byte reversal here
     u32 tilepix = eswap32(*(u32*)tile_ptr);
     if (hflip) tilepix <<= (start * 4);
     else       tilepix >>= (start * 4);
@@ -1035,7 +1036,7 @@ static inline void render_obj_part_tile_Nbpp(
     for (u32 i = start; i < end; i++, dest_ptr++) {
       // Honor hflip by selecting bytes in the correct order
       u32 sel = hflip ? (7-i) : i;
-      u8 pval = tile_ptr[sel];
+      u8 pval = tile_ptr[swizzle_b(sel)];
       // Alhpa mode stacks previous value
       if (pval) {
         if (rdtype == FULLCOLOR)
@@ -1059,7 +1060,7 @@ static inline void render_obj_part_tile_Nbpp(
     for (u32 i = start; i < end; i++, dest_ptr++) {
       u32 selb = hflip ? (3-i/2) : i/2;
       u32 seln = hflip ? ((i & 1) ^ 1) : (i & 1);
-      u8 pval = (tile_ptr[selb] >> (seln * 4)) & 0xF;
+      u8 pval = (tile_ptr[swizzle_b(selb)] >> (seln * 4)) & 0xF;
       const u16 *subpal = &pal[palette];
       if (pval) {
         if (rdtype == FULLCOLOR)