From 08bbe7f816c278560e1cdee2314fd41ff1194e62 Mon Sep 17 00:00:00 2001
From: kub <derkub@gmail.com>
Date: Sat, 12 Dec 2020 14:59:09 +0100
Subject: [PATCH] vdp rendering, fix handling of palettes 0-2 color 14 in
 sprite drawing

---
 pico/draw.c     | 27 +++++++++++---------
 pico/draw_arm.S | 65 ++++++++++++++++++++++++++++++++++++++++++-------
 2 files changed, 71 insertions(+), 21 deletions(-)

diff --git a/pico/draw.c b/pico/draw.c
index 6318713f..a9e7bde0 100644
--- a/pico/draw.c
+++ b/pico/draw.c
@@ -187,6 +187,14 @@ TileFlipMaker(TileFlip, pix_just_write)
 
 #ifndef _ASM_DRAW_C
 
+// draw low prio sprite non-s/h pixels in s/h mode
+#define pix_nonsh(x) \
+  if (t == 0xe) pd[x]=(pal|t)&~0x80; /* disable shadow for color 14 (hw bug?) */ \
+  else if (t) pd[x]=pal|t
+
+TileNormMaker(TileNormNonSH, pix_nonsh)
+TileFlipMaker(TileFlipNonSH, pix_nonsh)
+
 // draw sprite pixels, process operator colors
 #define pix_sh(x) \
   if (t) { \
@@ -824,6 +832,9 @@ static void DrawSprite(int *sprite, int sh, int w)
   if (sh && (code&0x6000) == 0x6000) {
     if(code&0x0800) fTileFunc=TileFlipSH_markop;
     else            fTileFunc=TileNormSH_markop;
+  } else if (sh) {
+    if(code&0x0800) fTileFunc=TileFlipNonSH;
+    else            fTileFunc=TileNormNonSH;
   } else {
     if(code&0x0800) fTileFunc=TileFlip;
     else            fTileFunc=TileNorm;
@@ -1556,26 +1567,23 @@ void PicoDoHighPal555_8bit(int sh, int line, struct PicoEState *est)
     // otherwise intensity difference between this and s/h will be wrong
     t = PXCONV(t);
     t |= (t >> 4) & PXMASKL;
-    dpal[i] = dpal[0xc0/2 + i] = t;
+    dpal[i] = t;
   }
 
   // norm: xxx0, sh: 0xxx, hi: 0xxx + 7
   if (sh)
   {
     // shadowed pixels
-    for (i = 0; i < 0x40 / 2; i++)
+    for (i = 0; i < 0x40 / 2; i++) {
+      dpal[0xc0/2 + i] = dpal[i];
       dpal[0x80/2 + i] = (dpal[i] >> 1) & PXMASKH;
+    }
     // hilighted pixels
     for (i = 0; i < 0x40 / 2; i++) {
       t = ((dpal[i] >> 1) & PXMASKH) + PXMASKH;
       t |= (t >> 4) & PXMASKL;
       dpal[0x40/2 + i] = t;
     }
-    // shadowed pixels in color 14 always appear normal (hw bug?)
-    unsigned short *hpal = est->HighPal;
-    hpal[0x80 + 0x0e] = hpal[0x0e];
-    hpal[0x80 + 0x1e] = hpal[0x1e];
-    hpal[0x80 + 0x2e] = hpal[0x2e];
   }
 }
 
@@ -1611,11 +1619,6 @@ void PicoDoHighPal555(int sh, int line, struct PicoEState *est)
       t |= (t >> 4) & PXMASKL;
       dpal[0x40/2 + i] = t;
     }
-    // shadowed pixels in color 14 always appear normal (hw bug?)
-    unsigned short *hpal = est->HighPal;
-    hpal[0x80 + 0x0e] = hpal[0x0e];
-    hpal[0x80 + 0x1e] = hpal[0x1e];
-    hpal[0x80 + 0x2e] = hpal[0x2e];
   }
 }
 
diff --git a/pico/draw_arm.S b/pico/draw_arm.S
index 37441222..8b717a50 100644
--- a/pico/draw_arm.S
+++ b/pico/draw_arm.S
@@ -69,6 +69,45 @@
 
 @ shadow/hilight mode
 
+@ 
+.macro TilePixelNonSH pat lsrr offs
+.if !\lsrr
+    ands    r4, \pat, r2
+.else
+    ands    r4, \pat, r2, lsr #\lsrr
+.endif
+    beq     0f
+    cmp     r4, #0xe
+    orr     r4, r3, r4
+    biceq   r4, #0x80
+    strb    r4, [r1,#\offs]
+0:
+.endm
+
+@ TileNormNonSH (r1=pdest, r2=pixels8, r3=pal) r4: scratch, pat: register with helper pattern 0xf
+.macro TileNormNonSH pat
+    TilePixelNonSH \pat, 12, 0    @ #0x0000f000
+    TilePixelNonSH \pat,  8, 1    @ #0x00000f00
+    TilePixelNonSH \pat,  4, 2    @ #0x000000f0
+    TilePixelNonSH \pat,  0, 3    @ #0x0000000f
+    TilePixelNonSH \pat, 28, 4    @ #0xf0000000
+    TilePixelNonSH \pat, 24, 5    @ #0x0f000000
+    TilePixelNonSH \pat, 20, 6    @ #0x00f00000
+    TilePixelNonSH \pat, 16, 7    @ #0x000f0000
+.endm
+
+@ TileFlipNonSH (r1=pdest, r2=pixels8, r3=pal) r4: scratch, pat: register with helper pattern 0xf
+.macro TileFlipNonSH pat
+    TilePixelNonSH \pat, 16, 0    @ #0x000f0000
+    TilePixelNonSH \pat, 20, 1    @ #0x00f00000
+    TilePixelNonSH \pat, 24, 2    @ #0x0f000000
+    TilePixelNonSH \pat, 28, 3    @ #0xf0000000
+    TilePixelNonSH \pat,  0, 4    @ #0x0000000f
+    TilePixelNonSH \pat,  4, 5    @ #0x000000f0
+    TilePixelNonSH \pat,  8, 6    @ #0x00000f00
+    TilePixelNonSH \pat, 12, 7    @ #0x0000f000
+.endm
+
 @ this one is for hi priority layer
 .macro TilePixelShHP lsrr offs
 .if !\lsrr
@@ -1260,6 +1299,9 @@ DrawSprite:
     cmp     r12, r9, lsr #28
     beq     .dspr_shadow
 
+    tst     r9, #0x80000000
+    bne     .dspr_shnonsh
+
     cmp     r2, r2, ror #4
     beq     .dspr_SingleColor @ tileline singlecolor 
 
@@ -1293,6 +1335,20 @@ DrawSprite:
     strneb  r4, [r1], #1
     b       .dspr_loop
 
+.dspr_shnonsh:
+    tst     r9, #0x0800
+    bne     .dspr_TileFlipNonSH
+
+    @ (r1=pdest, r2=pixels8, r3=pal) r4: scratch, r12: helper pattern
+@ scratch: r4, r7
+.dspr_TileNormNonSH:
+    TileNormNonSH r12
+    b       .dspr_loop
+
+.dspr_TileFlipNonSH:
+    TileFlipNonSH r12
+    b       .dspr_loop
+
 .dspr_shadow:
     cmp     r2, r2, ror #4
     beq     .dspr_singlec_sh
@@ -1567,15 +1623,6 @@ PicoDoHighPal555:
     stmia   r4!, {r1,r6}
     bne     .fl_loopcpRGB555_sh
 
-    @ fixup shadowed color 14 in palette 0,1,2 (always normal)
-    sub     r4, r3, #0x40*2
-    ldrh    r1, [r4, #0x0e*2] @ 0x0e, 0x1e, 0x2e
-    ldrh    r5, [r4, #0x1e*2]
-    ldrh    r6, [r4, #0x2e*2]
-    strh    r1, [r3, #0x4e*2] @ 0x8e, 0x9e, 0xae
-    strh    r5, [r3, #0x5e*2]
-    strh    r6, [r3, #0x6e*2]
-
     mov     r0, #1
 PicoDoHighPal555_end:
     ldmfd   sp!, {r4-r10,pc}
-- 
2.39.5