Support undocumented AGA sprite SPRxDATx write behavior where first 16 or 32 pixels...

diff --git a/custom.cpp b/custom.cpp
index e82f44e0f9ae3a87362cb9adef16dc990a819ac9..82fe8ccbb7580dfe22d24b0c6669305df29de50f 100644 (file)
--- a/custom.cpp
+++ b/custom.cpp
@@ -186,6 +186,7 @@ uae_u16 intena, intreq;
 uae_u16 dmacon;
 uae_u16 adkcon; /* used by audio code */
 uae_u32 last_custom_value1;
+uae_u16 last_custom_value2;
 
 static uae_u32 cop1lc, cop2lc, copcon;
 
@@ -1006,6 +1007,7 @@ static bool todisplay_fetched[2];
 #ifdef AGA
 static uae_u64 todisplay_aga[MAX_PLANES], todisplay2_aga[MAX_PLANES];
 static uae_u64 fetched_aga[MAX_PLANES];
+static uae_u32 fetched_aga_spr[MAX_PLANES];
 #endif
 
 /* Expansions from bplcon0/bplcon1.  */
@@ -1424,8 +1426,26 @@ static void fetch (int nr, int fm, bool modulo, int hpos)
                switch (fm)
                {
                case 0:
-                       fetched[nr] = fetched_aga[nr] = chipmem_wget_indirect (p);
-                       last_custom_value1 = fetched[nr];
+                       {
+                               uae_u16 v;
+                               if (aga_mode) {
+                                       // AGA always does 32-bit fetches, this is needed
+                                       // to emulate 64 pixel wide sprite side-effects.
+                                       uae_u32 vv = chipmem_lget_indirect(p & ~3);
+                                       if (p & 2) {
+                                               v = (uae_u16)vv;
+                                               fetched_aga_spr[nr] = (v << 16) | v;
+                                       } else {
+                                               v = vv >> 16;
+                                               fetched_aga_spr[nr] = vv;
+                                       }
+                               } else {
+                                       v = chipmem_wget_indirect(p);
+                               }
+                               fetched_aga[nr] = fetched[nr] = v;
+                               last_custom_value1 = v;
+                               last_custom_value2 = (uae_u16)last_custom_value1;
+                       }
                        break;
 #ifdef AGA
                case 1:
@@ -1441,6 +1461,7 @@ static void fetch (int nr, int fm, bool modulo, int hpos)
                                fetched_aga[nr] = chipmem_lget_indirect(pm);
                        }
                        last_custom_value1 = (uae_u32)fetched_aga[nr];
+                       last_custom_value2 = (uae_u16)last_custom_value1;
                        fetched[nr] = (uae_u16)fetched_aga[nr];
                        break;
                }
@@ -1466,6 +1487,7 @@ static void fetch (int nr, int fm, bool modulo, int hpos)
                                fetched_aga[nr] |= chipmem_lget_indirect(pm2);
                        }
                        last_custom_value1 = (uae_u32)fetched_aga[nr];
+                       last_custom_value2 = (uae_u16)last_custom_value1;
                        fetched[nr] = (uae_u16)fetched_aga[nr];
                        break;
                }
@@ -2139,11 +2161,17 @@ static int flush_plane_data_hr(int fm)
                i += 32;
                toscr_1_hr(32, fm);
        }
+
        if (out_nbits != 0) {
                i += 64 - out_nbits;
                toscr_1_hr(64 - out_nbits, fm);
        }
 
+       toscr_1_hr(32, fm);
+       i += 32;
+       toscr_1_hr(32, fm);
+       i += 32;
+
        int toshift = 32 << fm;
        while (i < toshift) {
                int n = toshift - i;
@@ -6147,6 +6175,10 @@ static void DIWSTRT (int hpos, uae_u16 v)
 {
        if (diwstrt == v && ! diwhigh_written)
                return;
+       // if hpos matches previous hstart: it gets ignored.
+       if (diw_hstrt >= hpos * 2 - 2 && diw_hstrt <= hpos * 2 + 2) {
+               diw_hstrt = max_diwlastword;
+       }
        decide_diw (hpos);
        decide_line (hpos);
        diwhigh_written = 0;
@@ -6158,6 +6190,9 @@ static void DIWSTOP (int hpos, uae_u16 v)
 {
        if (diwstop == v && ! diwhigh_written)
                return;
+       if (diw_hstop >= hpos * 2 - 2 && diw_hstop <= hpos * 2 + 2) {
+               diw_hstop = min_diwlastword;
+       }
        decide_diw (hpos);
        decide_line (hpos);
        diwhigh_written = 0;
@@ -6543,10 +6578,12 @@ static void SPRxDATA_1(uae_u16 v, int num, int hpos)
        struct sprite *s = &spr[num];
        s->data[0] = v;
 #ifdef AGA
-       s->data[1] = v;
-       s->data[2] = v;
-       s->data[3] = v;
-       s->width = sprite_width;
+       if (aga_mode) {
+               s->data[1] = v;
+               s->data[2] = v;
+               s->data[3] = v;
+               s->width = sprite_width;
+       }
 #endif
        spr_arm (num, 1);
 #if SPRITE_DEBUG >= 256
@@ -6561,10 +6598,12 @@ static void SPRxDATB_1(uae_u16 v, int num, int hpos)
        struct sprite *s = &spr[num];
        s->datb[0] = v;
 #ifdef AGA
-       s->datb[1] = v;
-       s->datb[2] = v;
-       s->datb[3] = v;
-       s->width = sprite_width;
+       if (aga_mode) {
+               s->datb[1] = v;
+               s->datb[2] = v;
+               s->datb[3] = v;
+               s->width = sprite_width;
+       }
 #endif
 #if SPRITE_DEBUG >= 256
        if (vpos >= SPRITE_DEBUG_MINY && vpos <= SPRITE_DEBUG_MAXY && (SPRITE_DEBUG & (1 << num))) {
@@ -6574,6 +6613,16 @@ static void SPRxDATB_1(uae_u16 v, int num, int hpos)
 #endif
 }
 
+// Undocumented AGA feature: if sprite is 64 pixel wide, SPRxDATx is written and next
+// cycle is DMA fetch: sprite's first 32 pixels get replaced with bitplane data.
+static void sprite_get_bpl_data(int hpos, struct sprite *s, uae_u16 *dat)
+{
+       int nr = is_bitplane_dma_inline(hpos + 1);
+       uae_u32 v = (fmode & 3) ? fetched_aga[nr] : fetched_aga_spr[nr];
+       dat[0] = v >> 16;
+       dat[1] = (uae_u16)v;
+}
+
 /*
  SPRxDATA and SPRxDATB is moved to shift register when SPRxPOS matches.
 
@@ -6591,13 +6640,33 @@ static void SPRxDATB_1(uae_u16 v, int num, int hpos)
 
 static void SPRxDATA (int hpos, uae_u16 v, int num)
 {
+       struct sprite *s = &spr[num];
        decide_sprites(-1, hpos, true, false);
        SPRxDATA_1(v, num, hpos);
+       // if 32 (16-bit double CAS only) or 64 pixel wide sprite and SPRxDATx write:
+       // - first 16 pixel part: previous chipset bus data
+       // - following 16 pixel parts: written data
+       if (fmode & 8) {
+               if ((fmode & 4) && is_bitplane_dma_inline(hpos - 1)) {
+                       sprite_get_bpl_data(hpos, s, &s->data[0]);
+               } else {
+                       s->data[0] = last_custom_value2;
+               }
+       }
 }
 static void SPRxDATB (int hpos, uae_u16 v, int num)
 {
+       struct sprite *s = &spr[num];
        decide_sprites(-1, hpos, true, false);
        SPRxDATB_1(v, num, hpos);
+       // See above
+       if (fmode & 8) {
+               if ((fmode & 4) && is_bitplane_dma_inline(hpos - 1)) {
+                       sprite_get_bpl_data(hpos, s, &s->datb[0]);
+               } else {
+                       s->datb[0] = last_custom_value2;
+               }
+       }
 }
 
 static void SPRxCTL (int hpos, uae_u16 v, int num)
@@ -7096,7 +7165,7 @@ static void update_copper (int until_hpos)
                        if (copper_cant_read (old_hpos, 1))
                                continue;
                        cop_state.state = COP_read1;
-                       cop_state.i1 = last_custom_value1 = chipmem_wget_indirect (cop_state.ip);
+                       cop_state.i1 = last_custom_value1 = last_custom_value2 = chipmem_wget_indirect (cop_state.ip);
                        alloc_cycle (old_hpos, CYCLE_COPPER);
 #ifdef DEBUGGER
                        if (debug_dma)
@@ -7110,7 +7179,7 @@ static void update_copper (int until_hpos)
                case COP_read1:
                        if (copper_cant_read (old_hpos, 1))
                                continue;
-                       cop_state.i1 = last_custom_value1 = chipmem_wget_indirect (cop_state.ip);
+                       cop_state.i1 = last_custom_value1 = last_custom_value2 = chipmem_wget_indirect (cop_state.ip);
                        alloc_cycle (old_hpos, CYCLE_COPPER);
 #ifdef DEBUGGER
                        if (debug_dma)
@@ -7125,7 +7194,7 @@ static void update_copper (int until_hpos)
                case COP_read2:
                        if (copper_cant_read (old_hpos, 1))
                                continue;
-                       cop_state.i2 = last_custom_value1 = chipmem_wget_indirect (cop_state.ip);
+                       cop_state.i2 = chipmem_wget_indirect (cop_state.ip);
                        alloc_cycle (old_hpos, CYCLE_COPPER);
                        cop_state.ip += 2;
                        cop_state.saved_i1 = cop_state.i1;
@@ -7190,6 +7259,7 @@ static void update_copper (int until_hpos)
 #endif
                                cop_state.ignore_next = 0;
                        }
+                       last_custom_value1 = last_custom_value2 = cop_state.i2;
                        check_copper_stop();
                        break;
 
@@ -8451,7 +8521,7 @@ static void dmal_emu (uae_u32 v)
                if (memwatch_enabled)
                        debug_wgetpeekdma_chipram(pt, dat, MW_MASK_AUDIO_0 << nr, 0xaa + nr * 16);
 #endif
-               last_custom_value1 = dat;
+               last_custom_value1 = last_custom_value2 = dat;
                AUDxDAT (nr, dat, pt);
        } else {
                uae_u16 dat = 0;
@@ -8462,7 +8532,7 @@ static void dmal_emu (uae_u32 v)
                        // write to disk
                        if (disk_fifostatus () <= 0) {
                                dat = chipmem_wget_indirect (pt);
-                               last_custom_value1 = dat;
+                               last_custom_value1 = last_custom_value2 = dat;
                                DSKDAT (dat);
                        }
                } else {
@@ -10726,7 +10796,7 @@ uae_u8 *restore_custom (uae_u8 *src)
        if (i & 0x8000)
                currprefs.ntscmode = changed_prefs.ntscmode = i & 1;
        fmode = fmode_saved = RW; /* 1FC FMODE */
-       last_custom_value1 = RW;/* 1FE ? */
+       last_custom_value1 = last_custom_value2 = RW;/* 1FE ? */
 
        current_colors.extra = 0;
        if (isbrdblank (-1, bplcon0, bplcon3))