From: kub <derkub@gmail.com>
Date: Mon, 17 Jul 2023 19:16:38 +0000 (+0200)
Subject: core, optimize vcounter handling
X-Git-Tag: v2.00~187
X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=46b4c1d322d73783fbc3238941906d167cc16c87;p=picodrive.git

core, optimize vcounter handling
---

diff --git a/pico/memory.c b/pico/memory.c
index 96a00744..818080fd 100644
--- a/pico/memory.c
+++ b/pico/memory.c
@@ -1367,7 +1367,7 @@ static unsigned char z80_md_vdp_read(unsigned short a)
       case 0x04: return PicoVideoRead8CtlH(1);
       case 0x05: return PicoVideoRead8CtlL(1);
       case 0x08:
-      case 0x0c: return PicoVideoGetV(get_scanline(1));
+      case 0x0c: return PicoVideoGetV(get_scanline(1), 1);
       case 0x09:
       case 0x0d: return Pico.m.rotate++;
     }
diff --git a/pico/pico_cmn.c b/pico/pico_cmn.c
index a06573e1..3e5a038e 100644
--- a/pico/pico_cmn.c
+++ b/pico/pico_cmn.c
@@ -128,8 +128,7 @@ static void do_timing_hacks_start(struct PicoVideo *pv)
   // XXX how to handle Z80 bus cycle stealing during DMA correctly?
   if ((Pico.t.z80_buscycles -= cycles) < 0)
     Pico.t.z80_buscycles = 0;
-  if (Pico.m.scanline&1)
-    Pico.t.m68c_aim += 1; // add cycle each other line for 488.5 cycles/line
+  Pico.t.m68c_aim += Pico.m.scanline&1; // add 1 every 2 lines for 488.5 cycles
 }
 
 static int PicoFrameHints(void)
@@ -151,15 +150,14 @@ static int PicoFrameHints(void)
   // === active display ===
   pv->status |= PVS_ACTIVE;
 
-  for (y = 0;; y++)
+  for (y = 0; y < 240; y++)
   {
-    Pico.m.scanline = y;
-    pv->v_counter = PicoVideoGetV(y);
-
-    lines_vis = (pv->reg[1] & 8) ? 240 : 224;
-    if (y == lines_vis)
+    if (y == 224 && !(pv->reg[1] & 8))
       break;
 
+    Pico.m.scanline = y;
+    pv->v_counter = PicoVideoGetV(y, 0);
+
     PAD_DELAY();
 
     // H-Interrupts:
@@ -170,7 +168,7 @@ static int PicoFrameHints(void)
     }
 
     // decide if we draw this line
-    if ((PicoIn.opt & POPT_ALT_RENDERER) && !skip)
+    if (unlikely(PicoIn.opt & POPT_ALT_RENDERER) && !skip)
     {
       // find the right moment for frame renderer, when display is no longer blanked
       if ((pv->reg[1]&0x40) || y > 100) {
@@ -213,6 +211,8 @@ static int PicoFrameHints(void)
   lines_vis = (pv->reg[1] & 8) ? 240 : 224;
   if (y == lines_vis)
     pv->status &= ~PVS_ACTIVE;
+  Pico.m.scanline = y;
+  pv->v_counter = PicoVideoGetV(y, 0);
 
   memcpy(PicoIn.padInt, PicoIn.pad, sizeof(PicoIn.padInt));
   PAD_DELAY();
@@ -267,7 +267,7 @@ static int PicoFrameHints(void)
   for (y++; y < lines - 1; y++)
   {
     Pico.m.scanline = y;
-    pv->v_counter = PicoVideoGetV(y);
+    pv->v_counter = PicoVideoGetV(y, 1);
 
     PAD_DELAY();
 
diff --git a/pico/pico_int.h b/pico/pico_int.h
index dc35426b..977e5cdb 100644
--- a/pico/pico_int.h
+++ b/pico/pico_int.h
@@ -916,9 +916,9 @@ static __inline void VideoWriteVRAM(u32 a, u16 d)
     UpdateSAT(a, d);
 }
 
-static __inline u8 PicoVideoGetV(int scanline)
+static __inline u8 PicoVideoGetV(int scanline, int maywrap)
 {
-  if (scanline >= Pico.t.vcnt_wrap) scanline -= Pico.t.vcnt_adj;
+  if (maywrap && scanline >= Pico.t.vcnt_wrap) scanline -= Pico.t.vcnt_adj;
   if ((Pico.video.reg[12]&6) == 6) scanline = (scanline<<1) | 1;
   return scanline;
 }