Update to v068r02 release.

byuu says:

This adds mosaic improvements to the S-PPU dot renderer. Specifically,
it eliminates the mosaic_table entirely, and performs mosaic adjustment
per pixel instead. It also moves from a mosaic countdown for mosaic Y to
a mosaic counter (incrementing).

In the process, I realized Sim Earth's map was broken, so I fixed that.
In doing so, I also fixed my old Mode7 demo that was always off-by-one,
causing different results on real hardware versus emulation. But then
I broke both Final Fantasy 5 and Air Strike Patrol effects that use
Mode7 but no mosaic.

I'm not really sure what's going on, but I think I am close. This is the
first time I can reproduce the Mode7 test ROM results without screwing
with M7Y which was obviously wrong. I think that somehow a mosaic >=
1 is glitching the Ycounter for the BG layers to tick one extra time.

There's a workaround that's not very nice to get everything going right
now. It could very well be that the workaround is hardware accurate, but
I can't help but feel there's a more eloquent way of doing this.

bsnes/Makefile

@@ -1,6 +1,6 @@
 include nall/Makefile
 snes := snes
-profile := compatibility
+profile := accuracy
 ui := qt
 
 # compiler

bsnes/snes/ppu/background/background.cpp

@@ -2,20 +2,26 @@
 
 #include "mode7.cpp"
 
+void PPU::Background::frame() {
+}
+
 void PPU::Background::scanline() {
   if(self.vcounter() == 1) {
-    t.mosaic_y = 1;
+    t.mosaic_y = regs.mosaic ? 1 : 0;  //TODO: this is most likely incorrect
-    t.mosaic_countdown = 0;
+    t.mosaic_vcounter = 0;
-  } else {
-    if(!regs.mosaic || !t.mosaic_countdown) t.mosaic_y = self.vcounter();
-    if(!t.mosaic_countdown) t.mosaic_countdown = regs.mosaic + 1;
-    t.mosaic_countdown--;
   }
 
-  t.x = 0;
+  if(t.mosaic_vcounter++ == regs.mosaic) {
+    t.mosaic_vcounter = 0;
+    t.mosaic_y += regs.mosaic + 1;
+  }
+
+  t.mosaic_x = 0;
+  t.mosaic_hcounter = 0;
 }
 
 void PPU::Background::run() {
+  if(self.vcounter() == 0) return;
   bool hires = (self.regs.bgmode == 5 || self.regs.bgmode == 6);
 
   if((self.hcounter() & 2) == 0) {
@@ -28,9 +34,13 @@ void PPU::Background::run() {
   if(regs.mode == Mode::Inactive) return;
   if(regs.main_enabled == false && regs.sub_enabled == false) return;
 
-  unsigned x = t.x++;
+  unsigned x = t.mosaic_x;
   unsigned y = t.mosaic_y;
-  if(regs.mode == Mode::Mode7) return run_mode7(x, y);
+  if(t.mosaic_hcounter++ == regs.mosaic) {
+    t.mosaic_hcounter = 0;
+    t.mosaic_x += regs.mosaic + 1;
+  }
+  if(regs.mode == Mode::Mode7) return run_mode7();
 
   unsigned color_depth = (regs.mode == Mode::BPP2 ? 0 : regs.mode == Mode::BPP4 ? 1 : 2);
   unsigned palette_offset = (self.regs.bgmode == 0 ? (id << 5) : 0);
@@ -56,7 +66,7 @@ void PPU::Background::run() {
     if(self.regs.interlace) y = (y << 1) + self.field();
   }
 
-  unsigned hoffset = hscroll + mosaic_table[regs.mosaic][x];
+  unsigned hoffset = hscroll + x;
   unsigned voffset = vscroll + y;
 
   if(self.regs.bgmode == 2 || self.regs.bgmode == 4 || self.regs.bgmode == 6) {
@@ -215,9 +225,11 @@ unsigned PPU::Background::get_color(unsigned x, unsigned y, uint16 offset) {
 }
 
 void PPU::Background::reset() {
-  t.x = 0;
+  t.mosaic_x = 0;
   t.mosaic_y = 0;
-  t.mosaic_countdown = 0;
+  t.mosaic_hcounter = 0;
+  t.mosaic_vcounter = 0;
+
   regs.tiledata_addr = 0;
   regs.screen_addr = 0;
   regs.screen_size = 0;
@@ -230,6 +242,7 @@ void PPU::Background::reset() {
   regs.sub_enabled = 0;
   regs.hoffset = 0;
   regs.voffset = 0;
+
   output.main.palette = 0;
   output.main.priority = 0;
   output.sub.palette = 0;
@@ -237,13 +250,6 @@ void PPU::Background::reset() {
 }
 
 PPU::Background::Background(PPU &self, unsigned id) : self(self), id(id) {
-  for(unsigned m = 0; m < 16; m++) {
-    for(unsigned x = 0; x < 4096; x++) {
-      mosaic_table[m][x] = (x / (m + 1)) * (m + 1);
-    }
-  }
 }
 
-uint16 PPU::Background::mosaic_table[16][4096];
-
 #endif

bsnes/snes/ppu/background/background.hpp

@@ -9,9 +9,10 @@ public:
   struct TileSize { enum { Size8x8, Size16x16 }; };
 
   struct {
-    unsigned x;
+    unsigned mosaic_x;
     unsigned mosaic_y;
-    unsigned mosaic_countdown;
+    unsigned mosaic_hcounter;
+    unsigned mosaic_vcounter;
   } t;
 
   struct {
@@ -40,6 +41,7 @@ public:
     } main, sub;
   } output;
 
+  void frame();
   void scanline();
   void run();
   unsigned get_tile(unsigned x, unsigned y);
@@ -50,9 +52,7 @@ public:
   Background(PPU &self, unsigned id);
 
 private:
-  static uint16 mosaic_table[16][4096];
-
   //mode7.cpp
   signed clip(signed n);
-  void run_mode7(unsigned x, unsigned y);
+  void run_mode7();
 };

bsnes/snes/ppu/background/mode7.cpp

@@ -5,7 +5,7 @@ signed PPU::Background::clip(signed n) {
   return n & 0x2000 ? (n | ~1023) : (n & 1023);
 }
 
-void PPU::Background::run_mode7(unsigned x, unsigned y) {
+void PPU::Background::run_mode7() {
   signed a = sclip<16>(self.regs.m7a);
   signed b = sclip<16>(self.regs.m7b);
   signed c = sclip<16>(self.regs.m7c);
@@ -16,24 +16,16 @@ void PPU::Background::run_mode7(unsigned x, unsigned y) {
   signed hoffset = sclip<13>(self.regs.mode7_hoffset);
   signed voffset = sclip<13>(self.regs.mode7_voffset);
 
+  unsigned x = t.mosaic_x;
+  unsigned y = self.bg1.t.mosaic_y;  //BG2 vertical mosaic uses BG1 mosaic size
   if(self.regs.mode7_hflip) x = 255 - x;
   if(self.regs.mode7_vflip) y = 255 - y;
 
-  unsigned mosaic_x;
+  signed psx = ((a * clip(hoffset - cx)) & ~63) + ((b * clip(voffset - cy)) & ~63) + ((b * y) & ~63) + (cx << 8);
-  unsigned mosaic_y;
+  signed psy = ((c * clip(hoffset - cx)) & ~63) + ((d * clip(voffset - cy)) & ~63) + ((d * y) & ~63) + (cy << 8);
-  if(id == ID::BG1) {
-    mosaic_x = mosaic_table[self.bg1.regs.mosaic][x];
-    mosaic_y = mosaic_table[self.bg1.regs.mosaic][y];
-  } else if(id == ID::BG2) {
-    mosaic_x = mosaic_table[self.bg2.regs.mosaic][x];
-    mosaic_y = mosaic_table[self.bg1.regs.mosaic][y];  //BG2 vertical mosaic uses BG1 mosaic size
-  }
 
-  signed psx = ((a * clip(hoffset - cx)) & ~63) + ((b * clip(voffset - cy)) & ~63) + ((b * mosaic_y) & ~63) + (cx << 8);
+  signed px = psx + (a * x);
-  signed psy = ((c * clip(hoffset - cx)) & ~63) + ((d * clip(voffset - cy)) & ~63) + ((d * mosaic_y) & ~63) + (cy << 8);
+  signed py = psy + (c * x);
-
-  signed px = psx + (a * mosaic_x);
-  signed py = psy + (c * mosaic_x);
 
   //mask pseudo-FP bits
   px >>= 8;

bsnes/snes/ppu/ppu.cpp

@@ -106,7 +106,14 @@ void PPU::reset() {
 }
 
 void PPU::scanline() {
-  if(vcounter() == 0) frame();
+  if(vcounter() == 0) {
+    frame();
+    bg1.frame();
+    bg2.frame();
+    bg3.frame();
+    bg4.frame();
+  }
+
   bg1.scanline();
   bg2.scanline();
   bg3.scanline();

bsnes/snes/ppu/serialization.cpp

@@ -89,9 +89,10 @@ void PPU::serialize(serializer &s) {
 void PPU::Background::serialize(serializer &s) {
   s.integer(id);
 
-  s.integer(t.x);
+  s.integer(t.mosaic_x);
   s.integer(t.mosaic_y);
-  s.integer(t.mosaic_countdown);
+  s.integer(t.mosaic_hcounter);
+  s.integer(t.mosaic_vcounter);
 
   s.integer(regs.tiledata_addr);
   s.integer(regs.screen_addr);

bsnes/snes/snes.hpp

@@ -1,12 +1,12 @@
 namespace SNES {
   namespace Info {
     static const char Name[] = "bsnes";
-    static const char Version[] = "068.01";
+    static const char Version[] = "068.02";
-    static const unsigned SerializerVersion = 12;
+    static const unsigned SerializerVersion = 13;
   }
 }
 
-#define DEBUGGER
+//#define DEBUGGER
 #define CHEAT_SYSTEM
 
 #include <libco/libco.h>