Update to v104r02 release.

byuu says:

Changelog:

  - md/vdp: backgrounds always update priority bit output [Cydrak]
  - md/vdp: vcounter.d0 becomes vcounter.d8 in interlace mode 3
  - md/vdp: return field number in interlace modes from status register
  - md/vdp: rework scanline/frame counting in main loop so first frame
    won't clock to field 1 instead of field 0
  - md/vdp: add support for shadow/highlight mode; optimize to minimal
    code [Cydrak]
  - md/vdp: update outputPixel() to support interlace modes
  - sfc/cpu: auto joypad polling start should clear the shift registers;
    fixes Nuke (PD)
      - thanks to BMF54123 for this bug report
  - tomoko: if an invalid video/audio/input driver is found in the
    configuration file, it's reset to "None"
      - prevents showing the wrong driver under advanced settings; no
        longer requires possibly two reboots to fix

Note: the Mega Drive interlace mode 1 should be working fully, but I
don't know any games that use it. Interlace mode 3 (Sonic 2's two-player
mode) does not work at all yet, but this is a good start.

higan/emulator/emulator.hpp

@@ -12,7 +12,7 @@ using namespace nall;
 
 namespace Emulator {
   static const string Name    = "higan";
-  static const string Version = "104.01";
+  static const string Version = "104.02";
   static const string Author  = "byuu";
   static const string License = "GPLv3";
   static const string Website = "http://byuu.org/";

higan/md/interface/interface.cpp

@@ -69,17 +69,24 @@ auto Interface::videoResolution() -> VideoResolution {
 }
 
 auto Interface::videoColors() -> uint32 {
-  return 1 << 9;
+  return 3 * (1 << 9);
 }
 
 auto Interface::videoColor(uint32 color) -> uint64 {
-  uint R = color.bits(0,2);
+  uint R = color.bits(0, 2);
-  uint G = color.bits(3,5);
+  uint G = color.bits(3, 5);
-  uint B = color.bits(6,8);
+  uint B = color.bits(6, 8);
+  uint M = color.bits(9,10);
 
-  uint64 r = image::normalize(R, 3, 16);
+  uint lookup[3][8] = {
-  uint64 g = image::normalize(G, 3, 16);
+    {  0,  29,  52,  70,  87, 101, 116, 130},  //shadow
-  uint64 b = image::normalize(B, 3, 16);
+    {  0,  52,  87, 116, 144, 172, 206, 255},  //normal
+    {130, 144, 158, 172, 187, 206, 228, 255},  //highlight
+  };
+
+  uint64 r = image::normalize(lookup[M][R], 8, 16);
+  uint64 g = image::normalize(lookup[M][G], 8, 16);
+  uint64 b = image::normalize(lookup[M][B], 8, 16);
 
   return r << 32 | g << 16 | b << 0;
 }

higan/md/vdp/background.cpp

@@ -47,9 +47,6 @@ auto VDP::Background::scanline(uint y) -> void {
 auto VDP::Background::run(uint x, uint y) -> void {
   updateVerticalScroll(x, y);
 
-  output.priority = 0;
-  output.color = 0;
-
   x -= state.horizontalScroll;
   y += state.verticalScroll;
 
@@ -70,13 +67,11 @@ auto VDP::Background::run(uint x, uint y) -> void {
 
   uint16 tileData = vdp.vram.read(tileAddress);
   uint4 color = tileData >> (((pixelX & 3) ^ 3) << 2);
-  if(color) {
+  output.color = color ? tileAttributes.bits(13,14) << 4 | color : 0;
-    output.color = tileAttributes.bits(13,14) << 4 | color;
   output.priority = tileAttributes.bit(15);
-  }
 }
 
 auto VDP::Background::power() -> void {
-  memory::fill(&io, sizeof(IO));
+  io = {};
-  memory::fill(&state, sizeof(State));
+  state = {};
 }

higan/md/vdp/io.cpp

@@ -13,7 +13,9 @@ auto VDP::read(uint24 addr) -> uint16 {
 
   //counter
   case 0xc00008: case 0xc0000a: case 0xc0000c: case 0xc0000e: {
-    return state.vcounter << 8 | (state.hdot >> 1) << 0;
+    auto vcounter = state.vcounter;
+    if(io.interlaceMode == 3) vcounter.bit(0) = vcounter.bit(8);
+    return vcounter << 8 | (state.hdot >> 1) << 0;
   }
 
   }
@@ -114,11 +116,12 @@ auto VDP::readControlPort() -> uint16 {
   io.commandPending = false;
 
   uint16 result = 0b0011'0100'0000'0000;
-  result |= 1 << 9;  //FIFO empty
-  result |= (state.vcounter >= screenHeight()) << 3;  //vertical blank
-  result |= (state.hcounter >= 1280) << 2;  //horizontal blank
-  result |= io.command.bit(5) << 1;  //DMA active
   result |= Region::PAL() << 0;
+  result |= io.command.bit(5) << 1;  //DMA active
+  result |= (state.hcounter >= 1280) << 2;  //horizontal blank
+  result |= (state.vcounter >= screenHeight()) << 3;  //vertical blank
+  result |= io.interlaceMode.bit(0) ? state.field << 4 : 0;
+  result |= 1 << 9;  //FIFO empty
   return result;
 }
 

higan/md/vdp/render.cpp

@@ -1,15 +1,4 @@
-auto VDP::frame() -> void {
-  latch.overscan = io.overscan;
-}
-
 auto VDP::scanline() -> void {
-  state.hdot = 0;
-  state.hcounter = 0;
-  if(++state.vcounter >= frameHeight()) state.vcounter = 0;
-  if(state.vcounter == 0) frame();
-
-  latch.displayWidth = io.displayWidth;
-
   if(state.vcounter < screenHeight()) {
     planeA.scanline(state.vcounter);
     window.scanline(state.vcounter);
@@ -31,22 +20,40 @@ auto VDP::run() -> void {
   planeB.run(state.hdot, state.vcounter);
   sprite.run(state.hdot, state.vcounter);
 
-  auto output = io.backgroundColor;
+  Pixel g = {io.backgroundColor, 0};
-  if(auto color = planeB.output.color) output = color;
+  Pixel a = planeA.output;
-  if(auto color = planeA.output.color) output = color;
+  Pixel b = planeB.output;
-  if(auto color = sprite.output.color) output = color;
+  Pixel s = sprite.output;
-  if(planeB.output.priority) if(auto color = planeB.output.color) output = color;
-  if(planeA.output.priority) if(auto color = planeA.output.color) output = color;
-  if(sprite.output.priority) if(auto color = sprite.output.color) output = color;
 
-  outputPixel(cram.read(output));
+  auto& bg = a.above() || a.color && !b.above() ? a : b.color ? b : g;
-  state.hdot++;
+  auto& fg = s.above() || s.color && !b.above() && !a.above() ? s : bg;
+  uint mode = a.priority || b.priority;
+
+  if(&fg == &s) switch(s.color) {
+  case 0x0e:
+  case 0x1e:
+  case 0x2e: mode  = 1; break;
+  case 0x3e: mode += 1; fg = bg; break;
+  case 0x3f: mode  = 0; fg = bg; break;
+  default:   mode |= s.priority; break;
+  }
+
+  auto color = cram.read(fg.color);
+  if(!io.shadowHighlightEnable) mode = 1;
+  outputPixel(mode << 9 | color);
 }
 
-auto VDP::outputPixel(uint9 color) -> void {
+auto VDP::outputPixel(uint32 color) -> void {
+  uint32* field[2] = {&state.output[0], &state.output[1280]};
+  if(!io.interlaceMode.bit(0)) {
     for(auto n : range(pixelWidth())) {
-    state.output[   0 + n] = color;
+      field[0][n] = color;
-    state.output[1280 + n] = color;
+      field[1][n] = color;
+    }
+  } else {
+    for(auto n : range(pixelWidth())) {
+      field[state.field][n] = color;
+    }
   }
   state.output += pixelWidth();
 }

higan/md/vdp/sprite.cpp

@@ -75,14 +75,14 @@ auto VDP::Sprite::run(uint x, uint y) -> void {
 
     uint16 tileData = vdp.vram.read(tileAddress);
     uint4 color = tileData >> (((pixelX & 3) ^ 3) << 2);
-    if(color) {
+    if(!color) continue;
+
     output.color = o.palette << 4 | color;
     output.priority = o.priority;
     break;
   }
-  }
 }
 
 auto VDP::Sprite::power() -> void {
-  memory::fill(&io, sizeof(IO));
+  io = {};
 }

higan/md/vdp/vdp.cpp

@@ -37,6 +37,7 @@ auto VDP::main() -> void {
   if(state.vcounter < screenHeight()) {
     while(state.hcounter < 1280) {
       run();
+      state.hdot++;
       step(pixelWidth());
     }
 
@@ -51,6 +52,15 @@ auto VDP::main() -> void {
   } else {
     step(1710);
   }
+
+  state.hdot = 0;
+  state.hcounter = 0;
+  if(++state.vcounter >= frameHeight()) {
+    state.vcounter = 0;
+    state.field ^= 1;
+    latch.overscan = io.overscan;
+  }
+  latch.displayWidth = io.displayWidth;
 }
 
 auto VDP::step(uint clocks) -> void {
@@ -74,9 +84,9 @@ auto VDP::power() -> void {
 
   output = buffer + 16 * 1280;  //overscan offset
 
-  memory::fill(&io, sizeof(IO));
+  io = {};
-  memory::fill(&latch, sizeof(Latch));
+  latch = {};
-  memory::fill(&state, sizeof(State));
+  state = {};
 
   planeA.power();
   window.power();

higan/md/vdp/vdp.hpp

@@ -41,10 +41,17 @@ struct VDP : Thread {
   } dma;
 
   //render.cpp
-  auto frame() -> void;
   auto scanline() -> void;
   auto run() -> void;
-  auto outputPixel(uint9 color) -> void;
+  auto outputPixel(uint32 color) -> void;
+
+  struct Pixel {
+    inline auto above() const -> bool { return priority == 1 && color; }
+    inline auto below() const -> bool { return priority == 0 && color; }
+
+    uint6 color;
+    uint1 priority;
+  };
 
   struct Background {
     enum class ID : uint { PlaneA, Window, PlaneB } id;
@@ -89,10 +96,7 @@ struct VDP : Thread {
       uint10 verticalScroll;
     } state;
 
-    struct Output {
+    Pixel output;
-      uint6 color;
-      uint1 priority;
-    } output;
   };
   Background planeA{Background::ID::PlaneA};
   Background window{Background::ID::Window};
@@ -127,10 +131,7 @@ struct VDP : Thread {
       uint7  link;
     };
 
-    struct Output {
+    Pixel output;
-      uint6 color;
-      uint1 priority;
-    } output;
 
     array<Object, 80> oam;
     array<Object, 20> objects;
@@ -243,9 +244,10 @@ private:
 
   struct State {
     uint32* output = nullptr;
-    uint hdot;
+    uint16 hdot;
-    uint hcounter;
+    uint16 hcounter;
-    uint vcounter;
+    uint16 vcounter;
+    uint1 field;
   } state;
 
   uint32 buffer[1280 * 512];

higan/sfc/cpu/timing.cpp

@@ -149,6 +149,12 @@ auto CPU::joypadEdge() -> void {
         controllerPort2.device->latch(1);
         controllerPort1.device->latch(0);
         controllerPort2.device->latch(0);
+
+        //shift registers are cleared at start of auto joypad polling
+        io.joy1 = 0;
+        io.joy2 = 0;
+        io.joy3 = 0;
+        io.joy4 = 0;
       }
 
       uint2 port0 = controllerPort1.device->data();

higan/target-tomoko/program/program.cpp

@@ -43,12 +43,18 @@ Program::Program(string_vector args) {
   settings["Crashed"].setValue(true);
   settings.save();
 
+  if(!Video::availableDrivers().find(settings["Video/Driver"].text())) {
+    settings["Video/Driver"].setValue("None");
+  }
   video = Video::create(settings["Video/Driver"].text());
   video->setContext(presentation->viewport.handle());
   video->setBlocking(settings["Video/Synchronize"].boolean());
   if(!video->ready()) MessageDialog().setText("Failed to initialize video driver").warning();
   presentation->clearViewport();
 
+  if(!Audio::availableDrivers().find(settings["Audio/Driver"].text())) {
+    settings["Audio/Driver"].setValue("None");
+  }
   audio = Audio::create(settings["Audio/Driver"].text());
   audio->setExclusive(settings["Audio/Exclusive"].boolean());
   audio->setContext(presentation->viewport.handle());
@@ -57,6 +63,9 @@ Program::Program(string_vector args) {
   audio->setChannels(2);
   if(!audio->ready()) MessageDialog().setText("Failed to initialize audio driver").warning();
 
+  if(!Input::availableDrivers().find(settings["Input/Driver"].text())) {
+    settings["Input/Driver"].setValue("None");
+  }
   input = Input::create(settings["Input/Driver"].text());
   input->setContext(presentation->viewport.handle());
   input->onChange({&InputManager::onChange, &inputManager()});