gen: implement WINDOW rendering

gen: initialize VDP registers to power-on values

BizHawk.Emulation/Consoles/Sega/Genesis/Compat.txt

@@ -7,25 +7,50 @@ Timings:
  - How many cycles does it take to accept an interrupt?
  - AND has some funky timings when it comes to immediates?
 
- GAMES:
+GAMES:
 
- Monster World 4 - Music is messed up now. Timing is all off. It used to work.
+Monster World 4 - Music is messed up now. Timing is all off. It used to work.
- Quackshot doesn't boot.
+Quackshot doesn't boot.
- Moonwalker doesn't boot.
+Moonwalker doesn't boot.
- Altered Beast: start with 0 health, 0 lives???
+Altered Beast: start with 0 health, 0 lives???
-  Contra Hard Corps: Scrolling is messed up in level 1... used to work.
+Contra Hard Corps: Scrolling is messed up in level 1... used to work. Window seemed to mess things up.
- After Burner 2: No music
+After Burner 2: No music
- MUSHA: Intro music starts too soon
+MUSHA: Intro music starts too soon
- MUSHA: uses unimplemented VRAM copy
+MUSHA: uses unimplemented VRAM copy
- MUSHA: Some sprites have messed up left/right symmetry
+MUSHA: Some sprites have messed up left/right symmetry
- Landstalker: freezes during new game sequence, very early
+Landstalker: freezes during new game sequence, very early
- 
+Arcus Odyssey does UNHANDLED Z80 READs... is this a problem?
- Things that read from VRAM work like 50%-90%, but not 100%. It's frustrating. Kid Chameleon and Eternal Champions are examples.
+ahhh! real monsters - no sound
+Alien Storm.... Controls all messed up. Same with Aero the Acrobat.
+Devilish/Bad Omen - uses VRAM copy (unimpl)
+Blood Shot - FPS game - some texture corruption
 
- Some games flicker in the rightmost columns. Is this caused by mid-frame mode shifting(32/40 col modes?) Alisia Dragoon is one example.
+Things that read from VRAM work like 50%-90%, but not 100%. It's frustrating. Kid Chameleon and Eternal Champions are examples.
+
+Some games flicker in the rightmost columns. Is this caused by mid-frame mode shifting(32/40 col modes?) Alisia Dragoon is one example.
 
 
- TODO: non-instant DMA emulation
+TODO: non-instant DMA emulation
- TODO: Add 68000/VDP interrupt enable delay (one instruction, similar to After Burner/PCE)
+TODO: Add 68000/VDP interrupt enable delay (one instruction, similar to After Burner/PCE)
- TODO: freaking H-interrupts
+TODO: freaking H-interrupts
- TODO: Test DMA/ VDP command words.... I'm not at all convinced that VRAM is always correct
+TODO: Test DMA/ VDP command words.... I'm not at all convinced that VRAM is always correct
+
+
+
+
+
+
+
+
+==============
+Notable games:
+==============
+
+Ghouls n Ghosts sets up the graphics planes backwards from normal, by setting the plane A to be low priority and Plane B to be high priority.
+If you have a bug in your priority code this may find it.
+
+Revenge of Shinobi will not play DAC sounds if YM2612 registers are not initialized to L/R channels enabled.
+
+Ballz doesnt really initialize hardly any VDP registers, relies on VDP registers powered-on to the correct values
+
+Contra appears to use VDP A0 set = byte-swap. Not sure if its important in anyway in that game, but the byte swap happens.

BizHawk.Emulation/Consoles/Sega/Genesis/GenVDP.DMA.cs

@@ -26,7 +26,7 @@ namespace BizHawk.Emulation.Consoles.Sega
 
         void ExecuteDmaFill(ushort data)
         {
-            Log.Note("VDP","DMA FILL REQD, WRITE {0:X4}, {1:X4} times, at {2:X4}", data, DmaLength, VdpDataAddr);
+            //Log.Error("VDP","DMA FILL REQD, WRITE {0:X4}, {1:X4} times, at {2:X4}", data, DmaLength, VdpDataAddr);
 
             // TODO: It should spread this out, not do it all at once.
             // TODO: DMA can go to places besides just VRAM (eg CRAM, VSRAM) ??? can it?
@@ -50,7 +50,7 @@ namespace BizHawk.Emulation.Consoles.Sega
 
         void Execute68000VramCopy()
         {
-            Log.Note("VDP", "DMA 68000 -> VRAM COPY REQ'D. LENGTH {0:X4}, SOURCE {1:X4}", DmaLength, DmaSource);
+            //Log.Error("VDP", "DMA 68000 -> VRAM COPY REQ'D. LENGTH {0:X4}, SOURCE {1:X4}", DmaLength, DmaSource);
             
             int length = DmaLength;
             if (length == 0)

BizHawk.Emulation/Consoles/Sega/Genesis/GenVDP.Render.cs

@@ -16,13 +16,9 @@ namespace BizHawk.Emulation.Consoles.Sega
 
         static readonly byte[] PalXlatTable = { 0, 0, 36, 36, 73, 73, 109, 109, 145, 145, 182, 182, 219, 219, 255, 255 };
 
-        // TODO, should provide startup register values.
         public void RenderLine()
         {
             Array.Clear(PriorityBuffer, 0, 320);
-            int bgcolor = BackgroundColor;
-            for (int ofs = ScanLine * FrameWidth, i = 0; i < FrameWidth; i++, ofs++)
-                FrameBuffer[ofs] = bgcolor;
 
             if (DisplayEnabled)
             {
@@ -42,20 +38,25 @@ namespace BizHawk.Emulation.Consoles.Sega
                     FrameBuffer[(p*FrameWidth) + i] = Palette[(p*16) + i];
         }
 
-        void RenderBackgroundScanline(int xScroll, int yScroll, int nameTableBase, int lowPriority, int highPriority)
+        void RenderScrollAScanline(int xScroll, int yScroll, int nameTableBase, int startPixel, int endPixel)
         {
+            const int lowPriority = 2;
+            const int highPriority = 5;
             int yTile = ((ScanLine + yScroll) / 8) % NameTableHeight;
+            int nameTableWidth = NameTableWidth;
+            if (nameTableBase == NameTableAddrWindow)
+                nameTableWidth = Display40Mode ? 64 : 32;
 
             // this is hellllla slow. but not optimizing until we implement & understand
             // all scrolling modes, shadow & hilight, etc.
             // in thinking about this, you could convince me to optimize the PCE background renderer now.
             // Its way simple in comparison. But the PCE sprite renderer is way worse than gen.
-            for (int x = 0; x < FrameWidth; x++)
+            for (int x = startPixel; x < endPixel; x++)
             {
-                int xTile = Math.Abs(((x + (1024-xScroll)) / 8) % NameTableWidth);
+                int xTile = Math.Abs(((x + (1024-xScroll)) / 8) % nameTableWidth);
                 int xOfs = Math.Abs((x + (1024-xScroll)) & 7);
                 int yOfs = (ScanLine + yScroll) % 8;
-                int cellOfs = nameTableBase + (yTile * NameTableWidth * 2) + (xTile * 2);
+                int cellOfs = nameTableBase + (yTile * nameTableWidth * 2) + (xTile * 2);
                 int nameTableEntry = VRAM[cellOfs] | (VRAM[cellOfs+1] << 8);
                 int patternNo = nameTableEntry & 0x7FF;
                 bool hFlip = ((nameTableEntry >> 11) & 1) != 0;
@@ -77,19 +78,134 @@ namespace BizHawk.Emulation.Consoles.Sega
             }
         }
 
+        void CalculateWindowScanlines(out int startScanline, out int endScanline)
+        {
+            int data = Registers[0x12];
+            int windowVPosition = data & 31;
+            bool fromTop = (data & 0x80) == 0;
+            
+            if (windowVPosition == 0)
+            {
+                startScanline = -1;
+                endScanline = -1;
+                return;
+            }
+
+            if (fromTop)
+            {
+                startScanline = 0;
+                endScanline = (windowVPosition * 8);
+            } else {
+                startScanline = windowVPosition * 8;
+                endScanline = FrameHeight;
+            }
+        }
+
+        void CalculateWindowPosition(out int startPixel, out int endPixel)
+        {
+            int data = Registers[0x11];
+            int windowHPosition = (data & 31) * 2; // Window H position is set in 2-cell increments
+            bool fromLeft = (data & 0x80) == 0;
+
+            if (windowHPosition == 0)
+            {
+                startPixel = -1;
+                endPixel = -1;
+                return;
+            }
+
+            if (fromLeft)
+            {
+                startPixel = 0;
+                endPixel = (windowHPosition * 8);
+            }
+            else
+            {
+                startPixel = windowHPosition * 8;
+                endPixel = FrameWidth;
+            }
+        }
+
         void RenderScrollA()
         {
-            // todo scroll values
+            // Calculate scroll offsets
+
             int hscroll = CalcHScrollPlaneA(ScanLine);
             int vscroll = VSRAM[0] & 0x3FF;
-            RenderBackgroundScanline(hscroll, vscroll, NameTableAddrA, 2, 5);
+
+            // Calculate window dimensions
+
+            int startWindowScanline, endWindowScanline;
+            int startWindowPixel, endWindowPixel;
+            CalculateWindowScanlines(out startWindowScanline, out endWindowScanline);
+            CalculateWindowPosition(out startWindowPixel, out endWindowPixel);
+
+            // Render scanline
+
+            if (ScanLine >= startWindowScanline && ScanLine < endWindowScanline)  // Window takes up whole scanline
+            {
+                RenderScrollAScanline(0, 0, NameTableAddrWindow, 0, FrameWidth);
+            }
+            else if (startWindowPixel != -1) // Window takes up partial scanline
+            {
+                if (startWindowPixel == 0) // Window grows from left side
+                {
+                    RenderScrollAScanline(0, 0, NameTableAddrWindow, 0, endWindowPixel);
+                    RenderScrollAScanline(hscroll, vscroll, NameTableAddrA, endWindowPixel, FrameWidth);
+                }
+                else // Window grows from right side
+                {
+                    RenderScrollAScanline(hscroll, vscroll, NameTableAddrA, 0, startWindowPixel);
+                    RenderScrollAScanline(0, 0, NameTableAddrWindow, startWindowPixel, FrameWidth);
+                }
+            } 
+            else // No window
+            {   
+                RenderScrollAScanline(hscroll, vscroll, NameTableAddrA, 0, FrameWidth);
+            }
         }
 
         void RenderScrollB()
         {
-            int hscroll = CalcHScrollPlaneB(ScanLine);
+            int bgColor = BackgroundColor;
-            int vscroll = VSRAM[1] & 0x3FF;
+            int xScroll = CalcHScrollPlaneB(ScanLine);
-            RenderBackgroundScanline(hscroll, vscroll, NameTableAddrB, 1, 4);
+            int yScroll = VSRAM[1] & 0x3FF;
+
+            const int lowPriority = 1;
+            const int highPriority = 4;
+
+            int yTile = ((ScanLine + yScroll) / 8) % NameTableHeight;
+
+            // this is hellllla slow. but not optimizing until we implement & understand
+            // all scrolling modes, shadow & hilight, etc.
+            // in thinking about this, you could convince me to optimize the PCE background renderer now.
+            // Its way simple in comparison. But the PCE sprite renderer is way worse than gen.
+            for (int x = 0; x < FrameWidth; x++)
+            {
+                int xTile = Math.Abs(((x + (1024 - xScroll)) / 8) % NameTableWidth);
+                int xOfs = Math.Abs((x + (1024 - xScroll)) & 7);
+                int yOfs = (ScanLine + yScroll) % 8;
+                int cellOfs = NameTableAddrB + (yTile * NameTableWidth * 2) + (xTile * 2);
+                int nameTableEntry = VRAM[cellOfs] | (VRAM[cellOfs + 1] << 8);
+                int patternNo = nameTableEntry & 0x7FF;
+                bool hFlip = ((nameTableEntry >> 11) & 1) != 0;
+                bool vFlip = ((nameTableEntry >> 12) & 1) != 0;
+                bool priority = ((nameTableEntry >> 15) & 1) != 0;
+                int palette = (nameTableEntry >> 13) & 3;
+
+                if (priority && PriorityBuffer[x] >= highPriority) continue;
+                if (!priority && PriorityBuffer[x] >= lowPriority) continue;
+
+                if (vFlip) yOfs = 7 - yOfs;
+                if (hFlip) xOfs = 7 - xOfs;
+
+                int texel = PatternBuffer[(patternNo * 64) + (yOfs * 8) + (xOfs)];
+                int pixel = Palette[(palette * 16) + texel];
+                if (texel == 0)
+                    pixel = bgColor;
+                FrameBuffer[(ScanLine * FrameWidth) + x] = pixel;
+                PriorityBuffer[x] = (byte)(priority ? highPriority : lowPriority);
+            }
         }
 
         static readonly int[] SpriteSizeTable = { 8, 16, 24, 32 };

BizHawk.Emulation/Consoles/Sega/Genesis/GenVDP.cs

@@ -14,8 +14,9 @@ namespace BizHawk.Emulation.Consoles.Sega
         
         public byte[] PatternBuffer = new byte[0x20000];
         public int[] Palette = new int[64];
-        public int[] FrameBuffer = new int[256*224];
+        public int[] FrameBuffer = new int[320*224];
-        public int FrameWidth = 256;
+        public int FrameWidth = 320;
+        public int FrameHeight = 224;
 
         public int ScanLine;
         public int HIntLineCounter;
@@ -56,6 +57,19 @@ namespace BizHawk.Emulation.Consoles.Sega
         public const int StatusSpriteOverflow           = 0x40;
         public const int StatusVerticalInterruptPending = 0x80;
 
+        public GenVDP()
+        {
+            WriteVdpRegister(00, 0x04);
+            WriteVdpRegister(01, 0x04);
+            WriteVdpRegister(02, 0x30);
+            WriteVdpRegister(03, 0x3C);
+            WriteVdpRegister(04, 0x07);
+            WriteVdpRegister(05, 0x67);
+            WriteVdpRegister(10, 0xFF);
+            WriteVdpRegister(12, 0x81);
+            WriteVdpRegister(15, 0x02);
+        }
+
         public ushort ReadVdp(int addr)
         {
             switch (addr)
@@ -157,7 +171,7 @@ namespace BizHawk.Emulation.Consoles.Sega
             ControlWordPending = false; 
 
             // byte-swap incoming data when A0 is set
-            if ((VdpDataAddr & 1) != 0)
+             if ((VdpDataAddr & 1) != 0)
             {
                 data = (ushort)((data >> 8) | (data << 8));
                 Console.WriteLine("VRAM byte-swap is happening because A0 is not 0");
@@ -173,6 +187,7 @@ namespace BizHawk.Emulation.Consoles.Sega
                 case CommandVramWrite: // VRAM Write
                     VRAM[VdpDataAddr & 0xFFFE] = (byte) data;
                     VRAM[(VdpDataAddr & 0xFFFE) + 1] = (byte) (data >> 8);
+                    //Log.Error("VDP", "VRAM[{0:X4}] = {1:X4}", VdpDataAddr, data);
                     UpdatePatternBuffer(VdpDataAddr & 0xFFFE);
                     UpdatePatternBuffer((VdpDataAddr & 0xFFFE) + 1);
                     //Console.WriteLine("Wrote VRAM[{0:X4}] = {1:X4}", VdpDataAddr, data);
@@ -227,10 +242,11 @@ namespace BizHawk.Emulation.Consoles.Sega
 
             // TODO dont tie this to musashi cycle count.
             // Figure out a "clean" way to get cycle counter information available to VDP.
+            // Oh screw that. The VDP and the cpu cycle counters are going to be intertwined pretty tightly.
             int hcounter = (487 - Native68000.Musashi.GetCyclesRemaining()) * 255 / 487;
 
             ushort res = (ushort) ((vcounter << 8) | (hcounter & 0xFF));
-            Console.WriteLine("READ HVC: V={0:X2} H={1:X2}  ret={2:X4}", vcounter, hcounter, res);
+            //Console.WriteLine("READ HVC: V={0:X2} H={1:X2}  ret={2:X4}", vcounter, hcounter, res);
 
             return res;
         }
@@ -254,22 +270,22 @@ namespace BizHawk.Emulation.Consoles.Sega
 
                 case 0x02: // Name Table Address for Layer A
                     NameTableAddrA = (ushort) ((data & 0x38) << 10);
-                    //Log.Note("VDP", "SET NTa A = {0:X4}", NameTableAddrA);
+                    //Log.Error("VDP", "SET NTa A = {0:X4}", NameTableAddrA);
                     break;
 
                 case 0x03: // Name Table Address for Window
                     NameTableAddrWindow = (ushort) ((data & 0x3E) << 10);
-                    //Log.Note("VDP", "SET NTa W = {0:X4}", NameTableAddrWindow);
+                    //Log.Error("VDP", "SET NTa W = {0:X4}", NameTableAddrWindow);
                     break;
 
                 case 0x04: // Name Table Address for Layer B
                     NameTableAddrB = (ushort) (data << 13);
-                    //Log.Note("VDP", "SET NTa B = {0:X4}", NameTableAddrB);
+                    //Log.Error("VDP", "SET NTa B = {0:X4}", NameTableAddrB);
                     break;
 
                 case 0x05: // Sprite Attribute Table Address
                     SpriteAttributeTableAddr = (ushort) (data << 9);
-                    //Log.Note("VDP", "SET SAT attr = {0:X4}", SpriteAttributeTableAddr);
+                    //Log.Error("VDP", "SET SAT attr = {0:X4}", SpriteAttributeTableAddr);
                     break;
 
                 case 0x0A: // H Interrupt Register
@@ -338,7 +354,6 @@ namespace BizHawk.Emulation.Consoles.Sega
                         case 2: NameTableHeight = 32; break; // invalid setting
                         case 3: NameTableHeight = 128; break;
                     }
-                    //Log.Note("VDP", "Name Table Dimensions set to {0}x{1}", NameTableWidth, NameTableHeight);
                     break;
 
                 case 0x11: // Window H Position
@@ -348,8 +363,8 @@ namespace BizHawk.Emulation.Consoles.Sega
                     break;
 
                 case 0x12: // Window V
-                    whp = data & 31;
+                    //whp = data & 31;
-                    fromright = (data & 0x80) != 0;
+                    //fromright = (data & 0x80) != 0;
                     //Log.Error("VDP", "Window V is {0} units from {1}", whp, fromright ? "lower" : "upper");
                     break;
 
@@ -408,7 +423,7 @@ namespace BizHawk.Emulation.Consoles.Sega
 
         public int BufferHeight
         {
-            get { return 224; }
+            get { return FrameHeight; }
         }
 
         public int BackgroundColor