using System; namespace BizHawk.Emulation.Consoles.Sega { public sealed partial class GenVDP : IVideoProvider { // Memory public byte[] VRAM = new byte[0x10000]; public ushort[] CRAM = new ushort[64]; public ushort[] VSRAM = new ushort[40]; public byte[] Registers = new byte[0x20]; public byte[] PatternBuffer = new byte[0x20000]; public int[] Palette = new int[64]; public int[] FrameBuffer = new int[256*224]; public int FrameWidth = 256; public int ScanLine; public bool HInterruptsEnabled { get { return (Registers[0] & 0x10) != 0; } } public bool DisplayEnabled { get { return (Registers[1] & 0x40) != 0; } } public bool VInterruptEnabled { get { return (Registers[1] & 0x20) != 0; } } public bool DmaEnabled { get { return (Registers[1] & 0x10) != 0; } } public bool CellBasedVertScroll { get { return (Registers[11] & 0x08) != 0; } } public bool Display40Mode { get { return (Registers[12] & 0x81) != 0; } } ushort NameTableAddrA; ushort NameTableAddrB; ushort NameTableAddrWindow; ushort SpriteAttributeTableAddr; ushort HScrollTableAddr; byte NameTableWidth; byte NameTableHeight; bool ControlWordPending; ushort VdpDataAddr; byte VdpDataCode; static readonly byte[] PalXlatTable = { 0, 0, 36, 36, 73, 73, 109, 109, 145, 145, 182, 182, 219, 219, 255, 255 }; public void WriteVdpControl(ushort data) { Log.Note("VDP", "VDP: Control Write {0:X4}", data); if (ControlWordPending == false) { if ((data & 0xC000) == 0x8000) { int reg = (data >> 8) & 0x1F; byte value = (byte) (data & 0xFF); WriteVdpRegister(reg, value); VdpDataCode = 0; } else { ControlWordPending = true; VdpDataAddr &= 0xC000; VdpDataAddr |= (ushort) (data & 0x3FFF); VdpDataCode &= 0x3C; VdpDataCode |= (byte) (data >> 14); //Console.WriteLine("Address = {0:X4}", VdpDataAddr); //Console.WriteLine("Code = {0:X2}", VdpDataCode); } } else { ControlWordPending = false; // Update data address and code VdpDataAddr &= 0x3FFF; VdpDataAddr |= (ushort) ((data & 0x03) << 14); //Console.WriteLine("Address = {0:X4}", VdpDataAddr); VdpDataCode &= 0x03; VdpDataCode |= (byte) ((data >> 2) & 0x3C); //Console.WriteLine("Code = {0:X2}", VdpDataCode); if ((VdpDataCode & 0x20) != 0 && DmaEnabled) // DMA triggered { //Console.WriteLine("DMA TIME!"); // what type of DMA? switch (Registers[23] >> 6) { case 2: Log.Note("VDP", "VRAM FILL"); DmaFillModePending = true; break; case 3: Log.Note("VDP", "VRAM COPY **** UNIMPLEMENTED ***"); break; default: Log.Note("VDP", "68k->VRAM COPY"); Execute68000VramCopy(); break; } Log.Note("VDP", "DMA LEN = " + DmaLength); } } } public ushort ReadVdpControl() { ushort value = 0x3400; // fixed bits per genvdp.txt TODO test on everdrive, I guess. value |= 0x0200; // Fifo empty Log.Note("VDP", "VDP: Control Read {0:X4}", value); return value; } public void WriteVdpData(ushort data) { ControlWordPending = false; // byte-swap incoming data when A0 is set if ((VdpDataAddr & 1) != 0) data = (ushort) ((data >> 8) | (data << 8)); if (DmaFillModePending) { ExecuteDmaFill(data); } switch (VdpDataCode & 7) { case 1: // VRAM Write VRAM[VdpDataAddr & 0xFFFE] = (byte) data; VRAM[(VdpDataAddr & 0xFFFE) + 1] = (byte) (data >> 8); UpdatePatternBuffer(VdpDataAddr & 0xFFFE); UpdatePatternBuffer((VdpDataAddr & 0xFFFE) + 1); //Console.WriteLine("Wrote VRAM[{0:X4}] = {1:X4}", VdpDataAddr, data); VdpDataAddr += Registers[0x0F]; break; case 3: // CRAM write CRAM[(VdpDataAddr / 2) % 64] = data; //Console.WriteLine("Wrote CRAM[{0:X2}] = {1:X4}", (VdpDataAddr / 2) % 64, data); ProcessPalette((VdpDataAddr/2)%64); VdpDataAddr += Registers[0x0F]; break; case 5: // VSRAM write VSRAM[(VdpDataAddr / 2) % 40] = data; //Console.WriteLine("Wrote VSRAM[{0:X2}] = {1:X4}", (VdpDataAddr / 2) % 40, data); VdpDataAddr += Registers[0x0F]; break; default: Console.WriteLine("VDP DATA WRITE WITH UNHANDLED CODE!!!"); break; } } public ushort ReadVdpData() { Console.WriteLine("VDP: Data Read"); return 0; } public void WriteVdpRegister(int register, byte data) { Log.Note("VDP", "Register {0}: {1:X2}", register, data); switch (register) { case 0x00: // Mode Set Register 1 Registers[register] = data; //Log.Note("VDP", "HINT enabled: " + HInterruptsEnabled); break; case 0x01: // Mode Set Register 2 Registers[register] = data; //Log.Note("VDP", "DisplayEnabled: " + DisplayEnabled); //Log.Note("VDP", "DmaEnabled: " + DmaEnabled); //Log.Note("VDP", "VINT enabled: " + VInterruptEnabled); break; case 0x02: // Name Table Address for Layer A NameTableAddrA = (ushort) ((data & 0x38) << 10); //Log.Note("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); break; case 0x04: // Name Table Address for Layer B NameTableAddrB = (ushort) (data << 13); //Log.Note("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); break; case 0x0A: // H Interrupt Register //Log.Note("VDP", "HInt occurs every {0} lines.", data); break; case 0x0B: // VScroll/HScroll modes /*if ((data & 4) != 0) Log.Note("VDP", "VSCroll Every 2 Cells Enabled"); else Log.Note("VDP", "Full Screen VScroll");*/ int hscrollmode = data & 3; switch (hscrollmode) { //case 0: Log.Note("VDP", "Full Screen HScroll"); break; //case 1: Log.Note("VDP", "Prohibited HSCROLL mode!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"); break; //case 2: Log.Note("VDP", "HScroll every 1 cell"); break; //case 3: Log.Note("VDP", "HScroll every 2 cell"); break; } break; case 0x0C: // Mode Set #4 // TODO interlaced modes if ((data & 0x81) == 0) { // Display is 32 cells wide if (FrameWidth != 256) { FrameBuffer = new int[256*224]; FrameWidth = 256; //Log.Note("VDP", "SWITCH TO 32 CELL WIDE MODE"); } } else { // Display is 40 cells wide if (FrameWidth != 320) { FrameBuffer = new int[320*224]; FrameWidth = 320; //Log.Note("VDP", "SWITCH TO 40 CELL WIDE MODE"); } } break; case 0x0D: // H Scroll Table Address HScrollTableAddr = (ushort) (data << 10); //Log.Note("VDP", "SET HScrollTab attr = {0:X4}", HScrollTableAddr); break; case 0x0F: // Auto Address Register Increment //Log.Note("VDP", "Set Data Increment to " + data); break; case 0x10: // Nametable Dimensions switch (data & 0x03) { case 0: NameTableWidth = 32; break; case 1: NameTableWidth = 64; break; case 2: NameTableWidth = 32; break; // invalid setting case 3: NameTableWidth = 128; break; } switch ((data>>4) & 0x03) { case 0: NameTableHeight = 32; break; case 1: NameTableHeight = 64; break; 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 int whp = data & 31; bool fromright = (data & 0x80) != 0; //Log.Note("VDP", "Window H is {0} units from {1}", whp, fromright ? "right" : "left"); break; case 0x12: // Window V whp = data & 31; fromright = (data & 0x80) != 0; //Log.Note("VDP", "Window V is {0} units from {1}", whp, fromright ? "lower" : "upper"); break; case 0x13: // DMA Length Low Registers[register] = data; //Log.Note("VDP", "DMA Length = {0:X4}", DmaLength); break; case 0x14: // DMA Length High Registers[register] = data; //Log.Note("VDP", "DMA Length = {0:X4}", DmaLength); break; case 0x15: // DMA Source Low Registers[register] = data; //Log.Note("VDP", "DMA Source = {0:X6}", DmaSource); break; case 0x16: // DMA Source Mid Registers[register] = data; //Log.Note("VDP", "DMA Source = {0:X6}", DmaSource); break; case 0x17: // DMA Source High Registers[register] = data; //Log.Note("VDP", "DMA Source = {0:X6}", DmaSource); break; } Registers[register] = data; } void ProcessPalette(int slot) { byte r = PalXlatTable[(CRAM[slot] & 0x000F) >> 0]; byte g = PalXlatTable[(CRAM[slot] & 0x00F0) >> 4]; byte b = PalXlatTable[(CRAM[slot] & 0x0F00) >> 8]; Palette[slot] = Colors.ARGB(r, g, b); } void UpdatePatternBuffer(int addr) { PatternBuffer[(addr*2) + 1] = (byte) (VRAM[addr^1] & 0x0F); PatternBuffer[(addr*2) + 0] = (byte) (VRAM[addr^1] >> 4); } public int[] GetVideoBuffer() { return FrameBuffer; } public int BufferWidth { get { return FrameWidth; } } public int BufferHeight { get { return 224; } } public int BackgroundColor { get { return Palette[Registers[7] & 0x3F]; } } } }