8bitworkshop/src/machine/cpc.ts

//// WASM Machine

import { KeyFlags } from "../common/emu";
import { Machine } from "../common/baseplatform";
import { TrapCondition } from "../common/devices";
import { BaseWASMMachine } from "../common/wasmplatform";

const BIN_HEADER = [
  0,
  0,0,0,0,0,0,0,0,
  0,0,0,
  0,0,0,0,0,0,
  1,
  0,0,
  0x0, 0x40, // load addr
  0,
  0x0, 0x0,  // length
  0x0, 0x40, // start addr
  0,0,0,0,
  0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 
  0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 
  0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 
  0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 
  0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 
  0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 
];

export class CPC_WASMMachine extends BaseWASMMachine implements Machine {

  numTotalScanlines = 312;
  cpuCyclesPerLine = 224;

  joymask0 = 0;
  runaddr = 0x4000;

  loadROM(rom: Uint8Array) {
    let combined = new Uint8Array(rom.length + BIN_HEADER.length);
    combined.set(BIN_HEADER, 0);
    combined[24] = rom.length & 0xff;
    combined[25] = rom.length >> 8;
    combined[26] = this.runaddr & 0xff;
    combined[27] = this.runaddr >> 8;
    combined.set(rom, BIN_HEADER.length);
    super.loadROM(combined);
  }
  reset() {
    super.reset();
    // advance bios
    this.exports.machine_exec(this.sys, 1000000); // TODO?
    // load rom (SNA or BIN)
    if (this.romptr && this.romlen) {
      this.exports.machine_load_rom(this.sys, this.romptr, this.romlen);
        // advance clock until program starts
        for (var i=0; i<100000 && this.getPC() != this.runaddr; i++) {
          this.exports.machine_tick(this.sys);
        }
    }
  }
  advanceFrame(trap: TrapCondition) : number {
    var scanline = this.getRasterY();
    var clocks = Math.floor((this.numTotalScanlines - scanline) * (4000000/50) / this.numTotalScanlines);
    var probing = this.probe != null;
    if (probing) this.exports.machine_reset_probe_buffer();
    clocks = super.advanceFrameClock(trap, clocks);
    if (probing) this.copyProbeData();
    return clocks;
  }
  getRasterY() {
    return this.exports.machine_get_raster_line(this.sys);
  }
  getRasterCanvasPosition() {
    return {
      x: -1, // TODO?
      y: this.getRasterY() - 14,
    }
  }
  /*
    z80_tick_t tick_cb; // 0
    uint64_t bc_de_hl_fa; // 8
    uint64_t bc_de_hl_fa_; // 16
    uint64_t wz_ix_iy_sp; // 24
    uint64_t im_ir_pc_bits; // 32
    uint64_t pins;          // 48
    void* user_data;
    z80_trap_t trap_cb;
    void* trap_user_data;
    int trap_id;           
  */
  getCPUState() {
    this.exports.machine_save_cpu_state(this.sys, this.cpustateptr);
    var s = this.cpustatearr;
    var af = s[9] + (s[8]<<8); // not FA
    var hl = s[10] + (s[11]<<8);
    var de = s[12] + (s[13]<<8);
    var bc = s[14] + (s[15]<<8);
    var sp = s[24] + (s[25]<<8);
    var iy = s[26] + (s[27]<<8);
    var ix = s[28] + (s[29]<<8);
    var pc = s[34] + (s[35]<<8);
    var ir = s[36] + (s[37]<<8);
    return {
      PC:pc,
      SP:sp,
      AF:af,
      BC:bc,
      DE:de,
      HL:hl,
      IX:ix,
      IY:iy,
      IR:ir,
      o:this.readConst(pc),
    }
  }
  saveState() {
    this.exports.machine_save_state(this.sys, this.stateptr);
    return {
      c:this.getCPUState(),
      state:this.statearr.slice(0),
    };
  }
  loadState(state) : void {
    this.statearr.set(state.state);
    this.exports.machine_load_state(this.sys, this.stateptr);
  }
  getVideoParams() {
   return {width:768, height:272, overscan:true, videoFrequency:50, aspect:1.3};
  }
  setKeyInput(key: number, code: number, flags: number): void {
    // TODO: handle shifted keys
    if (key == 16 || key == 17 || key == 18 || key == 224) return; // meta keys
    //console.log(key, code, flags);
    //if (flags & KeyFlags.Shift) { key += 64; }
    var mask = 0;
    var mask2 = 0;
    if (key == 37) { key = 0x8; mask = 0x4; } // LEFT
    if (key == 38) { key = 0xb; mask = 0x1; } // UP
    if (key == 39) { key = 0x9; mask = 0x8; } // RIGHT
    if (key == 40) { key = 0xa; mask = 0x2; } // DOWN
    if (key == 32) { mask = 0x10; } // FIRE
    if (key == 65) { key = 65; mask2 = 0x4; } // LEFT
    if (key == 87) { key = 87; mask2 = 0x1; } // UP
    if (key == 68) { key = 68; mask2 = 0x8; } // RIGHT
    if (key == 83) { key = 83; mask2 = 0x2; } // DOWN
    if (key == 69) { mask2 = 0x10; } // FIRE
    if (key == 113) { key = 0xf1; } // F2
    if (key == 115) { key = 0xf3; } // F4
    if (key == 119) { key = 0xf5; } // F8
    if (key == 121) { key = 0xf7; } // F10
    if (flags & KeyFlags.KeyDown) {
      this.exports.machine_key_down(this.sys, key);
      this.joymask0 |= mask;
    } else if (flags & KeyFlags.KeyUp) {
      this.exports.machine_key_up(this.sys, key);
      this.joymask0 &= ~mask;
    }
    // TODO: this.exports.cpc_joystick(this.sys, this.joymask0, 0);
  }
}