dsp4emu.c

来自「linux下的任天堂模拟器代码。供大家参考。」· C语言 代码 · 共 2,173 行 · 第 1/5 页

  DSP4_vars.world_dx = DSP4_READ_DWORD();
  DSP4_vars.distance = DSP4_READ_WORD();
  DSP4_READ_WORD(); // 0x0000
  DSP4_vars.world_xenv = SEX78(DSP4_READ_WORD());
  DSP4_vars.world_ddy = DSP4_READ_WORD();
  DSP4_vars.world_ddx = DSP4_READ_WORD();
  DSP4_vars.view_yofsenv = DSP4_READ_WORD();

  // initial (x,y,offset) at starting DSP4_vars.raster line
  DSP4_vars.view_x1 = (int16)((DSP4_vars.world_x + DSP4_vars.world_xenv) >> 16);
  DSP4_vars.view_y1 = (int16)(DSP4_vars.world_y >> 16);
  DSP4_vars.view_xofs1 = (int16)(DSP4_vars.world_x >> 16);
  DSP4_vars.view_yofs1 = DSP4_vars.world_yofs;

  // first DSP4_vars.raster line
  DSP4_vars.poly_raster[0][0] = DSP4_vars.poly_bottom[0][0];


  do
  {
    ////////////////////////////////////////////////////
    // process one iteration of projection

    // perspective projection of world (x,y,scroll) points
    // based on the current projection lines
    DSP4_vars.view_x2 = (int16)(( ( ( DSP4_vars.world_x + DSP4_vars.world_xenv ) >> 16 ) * DSP4_vars.distance >> 15 ) + ( DSP4_vars.view_turnoff_x * DSP4_vars.distance >> 15 ));
    DSP4_vars.view_y2 = (int16)((DSP4_vars.world_y >> 16) * DSP4_vars.distance >> 15);
    DSP4_vars.view_xofs2 = DSP4_vars.view_x2;
    DSP4_vars.view_yofs2 = (DSP4_vars.world_yofs * DSP4_vars.distance >> 15) + DSP4_vars.poly_bottom[0][0] - DSP4_vars.view_y2;

    // 1. World x-location before transformation
    // 2. Viewer x-position at the current
    // 3. World y-location before perspective projection
    // 4. Viewer y-position below the horizon
    // 5. Number of DSP4_vars.raster lines drawn in this iteration

    DSP4_CLEAR_OUT();
    DSP4_WRITE_WORD((uint16)((DSP4_vars.world_x + DSP4_vars.world_xenv) >> 16));
    DSP4_WRITE_WORD(DSP4_vars.view_x2);
    DSP4_WRITE_WORD((uint16)(DSP4_vars.world_y >> 16));
    DSP4_WRITE_WORD(DSP4_vars.view_y2);

    //////////////////////////////////////////////////////////

    // SR = 0x00

    // determine # of DSP4_vars.raster lines used
    DSP4_vars.segments = DSP4_vars.view_y1 - DSP4_vars.view_y2;

    // prevent overdraw
    if (DSP4_vars.view_y2 >= DSP4_vars.poly_raster[0][0])
      DSP4_vars.segments = 0;
    else
      DSP4_vars.poly_raster[0][0] = DSP4_vars.view_y2;

    // don't draw outside the window
    if (DSP4_vars.view_y2 < DSP4_vars.poly_top[0][0])
    {
      DSP4_vars.segments = 0;

      // flush remaining DSP4_vars.raster lines
      if (DSP4_vars.view_y1 >= DSP4_vars.poly_top[0][0])
        DSP4_vars.segments = DSP4_vars.view_y1 - DSP4_vars.poly_top[0][0];
    }

    // SR = 0x80

    DSP4_WRITE_WORD(DSP4_vars.segments);

    //////////////////////////////////////////////////////////

    // scan next command if no SR check needed
    if (DSP4_vars.segments)
    {
      int32 px_dx, py_dy;
      int32 x_scroll, y_scroll;

      // SR = 0x00

      // linear interpolation (lerp) between projected points
      px_dx = (DSP4_vars.view_xofs2 - DSP4_vars.view_xofs1) * DSP4_Inverse(DSP4_vars.segments) << 1;
      py_dy = (DSP4_vars.view_yofs2 - DSP4_vars.view_yofs1) * DSP4_Inverse(DSP4_vars.segments) << 1;

      // starting step values
      x_scroll = SEX16(DSP4_vars.poly_cx[0][0] + DSP4_vars.view_xofs1);
      y_scroll = SEX16(-DSP4_vars.viewport_bottom + DSP4_vars.view_yofs1 + DSP4_vars.view_yofsenv + DSP4_vars.poly_cx[1][0] - DSP4_vars.world_yofs);

      // SR = 0x80

      // rasterize line
      for (DSP4_vars.lcv = 0; DSP4_vars.lcv < DSP4_vars.segments; DSP4_vars.lcv++)
      {
        // 1. HDMA memory pointer (bg1)
        // 2. vertical scroll offset ($210E)
        // 3. horizontal scroll offset ($210D)

        DSP4_WRITE_WORD(DSP4_vars.poly_ptr[0][0]);
        DSP4_WRITE_WORD((uint16)((y_scroll + 0x8000) >> 16));
        DSP4_WRITE_WORD((uint16)((x_scroll + 0x8000) >> 16));


        // update memory address
        DSP4_vars.poly_ptr[0][0] -= 4;

        // update screen values
        x_scroll += px_dx;
        y_scroll += py_dy;
      }
    }

    /////////////////////////////////////////////////////
    // Post-update

    // update new viewer (x,y,scroll) to last DSP4_vars.raster line drawn
    DSP4_vars.view_x1 = DSP4_vars.view_x2;
    DSP4_vars.view_y1 = DSP4_vars.view_y2;
    DSP4_vars.view_xofs1 = DSP4_vars.view_xofs2;
    DSP4_vars.view_yofs1 = DSP4_vars.view_yofs2;

    // add deltas for projection lines
    DSP4_vars.world_dx += SEX78(DSP4_vars.world_ddx);
    DSP4_vars.world_dy += SEX78(DSP4_vars.world_ddy);

    // update projection lines
    DSP4_vars.world_x += (DSP4_vars.world_dx + DSP4_vars.world_xenv);
    DSP4_vars.world_y += DSP4_vars.world_dy;

    ////////////////////////////////////////////////////
    // command check

    // scan next command
    DSP4.in_count = 2;
    DSP4_WAIT(1) resume1 :

    // inspect input
    DSP4_vars.distance = DSP4_READ_WORD();

    // terminate op
    if (DSP4_vars.distance == -0x8000)
      break;

    // already have 2 bytes in queue
    DSP4.in_count = 6;
    DSP4_WAIT(2) resume2:

    // inspect inputs
    DSP4_vars.world_ddy = DSP4_READ_WORD();
    DSP4_vars.world_ddx = DSP4_READ_WORD();
    DSP4_vars.view_yofsenv = DSP4_READ_WORD();

    // no envelope here
    DSP4_vars.world_xenv = 0;
  }
  while (1);

  DSP4.waiting4command = TRUE;
}

//////////////////////////////////////////////////////////////


void DSP4_OP0E()
{
  DSP4_vars.OAM_RowMax = 16;
  memset(DSP4_vars.OAM_Row, 0, 64);
}


//////////////////////////////////////////////////////////////

void DSP4_OP0F()
{
  DSP4.waiting4command = FALSE;

  // op flow control
  switch (DSP4_vars.DSP4_Logic)
  {
    case 1:
      goto resume1; break;
    case 2:
      goto resume2; break;
    case 3:
      goto resume3; break;
    case 4:
      goto resume4; break;
  }

  ////////////////////////////////////////////////////
  // process initial inputs

  // sort inputs
  DSP4_READ_WORD(); // 0x0000
  DSP4_vars.world_y = DSP4_READ_DWORD();
  DSP4_vars.poly_bottom[0][0] = DSP4_READ_WORD();
  DSP4_vars.poly_top[0][0] = DSP4_READ_WORD();
  DSP4_vars.poly_cx[1][0] = DSP4_READ_WORD();
  DSP4_vars.viewport_bottom = DSP4_READ_WORD();
  DSP4_vars.world_x = DSP4_READ_DWORD();
  DSP4_vars.poly_cx[0][0] = DSP4_READ_WORD();
  DSP4_vars.poly_ptr[0][0] = DSP4_READ_WORD();
  DSP4_vars.world_yofs = DSP4_READ_WORD();
  DSP4_vars.world_dy = DSP4_READ_DWORD();
  DSP4_vars.world_dx = DSP4_READ_DWORD();
  DSP4_vars.distance = DSP4_READ_WORD();
  DSP4_READ_WORD(); // 0x0000
  DSP4_vars.world_xenv = DSP4_READ_DWORD();
  DSP4_vars.world_ddy = DSP4_READ_WORD();
  DSP4_vars.world_ddx = DSP4_READ_WORD();
  DSP4_vars.view_yofsenv = DSP4_READ_WORD();

  // initial (x,y,offset) at starting DSP4_vars.raster line
  DSP4_vars.view_x1 = (int16)((DSP4_vars.world_x + DSP4_vars.world_xenv) >> 16);
  DSP4_vars.view_y1 = (int16)(DSP4_vars.world_y >> 16);
  DSP4_vars.view_xofs1 = (int16)(DSP4_vars.world_x >> 16);
  DSP4_vars.view_yofs1 = DSP4_vars.world_yofs;
  DSP4_vars.view_turnoff_x = 0;
  DSP4_vars.view_turnoff_dx = 0;

  // first DSP4_vars.raster line
  DSP4_vars.poly_raster[0][0] = DSP4_vars.poly_bottom[0][0];


  do
  {
    ////////////////////////////////////////////////////
    // process one iteration of projection

    // perspective projection of world (x,y,scroll) points
    // based on the current projection lines
    DSP4_vars.view_x2 = (int16)(((DSP4_vars.world_x + DSP4_vars.world_xenv) >> 16) * DSP4_vars.distance >> 15);
    DSP4_vars.view_y2 = (int16)((DSP4_vars.world_y >> 16) * DSP4_vars.distance >> 15);
    DSP4_vars.view_xofs2 = DSP4_vars.view_x2;
    DSP4_vars.view_yofs2 = (DSP4_vars.world_yofs * DSP4_vars.distance >> 15) + DSP4_vars.poly_bottom[0][0] - DSP4_vars.view_y2;

    // 1. World x-location before transformation
    // 2. Viewer x-position at the next
    // 3. World y-location before perspective projection
    // 4. Viewer y-position below the horizon
    // 5. Number of DSP4_vars.raster lines drawn in this iteration

    DSP4_CLEAR_OUT();
    DSP4_WRITE_WORD((uint16)((DSP4_vars.world_x + DSP4_vars.world_xenv) >> 16));
    DSP4_WRITE_WORD(DSP4_vars.view_x2);
    DSP4_WRITE_WORD((uint16)(DSP4_vars.world_y >> 16));
    DSP4_WRITE_WORD(DSP4_vars.view_y2);

    //////////////////////////////////////////////////////

    // SR = 0x00

    // determine # of DSP4_vars.raster lines used
    DSP4_vars.segments = DSP4_vars.poly_raster[0][0] - DSP4_vars.view_y2;

    // prevent overdraw
    if (DSP4_vars.view_y2 >= DSP4_vars.poly_raster[0][0])
      DSP4_vars.segments = 0;
    else
      DSP4_vars.poly_raster[0][0] = DSP4_vars.view_y2;

    // don't draw outside the window
    if (DSP4_vars.view_y2 < DSP4_vars.poly_top[0][0])
    {
      DSP4_vars.segments = 0;

      // flush remaining DSP4_vars.raster lines
      if (DSP4_vars.view_y1 >= DSP4_vars.poly_top[0][0])
        DSP4_vars.segments = DSP4_vars.view_y1 - DSP4_vars.poly_top[0][0];
    }

    // SR = 0x80

    DSP4_WRITE_WORD(DSP4_vars.segments);

    //////////////////////////////////////////////////////

    // scan next command if no SR check needed
    if (DSP4_vars.segments)
    {
      int32 px_dx, py_dy;
      int32 x_scroll, y_scroll;

      for (DSP4_vars.lcv = 0; DSP4_vars.lcv < 4; DSP4_vars.lcv++)
      {
        // grab inputs
        DSP4.in_count = 4;
        DSP4_WAIT(1);
        resume1 :
        for (;;)
        {
          int16 distance;
          int16 color, red, green, blue;

          distance = DSP4_READ_WORD();
          color = DSP4_READ_WORD();

          // U1+B5+G5+R5
          red = color & 0x1f;
          green = (color >> 5) & 0x1f;
          blue = (color >> 10) & 0x1f;

          // dynamic lighting
          red = (red * distance >> 15) & 0x1f;
          green = (green * distance >> 15) & 0x1f;
          blue = (blue * distance >> 15) & 0x1f;
          color = red | (green << 5) | (blue << 10);

          DSP4_CLEAR_OUT();
          DSP4_WRITE_WORD(color);
          break;
        }
      }

      //////////////////////////////////////////////////////

      // SR = 0x00

      // linear interpolation (lerp) between projected points
      px_dx = (DSP4_vars.view_xofs2 - DSP4_vars.view_xofs1) * DSP4_Inverse(DSP4_vars.segments) << 1;
      py_dy = (DSP4_vars.view_yofs2 - DSP4_vars.view_yofs1) * DSP4_Inverse(DSP4_vars.segments) << 1;


      // starting step values
      x_scroll = SEX16(DSP4_vars.poly_cx[0][0] + DSP4_vars.view_xofs1);
      y_scroll = SEX16(-DSP4_vars.viewport_bottom + DSP4_vars.view_yofs1 + DSP4_vars.view_yofsenv + DSP4_vars.poly_cx[1][0] - DSP4_vars.world_yofs);

      // SR = 0x80

      // rasterize line
      for (DSP4_vars.lcv = 0; DSP4_vars.lcv < DSP4_vars.segments; DSP4_vars.lcv++)
      {
        // 1. HDMA memory pointer
        // 2. vertical scroll offset ($210E)
        // 3. horizontal scroll offset ($210D)

        DSP4_WRITE_WORD(DSP4_vars.poly_ptr[0][0]);
        DSP4_WRITE_WORD((uint16)((y_scroll + 0x8000) >> 16));
        DSP4_WRITE_WORD((uint16)((x_scroll + 0x8000) >> 16));

        // update memory address
        DSP4_vars.poly_ptr[0][0] -= 4;

        // update screen values
        x_scroll += px_dx;
        y_scroll += py_dy;
      }
    }

    ////////////////////////////////////////////////////
    // Post-update

    // update new viewer (x,y,scroll) to last DSP4_vars.raster line drawn
    DSP4_vars.view_x1 = DSP4_vars.view_x2;
    DSP4_vars.view_y1 = DSP4_vars.view_y2;
    DSP4_vars.view_xofs1 = DSP4_vars.view_xofs2;
    DSP4_vars.view_yofs1 = DSP4_vars.view_yofs2;

    // add deltas for projection lines
    DSP4_vars.world_dx += SEX78(DSP4_vars.world_ddx);
    DSP4_vars.world_dy += SEX78(DSP4_vars.world_ddy);

    // update projection lines
    DSP4_vars.world_x += (DSP4_vars.world_dx + DSP4_vars.world_xenv);
    DSP4_vars.world_y += DSP4_vars.world_dy;

    // update road turnoff position
    DSP4_vars.view_turnoff_x += DSP4_vars.view_turnoff_dx;

    ////////////////////////////////////////////////////
    // command check

    // scan next command
    DSP4.in_count = 2;
    DSP4_WAIT(2) resume2:

    // check for termination
    DSP4_vars.distance = DSP4_READ_WORD();
    if (DSP4_vars.distance == -0x8000)
      break;

    // road splice
    if( (uint16) DSP4_vars.distance == 0x8001 )
    {
      DSP4.in_count = 6;
      DSP4_WAIT(3) resume3:

      DSP4_vars.distance = DSP4_READ_WORD();
      DSP4_vars.view_turnoff_x = DSP4_READ_WORD();
      DSP4_vars.view_turnoff_dx = DSP4_READ_WORD();

      // factor in new changes
      DSP4_vars.view_x1 += ( DSP4_vars.view_turnoff_x * DSP4_vars.distance >> 15 );
      DSP4_vars.view_xofs1 += ( DSP4_vars.view_turnoff_x * DSP4_vars.distance >> 15 );

      // update stepping values
      DSP4_vars.view_turnoff_x += DSP4_vars.view_turnoff_dx;

      DSP4.in_count = 2;
      DSP4_WAIT(2)
    }

    // already have 2 bytes in queue
    DSP4.in_count = 6;
    DSP4_WAIT(4) resume4 :

    // inspect inputs
    DSP4_vars.world_ddy = DSP4_READ_WORD();
    DSP4_vars.world_ddx = DSP4_READ_WORD();
    DSP4_vars.view_yofsenv = DSP4_READ_WORD();

    // no envelope here
    DSP4_vars.world_xenv = 0;
  }
  while (1);

  // terminate op
  DSP4.waiting4command = TRUE;
}

//////////////////////////////////////////////////////////////


void DSP4_OP10()
{
  DSP4.waiting4command = FALSE;

  // op flow control
  switch (DSP4_vars.DSP4_Logic)
  {
    case 1:
      goto resume1; break;
    case 2:
      goto resume2; break;
    case 3:
      goto resume3; break;
  }