private void HovDrawInitialise()
{
// as: bugfix - Extended sintable length by 1, BuildTables writes one element past the end of the array
sintable = new fixed_t[ANGLES + ANGLES / 4 + 1];
costable = new costable_t(sintable);
for(short i = 0; i < walls.Length; i++)
walls[i] = new walltype(i);
}
/// <summary>Copies the walltype to another.</summary>
/// <remarks>For struct assignment.</remarks>
/// <param name="destination">The destination walltype.</param>
public void CopyTo(walltype destination)
{
destination._index = _index;
destination.x1 = x1;
destination.x2 = x2;
destination.leftclip = leftclip;
destination.rightclip = rightclip;
destination.height1 = height1;
destination.height2 = height2;
destination.color = color;
}
//==========================================================================
/*
=================
=
= StartView
=
= Called by player think
=
=================
*/
private void StartView()
{
//
// set up variables for this view
//
viewangle = objlist[0].angle;
viewsin = sintable[viewangle];
viewcos = costable[viewangle];
viewx = FixedAdd(objlist[0].x, FixedByFrac(FOCALLENGTH, viewcos) ^ SIGNBIT);
viewy = FixedAdd(objlist[0].y, FixedByFrac(FOCALLENGTH, viewsin));
focal.x = (short) (viewx >> TILESHIFT);
focal.y = (short) (viewy >> TILESHIFT);
//
// find the rightmost visable tile in view
//
short tracedir = (short) (viewangle + lastangle);
if(tracedir < 0)
tracedir += ANGLES;
else if(tracedir >= ANGLES)
tracedir -= ANGLES;
TraceRay((ushort) tracedir);
right.x = tile.x;
right.y = tile.y;
//
// find the leftmost visable tile in view
//
tracedir = (short) (viewangle + firstangle);
if(tracedir < 0)
tracedir += ANGLES;
else if(tracedir >= ANGLES)
tracedir -= ANGLES;
TraceRay((ushort) tracedir);
//
// follow the walls from there to the right
//
rightwall = walls[1];
#if DEBUG_IGNORE_RENDER_FAILS
// FIXME as: Prevent rendering errors crashing the game
try { FollowWalls(); }
catch { }
#else
FollowWalls();
#endif
}
/*
===================
=
= DrawWall
=
= Special polygon with vertical edges and symetrical top / bottom
= Clips horizontally to clipleft/clipright
= Clips vertically to VIEWY/VIEWYH
= Should only be called if the wall is at least partially visable
=
==================
*/
private void DrawWall(walltype wallptr)
{
wallptr.CopyTo(drawWall_wall);
short i = (short) (drawWall_wall.height1 / 2);
drawWall_y1l = (short) (CENTERY - i);
drawWall_y1h = (short) (CENTERY + i);
i = (short) (drawWall_wall.height2 / 2);
drawWall_y2l = (short) (CENTERY - i);
drawWall_y2h = (short) (CENTERY + i);
if(drawWall_wall.x1 > drawWall_wall.leftclip)
drawWall_wall.leftclip = drawWall_wall.x1;
if(drawWall_wall.x2 < drawWall_wall.rightclip)
drawWall_wall.rightclip = drawWall_wall.x2;
//
// fill in the zbuffer
//
int height = (int) drawWall_wall.height1 << 16;
int heightstep;
if(drawWall_wall.x2 != drawWall_wall.x1)
heightstep = ((int) (drawWall_wall.height2 - drawWall_wall.height1) << 16) / (short) (drawWall_wall.x2 - drawWall_wall.x1);
else
heightstep = 0;
i = (short) (drawWall_wall.leftclip - drawWall_wall.x1);
if(i != 0)
height += heightstep * i; // adjust for clipped area
for(short x = drawWall_wall.leftclip; x <= drawWall_wall.rightclip; x++)
{
zbuffer[x] = (short) (height >> 16);
height += heightstep;
}
//
// draw the wall to the line buffer
//
if(drawWall_y1l == drawWall_y2l)
{
//
// rectangle, no slope
//
if(drawWall_y1l < VIEWY)
drawWall_y1l = VIEWY;
if(drawWall_y1h > VIEWYH)
drawWall_y1h = VIEWYH;
for(short y = drawWall_y1l; y <= drawWall_y1h; y++)
ADDLINE(drawWall_wall.leftclip, drawWall_wall.rightclip, y, (short) drawWall_wall.color);
return;
}
if(drawWall_y1l < drawWall_y2l)
{
//
// slopes down to the right
//
short slope = (short) (((int) (drawWall_wall.x2 - drawWall_wall.x1) << 6) / (drawWall_y2l - drawWall_y1l)); // in 128ths
short ysteps = (short) (drawWall_y2l - drawWall_y1l);
if(drawWall_y1l < VIEWY)
ysteps -= (short) (VIEWY - drawWall_y1l);
short endfrac = (short) (drawWall_wall.x2 << 6);
for(short y = 1; y < ysteps; y++) // top and bottom slopes
{
endfrac -= slope;
short end = (short) (endfrac >> 6);
if(end > drawWall_wall.rightclip)
end = drawWall_wall.rightclip;
else if(end < drawWall_wall.leftclip) // the rest is hidden
break;
ADDLINE(drawWall_wall.leftclip, end, (short) (drawWall_y2l - y), (short) drawWall_wall.color);
ADDLINE(drawWall_wall.leftclip, end, (short) (drawWall_y2h + y), (short) drawWall_wall.color);
}
if(drawWall_y2l < VIEWY)
drawWall_y2l = VIEWY;
if(drawWall_y2h > VIEWYH)
drawWall_y2h = VIEWYH;
for(short y = drawWall_y2l; y <= drawWall_y2h; y++) // middle
ADDLINE(drawWall_wall.leftclip, drawWall_wall.rightclip, y, (short) drawWall_wall.color);
}
else
{
//
// slopes down to the left
//
short slope = (short) (((int) (drawWall_wall.x2 - drawWall_wall.x1) << 6) / (drawWall_y1l - drawWall_y2l)); // in 128ths
short ysteps = (short) (drawWall_y1l - drawWall_y2l);
if(drawWall_y2l < VIEWY)
ysteps -= (short) (VIEWY - drawWall_y2l);
short endfrac = (short) (drawWall_wall.x1 << 6);
for(short y = 1; y < ysteps; y++) // top and bottom slopes
{
endfrac += slope;
short end = (short) (endfrac >> 6);
if(end < drawWall_wall.leftclip)
end = drawWall_wall.leftclip;
else if(end > drawWall_wall.rightclip) // the rest is hidden
break;
ADDLINE(end, drawWall_wall.rightclip, (short) (drawWall_y1l - y), (short) drawWall_wall.color);
ADDLINE(end, drawWall_wall.rightclip, (short) (drawWall_y1h + y), (short) drawWall_wall.color);
}
if(drawWall_y1l < VIEWY)
drawWall_y1l = VIEWY;
if(drawWall_y1h > VIEWYH)
drawWall_y1h = VIEWYH;
for(short y = drawWall_y1l; y <= drawWall_y1h; y++) // middle
ADDLINE(drawWall_wall.leftclip, drawWall_wall.rightclip, y, (short) drawWall_wall.color);
}
}
//===========================================================================
/*
=================
=
= FinishWall
=
= Transforms edgex,edgey as the next point of the current wall
= and sticks it in the wall list
=
=================
*/
private bool FinishWall()
{
oldwall = rightwall;
if((wallon & 1) != 0)
rightwall.color = (ushort) (basecolor + 8); // high intensity walls
else
rightwall.color = (ushort) basecolor;
TransformPoint(edgex, edgey, ref rightwall.x2, ref rightwall.height2);
walltype rightwall_1 = walls[rightwall.index - 1];
if(rightwall.x2 <= rightwall_1.x2 + 2 && rightwall.height2 < rightwall_1.height2)
return false;
rightwall = walls[rightwall.index + 1];
return true;
}