C++ FixedDiv函数代码示例

fixed_t FixedHypot(fixed_t x, fixed_t y)
{
#ifdef HAVE_HYPOT
	const float fx = FIXED_TO_FLOAT(x);
	const float fy = FIXED_TO_FLOAT(y);
	float fz;
#ifdef HAVE_HYPOTF
	fz = hypotf(fx, fy);
#else
	fz = (float)hypot(fx, fy);
#endif
	return FLOAT_TO_FIXED(fz);
#else // !HAVE_HYPOT
	fixed_t ax, yx, yx2, yx1;
	if (abs(y) > abs(x)) // |y|>|x|
	{
		ax = abs(y); // |y| => ax
		yx = FixedDiv(x, y); // (x/y)
	}
	else // |x|>|y|
	{
		ax = abs(x); // |x| => ax
		yx = FixedDiv(y, x); // (x/y)
	}
	yx2 = FixedMul(yx, yx); // (x/y)^2
	yx1 = FixedSqrt(1+FRACUNIT + yx2); // (1 + (x/y)^2)^1/2
	return FixedMul(ax, yx1); // |x|*((1 + (x/y)^2)^1/2)
#endif
}

/*
void AM_addMark(void)
{
  markpoints[markpointnum].x = m_x + m_w/2;
  markpoints[markpointnum].y = m_y + m_h/2;
  markpointnum = (markpointnum + 1) % AM_NUMMARKPOINTS;

}
*/
void AM_findMinMaxBoundaries(void)
{
    int i;
    fixed_t a, b;

    min_x = min_y = INT_MAX;
    max_x = max_y = -INT_MAX;
    for (i = 0; i < numvertexes; i++)
    {
        if (vertexes[i].x < min_x)
            min_x = vertexes[i].x;
        else if (vertexes[i].x > max_x)
            max_x = vertexes[i].x;
        if (vertexes[i].y < min_y)
            min_y = vertexes[i].y;
        else if (vertexes[i].y > max_y)
            max_y = vertexes[i].y;
    }
    max_w = max_x - min_x;
    max_h = max_y - min_y;
    min_w = 2 * PLAYERRADIUS;
    min_h = 2 * PLAYERRADIUS;

    a = FixedDiv(f_w << FRACBITS, max_w);
    b = FixedDiv(f_h << FRACBITS, max_h);
    min_scale_mtof = a < b ? a : b;

    max_scale_mtof = FixedDiv(f_h << FRACBITS, 2 * PLAYERRADIUS);

}

vector_t *FV_DivideEx(const vector_t *a_i, fixed_t a_c, vector_t *a_o)
{
	a_o->x = FixedDiv(a_i->x, a_c);
	a_o->y = FixedDiv(a_i->y, a_c);
	a_o->z = FixedDiv(a_i->z, a_c);
	return a_o;
}

int EV_BuildPillar(line_t *line, byte *args, boolean crush)
{
	int secnum;
	sector_t *sec;
	pillar_t *pillar;
	int newHeight;
	int rtn;

	rtn = 0;
	secnum = -1;
	while((secnum = P_FindSectorFromTag(args[0], secnum)) >= 0)
	{
		sec = &sectors[secnum];
		if(sec->specialdata)
			continue; // already moving
		if(sec->floorheight == sec->ceilingheight)
		{ // pillar is already closed
			continue;
		}
		rtn = 1;
		if(!args[2])
		{
			newHeight = sec->floorheight+
				((sec->ceilingheight-sec->floorheight)/2);
		}
		else
		{
			newHeight = sec->floorheight+(args[2]<<FRACBITS);
		}

		pillar = Z_Malloc(sizeof(*pillar), PU_LEVSPEC, 0);
		sec->specialdata = pillar;
		P_AddThinker(&pillar->thinker);
		pillar->thinker.function = T_BuildPillar;
		pillar->sector = sec;
		if(!args[2])
		{
			pillar->ceilingSpeed = pillar->floorSpeed = args[1]*(FRACUNIT/8);
		}
		else if(newHeight-sec->floorheight > sec->ceilingheight-newHeight)
		{
			pillar->floorSpeed = args[1]*(FRACUNIT/8);
			pillar->ceilingSpeed = FixedMul(sec->ceilingheight-newHeight,
				FixedDiv(pillar->floorSpeed, newHeight-sec->floorheight));
		}
		else
		{
			pillar->ceilingSpeed = args[1]*(FRACUNIT/8);
			pillar->floorSpeed = FixedMul(newHeight-sec->floorheight,
				FixedDiv(pillar->ceilingSpeed, sec->ceilingheight-newHeight));
		}
		pillar->floordest = newHeight;
		pillar->ceilingdest = newHeight;
		pillar->direction = 1;
		pillar->crush = crush*args[3];
		SN_StartSequence((mobj_t *)&pillar->sector->soundorg, 
			SEQ_PLATFORM+pillar->sector->seqType);
	}
	return rtn;
}

void R_InitSkyMap ()
{
	if (textureheight == NULL)
		return;

	if (textureheight[skytexture] <= (128 << FRACBITS))
	{
                skytexturemid = 100*FRACUNIT;
                skystretch = (r_stretchsky && allowfreelook);
	}
	else
	{
		skytexturemid = 100*FRACUNIT;
		skystretch = 0;
	}
	skyheight = textureheight[skytexture] << skystretch;

	if (viewwidth && viewheight)
	{
		skyiscale = (200*FRACUNIT) / (((freelookviewheight<<detailxshift) * viewwidth) / (viewwidth<<detailxshift));
		skyscale = ((((freelookviewheight<<detailxshift) * viewwidth) / (viewwidth<<detailxshift)) << FRACBITS) /(200);

		skyiscale = FixedMul (skyiscale, FixedDiv (clipangle, ANG45));
		skyscale = FixedMul (skyscale, FixedDiv (ANG45, clipangle));
	}

	// The sky map is 256*128*4 maps.
	skyshift = 22+skystretch-16;
	if (texturewidthmask[skytexture] >= 256*2-1)
		skyshift -= skystretch;
}

void R_ClearPlanes(void)
{
    int i;
    angle_t angle;

//
// opening / clipping determination
//      
    for (i = 0; i < viewwidth; i++)
    {
        floorclip[i] = viewheight;
        ceilingclip[i] = -1;
    }

    lastvisplane = visplanes;
    lastopening = openings;

//
// texture calculation
//
    memset(cachedheight, 0, sizeof(cachedheight));
    angle = (viewangle - ANG90) >> ANGLETOFINESHIFT;    // left to right mapping

    // scale will be unit scale at SCREENWIDTH/2 distance
    basexscale = FixedDiv(finecosine[angle], centerxfrac);
    baseyscale = -FixedDiv(finesine[angle], centerxfrac);
}

void R_BlastSpriteColumn(void (*drawfunc)())
{
	tallpost_t* post = dcol.post;

	while (!post->end())
	{
		// calculate unclipped screen coordinates for post
		int topscreen = sprtopscreen + spryscale * post->topdelta + 1;

		dcol.yl = (topscreen + FRACUNIT) >> FRACBITS;
		dcol.yh = (topscreen + spryscale * post->length) >> FRACBITS;

		dcol.yl = MAX(dcol.yl, mceilingclip[dcol.x] + 1);
		dcol.yh = MIN(dcol.yh, mfloorclip[dcol.x] - 1);

		dcol.texturefrac = dcol.texturemid - (post->topdelta << FRACBITS)
			+ (dcol.yl * dcol.iscale) - FixedMul(centeryfrac - FRACUNIT, dcol.iscale);

		if (dcol.texturefrac < 0)
		{
			int cnt = (FixedDiv(-dcol.texturefrac, dcol.iscale) + FRACUNIT - 1) >> FRACBITS;
			dcol.yl += cnt;
			dcol.texturefrac += cnt * dcol.iscale;
		}

		const fixed_t endfrac = dcol.texturefrac + (dcol.yh - dcol.yl) * dcol.iscale;
		const fixed_t maxfrac = post->length << FRACBITS;
		
		if (endfrac >= maxfrac)
		{
			int cnt = (FixedDiv(endfrac - maxfrac - 1, dcol.iscale) + FRACUNIT - 1) >> FRACBITS;
			dcol.yh -= cnt;
		}

void Scene::showSprites() {
	// TODO: This is all experimental code, it needs heavy restructuring
	// and cleanup

	// taken from set_walker_scaling() in adv_walk.cpp. A proper implementation will need
	// to store these in global variables
	int minScaling = FixedDiv(_sceneResources->backScale << 16, 100 << 16);
	int maxScaling = FixedDiv(_sceneResources->frontScale << 16, 100 << 16);
	int scaler;

	_vm->_actor->setWalkerDirection(kFacingSouthEast);
	//_vm->_actor->setWalkerPalette();

	// taken from set_walker_scaling() in adv_walk.cpp
	if (_sceneResources->frontY == _sceneResources->backY)
		scaler = 0;
	else
		scaler = FixedDiv(maxScaling - minScaling,
				 (_sceneResources->frontY << 16) - (_sceneResources->backY << 16));

	// FIXME: For now, we (incorrectly) scale the walker to 50% of the scene's max scaling
	_vm->_actor->setWalkerScaling(scaler / 2);
	// Test code to display the protagonist
	_vm->_actor->placeWalkerSpriteAt(0, 320, 200);

	// Test code to display scene sprites
	// TODO
}

static void InitializeFade(boolean fadeIn)
{
	unsigned i;

	Palette = Z_Malloc(768*sizeof(fixed_t), PU_STATIC, 0);
	PaletteDelta = Z_Malloc(768*sizeof(fixed_t), PU_STATIC, 0);
	RealPalette = Z_Malloc(768*sizeof(byte), PU_STATIC, 0);

	if(fadeIn)
	{
		memset(RealPalette, 0, 768*sizeof(byte));
		for(i = 0; i < 768; i++)
		{
			Palette[i] = 0;
			PaletteDelta[i] = FixedDiv((*((byte *)W_CacheLumpName("playpal", 
				PU_CACHE)+i))<<FRACBITS, 70*FRACUNIT);
		}
	}
	else
	{
		for(i = 0; i < 768; i++)
		{
			RealPalette[i] = *((byte *)W_CacheLumpName("playpal", PU_CACHE)+i);
			Palette[i] = RealPalette[i]<<FRACBITS;
			PaletteDelta[i] = FixedDiv(Palette[i], -70*FRACUNIT);
		}
	}
	I_SetPalette(RealPalette);
}

// Also returns the magnitude
fixed_t FV_NormalizeEx(const vector_t *a_normal, vector_t *a_o)
{
	fixed_t magnitude = FV_Magnitude(a_normal);
	a_o->x = FixedDiv(a_normal->x, magnitude);
	a_o->y = FixedDiv(a_normal->y, magnitude);
	a_o->z = FixedDiv(a_normal->z, magnitude);
	return magnitude;
}

//
// PTR_chaseTraverse
//
// go til you hit a wall
// set the chasecam target x and ys if you hit one
// originally based on the shooting traverse function in p_maputl.c
//
static bool PTR_chaseTraverse(intercept_t *in)
{
   fixed_t dist, frac;
   subsector_t *ss;
   int x, y;
   int z;
   sector_t *othersector;

   if(in->isaline)
   {
      line_t *li = in->d.line;
      
      dist = FixedMul(trace.attackrange, in->frac);
      frac = in->frac - FixedDiv(12*FRACUNIT, trace.attackrange);
      
      // hit line
      // position a bit closer
      
      x = trace.dl.x + FixedMul(trace.dl.dx, frac);
      y = trace.dl.y + FixedMul(trace.dl.dy, frac);

      // ioanch 20160225: portal lines are currently not crossed
      if(li->flags & ML_TWOSIDED && !(li->pflags & PS_PASSABLE))
      {  // crosses a two sided line

         // sf: find which side it hit
         
         ss = R_PointInSubsector (x, y);
         
         othersector = li->backsector;
         
         if(ss->sector==li->backsector)      // other side
            othersector = li->frontsector;

         // interpolate, find z at the point of intersection
         
         z = zi(dist, trace.attackrange, targetz, playermobj->z+28*FRACUNIT);
         
         // found which side, check for intersections
         if((li->flags & ML_BLOCKING) || 
            (othersector->floorheight>z) || (othersector->ceilingheight<z)
            || (othersector->ceilingheight-othersector->floorheight
                < 40*FRACUNIT));          // hit
         else
         {
            return true;    // continue
         }
      }

      targetx = x;        // point the new chasecam target at the intersection
      targety = y;
      targetz = zi(dist, trace.attackrange, targetz, playermobj->z+28*FRACUNIT);
      
      // don't go any farther
      
      return false;
   }
   
   return true;
}

//
// PlaneIntersection
//
// Returns the distance from
// rOrigin to where the ray
// intersects the plane. Assumes
// you already know it intersects
// the plane.
//
fixed_t FV_PlaneIntersection(const vector_t *pOrigin, const vector_t *pNormal, const vector_t *rOrigin, const vector_t *rVector)
{
  fixed_t d = -(FV_Dot(pNormal, pOrigin));
  fixed_t number = FV_Dot(pNormal,rOrigin) + d;
  fixed_t denom = FV_Dot(pNormal,rVector);
  return -FixedDiv(number, denom);
}

void R_InitLightTables (void)
{
  int i;

  // killough 4/4/98: dynamic colormaps
  c_zlight = malloc(sizeof(*c_zlight) * numcolormaps);

  // Calculate the light levels to use
  //  for each level / distance combination.
  for (i=0; i< LIGHTLEVELS; i++)
    {
      int j, startmap = ((LIGHTLEVELS-1-i)*2)*NUMCOLORMAPS/LIGHTLEVELS;
      for (j=0; j<MAXLIGHTZ; j++)
        {
    // CPhipps - use 320 here instead of SCREENWIDTH, otherwise hires is
    //           brighter than normal res
          int scale = FixedDiv ((320/2*FRACUNIT), (j+1)<<LIGHTZSHIFT);
          int t, level = startmap - (scale >>= LIGHTSCALESHIFT)/DISTMAP;

          if (level < 0)
            level = 0;
          else
            if (level >= NUMCOLORMAPS)
              level = NUMCOLORMAPS-1;

          // killough 3/20/98: Initialize multiple colormaps
          level *= 256;
          for (t=0; t<numcolormaps; t++)         // killough 4/4/98
            c_zlight[t][i][j] = colormaps[t] + level;
        }
    }
}

void AM_LevelInit(void)
{
  leveljuststarted = 0;

  f_x = f_y = 0;
  f_w = finit_width;
  f_h = finit_height;
	mapxstart = mapystart = 0;


//  AM_clearMarks();

  AM_findMinMaxBoundaries();
  scale_mtof = FixedDiv(min_scale_mtof, (int) (0.7*FRACUNIT));
  if (scale_mtof > max_scale_mtof) scale_mtof = min_scale_mtof;
  scale_ftom = FixedDiv(FRACUNIT, scale_mtof);
}

//
// AM_getIslope()
//
// Calculates the slope and slope according to the x-axis of a line
// segment in map coordinates (with the upright y-axis n' all) so
// that it can be used with the brain-dead drawing stuff.
//
// Passed the line slope is desired for and an islope_t structure for return
// Returns nothing
//
void AM_getIslope
( mline_t*  ml,
  islope_t* is )
{
  int dx, dy;

  dy = ml->a.y - ml->b.y;
  dx = ml->b.x - ml->a.x;
  if (!dy)
    is->islp = (dx<0?-MAXINT:MAXINT);
  else
    is->islp = FixedDiv(dx, dy);
  if (!dx)
    is->slp = (dy<0?-MAXINT:MAXINT);
  else
    is->slp = FixedDiv(dy, dx);
}