shithub: qk1

ref: 7240eb5e3f0f766939ab5f14add6384b286d253a
dir: /d_scan.c/

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#include <u.h>
#include <libc.h>
#include "dat.h"
#include "quakedef.h"
#include "fns.h"

unsigned char	*r_turb_pbase, *r_turb_pdest;
fixed16_t		r_turb_s, r_turb_t, r_turb_sstep, r_turb_tstep;
int				*r_turb_turb;
int				r_turb_spancount;
static uzint	*r_turb_z;

/*
=============
D_WarpScreen

// this performs a slight compression of the screen at the same time as
// the sine warp, to keep the edges from wrapping
=============
*/
void D_WarpScreen (void)
{
	int		w, h;
	int		u,v;
	byte	*dest;
	int		*turb;
	int		*col;
	byte	**row;
	static byte	*rowptr[MAXHEIGHT+(AMP2*2)];
	static int		column[MAXWIDTH+(AMP2*2)];
	float	wratio, hratio;

	w = r_refdef.vrect.width;
	h = r_refdef.vrect.height;

	wratio = w / (float)scr_vrect.width;
	hratio = h / (float)scr_vrect.height;

	for (v=0 ; v<scr_vrect.height+AMP2*2 ; v++)
	{
		rowptr[v] = d_viewbuffer + (r_refdef.vrect.y * screenwidth) +
				 (screenwidth * (int)((float)v * hratio * h / (h + AMP2 * 2)));
	}

	for (u=0 ; u<scr_vrect.width+AMP2*2 ; u++)
	{
		column[u] = r_refdef.vrect.x +
				(int)((float)u * wratio * w / (w + AMP2 * 2));
	}

	turb = intsintable + ((int)(cl.time*SPEED)&(CYCLE-1));
	dest = vid.buffer + scr_vrect.y * vid.rowbytes + scr_vrect.x;

	for (v=0 ; v<scr_vrect.height ; v++, dest += vid.rowbytes)
	{
		col = &column[turb[v]];
		row = &rowptr[v];

		for (u=0 ; u<scr_vrect.width ; u+=4)
		{
			dest[u+0] = row[turb[u+0]][col[u+0]];
			dest[u+1] = row[turb[u+1]][col[u+1]];
			dest[u+2] = row[turb[u+2]][col[u+2]];
			dest[u+3] = row[turb[u+3]][col[u+3]];
		}
	}
}

/*
=============
D_DrawTurbulent8Span
=============
*/
void D_DrawTurbulent8Span (int izi, byte alpha)
{
	int		sturb, tturb;

	do
	{
		sturb = ((r_turb_s + r_turb_turb[(r_turb_t>>16)&(CYCLE-1)])>>16)&63;
		tturb = ((r_turb_t + r_turb_turb[(r_turb_s>>16)&(CYCLE-1)])>>16)&63;
		if (*r_turb_z <= (izi >> 16))
			*r_turb_pdest = blendalpha(*(r_turb_pbase + (tturb<<6) + sturb), *r_turb_pdest, alpha);
		r_turb_s += r_turb_sstep;
		r_turb_t += r_turb_tstep;
		r_turb_pdest++;
		r_turb_z++;
	} while (--r_turb_spancount > 0);
}


/*
=============
Turbulent8
=============
*/
void Turbulent8 (espan_t *pspan, byte alpha)
{
	int				count;
	fixed16_t		snext, tnext;
	float			sdivz, tdivz, zi, z, du, dv, spancountminus1;
	float			sdivz16stepu, tdivz16stepu, zi16stepu;
	
	r_turb_turb = sintable + ((int)(cl.time*SPEED)&(CYCLE-1));

	r_turb_sstep = 0;	// keep compiler happy
	r_turb_tstep = 0;	// ditto

	r_turb_pbase = (unsigned char *)cacheblock;

	sdivz16stepu = d_sdivzstepu * 16;
	tdivz16stepu = d_tdivzstepu * 16;
	zi16stepu = d_zistepu * 16;

	do
	{
		r_turb_pdest = (unsigned char *)((byte *)d_viewbuffer +
				(screenwidth * pspan->v) + pspan->u);
		r_turb_z = d_pzbuffer + (d_zwidth * pspan->v) + pspan->u;

		count = pspan->count;

	// calculate the initial s/z, t/z, 1/z, s, and t and clamp
		du = (float)pspan->u;
		dv = (float)pspan->v;

		sdivz = d_sdivzorigin + dv*d_sdivzstepv + du*d_sdivzstepu;
		tdivz = d_tdivzorigin + dv*d_tdivzstepv + du*d_tdivzstepu;
		zi = d_ziorigin + dv*d_zistepv + du*d_zistepu;
		z = (float)0x10000 / zi;	// prescale to 16.16 fixed-point

		r_turb_s = (int)(sdivz * z) + sadjust;
		if (r_turb_s > bbextents)
			r_turb_s = bbextents;
		else if (r_turb_s < 0)
			r_turb_s = 0;

		r_turb_t = (int)(tdivz * z) + tadjust;
		if (r_turb_t > bbextentt)
			r_turb_t = bbextentt;
		else if (r_turb_t < 0)
			r_turb_t = 0;

		do
		{
		// calculate s and t at the far end of the span
			if (count >= 16)
				r_turb_spancount = 16;
			else
				r_turb_spancount = count;

			count -= r_turb_spancount;

			if (count)
			{
			// calculate s/z, t/z, zi->fixed s and t at far end of span,
			// calculate s and t steps across span by shifting
				sdivz += sdivz16stepu;
				tdivz += tdivz16stepu;
				zi += zi16stepu;
				z = (float)0x10000 / zi;	// prescale to 16.16 fixed-point

				snext = (int)(sdivz * z) + sadjust;
				if (snext > bbextents)
					snext = bbextents;
				else if (snext < 16)
					snext = 16;	// prevent round-off error on <0 steps from
								//  from causing overstepping & running off the
								//  edge of the texture

				tnext = (int)(tdivz * z) + tadjust;
				if (tnext > bbextentt)
					tnext = bbextentt;
				else if (tnext < 16)
					tnext = 16;	// guard against round-off error on <0 steps

				r_turb_sstep = (snext - r_turb_s) >> 4;
				r_turb_tstep = (tnext - r_turb_t) >> 4;
			}
			else
			{
			// calculate s/z, t/z, zi->fixed s and t at last pixel in span (so
			// can't step off polygon), clamp, calculate s and t steps across
			// span by division, biasing steps low so we don't run off the
			// texture
				spancountminus1 = (float)(r_turb_spancount - 1);
				sdivz += d_sdivzstepu * spancountminus1;
				tdivz += d_tdivzstepu * spancountminus1;
				zi += d_zistepu * spancountminus1;
				z = (float)0x10000 / zi;	// prescale to 16.16 fixed-point
				snext = (int)(sdivz * z) + sadjust;
				if (snext > bbextents)
					snext = bbextents;
				else if (snext < 16)
					snext = 16;	// prevent round-off error on <0 steps from
								//  from causing overstepping & running off the
								//  edge of the texture

				tnext = (int)(tdivz * z) + tadjust;
				if (tnext > bbextentt)
					tnext = bbextentt;
				else if (tnext < 16)
					tnext = 16;	// guard against round-off error on <0 steps

				if (r_turb_spancount > 1)
				{
					r_turb_sstep = (snext - r_turb_s) / (r_turb_spancount - 1);
					r_turb_tstep = (tnext - r_turb_t) / (r_turb_spancount - 1);
				}
			}

			r_turb_s = r_turb_s & ((CYCLE<<16)-1);
			r_turb_t = r_turb_t & ((CYCLE<<16)-1);

			D_DrawTurbulent8Span ((int)(zi * 0x8000 * 0x10000), alpha);

			r_turb_s = snext;
			r_turb_t = tnext;

		} while (count > 0);

	} while ((pspan = pspan->pnext) != nil);
}

#define WRITEFENCE(i) do{ \
	fencepix = *(pbase + (s >> 16) + (t >> 16) * cachewidth); \
	if (pz[i] <= (izi >> 16) && fencepix != 255){ \
		pdest[i] = blendalpha(fencepix, pdest[i], alpha); \
		pz[i] = (izi >> 16); \
	} \
	izi += izistep; \
	s += sstep; \
	t += tstep; \
}while(0)

void D_DrawSpans16_Fence (espan_t *pspan, byte alpha)
{
	byte fencepix;
	byte *pbase = (byte *)cacheblock, *pdest;
	int count, spancount, izi, izistep;
	fixed16_t s, t, snext, tnext, sstep, tstep;
	float sdivz, tdivz, zi, z, du, dv, spancountminus1;
	float sdivzstepu, tdivzstepu, zistepu;
	uzint *pz;

	sdivzstepu = d_sdivzstepu * 16;
	tdivzstepu = d_tdivzstepu * 16;
	zistepu = d_zistepu * 16;

	// we count on FP exceptions being turned off to avoid range problems
	izistep = (int)(d_zistepu * 0x8000 * 0x10000);
	sstep = tstep = 0;

	do
	{
		pdest = (byte *)((byte *)d_viewbuffer + (screenwidth * pspan->v) + pspan->u);
		pz = d_pzbuffer + (d_zwidth * pspan->v) + pspan->u;

		count = pspan->count >> 4;
		spancount = pspan->count % 16;

		// calculate the initial s/z, t/z, 1/z, s, and t and clamp
		du = (float)pspan->u;
		dv = (float)pspan->v;

		sdivz = d_sdivzorigin + dv*d_sdivzstepv + du*d_sdivzstepu;
		tdivz = d_tdivzorigin + dv*d_tdivzstepv + du*d_tdivzstepu;
		zi = d_ziorigin + dv*d_zistepv + du*d_zistepu;
		z = (float)0x10000 / zi;		// prescale to 16.16 fixed-point
		// we count on FP exceptions being turned off to avoid range problems
		izi = (int)(zi * 0x8000 * 0x10000);

		s = (int)(sdivz * z) + sadjust;
		if (s > bbextents)
			s = bbextents;
		else if (s < 0)
			s = 0;

		t = (int)(tdivz * z) + tadjust;
		if (t > bbextentt)
			t = bbextentt;
		else if (t < 0)
			t = 0;

		while (count--){
			// calculate s/z, t/z, zi->fixed s and t at far end of span,
			// calculate s and t steps across span by shifting
			sdivz += sdivzstepu;
			tdivz += tdivzstepu;
			zi += zistepu;
			z = (float)0x10000 / zi;   // prescale to 16.16 fixed-point

			snext = (int) (sdivz * z) + sadjust;
			if (snext > bbextents)
				snext = bbextents;
			else if (snext <= 16)
				snext = 16;   // prevent round-off error on <0 steps causing overstepping & running off the edge of the texture

			tnext = (int) (tdivz * z) + tadjust;
			if (tnext > bbextentt)
				tnext = bbextentt;
			else if (tnext < 16)
				tnext = 16;   // guard against round-off error on <0 steps

			sstep = (snext - s) >> 4;
			tstep = (tnext - t) >> 4;

			pdest += 16;
			pz += 16;
			WRITEFENCE(-16);
			WRITEFENCE(-15);
			WRITEFENCE(-14);
			WRITEFENCE(-13);
			WRITEFENCE(-12);
			WRITEFENCE(-11);
			WRITEFENCE(-10);
			WRITEFENCE(-9);
			WRITEFENCE(-8);
			WRITEFENCE(-7);
			WRITEFENCE(-6);
			WRITEFENCE(-5);
			WRITEFENCE(-4);
			WRITEFENCE(-3);
			WRITEFENCE(-2);
			WRITEFENCE(-1);
			USED(s, t);

			s = snext;
			t = tnext;
		}
		if (spancount > 0)
		{
			// calculate s/z, t/z, zi->fixed s and t at last pixel in span (so can't step off polygon),
			// clamp, calculate s and t steps across span by division, biasing steps low so we don't run off the texture
			spancountminus1 = (float)(spancount - 1);
			sdivz += d_sdivzstepu * spancountminus1;
			tdivz += d_tdivzstepu * spancountminus1;
			zi += d_zistepu * spancountminus1;
			z = (float)0x10000 / zi;   // prescale to 16.16 fixed-point
			snext = (int)(sdivz * z) + sadjust;
			if (snext > bbextents)
				snext = bbextents;
			else if (snext < 16)
				snext = 16;   // prevent round-off error on <0 steps from causing overstepping & running off the edge of the texture

			tnext = (int)(tdivz * z) + tadjust;
			if (tnext > bbextentt)
				tnext = bbextentt;
			else if (tnext < 16)
				tnext = 16;   // guard against round-off error on <0 steps

			if (spancount > 1){
				sstep = (snext - s) / (spancount - 1);
				tstep = (tnext - t) / (spancount - 1);
			}

			pdest += spancount;
			pz += spancount;
			switch (spancount){
			case 16: WRITEFENCE(-16);
			case 15: WRITEFENCE(-15);
			case 14: WRITEFENCE(-14);
			case 13: WRITEFENCE(-13);
			case 12: WRITEFENCE(-12);
			case 11: WRITEFENCE(-11);
			case 10: WRITEFENCE(-10);
			case  9: WRITEFENCE(-9);
			case  8: WRITEFENCE(-8);
			case  7: WRITEFENCE(-7);
			case  6: WRITEFENCE(-6);
			case  5: WRITEFENCE(-5);
			case  4: WRITEFENCE(-4);
			case  3: WRITEFENCE(-3);
			case  2: WRITEFENCE(-2);
			case  1: WRITEFENCE(-1);
			USED(izi, s, t);
			}
		}
	}
	while ((pspan = pspan->pnext) != nil);
}

/*
=============
D_DrawSpans16
=============
*/
void D_DrawSpans16 (espan_t *pspan, byte alpha) //qbism- up it from 8 to 16
{
	int				count, spancount;
	unsigned char	*pbase, *pdest;
	uzint			*pz;
	fixed16_t		s, t, snext, tnext, sstep, tstep;
	float			sdivz, tdivz, zi, z, du, dv, spancountminus1;
	float			sdivzstepu, tdivzstepu, zistepu;

	sstep = 0;	// keep compiler happy
	tstep = 0;	// ditto

	pbase = (unsigned char *)cacheblock;

	sdivzstepu = d_sdivzstepu * 16;
	tdivzstepu = d_tdivzstepu * 16;
	zistepu = d_zistepu * 16;

	do
	{
		pdest = (unsigned char *)((byte *)d_viewbuffer +
				(screenwidth * pspan->v) + pspan->u);
		pz = d_pzbuffer + (d_zwidth * pspan->v) + pspan->u;

		count = pspan->count;

	// calculate the initial s/z, t/z, 1/z, s, and t and clamp
		du = (float)pspan->u;
		dv = (float)pspan->v;

		sdivz = d_sdivzorigin + dv*d_sdivzstepv + du*d_sdivzstepu;
		tdivz = d_tdivzorigin + dv*d_tdivzstepv + du*d_tdivzstepu;
		zi = d_ziorigin + dv*d_zistepv + du*d_zistepu;
		z = (float)0x10000 / zi;	// prescale to 16.16 fixed-point

		s = (int)(sdivz * z) + sadjust;
		if (s > bbextents)
			s = bbextents;
		else if (s < 0)
			s = 0;

		t = (int)(tdivz * z) + tadjust;
		if (t > bbextentt)
			t = bbextentt;
		else if (t < 0)
			t = 0;

		do
		{
		// calculate s and t at the far end of the span
			if (count >= 16)
				spancount = 16;
			else
				spancount = count;

			count -= spancount;

			if (count)
			{
			// calculate s/z, t/z, zi->fixed s and t at far end of span,
			// calculate s and t steps across span by shifting
				sdivz += sdivzstepu;
				tdivz += tdivzstepu;
				zi += zistepu;
				z = (float)0x10000 / zi;	// prescale to 16.16 fixed-point

				snext = (int)(sdivz * z) + sadjust;
				if (snext > bbextents)
					snext = bbextents;
				else if (snext <= 16)
					snext = 16;	// prevent round-off error on <0 steps from
								//  from causing overstepping & running off the
								//  edge of the texture

				tnext = (int)(tdivz * z) + tadjust;
				if (tnext > bbextentt)
					tnext = bbextentt;
				else if (tnext < 16)
					tnext = 16;	// guard against round-off error on <0 steps

				sstep = (snext - s) >> 4;
				tstep = (tnext - t) >> 4;
			}
			else
			{
			// calculate s/z, t/z, zi->fixed s and t at last pixel in span (so
			// can't step off polygon), clamp, calculate s and t steps across
			// span by division, biasing steps low so we don't run off the
			// texture
				spancountminus1 = (float)(spancount - 1);
				sdivz += d_sdivzstepu * spancountminus1;
				tdivz += d_tdivzstepu * spancountminus1;
				zi += d_zistepu * spancountminus1;
				z = (float)0x10000 / zi;	// prescale to 16.16 fixed-point
				snext = (int)(sdivz * z) + sadjust;
				if (snext > bbextents)
					snext = bbextents;
				else if (snext < 16)
					snext = 16;	// prevent round-off error on <0 steps from
								//  from causing overstepping & running off the
								//  edge of the texture

				tnext = (int)(tdivz * z) + tadjust;
				if (tnext > bbextentt)
					tnext = bbextentt;
				else if (tnext < 16)
					tnext = 16;	// guard against round-off error on <0 steps

				if (spancount > 1)
				{
					sstep = (snext - s) / (spancount - 1);
					tstep = (tnext - t) / (spancount - 1);
				}
			}

			if(spancount > 0){
				void dospan(uchar *, uchar *, int, int, int, int, int, int);
				void dospan_alpha(uchar *, uchar *, int, int, int, int, int, int, byte, uzint *, int);
				if(r_drawflags & DRAW_BLEND)
					dospan_alpha(pdest, pbase, s, t, sstep, tstep, spancount, cachewidth, alpha, pz, (int)(zi * 0x8000 * 0x10000));
				else
					dospan(pdest, pbase, s, t, sstep, tstep, spancount, cachewidth);
			}
			pdest += spancount;
			pz += spancount;
			s = snext;
			t = tnext;

		} while (count > 0);

	} while ((pspan = pspan->pnext) != nil);
}

/*
=============
D_DrawZSpans
=============
*/
void D_DrawZSpans (espan_t *pspan)
{
	int				count, doublecount, izistep;
	int				izi;
	uzint			*pdest;
	unsigned		ltemp;
	double			zi;
	float			du, dv;

	if((r_drawflags & DRAW_BLEND) != 0)
		return;

// FIXME: check for clamping/range problems
// we count on FP exceptions being turned off to avoid range problems
	izistep = (int)(d_zistepu * 0x8000 * 0x10000);

	do
	{
		pdest = d_pzbuffer + (d_zwidth * pspan->v) + pspan->u;

		count = pspan->count;

	// calculate the initial 1/z
		du = (float)pspan->u;
		dv = (float)pspan->v;

		zi = d_ziorigin + dv*d_zistepv + du*d_zistepu;
	// we count on FP exceptions being turned off to avoid range problems
		izi = (int)(zi * 0x8000 * 0x10000);

		if ((uintptr)pdest & 0x02)
		{
			*pdest++ = (short)(izi >> 16);
			izi += izistep;
			count--;
		}

		if ((doublecount = count >> 1) > 0)
		{
			do
			{
				ltemp = izi >> 16;
				izi += izistep;
				ltemp |= izi & 0xFFFF0000;
				izi += izistep;
				*(int *)pdest = ltemp;
				pdest += 2;
			} while (--doublecount > 0);
		}

		if (count & 1)
			*pdest = (short)(izi >> 16);

	} while ((pspan = pspan->pnext) != nil);
}