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-rw-r--r--src/sw_scan.c587
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diff --git a/src/sw_scan.c b/src/sw_scan.c
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index 0000000..16754ed
--- /dev/null
+++ b/src/sw_scan.c
@@ -0,0 +1,587 @@
+/*
+Copyright (C) 1997-2001 Id Software, Inc.
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; either version 2
+of the License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+
+See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+*/
+// d_scan.c
+//
+// Portable C scan-level rasterization code, all pixel depths.
+
+#include "sw_local.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;
+
+void D_DrawTurbulent8Span (void);
+
+
+/*
+=============
+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, u2, v2;
+ byte *dest;
+ int *turb;
+ int *col;
+ byte **row;
+
+ static int cached_width, cached_height;
+ static byte *rowptr[MAXHEIGHT*2+AMP2*2];
+ static int column[MAXWIDTH*2+AMP2*2];
+
+ //
+ // these are constant over resolutions, and can be saved
+ //
+ w = r_newrefdef.width;
+ h = r_newrefdef.height;
+ if (w != cached_width || h != cached_height)
+ {
+ cached_width = w;
+ cached_height = h;
+ for (v=0 ; v<h+AMP2*2 ; v++)
+ {
+ v2 = (int)((float)v/(h + AMP2 * 2) * r_refdef.vrect.height);
+ rowptr[v] = r_warpbuffer + (WARP_WIDTH * v2);
+ }
+
+ for (u=0 ; u<w+AMP2*2 ; u++)
+ {
+ u2 = (int)((float)u/(w + AMP2 * 2) * r_refdef.vrect.width);
+ column[u] = u2;
+ }
+ }
+
+ turb = intsintable + ((int)(r_newrefdef.time*SPEED)&(CYCLE-1));
+ dest = vid.buffer + r_newrefdef.y * vid.rowbytes + r_newrefdef.x;
+
+ for (v=0 ; v<h ; v++, dest += vid.rowbytes)
+ {
+ col = &column[turb[v&(CYCLE-1)]];
+ row = &rowptr[v];
+ for (u=0 ; u<w ; u+=4)
+ {
+ dest[u+0] = row[turb[(u+0)&(CYCLE-1)]][col[u+0]];
+ dest[u+1] = row[turb[(u+1)&(CYCLE-1)]][col[u+1]];
+ dest[u+2] = row[turb[(u+2)&(CYCLE-1)]][col[u+2]];
+ dest[u+3] = row[turb[(u+3)&(CYCLE-1)]][col[u+3]];
+ }
+ }
+}
+
+
+#if !USE_ASM
+
+/*
+=============
+D_DrawTurbulent8Span
+=============
+*/
+void D_DrawTurbulent8Span (void)
+{
+ 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;
+ *r_turb_pdest++ = *(r_turb_pbase + (tturb<<6) + sturb);
+ r_turb_s += r_turb_sstep;
+ r_turb_t += r_turb_tstep;
+ } while (--r_turb_spancount > 0);
+}
+
+#endif // !USE_ASM
+
+
+/*
+=============
+Turbulent8
+=============
+*/
+void Turbulent8 (espan_t *pspan)
+{
+ int count;
+ fixed16_t snext, tnext;
+ float sdivz, tdivz, zi, z, du, dv, spancountminus1;
+ float sdivz16stepu, tdivz16stepu, zi16stepu;
+
+ r_turb_turb = sintable + ((int)(r_newrefdef.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 +
+ (r_screenwidth * 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 ();
+
+ r_turb_s = snext;
+ r_turb_t = tnext;
+
+ } while (count > 0);
+
+ } while ((pspan = pspan->pnext) != NULL);
+}
+
+//====================
+//PGM
+/*
+=============
+NonTurbulent8 - this is for drawing scrolling textures. they're warping water textures
+ but the turbulence is automatically 0.
+=============
+*/
+void NonTurbulent8 (espan_t *pspan)
+{
+ int count;
+ fixed16_t snext, tnext;
+ float sdivz, tdivz, zi, z, du, dv, spancountminus1;
+ float sdivz16stepu, tdivz16stepu, zi16stepu;
+
+// r_turb_turb = sintable + ((int)(r_newrefdef.time*SPEED)&(CYCLE-1));
+ r_turb_turb = blanktable;
+
+ 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 +
+ (r_screenwidth * 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 ();
+
+ r_turb_s = snext;
+ r_turb_t = tnext;
+
+ } while (count > 0);
+
+ } while ((pspan = pspan->pnext) != NULL);
+}
+//PGM
+//====================
+
+
+#if !USE_ASM
+
+/*
+=============
+D_DrawSpans16
+
+ FIXME: actually make this subdivide by 16 instead of 8!!!
+=============
+*/
+void D_DrawSpans16 (espan_t *pspan)
+{
+ int count, spancount;
+ unsigned char *pbase, *pdest;
+ fixed16_t s, t, snext, tnext, sstep, tstep;
+ float sdivz, tdivz, zi, z, du, dv, spancountminus1;
+ float sdivz8stepu, tdivz8stepu, zi8stepu;
+
+ sstep = 0; // keep compiler happy
+ tstep = 0; // ditto
+
+ pbase = (unsigned char *)cacheblock;
+
+ sdivz8stepu = d_sdivzstepu * 8;
+ tdivz8stepu = d_tdivzstepu * 8;
+ zi8stepu = d_zistepu * 8;
+
+ do
+ {
+ pdest = (unsigned char *)((byte *)d_viewbuffer +
+ (r_screenwidth * 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 >= 8)
+ spancount = 8;
+ 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 += sdivz8stepu;
+ tdivz += tdivz8stepu;
+ zi += zi8stepu;
+ z = (float)0x10000 / zi; // prescale to 16.16 fixed-point
+
+ snext = (int)(sdivz * z) + sadjust;
+ if (snext > bbextents)
+ snext = bbextents;
+ else if (snext < 8)
+ snext = 8; // 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 < 8)
+ tnext = 8; // guard against round-off error on <0 steps
+
+ sstep = (snext - s) >> 3;
+ tstep = (tnext - t) >> 3;
+ }
+ 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 < 8)
+ snext = 8; // 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 < 8)
+ tnext = 8; // guard against round-off error on <0 steps
+
+ if (spancount > 1)
+ {
+ sstep = (snext - s) / (spancount - 1);
+ tstep = (tnext - t) / (spancount - 1);
+ }
+ }
+
+ do
+ {
+ *pdest++ = *(pbase + (s >> 16) + (t >> 16) * cachewidth);
+ s += sstep;
+ t += tstep;
+ } while (--spancount > 0);
+
+ s = snext;
+ t = tnext;
+
+ } while (count > 0);
+
+ } while ((pspan = pspan->pnext) != NULL);
+}
+
+
+/*
+=============
+D_DrawZSpans
+=============
+*/
+void D_DrawZSpans (espan_t *pspan)
+{
+ int count, doublecount, izistep;
+ int izi;
+ short *pdest;
+ unsigned ltemp;
+ float zi;
+ float du, dv;
+
+// 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 ((long)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) != NULL);
+}
+
+#endif
+
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