1 files changed, 138 insertions, 0 deletions
diff --git a/apps/plugins/sdl/progs/quake/d_sky.c b/apps/plugins/sdl/progs/quake/d_sky.c
new file mode 100644
index 0000000..2f77d93
--- /dev/null
+++ b/apps/plugins/sdl/progs/quake/d_sky.c
@@ -0,0 +1,138 @@
+/*
+Copyright (C) 1996-1997 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_sky.c
+
+#include "quakedef.h"
+#include "r_local.h"
+#include "d_local.h"
+
+#define SKY_SPAN_SHIFT	5
+#define SKY_SPAN_MAX	(1 << SKY_SPAN_SHIFT)
+
+
+/*
+=================
+D_Sky_uv_To_st
+=================
+*/
+void D_Sky_uv_To_st (int u, int v, fixed16_t *s, fixed16_t *t)
+{
+	float	wu, wv, temp;
+	vec3_t	end;
+
+	if (r_refdef.vrect.width >= r_refdef.vrect.height)
+		temp = (float)r_refdef.vrect.width;
+	else
+		temp = (float)r_refdef.vrect.height;
+
+	wu = 8192.0 * (float)(u-((int)vid.width>>1)) / temp;
+	wv = 8192.0 * (float)(((int)vid.height>>1)-v) / temp;
+
+	end[0] = 4096*vpn[0] + wu*vright[0] + wv*vup[0];
+	end[1] = 4096*vpn[1] + wu*vright[1] + wv*vup[1];
+	end[2] = 4096*vpn[2] + wu*vright[2] + wv*vup[2];
+	end[2] *= 3;
+	VectorNormalize (end);
+
+	temp = skytime*skyspeed;	// TODO: add D_SetupFrame & set this there
+	*s = (int)((temp + 6*(SKYSIZE/2-1)*end[0]) * 0x10000);
+	*t = (int)((temp + 6*(SKYSIZE/2-1)*end[1]) * 0x10000);
+}
+
+
+/*
+=================
+D_DrawSkyScans8
+=================
+*/
+void D_DrawSkyScans8 (espan_t *pspan)
+{
+	int				count, spancount, u, v;
+	unsigned char	*pdest;
+	fixed16_t		s, t, snext, tnext, sstep, tstep;
+	int				spancountminus1;
+
+	sstep = 0;	// keep compiler happy
+	tstep = 0;	// ditto
+
+	do
+	{
+		pdest = (unsigned char *)((byte *)d_viewbuffer +
+				(screenwidth * pspan->v) + pspan->u);
+
+		count = pspan->count;
+
+	// calculate the initial s & t
+		u = pspan->u;
+		v = pspan->v;
+		D_Sky_uv_To_st (u, v, &s, &t);
+
+		do
+		{
+			if (count >= SKY_SPAN_MAX)
+				spancount = SKY_SPAN_MAX;
+			else
+				spancount = count;
+
+			count -= spancount;
+
+			if (count)
+			{
+				u += spancount;
+
+			// calculate s and t at far end of span,
+			// calculate s and t steps across span by shifting
+				D_Sky_uv_To_st (u, v, &snext, &tnext);
+
+				sstep = (snext - s) >> SKY_SPAN_SHIFT;
+				tstep = (tnext - t) >> SKY_SPAN_SHIFT;
+			}
+			else
+			{
+			// calculate s and t at last pixel in span,
+			// calculate s and t steps across span by division
+				spancountminus1 = (float)(spancount - 1);
+
+				if (spancountminus1 > 0)
+				{
+					u += spancountminus1;
+					D_Sky_uv_To_st (u, v, &snext, &tnext);
+
+					sstep = (snext - s) / spancountminus1;
+					tstep = (tnext - t) / spancountminus1;
+				}
+			}
+
+			do
+			{
+				*pdest++ = r_skysource[((t & R_SKY_TMASK) >> 8) +
+						((s & R_SKY_SMASK) >> 16)];
+				s += sstep;
+				t += tstep;
+			} while (--spancount > 0);
+
+			s = snext;
+			t = tnext;
+
+		} while (count > 0);
+
+	} while ((pspan = pspan->pnext) != NULL);
+}
+