rockbox/apps/plugins/sdl/progs/quake/d_scan.c
Franklin Wei 5d05b9d3e9 Quake!
This ports id Software's Quake to run on the SDL plugin runtime. The
source code originated from id under the GPLv2 license. I used
https://github.com/ahefner/sdlquake as the base of my port.

Performance is, unsurprisingly, not on par with what you're probably
used to on PC. I average about 10FPS on ipod6g, but it's still
playable.

Sound works well enough, but in-game music is not supported. I've
written ARM assembly routines for the inner sound loop. Make sure you
turn the "brightness" all the way down, or colors will look funky.

To run, extract Quake's data files to /.rockbox/quake. Have fun!

Change-Id: I4285036e967d7f0722802d43cf2096c808ca5799
2019-07-19 22:37:40 -04:00

449 lines
11 KiB
C

/*
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_scan.c
//
// Portable C scan-level rasterization code, all pixel depths.
#include "quakedef.h"
#include "r_local.h"
#include "d_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;
byte *dest;
int *turb;
int *col;
byte **row;
byte *rowptr[MAXHEIGHT+(AMP2*2)];
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]];
}
}
}
#if !id386
/*
=============
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 // !id386
/*
=============
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)(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);
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);
}
#if !id386
/*
=============
D_DrawSpans8
=============
*/
void D_DrawSpans8 (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 +
(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);
}
#endif
#if !id386
/*
=============
D_DrawZSpans
=============
*/
void D_DrawZSpans (espan_t *pspan)
{
int count, doublecount, izistep;
int izi;
short *pdest;
unsigned ltemp;
double 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