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

1 files changed, 442 insertions, 0 deletions

diff --git a/apps/plugins/sdl/progs/quake/d_sprite.c b/apps/plugins/sdl/progs/quake/d_sprite.c
new file mode 100644
index 0000000000..2f02ad2c64
--- /dev/null
+++ b/apps/plugins/sdl/progs/quake/d_sprite.c
@@ -0,0 +1,442 @@
+/*
+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_sprite.c: software top-level rasterization driver module for drawing
+// sprites
+
+#include "quakedef.h"
+#include "d_local.h"
+
+static int              sprite_height;
+static int              minindex, maxindex;
+static sspan_t  *sprite_spans;
+
+#if     !id386
+
+/*
+=====================
+D_SpriteDrawSpans
+=====================
+*/
+void D_SpriteDrawSpans (sspan_t *pspan)
+{
+        int                     count, spancount, izistep;
+        int                     izi;
+        byte            *pbase, *pdest;
+        fixed16_t       s, t, snext, tnext, sstep, tstep;
+        float           sdivz, tdivz, zi, z, du, dv, spancountminus1;
+        float           sdivz8stepu, tdivz8stepu, zi8stepu;
+        byte            btemp;
+        short           *pz;
+
+        sstep = 0;      // keep compiler happy
+        tstep = 0;      // ditto
+
+        pbase = cacheblock;
+
+        sdivz8stepu = d_sdivzstepu * 8;
+        tdivz8stepu = d_tdivzstepu * 8;
+        zi8stepu = d_zistepu * 8;
+
+// we count on FP exceptions being turned off to avoid range problems
+        izistep = (int)(d_zistepu * 0x8000 * 0x10000);
+
+        do
+        {
+                pdest = (byte *)d_viewbuffer + (screenwidth * pspan->v) + pspan->u;
+                pz = d_pzbuffer + (d_zwidth * pspan->v) + pspan->u;
+
+                count = pspan->count;
+
+                if (count <= 0)
+                        goto NextSpan;
+
+        // 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;
+
+                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
+                        {
+                                btemp = *(pbase + (s >> 16) + (t >> 16) * cachewidth);
+                                if (btemp != 255)
+                                {
+                                        if (*pz <= (izi >> 16))
+                                        {
+                                                *pz = izi >> 16;
+                                                *pdest = btemp;
+                                        }
+                                }
+
+                                izi += izistep;
+                                pdest++;
+                                pz++;
+                                s += sstep;
+                                t += tstep;
+                        } while (--spancount > 0);
+
+                        s = snext;
+                        t = tnext;
+
+                } while (count > 0);
+
+NextSpan:
+                pspan++;
+
+        } while (pspan->count != DS_SPAN_LIST_END);
+}
+
+#endif
+
+
+/*
+=====================
+D_SpriteScanLeftEdge
+=====================
+*/
+void D_SpriteScanLeftEdge (void)
+{
+        int                     i, v, itop, ibottom, lmaxindex;
+        emitpoint_t     *pvert, *pnext;
+        sspan_t         *pspan;
+        float           du, dv, vtop, vbottom, slope;
+        fixed16_t       u, u_step;
+
+        pspan = sprite_spans;
+        i = minindex;
+        if (i == 0)
+                i = r_spritedesc.nump;
+
+        lmaxindex = maxindex;
+        if (lmaxindex == 0)
+                lmaxindex = r_spritedesc.nump;
+
+        vtop = ceil (r_spritedesc.pverts[i].v);
+
+        do
+        {
+                pvert = &r_spritedesc.pverts[i];
+                pnext = pvert - 1;
+
+                vbottom = ceil (pnext->v);
+
+                if (vtop < vbottom)
+                {
+                        du = pnext->u - pvert->u;
+                        dv = pnext->v - pvert->v;
+                        slope = du / dv;
+                        u_step = (int)(slope * 0x10000);
+                // adjust u to ceil the integer portion
+                        u = (int)((pvert->u + (slope * (vtop - pvert->v))) * 0x10000) +
+                                        (0x10000 - 1);
+                        itop = (int)vtop;
+                        ibottom = (int)vbottom;
+
+                        for (v=itop ; v<ibottom ; v++)
+                        {
+                                pspan->u = u >> 16;
+                                pspan->v = v;
+                                u += u_step;
+                                pspan++;
+                        }
+                }
+
+                vtop = vbottom;
+
+                i--;
+                if (i == 0)
+                        i = r_spritedesc.nump;
+
+        } while (i != lmaxindex);
+}
+
+
+/*
+=====================
+D_SpriteScanRightEdge
+=====================
+*/
+void D_SpriteScanRightEdge (void)
+{
+        int                     i, v, itop, ibottom;
+        emitpoint_t     *pvert, *pnext;
+        sspan_t         *pspan;
+        float           du, dv, vtop, vbottom, slope, uvert, unext, vvert, vnext;
+        fixed16_t       u, u_step;
+
+        pspan = sprite_spans;
+        i = minindex;
+
+        vvert = r_spritedesc.pverts[i].v;
+        if (vvert < r_refdef.fvrecty_adj)
+                vvert = r_refdef.fvrecty_adj;
+        if (vvert > r_refdef.fvrectbottom_adj)
+                vvert = r_refdef.fvrectbottom_adj;
+
+        vtop = ceil (vvert);
+
+        do
+        {
+                pvert = &r_spritedesc.pverts[i];
+                pnext = pvert + 1;
+
+                vnext = pnext->v;
+                if (vnext < r_refdef.fvrecty_adj)
+                        vnext = r_refdef.fvrecty_adj;
+                if (vnext > r_refdef.fvrectbottom_adj)
+                        vnext = r_refdef.fvrectbottom_adj;
+
+                vbottom = ceil (vnext);
+
+                if (vtop < vbottom)
+                {
+                        uvert = pvert->u;
+                        if (uvert < r_refdef.fvrectx_adj)
+                                uvert = r_refdef.fvrectx_adj;
+                        if (uvert > r_refdef.fvrectright_adj)
+                                uvert = r_refdef.fvrectright_adj;
+
+                        unext = pnext->u;
+                        if (unext < r_refdef.fvrectx_adj)
+                                unext = r_refdef.fvrectx_adj;
+                        if (unext > r_refdef.fvrectright_adj)
+                                unext = r_refdef.fvrectright_adj;
+
+                        du = unext - uvert;
+                        dv = vnext - vvert;
+                        slope = du / dv;
+                        u_step = (int)(slope * 0x10000);
+                // adjust u to ceil the integer portion
+                        u = (int)((uvert + (slope * (vtop - vvert))) * 0x10000) +
+                                        (0x10000 - 1);
+                        itop = (int)vtop;
+                        ibottom = (int)vbottom;
+
+                        for (v=itop ; v<ibottom ; v++)
+                        {
+                                pspan->count = (u >> 16) - pspan->u;
+                                u += u_step;
+                                pspan++;
+                        }
+                }
+
+                vtop = vbottom;
+                vvert = vnext;
+
+                i++;
+                if (i == r_spritedesc.nump)
+                        i = 0;
+
+        } while (i != maxindex);
+
+        pspan->count = DS_SPAN_LIST_END;        // mark the end of the span list 
+}
+
+
+/*
+=====================
+D_SpriteCalculateGradients
+=====================
+*/
+void D_SpriteCalculateGradients (void)
+{
+        vec3_t          p_normal, p_saxis, p_taxis, p_temp1;
+        float           distinv;
+
+        TransformVector (r_spritedesc.vpn, p_normal);
+        TransformVector (r_spritedesc.vright, p_saxis);
+        TransformVector (r_spritedesc.vup, p_taxis);
+        VectorInverse (p_taxis);
+
+        distinv = 1.0 / (-DotProduct (modelorg, r_spritedesc.vpn));
+
+        d_sdivzstepu = p_saxis[0] * xscaleinv;
+        d_tdivzstepu = p_taxis[0] * xscaleinv;
+
+        d_sdivzstepv = -p_saxis[1] * yscaleinv;
+        d_tdivzstepv = -p_taxis[1] * yscaleinv;
+
+        d_zistepu = p_normal[0] * xscaleinv * distinv;
+        d_zistepv = -p_normal[1] * yscaleinv * distinv;
+
+        d_sdivzorigin = p_saxis[2] - xcenter * d_sdivzstepu -
+                        ycenter * d_sdivzstepv;
+        d_tdivzorigin = p_taxis[2] - xcenter * d_tdivzstepu -
+                        ycenter * d_tdivzstepv;
+        d_ziorigin = p_normal[2] * distinv - xcenter * d_zistepu -
+                        ycenter * d_zistepv;
+
+        TransformVector (modelorg, p_temp1);
+
+        sadjust = ((fixed16_t)(DotProduct (p_temp1, p_saxis) * 0x10000 + 0.5)) -
+                        (-(cachewidth >> 1) << 16);
+        tadjust = ((fixed16_t)(DotProduct (p_temp1, p_taxis) * 0x10000 + 0.5)) -
+                        (-(sprite_height >> 1) << 16);
+
+// -1 (-epsilon) so we never wander off the edge of the texture
+        bbextents = (cachewidth << 16) - 1;
+        bbextentt = (sprite_height << 16) - 1;
+}
+
+
+/*
+=====================
+D_DrawSprite
+=====================
+*/
+void D_DrawSprite (void)
+{
+        int                     i, nump;
+        float           ymin, ymax;
+        emitpoint_t     *pverts;
+        sspan_t         spans[MAXHEIGHT+1];
+
+        sprite_spans = spans;
+
+// find the top and bottom vertices, and make sure there's at least one scan to
+// draw
+        ymin = 999999.9;
+        ymax = -999999.9;
+        pverts = r_spritedesc.pverts;
+
+        for (i=0 ; i<r_spritedesc.nump ; i++)
+        {
+                if (pverts->v < ymin)
+                {
+                        ymin = pverts->v;
+                        minindex = i;
+                }
+
+                if (pverts->v > ymax)
+                {
+                        ymax = pverts->v;
+                        maxindex = i;
+                }
+
+                pverts++;
+        }
+
+        ymin = ceil (ymin);
+        ymax = ceil (ymax);
+
+        if (ymin >= ymax)
+                return;         // doesn't cross any scans at all
+
+        cachewidth = r_spritedesc.pspriteframe->width;
+        sprite_height = r_spritedesc.pspriteframe->height;
+        cacheblock = (byte *)&r_spritedesc.pspriteframe->pixels[0];
+
+// copy the first vertex to the last vertex, so we don't have to deal with
+// wrapping
+        nump = r_spritedesc.nump;
+        pverts = r_spritedesc.pverts;
+        pverts[nump] = pverts[0];
+
+        D_SpriteCalculateGradients ();
+        D_SpriteScanLeftEdge ();
+        D_SpriteScanRightEdge ();
+        D_SpriteDrawSpans (sprite_spans);
+}
+