ref: 35e90d35971631b97c76cb3a28ae222f8e6ba79b
dir: /rend.c/
#include <u.h>
#include <libc.h>
#include "dat.h"
#include "fns.h"
s32int sint[360+90], *cost;
int vwsize;
typedef struct Vis Vis;
typedef struct Scaler Scaler;
enum{
Nvis = 50<<2, /* raised from original 50 */
Nscal = 256+1,
Wdxy = 64,
Fineθ = 3600,
Dfoclen = 0x5700,
Dglob = 0x10000,
Dtile = 0x2000,
Dobj = 0x4000
};
struct Vis{
s16int vwx;
s16int vwdy;
Spr *spr;
};
#define Pi 3.141592657
static float Rad = (float)Fineθ / 2 / Pi;
static s32int ftan[Fineθ/4];
static s16int midθ;
static int Δvwθ[Vw];
static int prjw, prjh;
static s32int xin, yin;
static int dtx, dty;
static u16int ∂xdown, ∂xup, ∂ydown, ∂yup;
struct Scaler{
int skip;
int ps;
int pe;
int dx;
};
static Scaler scals[Nscal][Wdxy+1], *sce;
static uchar *scps, *scts;
static int scx, scdx, scdy;
static int waldy[Vw];
static s32int lastin;
static int lasttile, lastside;
static void
scalscol(Scaler *ss, Sprc *c, int dx)
{
int ps, pe, w;
uchar n, *d, *sp, *ds;
Scaler *s, *se;
ds = pxb + vw.ofs + scx;
se = ss + c->e;
while(se != ss){
sp = c->p;
s = ss + c->s;
for(; s<se; s++, sp++){
if(s->skip)
continue;
n = *sp;
for(ps=s->ps, pe=s->pe; ps<pe; ps++){
if(ps >= vw.dy)
break;
if(ps < 0)
continue;
d = ds + ps * Vw;
w = dx;
while(w-- > 0)
*d++ = n;
}
}
c++;
se = ss + c->e;
}
}
static void
scalvis(Vis *v)
{
int x, dx, lx, rx, *lw, *rw;
Scaler *ss, *s, *se;
Spr *spr;
Sprc **c;
ss = scals[v->vwdy >> 3];
if(ss == scals[0] || ss > sce)
return;
spr = v->spr;
lx = spr->lx;
rx = spr->rx;
scx = v->vwx;
if(lx < 32){
s = ss + lx;
se = ss + 32;
while(s < se)
scx -= s++->dx;
}else{
s = ss + 32;
se = ss + lx;
while(s < se)
scx += s++->dx;
}
c = spr->cs;
for(s=ss+lx, se=ss+rx+1; s<se && scx<vw.dx; c++, scx+=dx){
dx = s++->dx;
if(dx == 0)
continue;
if(dx == 1){
if(scx >= 0 && waldy[scx] < v->vwdy)
scalscol(ss, *c, 1);
continue;
}
x = scx + dx;
if(scx < 0){
if(x <= 0)
continue;
dx = x;
scx = 0;
}else if(x > vw.dx)
dx = vw.dx - scx;
lw = waldy + scx;
rw = lw + dx - 1;
if(*lw < v->vwdy){
if(*rw < v->vwdy){
scalscol(ss, *c, dx);
continue;
}
while(*rw >= v->vwdy)
rw--, dx--;
scalscol(ss, *c, dx);
break;
}else{
if(*rw >= v->vwdy)
continue;
while(*lw >= v->vwdy){
lw++, scx++;
dx--;
}
scalscol(ss, *c, dx);
}
}
}
static void
scalcol(void)
{
int i, n, x, dx;
uchar c, *ds, *d;
Scaler *s;
s = scals[(waldy[scx] & 0xfff8) >> 3];
if(s > sce)
s = sce;
ds = pxb + vw.ofs + scx;
for(x=0; x<Wdxy; x++, s++){
if(s->skip)
continue;
c = scps[x];
for(i=s->ps, n=s->pe; i<n; i++){
if(i >= vw.dy)
break;
if(i < 0)
continue;
d = ds + i * Vw;
dx = scdx;
while(dx-- > 0)
*d++ = c;
}
}
}
static void
topspr(void)
{
if(ver < SDM && gm.won){
if(oplr->s == stt+GSplrcam && qtc & 32)
scalspr(SPcam, vw.dx/2, vw.dy+1);
return;
}
if(gm.w != WPnone)
scalspr(wspr[gm.w] + gm.wfrm, vw.dx/2, vw.dy+1);
if(gm.record || gm.demo)
scalspr(SPdemo, vw.dx/2, vw.dy+1);
}
static int
rot(Obj *o)
{
int θ;
θ = oplr->θ + (vw.mid - o->vwdx) / 8 + 180 + 360 - o->θ + 45/2;
θ %= 360;
if(o->s->rot == 2)
return 4 * (θ / 180);
return θ / 45;
}
static int
projtl(Tile *tl, Vis *v)
{
int x, y, cx, cy;
x = ((tl-tiles) % Mapdxy << Dtlshift) + 0x8000 - vw.x;
y = ((tl-tiles) / Mapdxy << Dtlshift) + 0x8000 - vw.y;
cx = ffs(x, vw.cos);
cx -= ffs(y, vw.sin) + Dtile;
cy = ffs(y, vw.cos);
cy += ffs(x, vw.sin);
if(cx < Dmin){
v->vwdy = 0;
return 0;
}
v->vwx = vw.mid + cy * prjw / cx;
/* low 3 bits are fractional */
v->vwdy = prjh / (cx >> 8);
return cx < Dtlglobal && abs(cy) < Dtlglobal / 2;
}
static void
projob(Obj *o)
{
int x, y, cx, cy;
x = o->x - vw.x;
y = o->y - vw.y;
cx = ffs(x, vw.cos);
cx -= ffs(y, vw.sin) + Dobj;
cy = ffs(x, vw.sin);
cy += ffs(y, vw.cos);
o->vwx = cx;
if(cx < Dmin){
o->vwdy = 0;
return;
}
o->vwdx = vw.mid + cy * prjw / cx;
o->vwdy = prjh / (cx >> 8);
}
static void
scalobj(void)
{
int i, n, min;
Obj *o;
Tile *tl;
Static *st;
Vis viss[Nvis], *v, *e, *m;
memset(viss, 0, sizeof viss);
e = viss;
for(st=stcs; st<stce; st++){
if(st->tl == nil || st->tl->vis == 0)
continue;
if(projtl(st->tl, e) && st->f & OFbonus){
bonus(st);
continue;
}
if(e->vwdy == 0)
continue;
e->spr = st->spr;
if(e < viss + nelem(viss)-1)
e++;
}
for(o=oplr->n; o!=objs; o=o->n){
if(o->s->spr == nil)
continue;
tl = tiles + o->ty * Mapdxy + o->tx;
if(tl[0].vis
|| tl[-1].vis && tl[-1].tl == 0
|| tl[+1].vis && tl[+1].tl == 0
|| tl[-Mapdxy-1].vis && tl[-Mapdxy-1].tl == 0
|| tl[-Mapdxy].vis && tl[-Mapdxy].tl == 0
|| tl[-Mapdxy+1].vis && tl[-Mapdxy+1].tl == 0
|| tl[Mapdxy+1].vis && tl[Mapdxy+1].tl == 0
|| tl[Mapdxy].vis && tl[Mapdxy].tl == 0
|| tl[Mapdxy-1].vis && tl[Mapdxy-1].tl == 0){
o->on = 1;
projob(o);
if(o->vwdy == 0)
continue;
o->f |= OFvis;
e->vwx = o->vwdx;
e->vwdy = o->vwdy;
e->spr = o->s->spr;
if(o->s->rot)
e->spr += rot(o);
if(e < viss + nelem(viss)-1)
e++;
}else
o->f &= ~OFvis;
}
for(i=0, n=e-viss; i<n; i++){
min = 32000;
v = m = viss;
while(v < e){
if(v->vwdy < min){
min = v->vwdy;
m = v;
}
v++;
}
scalvis(m);
m->vwdy = 32000;
}
}
static s16int
walldy(void)
{
s32int cx, dy;
cx = ffs(xin - vw.x, vw.cos);
dy = cx - ffs(yin - vw.y, vw.sin);
if(dy < Dmin)
dy = Dmin;
return prjh / (dy >> 8);
}
static void
vwall(int i, int tx, int ty, int tile)
{
int n;
u16int tex;
tex = yin >> 4 & 0xfc0;
if(dtx == -1){
tex = 0xfc0 - tex;
xin += Dtlglobal;
}
waldy[i] = walldy();
if(lastside == 1 && lastin == tx && lasttile == tile){
if(scps == scts + tex){
scdx++;
waldy[i] = waldy[i-1];
}else{
scalcol();
scps = scts + tex;
scdx = 1;
scx = i;
}
return;
}
if(lastside != -1)
scalcol();
lastside = 1;
lastin = tx;
lasttile = tile;
scx = i;
scdx = 1;
if(tile & 0x40){
if(tiles[ty*Mapdxy + tx-dtx].tl & 0x80)
n = drofs + 3;
else
n = ((tile & ~0x40) - 1) * 2 + 1;
}else
n = (tile - 1) * 2 + 1;
scts = wals[n];
if(scts == nil)
sysfatal("sparse wall %d\n", n);
scps = scts + tex;
}
static void
hwall(int i, int tx, int ty, int tile)
{
int n;
u16int tex;
tex = xin >> 4 & 0xfc0;
if(dty == -1)
yin += Dtlglobal;
else
tex = 0xfc0 - tex;
waldy[i] = walldy();
if(lastside == 0 && lastin == ty && lasttile == tile){
if(scps == scts + tex){
scdx++;
waldy[i] = waldy[i-1];
}else{
scalcol();
scps = scts + tex;
scdx = 1;
scx = i;
}
return;
}
if(lastside != -1)
scalcol();
lastside = 0;
lastin = ty;
lasttile = tile;
scx = i;
scdx = 1;
if(tile & 0x40){
tx = xin >> Dtlshift;
if(tiles[(ty-dty)*Mapdxy + tx].tl & 0x80)
n = drofs + 2;
else
n = ((tile & ~0x40) - 1) * 2;
}else
n = (tile - 1) * 2;
scts = wals[n];
if(scts == nil)
sysfatal("sparse wall %d\n", n);
scps = scts + tex;
}
static void
vdoor(int i, int tile)
{
int n;
u16int tex;
Door *d;
waldy[i] = walldy();
d = doors + (tile & 0x7f);
tex = yin - d->dopen >> 4 & 0xfc0;
if(lasttile == tile){
if(scps == scts + tex){
scdx++;
waldy[i] = waldy[i-1];
}else{
scalcol();
scps = scts + tex;
scdx = 1;
scx = i;
}
return;
}
if(lastside != -1)
scalcol();
lastside = 2;
lasttile = tile;
scx = i;
scdx = 1;
n = 1;
switch(d->lock){
case DRunlk: n += drofs; break;
case DRlock1:
case DRlock2:
case DRlock3:
case DRlock4: n += drofs + 6; break;
case DRup: n += drofs + 4; break;
}
scts = wals[n];
if(scts == nil)
sysfatal("sparse wall %d\n", n);
scps = scts + tex;
}
static void
hdoor(int i, int tile)
{
int n;
u16int tex;
Door *d;
waldy[i] = walldy();
d = doors + (tile & 0x7f);
tex = xin - d->dopen >> 4 & 0xfc0;
if(lasttile == tile){
if(scps == scts + tex){
scdx++;
waldy[i] = waldy[i-1];
}else{
scalcol();
scps = scts + tex;
scdx = 1;
scx = i;
}
return;
}
if(lastside != -1)
scalcol();
lastside = 2;
lasttile = tile;
scx = i;
scdx = 1;
n = 0;
switch(d->lock){
case DRunlk: n = drofs; break;
case DRlock1:
case DRlock2:
case DRlock3:
case DRlock4: n = drofs + 6; break;
case DRup: n = drofs + 4; break;
}
scts = wals[n];
if(scts == nil)
sysfatal("sparse wall %d\n", n);
scps = scts + tex;
}
static void
vpush(int i, int tile)
{
int n;
u16int tex, ofs;
tex = yin >> 4 & 0xfc0;
ofs = pusher.dopen << 10;
if(dtx == -1){
xin += Dtlglobal - ofs;
tex = 0xfc0 - tex;
}else
xin += ofs;
waldy[i] = walldy();
if(lasttile == tile){
if(scps == scts + tex){
scdx++;
waldy[i] = waldy[i-1];
}else{
scalcol();
scps = scts + tex;
scdx = 1;
scx = i;
}
return;
}
if(lastside != -1)
scalcol();
lasttile = tile;
scx = i;
scdx = 1;
n = ((tile & 63) - 1) * 2 + 1;
scts = wals[n];
if(scts == nil)
sysfatal("sparse wall %d\n", n);
scps = scts + tex;
}
static void
hpush(int i, int tile)
{
int n;
u16int tex, ofs;
tex = xin >> 4 & 0xfc0;
ofs = pusher.dopen << 10;
if(dty == -1)
yin += Dtlglobal - ofs;
else{
tex = 0xfc0 - tex;
yin += ofs;
}
waldy[i] = walldy();
if(lasttile == tile){
if(scps == scts + tex){
scdx++;
waldy[i] = waldy[i-1];
}else{
scalcol();
scps = scts + tex;
scdx = 1;
scx = i;
}
return;
}
if(lastside != -1)
scalcol();
lasttile = tile;
scx = i;
scdx = 1;
n = ((tile & 63) - 1) * 2;
scts = wals[n];
if(scts == nil)
sysfatal("sparse wall %d\n", n);
scps = scts + tex;
}
static void
raytrace(void)
{
int i, θ, tx, ty;
u8int n;
s16int in, xinh, yinh;
u16int dr, x, y, ∂x, ∂y, tilehit;
s32int rs, dx, dy;
vw.θ = oplr->θ;
midθ = vw.θ * (Fineθ / 360);
vw.sin = sint[vw.θ];
vw.cos = cost[vw.θ];
vw.x = oplr->x - ffs(Dfoclen, vw.cos);
vw.y = oplr->y + ffs(Dfoclen, vw.sin);
vw.tx = vw.x >> Dtlshift;
vw.ty = vw.y >> Dtlshift;
∂xdown = vw.x & Dtlglobal - 1;
∂xup = Dtlglobal - ∂xdown;
∂ydown = vw.y & Dtlglobal - 1;
∂yup = Dtlglobal - ∂ydown;
lastside = -1;
i = 0;
tilehit = 0;
loop:
θ = (midθ + Δvwθ[i]) % Fineθ;
if(θ < 0)
θ += Fineθ;
if(θ < 900){
dtx = 1;
dty = -1;
dx = ftan[900-1-θ];
dy = -ftan[θ];
∂x = ∂xup;
∂y = ∂ydown;
}else if(θ < 1800){
dtx = -1;
dty = -1;
dx = -ftan[θ-900];
dy = -ftan[1800-1-θ];
∂x = ∂xdown;
∂y = ∂ydown;
}else if(θ < 2700){
dtx = -1;
dty = 1;
dx = -ftan[2700-1-θ];
dy = ftan[θ-1800];
∂x = ∂xdown;
∂y = ∂yup;
}else{
dtx = 1;
dty = 1;
dx = ftan[θ-2700];
dy = ftan[3600-1-θ];
∂x = ∂xup;
∂y = ∂yup;
}
yin = ffs(dy, ∂x) + vw.y;
yinh = yin >> 16;
tx = vw.tx + dtx;
x = yinh * Mapdxy + tx;
xin = ffs(dx, ∂y) + vw.x;
xinh = xin >> 16;
ty = vw.ty + dty;
y = ty * Mapdxy + xinh;
vcheck:
if(dty * (yinh - ty) >= 0)
goto hentry;
ventry:
n = tiles[x].tl;
if(n == 0){
vpass:
tiles[x].vis = 1;
tx += dtx;
rs = (yinh << 16 | yin & 0xffff) + dy;
yinh = rs >> 16;
yin = yin & 0xffff0000 | rs & 0xffff;
x = yinh * Mapdxy + tx;
goto vcheck;
}
tilehit = tilehit & 0xff00 | n;
if(~n & 1<<7){
xin = tx << 16;
ty = yinh;
yin = yinh << 16 | yin & 0xffff;
vwall(i, tx, ty, tilehit);
goto next;
}
yin = yinh << 16 | yin & 0xffff;
if(n & 1<<6){
rs = ((s32int)pusher.dopen * dy >> 6) + yin; /* sar */
in = rs >> Dtlshift;
if(in != yinh)
goto vpass;
yin = rs;
xin = tx << 16;
vpush(i, tilehit);
goto next;
}
rs = yin + (dy >> 1); /* sar */
in = rs >> Dtlshift;
dr = rs & 0xffff;
if(yinh != in || dr < doors[n&0x7f].dopen)
goto vpass;
yin = yinh << 16 | dr;
xin = tx << 16 | 0x8000; /* intercept in middle of tile */
vdoor(i, tilehit);
goto next;
hcheck:
if(dtx * (xinh - tx) >= 0)
goto ventry;
hentry:
n = tiles[y].tl;
if(n == 0){
hpass:
tiles[y].vis = 1;
ty += dty;
rs = (xinh << 16 | xin & 0xffff) + dx;
xinh = rs >> 16;
xin = xin & 0xffff0000 | rs & 0xffff;
y = ty * Mapdxy + xinh;
goto hcheck;
}
tilehit = tilehit & 0xff00 | n;
if(~n & 1<<7){
xin = xinh << 16 | xin & 0xffff;
tx = xinh;
yin = ty << 16;
hwall(i, tx, ty, tilehit);
goto next;
}
yin = yinh << 16 | yin & 0xffff;
if(n & 1<<6){
rs = ((s32int)pusher.dopen * dx >> 6) + (xinh << 16 | xin & 0xffff); /* sar */
in = rs >> Dtlshift;
if(in != xinh)
goto hpass;
xin = rs;
yin = ty << 16;
hpush(i, tilehit);
goto next;
}
rs = (xinh << 16 | xin & 0xffff) + (dx >> 1); /* sar */
in = rs >> Dtlshift;
dr = rs & 0xffff;
if(xinh != in || dr < doors[n&0x7f].dopen)
goto hpass;
xin = xinh << 16 | dr;
yin = ty << 16 | 0x8000; /* intercept in middle of tile */
hdoor(i, tilehit);
next:
if(++i < vw.dx)
goto loop;
scalcol();
}
static void
calcscal(Scaler *s, int dy)
{
int i, step, fix, top, ps, pe;
top = (vw.dy - dy) / 2;
step = (dy << 16) / 64;
fix = 0;
for(i=0; i<nelem(scals[0]); i++, s++){
ps = (fix >> 16) + top;
fix += step;
pe = (fix >> 16) + top;
s->dx = pe > ps ? pe - ps : 0;
s->skip = ps == pe || pe < 0 || ps >= vw.dy || i == nelem(scals[0])-1;
if(s->skip)
continue;
s->ps = ps;
s->pe = pe;
}
}
static void
scaltab(int maxdy)
{
int dy;
Scaler (*s)[nelem(scals[0])];
dy = 1;
memset(scals, 0, sizeof scals);
s = scals + 1;
while(dy <= maxdy)
calcscal(*s++, dy++ * 2);
memcpy(scals, scals+1, sizeof *scals);
sce = scals[dy-1];
}
void
scalspr(int n, int x, int dy)
{
int dx, lx, rx;
Scaler *ss, *s, *se;
Spr *spr;
Sprc **c;
spr = sprs + n;
if(spr == nil)
sysfatal("scalspr: missing sprite %d\n", n);
dy >>= 1;
ss = scals[dy];
lx = spr->lx;
rx = spr->rx;
scx = x;
if(lx < 32){
s = ss + lx;
se = ss + 32;
while(s < se)
scx -= s++->dx;
}else{
s = ss + 32;
se = ss + lx;
while(s < se)
scx += s++->dx;
}
c = spr->cs;
for(s=ss+lx, se=ss+rx+1; s<se; c++, scx+=dx){
dx = s++->dx;
if(dx != 0)
scalscol(ss, *c, dx);
}
}
s32int
ffs(s32int a, s32int b)
{
int s;
u32int r;
uvlong h, l;
s = 0;
if(a < 0){
a = -a;
s ^= 1;
}
if(b < 0)
s ^= 1;
b &= 0xffff;
h = a >> 16;
l = a & 0xffff;
r = h * b + (l * b >> 16 & 0xffff);
return s ? -r : r;
}
void
render(void)
{
Tile *tl;
for(tl=tiles; tl<tiles+nelem(tiles); tl++)
tl->vis = 0;
clear();
raytrace();
scalobj();
topspr();
}
void
setvw(void)
{
int i, an, dx, *p, *q, *e;
double dface;
vw.dx = vwsize * 16 & ~15;
vw.dy = vwsize * 16 / 2 & ~1;
vw.mid = vw.dx / 2 - 1;
vw.Δhit = vw.dx / 10;
vw.ofs = Vw * (160 - vw.dy) / 2 + (Vw - vw.dx) / 2;
scaltab((vw.dx * 1.5) / 2);
dx = vw.dx / 2;
dface = Dfoclen + Dmin;
i = 0;
p = Δvwθ + dx;
e = p + dx;
q = p - 1;
while(p < e){
/* start 0.5px over so vw.θ bisects two middle pixels */
an = (float)atan(i++ * Dglob / vw.dx / dface) * Rad;
*p++ = -an;
*q-- = an;
}
prjw = dx * dface / (Dglob/2);
prjh = prjw * Dtlglobal >> 6;
}
void
tab(void)
{
s32int i, *f, *fe;
float a;
double t;
i = 0;
f = ftan;
fe = ftan + nelem(ftan) - 1;
while(f < fe){
t = tan((i++ + 0.5) / (double)Rad);
*f++ = t * Dtlglobal;
*fe-- = 1/t * Dtlglobal;
}
/* low word: fraction; high word: mbz except 1<<31, sign bit */
a = 0;
f = fe = sint;
while(f < sint + 91){
i = Dtlglobal * sin(a);
f[0] = f[360] = fe[180] = i;
fe[360] = f[180] = i | 1<<31;
a += Pi / 2 / 90;
f++, fe--;
}
cost = sint + 90;
}