ref: 7d1bc4ab95db2a1199150eb91cc0d7b1a5dd1128
dir: /rend.c/
#include <u.h>
#include <libc.h>
#include "dat.h"
#include "fns.h"
s32int sint[360+90], *cost;
typedef struct Vis Vis;
struct Vis{
s16int vwdx;
s16int vwdy;
Dat *spr;
};
enum{
Nvis = 50,
Fineθ = 3600,
Dfoclen = 0x5700,
Dglob = 0x10000,
Dtile = 0x2000,
Dobj = 0x4000
};
#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;
static int lastside;
static void
scalespr(int, int, int)
{
}
static void
scalevis(Vis *)
{
}
static void
topspr(void)
{
if(ver < SDM && gm.won){
if(oplr->s == stt+GSplrcam && mtc & 32)
scalespr(SPcam, vw.dx/2, vw.dy+1);
return;
}
if(gm.w != -1)
scalespr(wspr[gm.w] + gm.wfrm, vw.dx/2, vw.dy+1);
if(gm.record || gm.demo)
scalespr(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->vwdx = vw.mid + cy * prjw / cx;
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
scaleall(void)
{
Obj *o;
Tile *tl;
Static *st;
Vis viss[Nvis], *v, *w, *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->vwdx = o->vwdx;
e->vwdy = o->vwdy;
e->spr = o->s->spr;
if(e->spr == nil)
e->spr = sprs + o->sdt;
if(o->s->rot)
e->spr += rot(o);
if(e < viss + nelem(viss)-1)
e++;
}else
o->f &= ~OFvis;
}
for(v=viss; v<e; v++){
for(w=v, m=v; w<=e; w++)
if(w->vwdy < m->vwdy)
m = w;
scalevis(m);
if(v != m)
memcpy(m, v, sizeof *m);
}
if(e != viss)
scalevis(e);
}
static s16int
walldy(s32int xin, s32int yin)
{
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)
{
s16int p;
u16int tex;
tex = yin >> 4 & 0xfc0;
if(dtx == -1){
tex = 0xfc0 - tex;
xin += Dtlglobal;
}
p = 0;
USED(tex, p, tx, ty, tile, xin, i);
#ifdef DICKS
wallheight[i] = walldy();
if(lastside==1 && lastintercept == tx && lasttilehit == tile){
/* in the same wall type as last time, so check for
* optimized draw */
if(tex == (u16int)postsource){
// wide scale
postwidth++;
wallheight[i] = wallheight[i-1];
}else{
ScalePost();
(u16int)postsource = tex;
postwidth = 1;
postx = i;
}
return;
}
/* new wall */
if(lastside != -1) /* if not the first scaled post */
ScalePost();
lastside = true;
lastintercept = tx;
lasttilehit = tile;
postx = i;
postwidth = 1;
if(tile & 0x40){ /* check for adjacent doors */
if(tiles[ty][tx-dtx].tl & 0x80)
p = SPdoor+3;
else
p = vertwall[tile & ~0x40];
}else
p = vertwall[tile];
*(((u16int *)&postsource)+1) = (u16int)PM_GetPage(p);
(u16int)postsource = tex;
#endif
}
static void
hwall(int i, int tx, int ty, int tile)
{
s16int p;
u16int tex;
tex = xin >> 4 & 0xfc0;
if(dty == -1)
yin += Dtlglobal;
else
tex = 0xfc0 - tex;
p = 0;
USED(i, tx, ty, tile, tex, p);
#ifdef DICKS
wallheight[i] = walldy();
if(lastside == 0 && lastintercept == ty && lasttilehit == tile){
/* in the same wall type as last time, so check for
* optimized draw */
if(tex == (u16int)postsource){ /* wide scale */
postwidth++;
wallheight[i] = wallheight[i-1];
return;
}else{
ScalePost();
(u16int)postsource = tex;
postwidth = 1;
postx = i;
}
}else{ /* new wall */
if(lastside != -1) /* if not the first scaled post */
ScalePost();
lastside = 0;
lastintercept = ty;
lasttilehit = tile;
postx = i;
postwidth = 1;
if(tile & 0x40){ /* check for adjacent doors */
tx = xin >> Dtlshift;
if(tiles[ty-dty][tx].tl & 0x80)
p = SPdoor+2;
else
p = horizwall[tile & ~0x40];
}else
p = horizwall[tile];
*( ((u16int *)&postsource)+1) = (u16int)PM_GetPage(p);
(u16int)postsource = tex;
}
#endif
}
static void
vdoor(int i, int tile)
{
USED(i, xin, yin, tile);
#ifdef DICKS
Door *d;
u16int tex, p;
wallheight[i] = walldy(xin, yin);
d = doors + (tile & 0x7f);
tex = yin - d->dopen >> 4 & 0xfc0;
if(lasttilehit == tile){
/* in the same door as last time, so check for optimized draw */
if(tex == (u16int)postsource){
/* wide scale */
postwidth++;
wallheight[i] = wallheight[i-1];
return;
}else{
ScalePost ();
(u16int)postsource = tex;
postwidth = 1;
postx = i;
}
}else{
if (lastside != -1) /* if not the first scaled post */
ScalePost (); /* draw last post */
/* first pixel in this door */
lastside = 2;
lasttile = tile;
postx = i;
postwidth = 1;
switch(d->lock){
case DRunlk: p = SPdoor; break;
case DRlock1:
case DRlock2:
case DRlock3:
case DRlock4: p = SPdoor+6; break;
case DRup: p = SPdoor+4; break;
}
*( ((u16int *)&postsource)+1) = (u16int)PM_GetPage(p+1);
(u16int)postsource = tex;
}
#endif
}
static void
hdoor(int i, int tile)
{
USED(i, xin, yin, tile);
#ifdef DICKS
Door *d;
u16int tex, p;
wallheight[i] = walldy(xin, yin);
d = doors + (tile & 0x7f);
tex = xin - d->dopen >> 4 & 0xfc0;
if(lasttilehit == tile){
/* in the same door as last time, so check for optimized draw */
if(tex == (u16int)postsource){ /* wide scale */
postwidth++;
wallheight[i] = wallheight[i-1];
return;
}else{
ScalePost();
(u16int)postsource = tex;
postwidth = 1;
postx = i;
}
}else{
if(lastside != -1) /* if not the first scaled post */
ScalePost(); /* draw last post */
/* first pixel in this door */
lastside = 2;
lasttile = tile;
postx = i;
postwidth = 1;
switch(d->lock){
case DRunlk: p = SPdoor; break;
case DRlock1:
case DRlock2:
case DRlock3:
case DRlock4: p = SPdoor+6; break;
case DRup: p = SPdoor+4; break;
}
*( ((u16int *)&postsource)+1) = (u16int)PM_GetPage(p);
(u16int)postsource = tex;
}
#endif
}
static void
vpush(int i, int tile)
{
s16int p;
u16int tex, ofs;
tex = yin >> 4 & 0xfc0;
ofs = pusher.dopen << 10;
if(dtx == -1){
xin += Dtlglobal - ofs;
tex = 0xfc0 - tex;
}else
xin += ofs;
p = 0;
USED(i, xin, tile, p, tex, ofs);
#ifdef DICKS
wallheight[i] = walldy(xin, yin);
if(lasttilehit == tile){
/* in the same wall type as last time, so check for
* optimized draw */
if(tex == (u16int)postsource){ /* wide scale */
postwidth++;
wallheight[i] = wallheight[i-1];
return;
}else{
ScalePost();
(u16int)postsource = tex;
postwidth = 1;
postx = i;
}
}else{ /* new wall */
if(lastside != -1) // if not the first scaled post
ScalePost ();
lasttile = tile;
postx = i;
postwidth = 1;
p = vertwall[tile&63];
*( ((u16int *)&postsource)+1) = (u16int)PM_GetPage(p);
(u16int)postsource = tex;
}
#endif
}
static void
hpush(int i, int tile)
{
s16int p;
u16int tex, ofs;
tex = xin >> 4 & 0xfc0;
ofs = pusher.dopen << 10;
if(dty == -1)
yin += Dtlglobal - ofs;
else{
tex = 0xfc0 - tex;
yin += ofs;
}
p = 0;
USED(i, yin, tile, p, tex, ofs);
#ifdef DICKS
wallheight[i] = walldy(xin, yin);
if(lasttilehit == tile){
/* in the same wall type as last time, so check for
* optimized draw */
if(tex == (u16int)postsource){ /* wide scale */
postwidth++;
wallheight[i] = wallheight[i-1];
return;
}else{
ScalePost();
(u16int)postsource = tex;
postwidth = 1;
postx = i;
}
}else{ /* new wall */
if(lastside != -1) /* if not the first scaled post */
ScalePost();
lasttile = tile;
postx = i;
postwidth = 1;
p = horizwall[tile&63];
*( ((u16int *)&postsource)+1) = (u16int)PM_GetPage(p);
(u16int)postsource = tex;
}
#endif
}
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;
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++;
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++;
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;
}
static void
ScalePost(void)
{
#ifdef DICKS
ax = SCREENSEG;
es = ax;
bx = postx >> 1;
asm mov bp,WORD PTR [wallheight+bx] // fractional height (low 3 bits frac)
asm and bp,0xfff8 // bp = heightscaler*4
asm shr bp,1
asm cmp bp,[maxscaleshl2]
asm jle heightok
asm mov bp,[maxscaleshl2]
heightok:
asm add bp,OFFSET fullscalefarcall
// scale a byte wide strip of wall
asm mov bx,[postx]
asm mov di,bx
asm shr di,2 // X in bytes
asm add di,[bufferofs]
asm and bx,3
asm shl bx,3 // bx = pixel*8+pixwidth
asm add bx,[postwidth]
asm mov al,BYTE PTR [mapmasks1-1+bx] // -1 because no widths of 0
asm mov dx,SC_INDEX+1
asm out dx,al // set bit mask register
asm lds si,DWORD PTR [postsource]
asm call DWORD PTR [bp] // scale the line of pixels
asm mov al,BYTE PTR [ss:mapmasks2-1+bx] // -1 because no widths of 0
asm or al,al
asm jz nomore
// draw a second byte for vertical strips that cross two bytes
asm inc di
asm out dx,al // set bit mask register
asm call DWORD PTR [bp] // scale the line of pixels
asm mov al,BYTE PTR [ss:mapmasks3-1+bx] // -1 because no widths of 0
asm or al,al
asm jz nomore
// draw a third byte for vertical strips that cross three bytes
asm inc di
asm out dx,al // set bit mask register
asm call DWORD PTR [bp] // scale the line of pixels
nomore:
asm mov ax,ss
asm mov ds,ax
#endif
}
static void
walls(void)
{
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; // the first pixel is on a new wall
raytrace();
ScalePost(); // no more optimization on last post
}
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();
walls();
scaleall();
topspr();
}
void
initscal(void)
{
int i, an, dx, *p, *q, *e;
double dface;
dx = vw.dx / 2;
dface = Dfoclen + Dmin;
prjw = dx * dface / (Dglob/2);
prjh = prjw * Dtlglobal >> 6;
i = 0;
p = Δvwθ + dx;
e = p + dx;
q = p - 1;
dx = vw.dx;
while(p < e){
/* start 0.5px over so vw.θ bisects two middle pixels */
an = (float)atan(i++ * Dglob / dx / dface) * Rad;
*p++ = -an;
*q-- = an;
}
//SetupScaling(vw.dx * 1.5);
}
void
setvw(int n)
{
vw.size = n;
vw.dx = n * 16 & ~15;
vw.dy = n * 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;
initscal();
}
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;
}