ref: 39e63bec577e4f5e105a7922a7f7d580cb3d76ae
dir: /render.c/
#include <u.h>
#include <libc.h>
#include <thread.h>
#include <draw.h>
#include <memdraw.h>
#include <geometry.h>
#include "graphics.h"
#include "internal.h"
Rectangle UR = {0,0,1,1};
static Vertexattr *
sparams_getuniform(Shaderparams *sp, char *id)
{
USED(sp, id);
return nil;
}
static Vertexattr *
sparams_getattr(Shaderparams *sp, char *id)
{
return getvattr(sp->v, id);
}
static void
sparams_setattr(Shaderparams *sp, char *id, int type, void *val)
{
addvattr(sp->v, id, type, val);
}
static void
sparams_toraster(Shaderparams *sp, char *rname, void *v)
{
Framebuf *fb;
Raster *r;
ulong c;
/* keep the user away from the color buffer */
if(rname == nil || v == nil)
return;
fb = sp->su->fb;
r = fb->fetchraster(fb, rname);
if(r == nil)
return;
switch(r->chan){
case COLOR32:
c = col2ul(*(Color*)v);
rasterput(r, sp->p, &c);
break;
case FLOAT32:
rasterput(r, sp->p, v);
break;
}
}
static void
pixel(Raster *fb, Point p, Color c, int blend)
{
Color dc;
if(blend){
dc = srgb2linear(ul2col(getpixel(fb, p)));
c = lerp3(dc, c, c.a); /* SoverD */
// c = addpt3(mulpt3(dc, 1), mulpt3(c, 1-c.a));
// c = subpt3(Vec3(1,1,1), subpt3(dc, c));
// c = subpt3(addpt3(dc, c), Vec3(1,1,1));
}
putpixel(fb, p, col2ul(linear2srgb(c)));
}
static int
isvisible(Point3 p)
{
if(p.x < -p.w || p.x > p.w ||
p.y < -p.w || p.y > p.w ||
p.z < -p.w || p.z > p.w)
return 0;
return 1;
}
static int
isfacingback(Primitive *p)
{
double sa; /* signed area */
sa = p->v[0].p.x * p->v[1].p.y - p->v[0].p.y * p->v[1].p.x +
p->v[1].p.x * p->v[2].p.y - p->v[1].p.y * p->v[2].p.x +
p->v[2].p.x * p->v[0].p.y - p->v[2].p.y * p->v[0].p.x;
return sa <= 0;
}
static void
pushtoAbuf(Framebuf *fb, Point p, Color c, float z)
{
Abuf *buf;
Astk *stk;
int i;
buf = &fb->abuf;
stk = &buf->stk[p.y*Dx(fb->r) + p.x];
stk->items = erealloc(stk->items, ++stk->size*sizeof(*stk->items));
memset(&stk->items[stk->size-1], 0, sizeof(*stk->items));
for(i = 0; i < stk->size; i++)
if(z > stk->items[i].z)
break;
if(i < stk->size){
memmove(&stk->items[i+1], &stk->items[i], (stk->size-1 - i)*sizeof(*stk->items));
stk->items[i] = (Fragment){c, z};
}else
stk->items[stk->size-1] = (Fragment){c, z};
if(!stk->active){
stk->active++;
stk->p = p;
qlock(buf);
buf->act = erealloc(buf->act, ++buf->nact*sizeof(*buf->act));
buf->act[buf->nact-1] = stk;
qunlock(buf);
}
}
static void
squashAbuf(Framebuf *fb, int blend)
{
Abuf *buf;
Astk *stk;
Raster *cr, *zr;
int i, j;
buf = &fb->abuf;
cr = fb->rasters;
zr = cr->next;
for(i = 0; i < buf->nact; i++){
stk = buf->act[i];
j = stk->size;
while(j--)
pixel(cr, stk->p, stk->items[j].c, blend);
/* write to the depth buffer as well */
putdepth(zr, stk->p, stk->items[0].z);
}
}
static Point3
_barycoords(Triangle2 t, Point2 p)
{
Point2 p0p1 = subpt2(t.p1, t.p0);
Point2 p0p2 = subpt2(t.p2, t.p0);
Point2 pp0 = subpt2(t.p0, p);
Point3 v = crossvec3(Vec3(p0p2.x, p0p1.x, pp0.x), Vec3(p0p2.y, p0p1.y, pp0.y));
/* handle degenerate triangles—i.e. the ones where every point lies on the same line */
if(fabs(v.z) < ε1)
return Pt3(-1,-1,-1,1);
return Pt3(1 - (v.x + v.y)/v.z, v.y/v.z, v.x/v.z, 1);
}
static void
rasterize(Rastertask *task)
{
SUparams *params;
Raster *cr, *zr;
Primitive *prim;
Vertex v;
Shaderparams fsp;
Triangle2 t;
Point p, dp, Δp, p0, p1;
Point3 bc;
Color c;
double dplen, perc;
float z, pcz;
uint ropts;
int steep = 0, Δe, e, Δy;
params = task->params;
prim = &task->p;
memset(&fsp, 0, sizeof fsp);
memset(&v, 0, sizeof v);
fsp.su = params;
fsp.v = &v;
fsp.getuniform = sparams_getuniform;
fsp.getattr = sparams_getattr;
fsp.setattr = nil;
fsp.toraster = sparams_toraster;
cr = params->fb->rasters;
zr = cr->next;
ropts = params->camera->rendopts;
switch(prim->type){
case PPoint:
p = Pt(prim->v[0].p.x, prim->v[0].p.y);
z = fclamp(prim->v[0].p.z, 0, 1);
if((ropts & RODepth) && z <= getdepth(zr, p))
break;
fsp.v = &prim->v[0];
fsp.p = p;
c = params->fshader(&fsp);
if(c.a == 0) /* discard non-colors */
break;
if(ropts & RODepth)
putdepth(zr, p, z);
if(ropts & ROAbuff)
pushtoAbuf(params->fb, p, c, z);
else
pixel(cr, p, c, ropts & ROBlend);
if(task->clipr->min.x < 0){
task->clipr->min = p;
task->clipr->max = addpt(p, Pt(1,1));
}else{
task->clipr->min = minpt(task->clipr->min, p);
task->clipr->max = maxpt(task->clipr->max, addpt(p, Pt(1,1)));
}
delvattrs(fsp.v);
break;
case PLine:
p0 = Pt(prim->v[0].p.x, prim->v[0].p.y);
p1 = Pt(prim->v[1].p.x, prim->v[1].p.y);
/* clip it against our wr */
if(rectclipline(task->wr, &p0, &p1, &prim->v[0], &prim->v[1]) < 0)
break;
/* transpose the points */
if(abs(p0.x-p1.x) < abs(p0.y-p1.y)){
steep = 1;
SWAP(int, &p0.x, &p0.y);
SWAP(int, &p1.x, &p1.y);
}
/* make them left-to-right */
if(p0.x > p1.x){
SWAP(Point, &p0, &p1);
SWAP(Vertex, &prim->v[0], &prim->v[1]);
}
dp = subpt(p1, p0);
Δe = 2*abs(dp.y);
e = 0;
Δy = p1.y > p0.y? 1: -1;
for(p = p0; p.x <= p1.x; p.x++){
Δp = subpt(p, p0);
dplen = hypot(dp.x, dp.y);
perc = dplen == 0? 0: hypot(Δp.x, Δp.y)/dplen;
if(steep) SWAP(int, &p.x, &p.y);
z = flerp(prim->v[0].p.z, prim->v[1].p.z, perc);
/* TODO get rid of the bounds check and make sure the clipping doesn't overflow */
if((ropts & RODepth) &&
!ptinrect(p, params->fb->r) || z <= getdepth(zr, p))
goto discard;
/* interpolate z⁻¹ and get actual z */
pcz = flerp(prim->v[0].p.w, prim->v[1].p.w, perc);
pcz = 1.0/(pcz < ε1? ε1: pcz);
/* perspective-correct attribute interpolation */
perc *= prim->v[0].p.w * pcz;
lerpvertex(fsp.v, &prim->v[0], &prim->v[1], perc);
fsp.p = p;
c = params->fshader(&fsp);
if(c.a == 0) /* discard non-colors */
goto discard;
if(ropts & RODepth)
putdepth(zr, p, z);
if(ropts & ROAbuff)
pushtoAbuf(params->fb, p, c, z);
else
pixel(cr, p, c, ropts & ROBlend);
if(task->clipr->min.x < 0){
task->clipr->min = p;
task->clipr->max = addpt(p, Pt(1,1));
}else{
task->clipr->min = minpt(task->clipr->min, p);
task->clipr->max = maxpt(task->clipr->max, addpt(p, Pt(1,1)));
}
discard:
if(steep) SWAP(int, &p.x, &p.y);
e += Δe;
if(e > dp.x){
p.y += Δy;
e -= 2*dp.x;
}
}
delvattrs(fsp.v);
break;
case PTriangle:
t.p0 = Pt2(prim->v[0].p.x, prim->v[0].p.y, 1);
t.p1 = Pt2(prim->v[1].p.x, prim->v[1].p.y, 1);
t.p2 = Pt2(prim->v[2].p.x, prim->v[2].p.y, 1);
for(p.y = task->wr.min.y; p.y < task->wr.max.y; p.y++)
for(p.x = task->wr.min.x; p.x < task->wr.max.x; p.x++){
bc = _barycoords(t, Pt2(p.x+0.5,p.y+0.5,1));
if(bc.x < 0 || bc.y < 0 || bc.z < 0)
continue;
z = fberp(prim->v[0].p.z, prim->v[1].p.z, prim->v[2].p.z, bc);
if((ropts & RODepth) && z <= getdepth(zr, p))
continue;
/* interpolate z⁻¹ and get actual z */
pcz = fberp(prim->v[0].p.w, prim->v[1].p.w, prim->v[2].p.w, bc);
pcz = 1.0/(pcz < ε1? ε1: pcz);
/* perspective-correct attribute interpolation */
bc = modulapt3(bc, Vec3(prim->v[0].p.w*pcz,
prim->v[1].p.w*pcz,
prim->v[2].p.w*pcz));
berpvertex(fsp.v, &prim->v[0], &prim->v[1], &prim->v[2], bc);
fsp.p = p;
c = params->fshader(&fsp);
if(c.a == 0) /* discard non-colors */
continue;
if(ropts & RODepth)
putdepth(zr, p, z);
if(ropts & ROAbuff)
pushtoAbuf(params->fb, p, c, z);
else
pixel(cr, p, c, ropts & ROBlend);
if(task->clipr->min.x < 0){
task->clipr->min = p;
task->clipr->max = addpt(p, Pt(1,1));
}else{
task->clipr->min = minpt(task->clipr->min, p);
task->clipr->max = maxpt(task->clipr->max, addpt(p, Pt(1,1)));
}
}
delvattrs(fsp.v);
break;
default: sysfatal("alien primitive detected");
}
}
static void
rasterizer(void *arg)
{
Rasterparam *rp;
Rastertask *task;
SUparams *params;
Renderjob *job;
uvlong t0;
int i;
rp = arg;
threadsetname("rasterizer %d", rp->id);
while((task = recvp(rp->taskc)) != nil){
t0 = nanosec();
params = task->params;
job = params->job;
if(job->rctl->doprof && job->times.Rn[rp->id].t0 == 0)
job->times.Rn[rp->id].t0 = t0;
/* end of job */
if(params->entity == nil){
if(decref(job) < 1){
if(job->camera->rendopts & ROAbuff)
squashAbuf(job->fb, job->camera->rendopts & ROBlend);
/* set the clipr to the union of bboxes from the rasterizers */
for(i = 1; i < job->ncliprects; i++){
if(job->cliprects[i].min.x < 0)
continue;
job->cliprects[0].min = job->cliprects[0].min.x < 0?
job->cliprects[i].min:
minpt(job->cliprects[0].min, job->cliprects[i].min);
job->cliprects[0].max = job->cliprects[0].max.x < 0?
job->cliprects[i].max:
maxpt(job->cliprects[0].max, job->cliprects[i].max);
}
job->fb->clipr = job->cliprects[0];
if(job->rctl->doprof)
job->times.Rn[rp->id].t1 = nanosec();
nbsend(job->donec, nil);
free(params);
}else if(job->rctl->doprof)
job->times.Rn[rp->id].t1 = nanosec();
free(task);
continue;
}
rasterize(task);
for(i = 0; i < task->p.type+1; i++)
delvattrs(&task->p.v[i]);
free(params);
free(task);
}
}
static void
tiler(void *arg)
{
Tilerparam *tp;
SUparams *params, *newparams;
Rastertask *task;
Shaderparams vsp;
Primitive *ep, *cp, *p; /* primitives to raster */
Rectangle *wr, bbox;
Channel **taskchans;
ulong Δy, nproc;
int i, np;
uvlong t0;
tp = arg;
threadsetname("tiler %d", tp->id);
cp = emalloc(sizeof(*cp)*16);
taskchans = tp->taskchans;
nproc = tp->nproc;
wr = emalloc(nproc*sizeof(Rectangle));
memset(&vsp, 0, sizeof vsp);
vsp.getuniform = sparams_getuniform;
vsp.getattr = sparams_getattr;
vsp.setattr = sparams_setattr;
vsp.toraster = nil;
while((params = recvp(tp->paramsc)) != nil){
t0 = nanosec();
if(params->job->rctl->doprof &&
params->job->times.Tn[tp->id].t0 == 0)
params->job->times.Tn[tp->id].t0 = t0;
/* end of job */
if(params->entity == nil){
if(params->job->rctl->doprof)
params->job->times.Tn[tp->id].t1 = nanosec();
if(decref(params->job) < 1){
params->job->ref = nproc;
for(i = 0; i < nproc; i++){
task = emalloc(sizeof *task);
memset(task, 0, sizeof *task);
task->params = params;
sendp(taskchans[i], task);
}
}
continue;
}
vsp.su = params;
wr[0] = params->fb->r;
Δy = Dy(wr[0])/nproc;
wr[0].max.y = wr[0].min.y + Δy;
for(i = 1; i < nproc; i++)
wr[i] = rectaddpt(wr[i-1], Pt(0,Δy));
if(wr[nproc-1].max.y < params->fb->r.max.y)
wr[nproc-1].max.y = params->fb->r.max.y;
for(ep = params->eb; ep != params->ee; ep++){
np = 1; /* start with one. after clipping it might change */
p = ep;
switch(p->type){
case PPoint:
p->v[0].mtl = p->mtl;
p->v[0].attrs = nil;
p->v[0].nattrs = 0;
vsp.v = &p->v[0];
vsp.idx = 0;
p->v[0].p = params->vshader(&vsp);
if(!isvisible(p->v[0].p))
break;
p->v[0].p = clip2ndc(p->v[0].p);
p->v[0].p = ndc2viewport(params->fb, p->v[0].p);
bbox.min.x = p->v[0].p.x;
bbox.min.y = p->v[0].p.y;
bbox.max.x = p->v[0].p.x+1;
bbox.max.y = p->v[0].p.y+1;
for(i = 0; i < nproc; i++)
if(rectXrect(bbox, wr[i])){
newparams = emalloc(sizeof *newparams);
*newparams = *params;
task = emalloc(sizeof *task);
task->params = newparams;
task->clipr = ¶ms->job->cliprects[i];
task->p = *p;
task->p.v[0] = dupvertex(&p->v[0]);
sendp(taskchans[i], task);
break;
}
delvattrs(&p->v[0]);
break;
case PLine:
for(i = 0; i < 2; i++){
p->v[i].mtl = p->mtl;
p->v[i].attrs = nil;
p->v[i].nattrs = 0;
vsp.v = &p->v[i];
vsp.idx = i;
p->v[i].p = params->vshader(&vsp);
}
if(!isvisible(p->v[0].p) || !isvisible(p->v[1].p)){
np = clipprimitive(p, cp);
p = cp;
}
if(np < 1)
break;
p->v[0].p = clip2ndc(p->v[0].p);
p->v[1].p = clip2ndc(p->v[1].p);
p->v[0].p = ndc2viewport(params->fb, p->v[0].p);
p->v[1].p = ndc2viewport(params->fb, p->v[1].p);
bbox.min.x = min(p->v[0].p.x, p->v[1].p.x);
bbox.min.y = min(p->v[0].p.y, p->v[1].p.y);
bbox.max.x = max(p->v[0].p.x, p->v[1].p.x)+1;
bbox.max.y = max(p->v[0].p.y, p->v[1].p.y)+1;
for(i = 0; i < nproc; i++)
if(rectXrect(bbox, wr[i])){
newparams = emalloc(sizeof *newparams);
*newparams = *params;
task = emalloc(sizeof *task);
task->params = newparams;
task->wr = wr[i];
task->clipr = ¶ms->job->cliprects[i];
task->p = *p;
task->p.v[0] = dupvertex(&p->v[0]);
task->p.v[1] = dupvertex(&p->v[1]);
sendp(taskchans[i], task);
}
delvattrs(&p->v[0]);
delvattrs(&p->v[1]);
break;
case PTriangle:
for(i = 0; i < 3; i++){
p->v[i].mtl = p->mtl;
p->v[i].attrs = nil;
p->v[i].nattrs = 0;
p->v[i].tangent = p->tangent;
vsp.v = &p->v[i];
vsp.idx = i;
p->v[i].p = params->vshader(&vsp);
}
if(!isvisible(p->v[0].p) || !isvisible(p->v[1].p) || !isvisible(p->v[2].p)){
np = clipprimitive(p, cp);
p = cp;
}
for(; np--; p++){
p->v[0].p = clip2ndc(p->v[0].p);
p->v[1].p = clip2ndc(p->v[1].p);
p->v[2].p = clip2ndc(p->v[2].p);
/* culling */
switch(params->camera->cullmode){
case CullFront: if(!isfacingback(p)) goto skiptri; break;
case CullBack: if(isfacingback(p)) goto skiptri; break;
}
p->v[0].p = ndc2viewport(params->fb, p->v[0].p);
p->v[1].p = ndc2viewport(params->fb, p->v[1].p);
p->v[2].p = ndc2viewport(params->fb, p->v[2].p);
bbox.min.x = min(min(p->v[0].p.x, p->v[1].p.x), p->v[2].p.x);
bbox.min.y = min(min(p->v[0].p.y, p->v[1].p.y), p->v[2].p.y);
bbox.max.x = max(max(p->v[0].p.x, p->v[1].p.x), p->v[2].p.x)+1;
bbox.max.y = max(max(p->v[0].p.y, p->v[1].p.y), p->v[2].p.y)+1;
for(i = 0; i < nproc; i++)
if(rectXrect(bbox, wr[i])){
newparams = emalloc(sizeof *newparams);
*newparams = *params;
task = emalloc(sizeof *task);
task->params = newparams;
task->wr = bbox;
rectclip(&task->wr, wr[i]);
task->clipr = ¶ms->job->cliprects[i];
task->p = *p;
task->p.v[0] = dupvertex(&p->v[0]);
task->p.v[1] = dupvertex(&p->v[1]);
task->p.v[2] = dupvertex(&p->v[2]);
sendp(taskchans[i], task);
}
skiptri:
delvattrs(&p->v[0]);
delvattrs(&p->v[1]);
delvattrs(&p->v[2]);
}
break;
default: sysfatal("alien primitive detected");
}
}
free(params);
}
}
static void
entityproc(void *arg)
{
Entityparam *ep;
Channel *paramsin, **paramsout, **taskchans;
Tilerparam *tp;
Rasterparam *rp;
SUparams *params, *newparams;
Primitive *eb, *ee;
ulong stride, nprims, nproc, nworkers;
int i;
uvlong t0;
threadsetname("entityproc");
ep = arg;
paramsin = ep->paramsc;
nproc = ep->rctl->nprocs;
if(nproc > 2)
nproc /= 2;
paramsout = emalloc(nproc*sizeof(*paramsout));
taskchans = emalloc(nproc*sizeof(*taskchans));
for(i = 0; i < nproc; i++){
paramsout[i] = chancreate(sizeof(SUparams*), 256);
tp = emalloc(sizeof *tp);
tp->id = i;
tp->paramsc = paramsout[i];
tp->taskchans = taskchans;
tp->nproc = nproc;
proccreate(tiler, tp, mainstacksize);
}
for(i = 0; i < nproc; i++){
rp = emalloc(sizeof *rp);
rp->id = i;
rp->taskc = taskchans[i] = chancreate(sizeof(Rastertask*), 512);
proccreate(rasterizer, rp, mainstacksize);
}
while((params = recvp(paramsin)) != nil){
t0 = nanosec();
if(params->job->rctl->doprof && params->job->times.E.t0 == 0)
params->job->times.E.t0 = t0;
/* prof: initialize timing slots for the next stages */
if(params->job->rctl->doprof && params->job->times.Tn == nil){
assert(params->job->times.Rn == nil);
params->job->times.Tn = emalloc(nproc*sizeof(Rendertime));
params->job->times.Rn = emalloc(nproc*sizeof(Rendertime));
memset(params->job->times.Tn, 0, nproc*sizeof(Rendertime));
memset(params->job->times.Rn, 0, nproc*sizeof(Rendertime));
}
/* end of job */
if(params->entity == nil){
params->job->ref = nproc;
for(i = 0; i < nproc; i++)
sendp(paramsout[i], params);
if(params->job->rctl->doprof)
params->job->times.E.t1 = nanosec();
continue;
}
if(params->job->cliprects == nil){
params->job->cliprects = emalloc(nproc*sizeof(Rectangle));
params->job->ncliprects = nproc;
for(i = 0; i < nproc; i++){
params->job->cliprects[i].min = Pt(-1,-1);
params->job->cliprects[i].max = Pt(-1,-1);
}
}
eb = params->entity->mdl->prims;
nprims = params->entity->mdl->nprims;
ee = eb + nprims;
if(nprims <= nproc){
nworkers = nprims;
stride = 1;
}else{
nworkers = nproc;
stride = nprims/nproc;
}
for(i = 0; i < nworkers; i++){
newparams = emalloc(sizeof *newparams);
*newparams = *params;
newparams->eb = eb + i*stride;
newparams->ee = i == nworkers-1? ee: newparams->eb + stride;
sendp(paramsout[i], newparams);
}
free(params);
}
}
static void
renderer(void *arg)
{
Renderer *rctl;
Renderjob *job;
Scene *sc;
Entity *ent;
SUparams *params;
Entityparam *ep;
uvlong time, lastid;
threadsetname("renderer");
rctl = arg;
lastid = 0;
ep = emalloc(sizeof *ep);
ep->rctl = rctl;
ep->paramsc = chancreate(sizeof(SUparams*), 256);
proccreate(entityproc, ep, mainstacksize);
while((job = recvp(rctl->jobq)) != nil){
time = nanosec();
if(job->rctl->doprof) job->times.R.t0 = time;
job->id = lastid++;
sc = job->scene;
if(sc->nents < 1){
nbsend(job->donec, nil);
continue;
}
/* initialize the A-buffer */
if((job->camera->rendopts & ROAbuff) && job->fb->abuf.stk == nil){
job->fb->abuf.stk = emalloc(Dx(job->fb->r)*Dy(job->fb->r)*sizeof(Astk));
memset(job->fb->abuf.stk, 0, Dx(job->fb->r)*Dy(job->fb->r)*sizeof(Astk));
}
for(ent = sc->ents.next; ent != &sc->ents; ent = ent->next){
params = emalloc(sizeof *params);
memset(params, 0, sizeof *params);
params->fb = job->fb;
params->job = job;
params->camera = job->camera;
params->entity = ent;
params->uni_time = time;
params->vshader = job->shaders->vshader;
params->fshader = job->shaders->fshader;
sendp(ep->paramsc, params);
}
/* mark end of job */
params = emalloc(sizeof *params);
memset(params, 0, sizeof *params);
params->job = job;
sendp(ep->paramsc, params);
if(job->rctl->doprof) job->times.R.t1 = nanosec();
}
}
Renderer *
initgraphics(void)
{
Renderer *r;
char *nprocs;
ulong nproc;
nprocs = getenv("NPROC");
if(nprocs == nil || (nproc = strtoul(nprocs, nil, 10)) < 2)
nproc = 1;
free(nprocs);
r = emalloc(sizeof *r);
memset(r, 0, sizeof *r);
r->jobq = chancreate(sizeof(Renderjob*), 8);
r->nprocs = nproc;
proccreate(renderer, r, mainstacksize);
return r;
}