diff options
| -rw-r--r-- | graphics.h | 43 | ||||
| -rw-r--r-- | internal.h | 7 | ||||
| -rw-r--r-- | mkfile | 1 | ||||
| -rw-r--r-- | render.c | 105 | ||||
| -rw-r--r-- | vertex.c | 148 |
5 files changed, 232 insertions, 72 deletions
@@ -11,7 +11,13 @@ enum { LIGHT_SPOT, }; +enum { + VAPoint, + VANumber, +}; + typedef struct Color Color; +typedef struct Vertexattr Vertexattr; typedef struct Vertex Vertex; typedef struct LightSource LightSource; typedef struct Material Material; @@ -32,16 +38,25 @@ struct Color double r, g, b, a; }; -struct Vertex +struct Vertexattr { - Point3 p; /* position */ - Point3 n; /* surface normal */ - Color c; /* shading color */ - Point2 uv; /* texture coordinate */ + char *id; + int type; + union { + Point3 p; + double n; + }; +}; - /* TODO these attributes should be replaced by a hash table */ - double intensity; - Point3 pos; +struct Vertex +{ + Point3 p; /* position */ + Point3 n; /* surface normal */ + Color c; /* shading color */ + Point2 uv; /* texture coordinate */ + /* TODO it'd be neat to use a dynamic hash table instead */ + Vertexattr *attrs; /* attributes (aka varyings) */ + ulong nattrs; }; typedef Vertex Triangle[3]; @@ -102,9 +117,9 @@ struct FSparams { SUparams *su; Memimage *frag; - Point p; - Point3 bc; uchar *cbuf; + Point p; + Vertex v; /* only for the attributes (varyings) */ }; /* shader unit params */ @@ -117,10 +132,6 @@ struct SUparams /* TODO replace with a Scene */ Entity *entity; - double var_intensity; - Point3 var_normal; - Point3 var_pos; - uvlong uni_time; Point3 (*vshader)(VSparams*); @@ -208,6 +219,10 @@ void delentity(Entity*); Scene *newscene(char*); void delscene(Scene*); +/* vertex */ +void addvattr(Vertex*, char*, int, void*); +Vertexattr *getvattr(Vertex*, char*); + /* util */ double fmin(double, double); double fmax(double, double); @@ -12,6 +12,13 @@ void rmfbctl(Framebufctl*); /* render */ void shade(Framebuf*, Scene*, Shader*); +/* vertex */ +Vertex dupvertex(Vertex*); +void lerpvertex(Vertex*, Vertex*, Vertex*, double); +void berpvertex(Vertex*, Vertex*, Vertex*, Vertex*, Point3); +void delvattrs(Vertex*); +void fprintvattrs(int, Vertex*); + /* util */ int min(int, int); int max(int, int); @@ -6,6 +6,7 @@ OFILES=\ viewport.$O\ render.$O\ scene.$O\ + vertex.$O\ alloc.$O\ fb.$O\ shadeop.$O\ @@ -65,6 +65,16 @@ swappoly(Polygon *a, Polygon *b) *b = tmp; } +static void +cleanpoly(Polygon *p) +{ + int i; + + for(i = 0; i < p->n; i++) + delvattrs(&p->v[i]); + p->n = 0; +} + /* * references: * - James F. Blinn, Martin E. Newell, “Clipping Using Homogeneous Coordinates”, @@ -96,7 +106,7 @@ cliptriangle(Triangle *t) for(i = 0; i < 3; i++) addvert(&Vin, t[0][i]); - for(j = 0; j < 6; j++){ + for(j = 0; j < 6 && Vin.n > 0; j++){ for(i = 0; i < Vin.n; i++){ v0 = &Vin.v[i]; v1 = &Vin.v[(i+1) % Vin.n]; @@ -114,31 +124,32 @@ cliptriangle(Triangle *t) d1 = (j&1) == 0? sd1[j]: -sd1[j]; perc = d0/(d0 - d1); - v.p = lerp3(v0->p, v1->p, perc); - v.n = lerp3(v0->n, v1->n, perc); - v.c = lerp3((Point3)v0->c, (Point3)v1->c, perc); - v.uv = lerp2(v0->uv, v1->uv, perc); - v.intensity = flerp(v0->intensity, v1->intensity, perc); - v.pos = lerp3(v0->pos, v1->pos, perc); + lerpvertex(&v, v0, v1, perc); addvert(&Vout, v); if(sd1[j] >= 0){ allin: - addvert(&Vout, *v1); + addvert(&Vout, dupvertex(v1)); } } - if(j < 6-1){ + cleanpoly(&Vin); + if(j < 6-1) swappoly(&Vin, &Vout); - Vout.n = 0; - } } /* triangulate */ - if(Vout.n >= 3) + if(Vout.n < 3) + cleanpoly(&Vout); + else for(i = 0; i < Vout.n-2; i++, nt++){ - t[nt][0] = Vout.v[0]; + /* + * when performing fan triangulation, indices 0 and 2 + * are referenced on every triangle, so duplicate them + * to avoid complications during rasterization. + */ + t[nt][0] = i < Vout.n-2-1? dupvertex(&Vout.v[0]): Vout.v[0]; t[nt][1] = Vout.v[i+1]; - t[nt][2] = Vout.v[i+2]; + t[nt][2] = i < Vout.n-2-1? dupvertex(&Vout.v[i+2]): Vout.v[i+2]; } free(Vout.v); free(Vin.v); @@ -262,8 +273,7 @@ static void rasterize(SUparams *params, Triangle t, Memimage *frag) { FSparams fsp; - Triangle2 t₂, tt₂; - Triangle3 ct; + Triangle2 t₂; Rectangle bbox; Point p, tp; Point3 bc; @@ -286,23 +296,7 @@ rasterize(SUparams *params, Triangle t, Memimage *frag) fsp.su = params; fsp.frag = frag; fsp.cbuf = cbuf; - - /* perspective-divide the attributes */ - t[0].n = mulpt3(t[0].n, t[0].p.w); - t[1].n = mulpt3(t[1].n, t[1].p.w); - t[2].n = mulpt3(t[2].n, t[2].p.w); - t[0].c = mulpt3(t[0].c, t[0].p.w); - t[1].c = mulpt3(t[1].c, t[1].p.w); - t[2].c = mulpt3(t[2].c, t[2].p.w); - t[0].uv = mulpt2(t[0].uv, t[0].p.w); - t[1].uv = mulpt2(t[1].uv, t[1].p.w); - t[2].uv = mulpt2(t[2].uv, t[2].p.w); - t[0].intensity = t[0].intensity*t[0].p.w; - t[1].intensity = t[1].intensity*t[1].p.w; - t[2].intensity = t[2].intensity*t[2].p.w; - t[0].pos = mulpt3(t[0].pos, t[0].p.w); - t[1].pos = mulpt3(t[1].pos, t[1].p.w); - t[2].pos = mulpt3(t[2].pos, t[2].p.w); + memset(&fsp.v, 0, sizeof fsp.v); for(p.y = bbox.min.y; p.y < bbox.max.y; p.y++) for(p.x = bbox.min.x; p.x < bbox.max.x; p.x++){ @@ -324,14 +318,16 @@ rasterize(SUparams *params, Triangle t, Memimage *frag) z = t[0].p.w*bc.x + t[1].p.w*bc.y + t[2].p.w*bc.z; z = 1.0/(z < 1e-5? 1e-5: z); - if((t[0].uv.w + t[1].uv.w + t[2].uv.w) != 0){ - /* lerp attribute and dissolve perspective */ - tt₂.p0 = mulpt2(t[0].uv, bc.x*z); - tt₂.p1 = mulpt2(t[1].uv, bc.y*z); - tt₂.p2 = mulpt2(t[2].uv, bc.z*z); + /* perspective-correct attribute interpolation */ + bc.x *= t[0].p.w; + bc.y *= t[1].p.w; + bc.z *= t[2].p.w; + bc = mulpt3(bc, z); + berpvertex(&fsp.v, &t[0], &t[1], &t[2], bc); - tp.x = (tt₂.p0.x + tt₂.p1.x + tt₂.p2.x)*Dx(params->entity->mdl->tex->r); - tp.y = (1 - (tt₂.p0.y + tt₂.p1.y + tt₂.p2.y))*Dy(params->entity->mdl->tex->r); + if(fsp.v.uv.w != 0){ + tp.x = fsp.v.uv.x*Dx(params->entity->mdl->tex->r); + tp.y = (1 - fsp.v.uv.y)*Dy(params->entity->mdl->tex->r); switch(params->entity->mdl->tex->chan){ case RGB24: @@ -348,28 +344,15 @@ rasterize(SUparams *params, Triangle t, Memimage *frag) break; } }else{ - /* lerp attribute and dissolve perspective */ - ct.p0 = mulpt3(t[0].c, bc.x*z); - ct.p1 = mulpt3(t[1].c, bc.y*z); - ct.p2 = mulpt3(t[2].c, bc.z*z); - cbuf[0] = (ct.p0.w + ct.p1.w + ct.p2.w)*0xFF; - cbuf[1] = (ct.p0.z + ct.p1.z + ct.p2.z)*0xFF; - cbuf[2] = (ct.p0.y + ct.p1.y + ct.p2.y)*0xFF; - cbuf[3] = (ct.p0.x + ct.p1.x + ct.p2.x)*0xFF; + cbuf[0] = fsp.v.c.a*0xFF; + cbuf[1] = fsp.v.c.b*0xFF; + cbuf[2] = fsp.v.c.g*0xFF; + cbuf[3] = fsp.v.c.r*0xFF; } - params->var_intensity = dotvec3(Vec3(t[0].intensity, t[1].intensity, t[2].intensity), bc)*z; - params->var_normal = normvec3(addpt3(addpt3( - mulpt3(t[0].n, bc.x*z), - mulpt3(t[1].n, bc.y*z)), - mulpt3(t[2].n, bc.z*z))); - params->var_pos = addpt3(addpt3( - mulpt3(t[0].pos, bc.x*z), - mulpt3(t[1].pos, bc.y*z)), - mulpt3(t[2].pos, bc.z*z)); fsp.p = p; - fsp.bc = bc; pixel(params->fb->cb, p, params->fshader(&fsp)); + delvattrs(&fsp.v); } } @@ -435,6 +418,8 @@ shaderunit(void *arg) t[0][i].c.g = (*ep)->mtl != nil? (*ep)->mtl->Kd.g: 1; t[0][i].c.b = (*ep)->mtl != nil? (*ep)->mtl->Kd.b: 1; t[0][i].c.a = 1; + t[0][i].attrs = nil; + t[0][i].nattrs = 0; } vsp.v = &t[0][0]; @@ -456,6 +441,10 @@ shaderunit(void *arg) t[nt][2].p = ndc2viewport(params->fb, clip2ndc(t[nt][2].p)); rasterize(params, t[nt], frag); + + delvattrs(&t[nt][0]); + delvattrs(&t[nt][1]); + delvattrs(&t[nt][2]); } } diff --git a/vertex.c b/vertex.c new file mode 100644 index 0000000..0cd6ce7 --- /dev/null +++ b/vertex.c @@ -0,0 +1,148 @@ +#include <u.h> +#include <libc.h> +#include <thread.h> +#include <draw.h> +#include <memdraw.h> +#include <geometry.h> +#include "libobj/obj.h" +#include "graphics.h" +#include "internal.h" + +static void +_addvattr(Vertex *v, Vertexattr *va) +{ + int i; + + for(i = 0; i < v->nattrs; i++) + if(strcmp(v->attrs[i].id, va->id) == 0){ + v->attrs[i] = *va; + return; + } + v->attrs = erealloc(v->attrs, ++v->nattrs*sizeof(*va)); + v->attrs[v->nattrs-1] = *va; +} + +static void +copyvattrs(Vertex *d, Vertex *s) +{ + int i; + + for(i = 0; i < s->nattrs; i++) + _addvattr(d, &s->attrs[i]); +} + +Vertex +dupvertex(Vertex *v) +{ + Vertex nv; + + nv = *v; + nv.attrs = nil; + nv.nattrs = 0; + copyvattrs(&nv, v); + return nv; +} + +void +lerpvertex(Vertex *v, Vertex *v0, Vertex *v1, double t) +{ + Vertexattr va; + int i; + + v->p = lerp3(v0->p, v1->p, t); + v->n = lerp3(v0->n, v1->n, t); + v->c = lerp3(v0->c, v1->c, t); + v->uv = lerp2(v0->uv, v1->uv, t); + v->attrs = nil; + v->nattrs = 0; + for(i = 0; i < v0->nattrs; i++){ + va.id = v0->attrs[i].id; + va.type = v0->attrs[i].type; + if(va.type == VAPoint) + va.p = lerp3(v0->attrs[i].p, v1->attrs[i].p, t); + else + va.n = flerp(v0->attrs[i].n, v1->attrs[i].n, t); + _addvattr(v, &va); + } +} + +/* + * perspective-correct barycentric attribute interpolation + */ +void +berpvertex(Vertex *v, Vertex *v0, Vertex *v1, Vertex *v2, Point3 bc) +{ + Vertexattr va; + int i; + + v->n = addpt3(addpt3( + mulpt3(v0->n, bc.x), + mulpt3(v1->n, bc.y)), + mulpt3(v2->n, bc.z)); + v->c = addpt3(addpt3( + mulpt3(v0->c, bc.x), + mulpt3(v1->c, bc.y)), + mulpt3(v2->c, bc.z)); + v->uv = addpt2(addpt2( + mulpt2(v0->uv, bc.x), + mulpt2(v1->uv, bc.y)), + mulpt2(v2->uv, bc.z)); + v->attrs = nil; + v->nattrs = 0; + for(i = 0; i < v0->nattrs; i++){ + va.id = v0->attrs[i].id; + va.type = v0->attrs[i].type; + if(va.type == VAPoint) + va.p = addpt3(addpt3( + mulpt3(v0->attrs[i].p, bc.x), + mulpt3(v1->attrs[i].p, bc.y)), + mulpt3(v2->attrs[i].p, bc.z)); + else + va.n = dotvec3(Vec3(v0->attrs[i].n, v1->attrs[i].n, v2->attrs[i].n), bc); + _addvattr(v, &va); + } +} + +void +addvattr(Vertex *v, char *id, int type, void *val) +{ + Vertexattr va; + + va.id = id; + va.type = type; + switch(type){ + case VAPoint: va.p = *(Point3*)val; break; + case VANumber: va.n = *(double*)val; break; + default: sysfatal("unknown vertex attribute type '%d'", type); + } + _addvattr(v, &va); +} + +Vertexattr * +getvattr(Vertex *v, char *id) +{ + int i; + + for(i = 0; i < v->nattrs; i++) + if(strcmp(v->attrs[i].id, id) == 0) + return &v->attrs[i]; + return nil; +} + +void +delvattrs(Vertex *v) +{ + free(v->attrs); + v->attrs= nil; + v->nattrs = 0; +} + +void +fprintvattrs(int fd, Vertex *v) +{ + int i; + + for(i = 0; i < v->nattrs; i++) + fprint(fd, "id %s type %d v %g\n", + v->attrs[i].id, v->attrs[i].type, v->attrs[i].n); +} |