diff options
Diffstat (limited to 'render.c')
| -rw-r--r-- | render.c | 99 |
1 files changed, 60 insertions, 39 deletions
@@ -30,7 +30,7 @@ triangulate(OBJElem **newe, OBJElem *e) OBJIndexArray *idxtab; idxtab = &e->indextab[OBJVGeometric]; - newe[0] = emalloc(sizeof *newe[0]); + newe[0] = emalloc(sizeof **newe); newe[0]->type = OBJEFace; newidxtab = &newe[0]->indextab[OBJVGeometric]; newidxtab->nindex = 3; @@ -58,7 +58,7 @@ triangulate(OBJElem **newe, OBJElem *e) } idxtab = &e->indextab[OBJVGeometric]; - newe[1] = emalloc(sizeof *newe[1]); + newe[1] = emalloc(sizeof **newe); newe[1]->type = OBJEFace; newidxtab = &newe[1]->indextab[OBJVGeometric]; newidxtab->nindex = 3; @@ -104,7 +104,7 @@ mulsdm(double r[6], double m[6][4], Point3 p) int i; for(i = 0; i < 6; i++) - r[i] += m[i][0]*p.x + m[i][1]*p.y + m[i][2]*p.z + m[i][3]*p.w; + r[i] = m[i][0]*p.x + m[i][1]*p.y + m[i][2]*p.z + m[i][3]*p.w; } typedef struct @@ -123,54 +123,59 @@ addvert(Polygon *p, Vertex v) return p->n; } +static void +swappoly(Polygon *a, Polygon *b) +{ + Polygon tmp; + + tmp = *a; + *a = *b; + *b = tmp; +} + +/* + * references: + * - James F. Blinn, Martin E. Newell, “Clipping Using Homogeneous Coordinates”, + * SIGGRAPH '78, pp. 245-251 + * - https://cs418.cs.illinois.edu/website/text/clipping.html + * - https://github.com/aap/librw/blob/14dab85dcae6f3762fb2b1eda4d58d8e67541330/tools/playground/tl_tests.cpp#L522 + */ static int cliptriangle(Triangle *t) { - /* TODO implement homogeneous clipping procedure */ - /* - * requirements: - * - * - normal and color attributes are carried over to the new - * intersecting points without modification. - * - uv coordinates must be adjusted in proportion to the new - * points. - */ - enum { L, R, B, T, F, N }; /* signed distance from each clipping plane */ static double sdm[6][4] = { - 1, 0, 0, 1, - -1, 0, 0, 1, - 0, 1, 0, 1, - 0, -1, 0, 1, - 0, 0, 1, 1, - 0, 0, -1, 1, + 1, 0, 0, 1, /* l */ + -1, 0, 0, 1, /* r */ + 0, 1, 0, 1, /* b */ + 0, -1, 0, 1, /* t */ + 0, 0, 1, 1, /* f */ + 0, 0, -1, 1, /* n */ }, sd0[6], sd1[6]; - double d0, d1; - Polygon Vout; - Vertex *v0, *v1, v; /* new vertex (line-plane intersection) */ + double d0, d1, perc; + Polygon Vin, Vout; + Vertex *v0, *v1, v; /* edge verts and new vertex (line-plane intersection) */ int i, j, nt; if(!isvisible(t[0][0].p) && !isvisible(t[0][1].p) && !isvisible(t[0][2].p)) return 0; nt = 0; + memset(&Vin, 0, sizeof Vin); memset(&Vout, 0, sizeof Vout); + for(i = 0; i < 3; i++) + addvert(&Vin, t[0][i]); + + for(j = 0; j < 6; j++){ + for(i = 0; i < Vin.n; i++){ + v0 = &Vin.v[i]; + v1 = &Vin.v[(i+1) % Vin.n]; + + mulsdm(sd0, sdm, v0->p); + mulsdm(sd1, sdm, v1->p); - for(i = 0; i < 3; i++){ - v0 = &t[0][i]; - v1 = &t[0][(i+1) % 3]; - memset(sd0, 0, sizeof sd0); - memset(sd1, 0, sizeof sd1); - mulsdm(sd0, sdm, v0->p); - mulsdm(sd1, sdm, v1->p); - - for(j = 0; j < 6; j++){ - /* - * if both verts are outside any of the planes, they - * are not in the frustum, so no need to keep testing. - */ if(sd0[j] < 0 && sd1[j] < 0) - break; + continue; if(sd0[j] >= 0 && sd1[j] >= 0) goto allin; @@ -180,8 +185,10 @@ cliptriangle(Triangle *t) d0 = (j&1) == 0? sd0[j]: -sd0[j]; d1 = (j&1) == 0? sd1[j]: -sd1[j]; - v.p = divpt3(subpt3(mulpt3(v0->p, d1), mulpt3(v1->p, d0)), d1-d0); - v.uv = divpt2(subpt2(mulpt2(v0->uv, d1), mulpt2(v1->uv, d0)), d1-d0); + perc = d0/(d0 - d1); + v.p = lerp3(v0->p, v1->p, perc); + v.uv = lerp2(v0->uv, v1->uv, perc); + v.intensity = flerp(v0->intensity, v1->intensity, perc); addvert(&Vout, v); if(sd1[j] >= 0){ @@ -189,6 +196,16 @@ allin: addvert(&Vout, *v1); } } + if(j < 6-1){ + swappoly(&Vin, &Vout); + Vout.n = 0; + } + } + + if(Vout.n < 3){ + free(Vout.v); + free(Vin.v); + return 0; } /* triangulate */ @@ -198,6 +215,7 @@ allin: t[nt][2] = Vout.v[i+2]; } free(Vout.v); + free(Vin.v); return nt; } @@ -390,6 +408,9 @@ rasterize(SUparams *params, Triangle t, Memimage *frag) }else memset(cbuf, 0xFF, sizeof cbuf); + params->var_intensity[0] = t[0].intensity; + params->var_intensity[1] = t[1].intensity; + params->var_intensity[2] = t[2].intensity; fsp.p = p; fsp.bc = bc; pixel(params->fb->cb, p, params->fshader(&fsp)); @@ -415,7 +436,7 @@ shaderunit(void *arg) threadsetname("shader unit #%d", params->id); - t = emalloc(sizeof(*t)*32); + t = emalloc(sizeof(*t)*16); verts = params->model->vertdata[OBJVGeometric].verts; tverts = params->model->vertdata[OBJVTexture].verts; nverts = params->model->vertdata[OBJVNormal].verts; |