/* ================ GL_SubdivideSurface Breaks a polygon up along axial 64 unit boundaries so that turbulent and sky warps can be done reasonably. ================ */ void GL_SubdivideSurface (msurface_t *fa) { vec3_t verts[64]; int numverts; int i; int lindex; float *vec; warpface = fa; // // convert edges back to a normal polygon // numverts = 0; for (i=0 ; i<fa->numedges ; i++) { lindex = loadmodel->surfedges[fa->firstedge + i]; if (lindex > 0) vec = loadmodel->vertexes[loadmodel->edges[lindex].v[0]].position; else vec = loadmodel->vertexes[loadmodel->edges[-lindex].v[1]].position; VectorCopy (vec, verts[numverts]); numverts++; } SubdividePolygon (numverts, verts[0]); }
/* ================ GL_SubdivideSurface ================ */ void GL_SubdivideSurface (msurface_t *fa) { vec3_t verts[64]; int i; warpface = fa; //the first poly in the chain is the undivided poly for newwater rendering. //grab the verts from that. for (i=0; i<fa->polys->numverts; i++) VectorCopy (fa->polys->verts[i], verts[i]); SubdividePolygon (fa->polys->numverts, verts[0]); }
void SubdividePolygon (int numverts, float *verts) { int i, j, k; vec3_t mins, maxs; float m; float *v; vec3_t front[64], back[64]; int f, b; float dist[64]; float frac; glpoly_t *poly; float s, t; vec3_t total; float total_s, total_t; if (numverts > 60) ri.Sys_Error (ERR_DROP, "numverts = %i", numverts); BoundPoly (numverts, verts, mins, maxs); for (i=0 ; i<3 ; i++) { m = (mins[i] + maxs[i]) * 0.5; m = SUBDIVIDE_SIZE * floor (m/SUBDIVIDE_SIZE + 0.5); if (maxs[i] - m < 8) continue; if (m - mins[i] < 8) continue; // cut it v = verts + i; for (j=0 ; j<numverts ; j++, v+= 3) dist[j] = *v - m; // wrap cases dist[j] = dist[0]; v-=i; VectorCopy (verts, v); f = b = 0; v = verts; for (j=0 ; j<numverts ; j++, v+= 3) { if (dist[j] >= 0) { VectorCopy (v, front[f]); f++; } if (dist[j] <= 0) { VectorCopy (v, back[b]); b++; } if (dist[j] == 0 || dist[j+1] == 0) continue; if ( (dist[j] > 0) != (dist[j+1] > 0) ) { // clip point frac = dist[j] / (dist[j] - dist[j+1]); for (k=0 ; k<3 ; k++) front[f][k] = back[b][k] = v[k] + frac*(v[3+k] - v[k]); f++; b++; } } SubdividePolygon (f, front[0]); SubdividePolygon (b, back[0]); return; } // add a point in the center to help keep warp valid poly = Hunk_Alloc (sizeof(glpoly_t) + ((numverts-4)+2) * VERTEXSIZE*sizeof(float)); poly->next = warpface->polys; warpface->polys = poly; poly->numverts = numverts+2; VectorClear (total); total_s = 0; total_t = 0; for (i=0 ; i<numverts ; i++, verts+= 3) { VectorCopy (verts, poly->verts[i+1]); s = DotProduct (verts, warpface->texinfo->vecs[0]); t = DotProduct (verts, warpface->texinfo->vecs[1]); total_s += s; total_t += t; VectorAdd (total, verts, total); poly->verts[i+1][3] = s; poly->verts[i+1][4] = t; } VectorScale (total, (1.0/numverts), poly->verts[0]); poly->verts[0][3] = total_s/numverts; poly->verts[0][4] = total_t/numverts; // copy first vertex to last memcpy (poly->verts[i+1], poly->verts[1], sizeof(poly->verts[0])); }
void SubdividePolygon (int numverts, float *verts) { int i, j, k; vec3_t mins, maxs; float m; float *v; vec3_t front[64], back[64]; int f, b; float dist[64]; float frac; glpoly_t *poly; float s, t; if (numverts > 60) Sys_Error ("numverts = %i", numverts); BoundPoly (numverts, verts, mins, maxs); for (i=0 ; i<3 ; i++) { m = (mins[i] + maxs[i]) * 0.5; m = gl_subdivide_size.value * floor (m/gl_subdivide_size.value + 0.5); if (maxs[i] - m < 8) continue; if (m - mins[i] < 8) continue; // cut it v = verts + i; for (j=0 ; j<numverts ; j++, v+= 3) dist[j] = *v - m; // wrap cases dist[j] = dist[0]; v-=i; VectorCopy (verts, v); f = b = 0; v = verts; for (j=0 ; j<numverts ; j++, v+= 3) { if (dist[j] >= 0) { VectorCopy (v, front[f]); f++; } if (dist[j] <= 0) { VectorCopy (v, back[b]); b++; } if (dist[j] == 0 || dist[j+1] == 0) continue; if ( (dist[j] > 0) != (dist[j+1] > 0) ) { // clip point frac = dist[j] / (dist[j] - dist[j+1]); for (k=0 ; k<3 ; k++) front[f][k] = back[b][k] = v[k] + frac*(v[3+k] - v[k]); f++; b++; } } SubdividePolygon (f, front[0]); SubdividePolygon (b, back[0]); return; } poly = (glpoly_t*) Hunk_Alloc (sizeof(glpoly_t) + (numverts-4) * VERTEXSIZE*sizeof(float)); poly->next = warpface->polys; warpface->polys = poly; poly->numverts = numverts; for (i=0 ; i<numverts ; i++, verts+= 3) { VectorCopy (verts, poly->verts[i]); s = DotProduct (verts, warpface->texinfo->vecs[0]); t = DotProduct (verts, warpface->texinfo->vecs[1]); poly->verts[i][3] = s; poly->verts[i][4] = t; } }