//projects a point void g3_project_point(g3s_point *p) { #ifndef __powerc fix tx,ty; if (p->p3_flags & PF_PROJECTED || p->p3_codes & CC_BEHIND) return; if (checkmuldiv(&tx,p->p3_x,Canv_w2,p->p3_z) && checkmuldiv(&ty,p->p3_y,Canv_h2,p->p3_z)) { p->p3_sx = Canv_w2 + tx; p->p3_sy = Canv_h2 - ty; p->p3_flags |= PF_PROJECTED; } else p->p3_flags |= PF_OVERFLOW; #else double fz; if ((p->p3_flags & PF_PROJECTED) || (p->p3_codes & CC_BEHIND)) return; if ( p->p3_z <= 0 ) { p->p3_flags |= PF_OVERFLOW; return; } fz = f2fl(p->p3_z); p->p3_sx = fl2f(fCanv_w2 + (f2fl(p->p3_x)*fCanv_w2 / fz)); p->p3_sy = fl2f(fCanv_h2 - (f2fl(p->p3_y)*fCanv_h2 / fz)); p->p3_flags |= PF_PROJECTED; #endif }
//draws a bitmap with the specified 3d width & height //returns 1 if off screen, 0 if drew void g3_draw_bitmap(const vms_vector &pos,fix width,fix height,grs_bitmap &bm) { g3s_point pnt; fix w,h; if (g3_rotate_point(pnt,pos) & CC_BEHIND) return; g3_project_point(pnt); if (pnt.p3_flags & PF_OVERFLOW) return; #ifndef __powerc fix t; if (checkmuldiv(&t,width,Canv_w2,pnt.p3_z)) w = fixmul(t,Matrix_scale.x); else return; if (checkmuldiv(&t,height,Canv_h2,pnt.p3_z)) h = fixmul(t,Matrix_scale.y); else return; #else if (pnt.p3_z == 0) return; double fz = f2fl(pnt.p3_z); w = fixmul(fl2f(((f2fl(width)*fCanv_w2) / fz)), Matrix_scale.x); h = fixmul(fl2f(((f2fl(height)*fCanv_h2) / fz)), Matrix_scale.y); #endif const fix blob0y = pnt.p3_sy - h, blob1x = pnt.p3_sx + w; const array<grs_point, 3> blob_vertices{{ {pnt.p3_sx - w, blob0y}, {blob1x, blob0y}, {blob1x, pnt.p3_sy + h}, }}; scale_bitmap(bm, blob_vertices, 0); }
//draw a sortof sphere - i.e., the 2d radius is proportional to the 3d //radius, but not to the distance from the eye int g3_draw_sphere(g3s_point *pnt,fix rad) { if (! (pnt->p3_codes & CC_BEHIND)) { if (! (pnt->p3_flags & PF_PROJECTED)) g3_project_point(pnt); if (! (pnt->p3_codes & PF_OVERFLOW)) { fix r2,t; r2 = fixmul(rad,Matrix_scale.x); #ifndef __powerc if (checkmuldiv(&t,r2,Canv_w2,pnt->p3_z)) return gr_disk(pnt->p3_sx,pnt->p3_sy,t); #else if (pnt->p3_z == 0) return 0; return gr_disk(pnt->p3_sx, pnt->p3_sy, fl2f(((f2fl(r2) * fCanv_w2) / f2fl(pnt->p3_z)))); #endif } } return 0; }
//draws a bitmap with the specified 3d width & height //returns 1 if off screen, 0 if drew bool g3_draw_bitmap(vms_vector *pos,fix width,fix height,grs_bitmap *bm) { #ifndef __powerc g3s_point pnt; fix t,w,h; if (g3_rotate_point(&pnt,pos) & CC_BEHIND) return 1; g3_project_point(&pnt); if (pnt.p3_flags & PF_OVERFLOW) return 1; if (checkmuldiv(&t,width,Canv_w2,pnt.p3_z)) w = fixmul(t,Matrix_scale.x); else return 1; if (checkmuldiv(&t,height,Canv_h2,pnt.p3_z)) h = fixmul(t,Matrix_scale.y); else return 1; blob_vertices[0].x = pnt.p3_sx - w; blob_vertices[0].y = blob_vertices[1].y = pnt.p3_sy - h; blob_vertices[1].x = blob_vertices[2].x = pnt.p3_sx + w; blob_vertices[2].y = pnt.p3_sy + h; scale_bitmap(bm,blob_vertices,0); return 0; #else g3s_point pnt; fix w,h; double fz; if (g3_rotate_point(&pnt,pos) & CC_BEHIND) return 1; g3_project_point(&pnt); if (pnt.p3_flags & PF_OVERFLOW) return 1; if (pnt.p3_z == 0) return 1; fz = f2fl(pnt.p3_z); w = fixmul(fl2f(((f2fl(width)*fCanv_w2) / fz)), Matrix_scale.x); h = fixmul(fl2f(((f2fl(height)*fCanv_h2) / fz)), Matrix_scale.y); blob_vertices[0].x = pnt.p3_sx - w; blob_vertices[0].y = blob_vertices[1].y = pnt.p3_sy - h; blob_vertices[1].x = blob_vertices[2].x = pnt.p3_sx + w; blob_vertices[2].y = pnt.p3_sy + h; scale_bitmap(bm, blob_vertices, 0); return 0; #endif }