ref: 42681cb8ee1bab11448ddda478f5791b6b7699e9
dir: /r_edge.c/
#include <u.h> #include <libc.h> #include "dat.h" #include "quakedef.h" #include "fns.h" /* FIXME the complex cases add new polys on most lines, so dont optimize for keeping them the same have multiple free span lists to try to get better coherence? low depth complexity -- 1 to 3 or so this breaks spans at every edge, even hidden ones (bad) have a sentinal at both ends? */ edge_t *auxedges; edge_t *r_edges, *edge_p, *edge_max; surf_t *surfaces, *surface_p, *surf_max; // surfaces are generated in back to front order by the bsp, so if a surf // pointer is greater than another one, it should be drawn in front // surfaces[1] is the background, and is used as the active surface stack edge_t *newedges[MAXHEIGHT]; edge_t *removeedges[MAXHEIGHT]; espan_t *span_p, *max_span_p; int r_currentkey; extern int screenwidth; int current_iv; int edge_head_u_shift20, edge_tail_u_shift20; static void (*pdrawfunc)(void); edge_t edge_head; edge_t edge_tail; edge_t edge_aftertail; edge_t edge_sentinel; float fv; void R_GenerateSpans (void); void R_GenerateSpansBackward (void); void R_LeadingEdge (edge_t *edge); void R_LeadingEdgeBackwards (edge_t *edge); void R_TrailingEdge (surf_t *surf, edge_t *edge); //============================================================================= /* ============== R_DrawCulledPolys ============== */ void R_DrawCulledPolys (void) { surf_t *s; msurface_t *pface; currententity = &cl_entities[0]; if (r_worldpolysbacktofront) { for (s=surface_p-1 ; s>&surfaces[1] ; s--) { if (!s->spans) continue; if (!(s->flags & SURF_DRAWBACKGROUND)) { pface = (msurface_t *)s->data; R_RenderPoly (pface, 15); } } } else { for (s = &surfaces[1] ; s<surface_p ; s++) { if (!s->spans) continue; if (!(s->flags & SURF_DRAWBACKGROUND)) { pface = (msurface_t *)s->data; R_RenderPoly (pface, 15); } } } } /* ============== R_BeginEdgeFrame ============== */ void R_BeginEdgeFrame (void) { int v; edge_p = r_edges; edge_max = &r_edges[r_numallocatededges]; surface_p = &surfaces[2]; // background is surface 1, // surface 0 is a dummy surfaces[1].spans = nil; // no background spans yet surfaces[1].flags = SURF_DRAWBACKGROUND; // put the background behind everything in the world if (r_draworder.value) { pdrawfunc = R_GenerateSpansBackward; surfaces[1].key = 0; r_currentkey = 1; } else { pdrawfunc = R_GenerateSpans; surfaces[1].key = 0x7FFFFFFF; r_currentkey = 0; } // FIXME: set with memset for (v=r_refdef.vrect.y ; v<r_refdef.vrectbottom ; v++) { newedges[v] = removeedges[v] = nil; } } /* ============== R_InsertNewEdges Adds the edges in the linked list edgestoadd, adding them to the edges in the linked list edgelist. edgestoadd is assumed to be sorted on u, and non-empty (this is actually newedges[v]). edgelist is assumed to be sorted on u, with a sentinel at the end (actually, this is the active edge table starting at edge_head.next). ============== */ void R_InsertNewEdges (edge_t *edgestoadd, edge_t *edgelist) { edge_t *next_edge; do { next_edge = edgestoadd->next; edgesearch: if (edgelist->u >= edgestoadd->u) goto addedge; edgelist=edgelist->next; if (edgelist->u >= edgestoadd->u) goto addedge; edgelist=edgelist->next; if (edgelist->u >= edgestoadd->u) goto addedge; edgelist=edgelist->next; if (edgelist->u >= edgestoadd->u) goto addedge; edgelist=edgelist->next; goto edgesearch; // insert edgestoadd before edgelist addedge: edgestoadd->next = edgelist; edgestoadd->prev = edgelist->prev; edgelist->prev->next = edgestoadd; edgelist->prev = edgestoadd; } while ((edgestoadd = next_edge) != nil); } /* ============== R_RemoveEdges ============== */ void R_RemoveEdges (edge_t *pedge) { do { pedge->next->prev = pedge->prev; pedge->prev->next = pedge->next; } while ((pedge = pedge->nextremove) != nil); } /* ============== R_StepActiveU ============== */ void R_StepActiveU (edge_t *pedge) { edge_t *pnext_edge, *pwedge; while (1) { nextedge: pedge->u += pedge->u_step; if (pedge->u < pedge->prev->u) goto pushback; pedge = pedge->next; pedge->u += pedge->u_step; if (pedge->u < pedge->prev->u) goto pushback; pedge = pedge->next; pedge->u += pedge->u_step; if (pedge->u < pedge->prev->u) goto pushback; pedge = pedge->next; pedge->u += pedge->u_step; if (pedge->u < pedge->prev->u) goto pushback; pedge = pedge->next; goto nextedge; pushback: if (pedge == &edge_aftertail) return; // push it back to keep it sorted pnext_edge = pedge->next; // pull the edge out of the edge list pedge->next->prev = pedge->prev; pedge->prev->next = pedge->next; // find out where the edge goes in the edge list pwedge = pedge->prev->prev; while (pwedge->u > pedge->u) { pwedge = pwedge->prev; } // put the edge back into the edge list pedge->next = pwedge->next; pedge->prev = pwedge; pedge->next->prev = pedge; pwedge->next = pedge; pedge = pnext_edge; if (pedge == &edge_tail) return; } } /* ============== R_CleanupSpan ============== */ void R_CleanupSpan (void) { surf_t *surf; int iu; espan_t *span; // now that we've reached the right edge of the screen, we're done with any // unfinished surfaces, so emit a span for whatever's on top surf = surfaces[1].next; iu = edge_tail_u_shift20; if (iu > surf->last_u) { span = span_p++; span->u = surf->last_u; span->count = iu - span->u; span->v = current_iv; span->pnext = surf->spans; surf->spans = span; } // reset spanstate for all surfaces in the surface stack do { surf->spanstate = 0; surf = surf->next; } while (surf != &surfaces[1]); } /* ============== R_LeadingEdgeBackwards ============== */ void R_LeadingEdgeBackwards (edge_t *edge) { espan_t *span; surf_t *surf, *surf2; int iu; // it's adding a new surface in, so find the correct place surf = &surfaces[edge->surfs[1]]; // don't start a span if this is an inverted span, with the end // edge preceding the start edge (that is, we've already seen the // end edge) if (++surf->spanstate == 1) { surf2 = surfaces[1].next; if (surf->key > surf2->key) goto newtop; // if it's two surfaces on the same plane, the one that's already // active is in front, so keep going unless it's a bmodel if (surf->insubmodel && (surf->key == surf2->key)) { // must be two bmodels in the same leaf; don't care, because they'll // never be farthest anyway goto newtop; } continue_search: do { surf2 = surf2->next; } while (surf->key < surf2->key); if (surf->key == surf2->key) { // if it's two surfaces on the same plane, the one that's already // active is in front, so keep going unless it's a bmodel if (!surf->insubmodel) goto continue_search; // must be two bmodels in the same leaf; don't care which is really // in front, because they'll never be farthest anyway } goto gotposition; newtop: // emit a span (obscures current top) iu = edge->u >> 20; if (iu > surf2->last_u) { span = span_p++; span->u = surf2->last_u; span->count = iu - span->u; span->v = current_iv; span->pnext = surf2->spans; surf2->spans = span; } // set last_u on the new span surf->last_u = iu; gotposition: // insert before surf2 surf->next = surf2; surf->prev = surf2->prev; surf2->prev->next = surf; surf2->prev = surf; } } /* ============== R_TrailingEdge ============== */ void R_TrailingEdge (surf_t *surf, edge_t *edge) { espan_t *span; int iu; // don't generate a span if this is an inverted span, with the end // edge preceding the start edge (that is, we haven't seen the // start edge yet) if (--surf->spanstate == 0) { if (surf->insubmodel) r_bmodelactive--; if (surf == surfaces[1].next) { // emit a span (current top going away) iu = edge->u >> 20; if (iu > surf->last_u) { span = span_p++; span->u = surf->last_u; span->count = iu - span->u; span->v = current_iv; span->pnext = surf->spans; surf->spans = span; } // set last_u on the surface below surf->next->last_u = iu; } surf->prev->next = surf->next; surf->next->prev = surf->prev; } } /* ============== R_LeadingEdge ============== */ void R_LeadingEdge (edge_t *edge) { espan_t *span; surf_t *surf, *surf2; int iu; double fu, newzi, testzi, newzitop, newzibottom; if (edge->surfs[1]) { // it's adding a new surface in, so find the correct place surf = &surfaces[edge->surfs[1]]; // don't start a span if this is an inverted span, with the end // edge preceding the start edge (that is, we've already seen the // end edge) if (++surf->spanstate == 1) { if (surf->insubmodel) r_bmodelactive++; surf2 = surfaces[1].next; if (surf->key < surf2->key) goto newtop; // if it's two surfaces on the same plane, the one that's already // active is in front, so keep going unless it's a bmodel if (surf->insubmodel && (surf->key == surf2->key)) { // must be two bmodels in the same leaf; sort on 1/z fu = (float)(edge->u - 0xFFFFF) * (1.0 / 0x100000); newzi = surf->d_ziorigin + fv*surf->d_zistepv + fu*surf->d_zistepu; newzibottom = newzi * 0.99; testzi = surf2->d_ziorigin + fv*surf2->d_zistepv + fu*surf2->d_zistepu; if (newzibottom >= testzi) { goto newtop; } newzitop = newzi * 1.01; if (newzitop >= testzi) { if (surf->d_zistepu >= surf2->d_zistepu) { goto newtop; } } } continue_search: do { surf2 = surf2->next; } while (surf->key > surf2->key); if (surf->key == surf2->key) { // if it's two surfaces on the same plane, the one that's already // active is in front, so keep going unless it's a bmodel if (!surf->insubmodel) goto continue_search; // must be two bmodels in the same leaf; sort on 1/z fu = (float)(edge->u - 0xFFFFF) * (1.0 / 0x100000); newzi = surf->d_ziorigin + fv*surf->d_zistepv + fu*surf->d_zistepu; newzibottom = newzi * 0.99; testzi = surf2->d_ziorigin + fv*surf2->d_zistepv + fu*surf2->d_zistepu; if (newzibottom >= testzi) { goto gotposition; } newzitop = newzi * 1.01; if (newzitop >= testzi) { if (surf->d_zistepu >= surf2->d_zistepu) { goto gotposition; } } goto continue_search; } goto gotposition; newtop: // emit a span (obscures current top) iu = edge->u >> 20; if (iu > surf2->last_u) { span = span_p++; span->u = surf2->last_u; span->count = iu - span->u; span->v = current_iv; span->pnext = surf2->spans; surf2->spans = span; } // set last_u on the new span surf->last_u = iu; gotposition: // insert before surf2 surf->next = surf2; surf->prev = surf2->prev; surf2->prev->next = surf; surf2->prev = surf; } } } /* ============== R_GenerateSpans ============== */ void R_GenerateSpans (void) { edge_t *edge; surf_t *surf; r_bmodelactive = 0; // clear active surfaces to just the background surface surfaces[1].next = surfaces[1].prev = &surfaces[1]; surfaces[1].last_u = edge_head_u_shift20; // generate spans for (edge=edge_head.next ; edge != &edge_tail; edge=edge->next) { if (edge->surfs[0]) { // it has a left surface, so a surface is going away for this span surf = &surfaces[edge->surfs[0]]; R_TrailingEdge (surf, edge); if (!edge->surfs[1]) continue; } R_LeadingEdge (edge); } R_CleanupSpan (); } /* ============== R_GenerateSpansBackward ============== */ void R_GenerateSpansBackward (void) { edge_t *edge; r_bmodelactive = 0; // clear active surfaces to just the background surface surfaces[1].next = surfaces[1].prev = &surfaces[1]; surfaces[1].last_u = edge_head_u_shift20; // generate spans for (edge=edge_head.next ; edge != &edge_tail; edge=edge->next) { if (edge->surfs[0]) R_TrailingEdge (&surfaces[edge->surfs[0]], edge); if (edge->surfs[1]) R_LeadingEdgeBackwards (edge); } R_CleanupSpan (); } /* ============== R_ScanEdges Input: newedges[] array this has links to edges, which have links to surfaces Output: Each surface has a linked list of its visible spans ============== */ void R_ScanEdges (void) { int iv, bottom; byte basespans[MAXSPANS*sizeof(espan_t)+CACHE_SIZE]; espan_t *basespan_p; surf_t *s; basespan_p = (espan_t *) ((uintptr)(basespans + CACHE_SIZE - 1) & ~(CACHE_SIZE - 1)); max_span_p = &basespan_p[MAXSPANS - r_refdef.vrect.width]; span_p = basespan_p; // clear active edges to just the background edges around the whole screen // FIXME: most of this only needs to be set up once edge_head.u = r_refdef.vrect.x << 20; edge_head_u_shift20 = edge_head.u >> 20; edge_head.u_step = 0; edge_head.prev = nil; edge_head.next = &edge_tail; edge_head.surfs[0] = 0; edge_head.surfs[1] = 1; edge_tail.u = (r_refdef.vrectright << 20) + 0xFFFFF; edge_tail_u_shift20 = edge_tail.u >> 20; edge_tail.u_step = 0; edge_tail.prev = &edge_head; edge_tail.next = &edge_aftertail; edge_tail.surfs[0] = 1; edge_tail.surfs[1] = 0; edge_aftertail.u = -1; // force a move edge_aftertail.u_step = 0; edge_aftertail.next = &edge_sentinel; edge_aftertail.prev = &edge_tail; // FIXME: do we need this now that we clamp x in r_draw.c? edge_sentinel.u = 2000 << 24; // make sure nothing sorts past this edge_sentinel.prev = &edge_aftertail; // // process all scan lines // bottom = r_refdef.vrectbottom - 1; for (iv=r_refdef.vrect.y ; iv<bottom ; iv++) { current_iv = iv; fv = (float)iv; // mark that the head (background start) span is pre-included surfaces[1].spanstate = 1; if (newedges[iv]) { R_InsertNewEdges (newedges[iv], edge_head.next); } (*pdrawfunc) (); // flush the span list if we can't be sure we have enough spans left for // the next scan if (span_p >= max_span_p) { if (r_drawculledpolys) { R_DrawCulledPolys (); } else { D_DrawSurfaces (); } // clear the surface span pointers for (s = &surfaces[1] ; s<surface_p ; s++) s->spans = nil; span_p = basespan_p; } if (removeedges[iv]) R_RemoveEdges (removeedges[iv]); if (edge_head.next != &edge_tail) R_StepActiveU (edge_head.next); } // do the last scan (no need to step or sort or remove on the last scan) current_iv = iv; fv = (float)iv; // mark that the head (background start) span is pre-included surfaces[1].spanstate = 1; if (newedges[iv]) R_InsertNewEdges (newedges[iv], edge_head.next); (*pdrawfunc) (); // draw whatever's left in the span list if (r_drawculledpolys) R_DrawCulledPolys (); else D_DrawSurfaces (); }