Returns the number of points to rotate, plus the actual numbers of the points are returned in the "n" array
| 2283 | // Returns the number of points to rotate, plus the actual numbers of the points |
| 2284 | // are returned in the "n" array |
| 2285 | int BuildEdgeLists(int *n, int tlist_index) { |
| 2286 | int lod, simplemul; |
| 2287 | int t, k; |
| 2288 | int smul_x, smul_z; // for tracing the very edge of the terrain |
| 2289 | |
| 2290 | // Now match up all edges of the differing levels of detail |
| 2291 | int cx, cz; |
| 2292 | int transcount; |
| 2293 | int offset; |
| 2294 | int maplod; |
| 2295 | int start = 0; |
| 2296 | int seg; |
| 2297 | int answer; |
| 2298 | int edgecount = 0; |
| 2299 | int edge1, edge2; |
| 2300 | float delta, cury; |
| 2301 | int max_edge_size = 1 << (MAX_TERRAIN_LOD - 1); |
| 2302 | |
| 2303 | t = Terrain_list[tlist_index].segment; |
| 2304 | lod = Terrain_list[tlist_index].lod; |
| 2305 | simplemul = 1 << ((MAX_TERRAIN_LOD - 1) - lod); |
| 2306 | ASSERT(simplemul <= max_edge_size); |
| 2307 | cx = t % TERRAIN_WIDTH; |
| 2308 | cz = t / TERRAIN_WIDTH; |
| 2309 | if (cx == TERRAIN_WIDTH - simplemul) { |
| 2310 | if (lod == MAX_TERRAIN_LOD - 1) |
| 2311 | return 0; |
| 2312 | |
| 2313 | smul_x = simplemul - 1; |
| 2314 | } else |
| 2315 | smul_x = simplemul; |
| 2316 | if (cz == TERRAIN_DEPTH - simplemul) { |
| 2317 | if (lod == MAX_TERRAIN_LOD - 1) |
| 2318 | return 0; |
| 2319 | |
| 2320 | smul_z = simplemul - 1; |
| 2321 | } else |
| 2322 | smul_z = simplemul; |
| 2323 | if (lod != MAX_TERRAIN_LOD - 1) { |
| 2324 | // Bottom edge |
| 2325 | // | | |
| 2326 | // 2-------1 |
| 2327 | |
| 2328 | Terrain_list[tlist_index].bottom_edge = 0; |
| 2329 | Terrain_list[tlist_index].bottom_count = 0; |
| 2330 | transcount = 0; |
| 2331 | if (cz != 0) { |
| 2332 | edge1 = t + smul_x; |
| 2333 | edge2 = t; |
| 2334 | delta = (Terrain_seg[edge2].mody - Terrain_seg[edge1].mody) / smul_x; |
| 2335 | cury = Terrain_seg[edge1].mody; |
| 2336 | |
| 2337 | offset = ((cz - 1) * TERRAIN_WIDTH) + cx + smul_x; |
| 2338 | for (k = 0; k < smul_x; k++, cury += delta) { |
| 2339 | maplod = TerrainJoinMap[offset - k]; |
| 2340 | answer = TerrainEdgeTest[maplod][k + simplemul - smul_x]; |
| 2341 | if (answer || k == 0) { |
| 2342 | seg = t + smul_x - k; |