// This file renders vertex buffers, converts raw meshes // to GL meshes, and manages threads that do the raw-mesh // building (found in cave_mesher.c) // This got lost somewhere // Q: How accurate is this as a Minecraft viewer? // // A: Not very. Many Minecraft blocks are not handled correctly: // // No signs, doors, redstone, rails, carpets, or other "flat" blocks // Only one wood type // Colored glass becomes regular glass // Glass panes become glass blocks // Stairs are turned into ramps // Upper slabs turn into lower slabs // Water level is incorrect // No biome coloration // Cactus is not shrunk, shows holes // Chests are not shrunk // Chests, pumpkins, etc. are not rotated properly // Torches do not attach to walls // Incorrect textures for blocks that postdate terrain.png // Transparent textures have black fringes due to non-premultiplied-alpha // If a 32x32x256 "quad-chunk" needs more than 300K quads, isn't handled // Only blocks at y=1..255 are shown (not y=0) // // Some of these are due to engine limitations, and some of // these are because I didn't make the effort since my // goal was to make a demo for stb_voxel_render.h, not // to make a proper Minecraft viewer. // // // Q: Could this be turned into a proper Minecraft viewer? // // A: Yes and no. Yes, you could do it, but no, it wouldn't // really resemble this code that much anymore. // // You could certainly use this engine to // render the parts of Minecraft it works for, but many // of the things it doesn't handle it can't handle at all // (stairs, water, fences, carpets, etc) because it uses // low-precision coordinates to store voxel data. // // You would have to render all of the stuff it doesn't // handle through another rendering path. In a game (not // a viewer) you would need such a path for movable entities // like doors and carts anyway, so possibly handling other // things that way wouldn't be so bad. // // Rails, ladders, and redstone lines could be implemented by // using tex2 to overlay those effects, but you can't rotate // tex1 and tex2 independently, so you'd have to have a // separate texture for each orientation of rail, etc, and // you'd need special rendering for rail up/down sections. // // You can use the face-color effect to do biome coloration, // but the change won't be smooth the way it is in Minecraft. // // // Q: Why isn't building the mesh data faster? // // A: Partly because converting from minecraft data is expensive. // // Here is the approximate breakdown of an older version // of this executable and lib that did the building single-threaded, // and was a bit slower at building mesh data. // // 25% loading & parsing minecraft files (4/5ths of this is zlib) // 18% converting from minecraft blockids & lighting to stb blockids & lighting // 10% reordering from data[z][y][x] (minecraft-style) to data[y][x][z] (stb-style) // 40% building mesh data // 7% uploading mesh data to OpenGL // // I did do significant optimizations after the above, so the // final breakdown is different, but it should give you some // sense of the costs. #include "stb_voxel_render.h" #define STB_GLEXT_DECLARE "glext_list.h" #include "stb_gl.h" #include "stb_image.h" #include "stb_glprog.h" #include "caveview.h" #include "cave_parse.h" #include "stb.h" #include "sdl.h" #include "sdl_thread.h" #include #include // currently no dynamic way to set mesh cache size or view distance //#define SHORTVIEW stbvox_mesh_maker g_mesh_maker; GLuint main_prog; GLint uniform_locations[64]; //#define MAX_QUADS_PER_DRAW (65536 / 4) // assuming 16-bit indices, 4 verts per quad //#define FIXED_INDEX_BUFFER_SIZE (MAX_QUADS_PER_DRAW * 6 * 2) // 16*1024 * 12 == ~192KB // while uploading texture data, this holds our each texture #define TEX_SIZE 64 uint32 texture[TEX_SIZE][TEX_SIZE]; GLuint voxel_tex[2]; // chunk state enum { STATE_invalid, STATE_needed, STATE_requested, STATE_abandoned, STATE_valid, }; // mesh is 32x32x255 ... this is hardcoded in that // a mesh covers 2x2 minecraft chunks, no #defines for it typedef struct { int state; int chunk_x, chunk_y; int num_quads; float priority; int vbuf_size, fbuf_size; float transform[3][3]; float bounds[2][3]; GLuint vbuf;// vbuf_tex; GLuint fbuf, fbuf_tex; } chunk_mesh; void scale_texture(unsigned char *src, int x, int y, int w, int h) { int i,j,k; assert(w == 256 && h == 256); for (j=0; j < TEX_SIZE; ++j) { for (i=0; i < TEX_SIZE; ++i) { uint32 val=0; for (k=0; k < 4; ++k) { val >>= 8; val += src[ 4*(x+(i>>2)) + 4*w*(y+(j>>2)) + k]<<24; } texture[j][i] = val; } } } void build_base_texture(int n) { int x,y; uint32 color = stb_rand() | 0x808080; for (y=0; ystate == STATE_valid) { glDeleteTextures(1, &cm->fbuf_tex); glDeleteBuffersARB(1, &cm->vbuf); glDeleteBuffersARB(1, &cm->fbuf); cached_chunk_mesh[slot_y][slot_x].state = STATE_invalid; } } void upload_mesh(chunk_mesh *cm, uint8 *build_buffer, uint8 *face_buffer) { glGenBuffersARB(1, &cm->vbuf); glBindBufferARB(GL_ARRAY_BUFFER_ARB, cm->vbuf); glBufferDataARB(GL_ARRAY_BUFFER_ARB, cm->num_quads*4*sizeof(uint32), build_buffer, GL_STATIC_DRAW_ARB); glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0); glGenBuffersARB(1, &cm->fbuf); glBindBufferARB(GL_TEXTURE_BUFFER_ARB, cm->fbuf); glBufferDataARB(GL_TEXTURE_BUFFER_ARB, cm->num_quads*sizeof(uint32), face_buffer , GL_STATIC_DRAW_ARB); glBindBufferARB(GL_TEXTURE_BUFFER_ARB, 0); glGenTextures(1, &cm->fbuf_tex); glBindTexture(GL_TEXTURE_BUFFER_ARB, cm->fbuf_tex); glTexBufferARB(GL_TEXTURE_BUFFER_ARB, GL_RGBA8UI, cm->fbuf); glBindTexture(GL_TEXTURE_BUFFER_ARB, 0); } static void upload_mesh_data(raw_mesh *rm) { int cx = rm->cx; int cy = rm->cy; int slot_x = (cx >> 1) & (CACHED_MESH_NUM_X-1); int slot_y = (cy >> 1) & (CACHED_MESH_NUM_Y-1); chunk_mesh *cm; free_chunk(slot_x, slot_y); cm = &cached_chunk_mesh[slot_y][slot_x]; cm->num_quads = rm->num_quads; upload_mesh(cm, rm->build_buffer, rm->face_buffer); cm->vbuf_size = rm->num_quads*4*sizeof(uint32); cm->fbuf_size = rm->num_quads*sizeof(uint32); cm->priority = 100000; cm->chunk_x = cx; cm->chunk_y = cy; memcpy(cm->bounds, rm->bounds, sizeof(cm->bounds)); memcpy(cm->transform, rm->transform, sizeof(cm->transform)); // write barrier here cm->state = STATE_valid; } GLint uniform_loc[16]; float table3[128][3]; GLint tablei[2]; void setup_uniforms(float pos[3]) { int i,j; for (i=0; i < STBVOX_UNIFORM_count; ++i) { stbvox_uniform_info *ui = stbvox_get_uniform_info(&g_mesh_maker, i); uniform_loc[i] = -1; if (i == STBVOX_UNIFORM_texscale || i == STBVOX_UNIFORM_texgen || i == STBVOX_UNIFORM_color_table) continue; if (ui) { void *data = ui->default_value; uniform_loc[i] = stbgl_find_uniform(main_prog, ui->name); switch (i) { case STBVOX_UNIFORM_face_data: tablei[0] = 2; data = tablei; break; case STBVOX_UNIFORM_tex_array: glActiveTextureARB(GL_TEXTURE0_ARB); glBindTexture(GL_TEXTURE_2D_ARRAY_EXT, voxel_tex[0]); glActiveTextureARB(GL_TEXTURE1_ARB); glBindTexture(GL_TEXTURE_2D_ARRAY_EXT, voxel_tex[1]); glActiveTextureARB(GL_TEXTURE0_ARB); tablei[0] = 0; tablei[1] = 1; data = tablei; break; case STBVOX_UNIFORM_color_table: data = ui->default_value; ((float *)data)[63*4+3] = 1.0f; // emissive break; case STBVOX_UNIFORM_camera_pos: data = table3[0]; table3[0][0] = pos[0]; table3[0][1] = pos[1]; table3[0][2] = pos[2]; break; case STBVOX_UNIFORM_ambient: { float amb[3][3]; // ambient direction is sky-colored upwards // "ambient" lighting is from above table3[0][0] = 0.3f; table3[0][1] = -0.5f; table3[0][2] = 0.9f; amb[1][0] = 0.3f; amb[1][1] = 0.3f; amb[1][2] = 0.3f; // dark-grey amb[2][0] = 1.0; amb[2][1] = 1.0; amb[2][2] = 1.0; // white // convert so (table[1]*dot+table[2]) gives // above interpolation // lerp((dot+1)/2, amb[1], amb[2]) // amb[1] + (amb[2] - amb[1]) * (dot+1)/2 // amb[1] + (amb[2] - amb[1]) * dot/2 + (amb[2]-amb[1])/2 for (j=0; j < 3; ++j) { table3[1][j] = (amb[2][j] - amb[1][j])/2; table3[2][j] = (amb[1][j] + amb[2][j])/2; } // fog color table3[3][0] = 0.6f, table3[3][1] = 0.7f, table3[3][2] = 0.9f; // fog distance //table3[3][3] = 1200; data = table3; break; } } switch (ui->type) { case STBVOX_UNIFORM_TYPE_sampler: stbglUniform1iv(uniform_loc[i], ui->array_length, data); break; case STBVOX_UNIFORM_TYPE_vec2: stbglUniform2fv(uniform_loc[i], ui->array_length, data); break; case STBVOX_UNIFORM_TYPE_vec3: stbglUniform3fv(uniform_loc[i], ui->array_length, data); break; case STBVOX_UNIFORM_TYPE_vec4: stbglUniform4fv(uniform_loc[i], ui->array_length, data); break; } } } } GLuint unitex[64], unibuf[64]; void make_texture_buffer_for_uniform(int uniform, int slot) { GLenum type; stbvox_uniform_info *ui = stbvox_get_uniform_info(&g_mesh_maker, uniform); GLint uloc = stbgl_find_uniform(main_prog, ui->name); if (uniform == STBVOX_UNIFORM_color_table) ((float *)ui->default_value)[63*4+3] = 1.0f; // emissive glGenBuffersARB(1, &unibuf[uniform]); glBindBufferARB(GL_ARRAY_BUFFER_ARB, unibuf[uniform]); glBufferDataARB(GL_ARRAY_BUFFER_ARB, ui->array_length * ui->bytes_per_element, ui->default_value, GL_STATIC_DRAW_ARB); glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0); glGenTextures(1, &unitex[uniform]); glBindTexture(GL_TEXTURE_BUFFER_ARB, unitex[uniform]); switch (ui->type) { case STBVOX_UNIFORM_TYPE_vec2: type = GL_RG32F; break; case STBVOX_UNIFORM_TYPE_vec3: type = GL_RGB32F; break; case STBVOX_UNIFORM_TYPE_vec4: type = GL_RGBA32F; break; default: assert(0); } glTexBufferARB(GL_TEXTURE_BUFFER_ARB, type, unibuf[uniform]); glBindTexture(GL_TEXTURE_BUFFER_ARB, 0); glActiveTextureARB(GL_TEXTURE0 + slot); glBindTexture(GL_TEXTURE_BUFFER_ARB, unitex[uniform]); glActiveTextureARB(GL_TEXTURE0); stbglUseProgram(main_prog); stbglUniform1i(uloc, slot); } #define MAX_MESH_WORKERS 8 #define MAX_CHUNK_LOAD_WORKERS 2 int num_mesh_workers; int num_chunk_load_workers; typedef struct { int state; int request_cx; int request_cy; int padding[13]; SDL_sem * request_received; SDL_sem * chunk_server_done_processing; int chunk_action; int chunk_request_x; int chunk_request_y; fast_chunk *chunks[4][4]; int padding2[16]; raw_mesh rm; int padding3[16]; uint8 *build_buffer; uint8 *face_buffer ; } mesh_worker; enum { WSTATE_idle, WSTATE_requested, WSTATE_running, WSTATE_mesh_ready, }; mesh_worker mesh_data[MAX_MESH_WORKERS]; int num_meshes_started; // stats int request_chunk(int chunk_x, int chunk_y); void update_meshes_from_render_thread(void); void render_init(void) { int i; char *binds[] = { "attr_vertex", "attr_face", NULL }; char vertex[5000]; int vertex_len; char fragment[5000]; int fragment_len; int w=0,h=0; unsigned char *texdata = stbi_load("terrain.png", &w, &h, NULL, 4); stbvox_init_mesh_maker(&g_mesh_maker); stbvox_config_use_gl(&g_mesh_maker, 1, 1, 1); for (i=0; i < num_mesh_workers; ++i) { stbvox_init_mesh_maker(&mesh_data[i].rm.mm); stbvox_config_use_gl(&mesh_data[i].rm.mm, 1,1,1); } vertex_len = stbvox_get_vertex_shader(&g_mesh_maker, vertex, sizeof(vertex)); fragment_len = stbvox_get_fragment_shader(&g_mesh_maker, fragment, sizeof(fragment)); if (vertex_len < 0) { ods("Vertex shader was too long!\n"); assert(0); exit(1); } if (fragment_len < 0) { ods("fragment shader was too long!\n"); assert(0); exit(1); } ods("Shader lengths: %d %d\n", vertex_len, fragment_len); { char error_buffer[1024]; char *main_vertex[] = { vertex, NULL }; char *main_fragment[] = { fragment, NULL }; main_prog = stbgl_create_program(main_vertex, main_fragment, binds, error_buffer, sizeof(error_buffer)); if (main_prog == 0) { ods("Compile error for main shader: %s\n", error_buffer); assert(0); exit(1); } } //init_index_buffer(); make_texture_buffer_for_uniform(STBVOX_UNIFORM_texscale , 3); make_texture_buffer_for_uniform(STBVOX_UNIFORM_texgen , 4); make_texture_buffer_for_uniform(STBVOX_UNIFORM_color_table , 5); glGenTextures(2, voxel_tex); glBindTexture(GL_TEXTURE_2D_ARRAY_EXT, voxel_tex[0]); glTexImage3DEXT(GL_TEXTURE_2D_ARRAY_EXT, 0, GL_RGBA, TEX_SIZE,TEX_SIZE,256, 0,GL_RGBA,GL_UNSIGNED_BYTE,NULL); for (i=0; i < 256; ++i) { if (texdata) scale_texture(texdata, (i&15)*w/16, (h/16)*(i>>4), w,h); else build_base_texture(i); glTexSubImage3DEXT(GL_TEXTURE_2D_ARRAY_EXT, 0, 0,0,i, TEX_SIZE,TEX_SIZE,1, GL_RGBA, GL_UNSIGNED_BYTE, texture[0]); } glTexParameteri(GL_TEXTURE_2D_ARRAY_EXT, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR); glTexParameteri(GL_TEXTURE_2D_ARRAY_EXT, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D_ARRAY_EXT, GL_TEXTURE_MAX_ANISOTROPY_EXT, 16); glGenerateMipmapEXT(GL_TEXTURE_2D_ARRAY_EXT); glBindTexture(GL_TEXTURE_2D_ARRAY_EXT, voxel_tex[1]); glTexImage3DEXT(GL_TEXTURE_2D_ARRAY_EXT, 0, GL_RGBA, TEX_SIZE,TEX_SIZE,128, 0,GL_RGBA,GL_UNSIGNED_BYTE,NULL); for (i=0; i < 128; ++i) { build_overlay_texture(i); glTexSubImage3DEXT(GL_TEXTURE_2D_ARRAY_EXT, 0, 0,0,i, TEX_SIZE,TEX_SIZE,1, GL_RGBA, GL_UNSIGNED_BYTE, texture[0]); } glTexParameteri(GL_TEXTURE_2D_ARRAY_EXT, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR); glTexParameteri(GL_TEXTURE_2D_ARRAY_EXT, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glGenerateMipmapEXT(GL_TEXTURE_2D_ARRAY_EXT); } // Timing stats while optimizing the single-threaded builder // 32..-32, 32..-32, !FILL_TERRAIN, !FANCY_LEAVES on 'mcrealm' data set // 6.27s - reblocked to do 16 z at a time instead of 256 (still using 66x66x258), 4 meshes in parallel // 5.96s - reblocked to use FAST_CHUNK (no intermediate data structure) // 5.45s - unknown change, or previous measurement was wrong // 6.12s - use preconverted data, not in-place // 5.91s - use preconverted, in-place // 5.34s - preconvert, in-place, avoid dependency chain (suggested by ryg) // 5.34s - preconvert, in-place, avoid dependency chain, use bit-table instead of byte-table // 5.50s - preconvert, in-place, branchless // 6.42s - non-preconvert, avoid dependency chain (not an error) // 5.40s - non-preconvert, w/dependency chain (same as earlier) // 5.50s - non-FAST_CHUNK, reblocked outer loop for better cache reuse // 4.73s - FAST_CHUNK non-preconvert, reblocked outer loop // 4.25s - preconvert, in-place, reblocked outer loop // 4.18s - preconvert, in-place, unrolled again // 4.10s - 34x34 1 mesh instead of 66x66 and 4 meshes (will make it easier to do multiple threads) // 4.83s - building bitmasks but not using them (2 bits per block, one if empty, one if solid) // 5.16s - using empty bitmasks to early out // 5.01s - using solid & empty bitmasks to early out - "foo" // 4.64s - empty bitmask only, test 8 at a time, then test geom // 4.72s - empty bitmask only, 8 at a time, then test bits // 4.46s - split bitmask building into three loops (each byte is separate) // 4.42s - further optimize computing bitmask // 4.58s - using solid & empty bitmasks to early out, same as "foo" but faster bitmask building // 4.12s - using solid & empty bitmasks to efficiently test neighbors // 4.04s - using 16-bit fetches (not endian-independent) // - note this is first place that beats previous best '4.10s - 34x34 1 mesh' // 4.30s - current time with bitmasks disabled again (note was 4.10s earlier) // 3.95s - bitmasks enabled again, no other changes // 4.00s - current time with bitmasks disabled again, no other changes -- wide variation that is time dependent? // (note that most of the numbers listed here are median of 3 values already) // 3.98s - bitmasks enabled // Bitmasks removed from the code as not worth the complexity increase void world_init(void) { int a,b,x,y; Uint64 start_time, end_time; #ifdef NDEBUG int range = 32; #else int range = 12; #endif start_time = SDL_GetPerformanceCounter(); // iterate in 8x8 clusters of qchunks at a time to get better converted-chunk-cache reuse // than a purely row-by-row ordering is (single-threaded this is a bigger win than // any of the above optimizations were, since it halves zlib/mc-conversion costs) for (x=-range; x <= range; x += 16) for (y=-range; y <= range; y += 16) for (b=y; b < y+16 && b <= range; b += 2) for (a=x; a < x+16 && a <= range; a += 2) while (!request_chunk(a, b)) { // if request fails, all threads are busy update_meshes_from_render_thread(); SDL_Delay(1); } // wait until all the workers are done, // (this is only needed if we want to time // when the build finishes, or when we want to reset the // cache size; otherwise we could just go ahead and // start rendering whatever we've got) for(;;) { int i; update_meshes_from_render_thread(); for (i=0; i < num_mesh_workers; ++i) if (mesh_data[i].state != WSTATE_idle) break; if (i == num_mesh_workers) break; SDL_Delay(3); } end_time = SDL_GetPerformanceCounter(); ods("Build time: %7.2fs\n", (end_time - start_time) / (float) SDL_GetPerformanceFrequency()); // don't waste lots of storage on chunk caches once it's finished starting-up; // this was only needed to be this large because we worked in large blocks // to maximize sharing reset_cache_size(32); } extern SDL_mutex * chunk_cache_mutex; int mesh_worker_handler(void *data) { mesh_worker *mw = data; mw->face_buffer = malloc(FACE_BUFFER_SIZE); mw->build_buffer = malloc(BUILD_BUFFER_SIZE); // this loop only works because the compiler can't // tell that the SDL_calls don't access mw->state; // really we should barrier that stuff for(;;) { int i,j; int cx,cy; // wait for a chunk request SDL_SemWait(mw->request_received); // analyze the chunk request assert(mw->state == WSTATE_requested); cx = mw->request_cx; cy = mw->request_cy; // this is inaccurate as it can block while another thread has the cache locked mw->state = WSTATE_running; // get the chunks we need (this takes a lock and caches them) for (j=0; j < 4; ++j) for (i=0; i < 4; ++i) mw->chunks[j][i] = get_converted_fastchunk(cx-1 + i, cy-1 + j); // build the mesh based on the chunks mw->rm.build_buffer = mw->build_buffer; mw->rm.face_buffer = mw->face_buffer; build_chunk(cx, cy, mw->chunks, &mw->rm); mw->state = WSTATE_mesh_ready; // don't need to notify of this, because it gets polled // when done, free the chunks // for efficiency we just take the mutex once around the whole thing, // though this spreads the mutex logic over two files SDL_LockMutex(chunk_cache_mutex); for (j=0; j < 4; ++j) for (i=0; i < 4; ++i) { deref_fastchunk(mw->chunks[j][i]); mw->chunks[j][i] = NULL; } SDL_UnlockMutex(chunk_cache_mutex); } return 0; } int request_chunk(int chunk_x, int chunk_y) { int i; for (i=0; i < num_mesh_workers; ++i) { mesh_worker *mw = &mesh_data[i]; if (mw->state == WSTATE_idle) { mw->request_cx = chunk_x; mw->request_cy = chunk_y; mw->state = WSTATE_requested; SDL_SemPost(mw->request_received); ++num_meshes_started; return 1; } } return 0; } void prepare_threads(void) { int i; int num_proc = SDL_GetCPUCount(); if (num_proc > 6) num_mesh_workers = num_proc/2; else if (num_proc > 4) num_mesh_workers = 4; else num_mesh_workers = num_proc-1; // @TODO // Thread usage is probably pretty terrible; need to make a // separate queue of needed chunks, instead of just generating // one request per thread per frame, and a separate queue of // results. (E.g. If it takes 1.5 frames to build mesh, thread // is idle for 0.5 frames.) To fake this for now, I've just // doubled the number of threads to let those serve as a 'queue', // but that's dumb. num_mesh_workers *= 2; // try to get better thread usage if (num_mesh_workers > MAX_MESH_WORKERS) num_mesh_workers = MAX_MESH_WORKERS; for (i=0; i < num_mesh_workers; ++i) { mesh_worker *data = &mesh_data[i]; data->request_received = SDL_CreateSemaphore(0); data->chunk_server_done_processing = SDL_CreateSemaphore(0); SDL_CreateThread(mesh_worker_handler, "mesh worker", data); } } // "better" buffer uploading #if 0 if (glBufferStorage) { glDeleteBuffersARB(1, &vb->vbuf); glGenBuffersARB(1, &vb->vbuf); glBindBufferARB(GL_ARRAY_BUFFER_ARB, vb->vbuf); glBufferStorage(GL_ARRAY_BUFFER_ARB, sizeof(build_buffer), build_buffer, 0); glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0); } else { glBindBufferARB(GL_ARRAY_BUFFER_ARB, vb->vbuf); glBufferDataARB(GL_ARRAY_BUFFER_ARB, sizeof(build_buffer), build_buffer, GL_STATIC_DRAW_ARB); glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0); } #endif typedef struct { float x,y,z,w; } plane; static plane frustum[6]; static void matd_mul(double out[4][4], double src1[4][4], double src2[4][4]) { int i,j,k; for (j=0; j < 4; ++j) { for (i=0; i < 4; ++i) { double t=0; for (k=0; k < 4; ++k) t += src1[k][i] * src2[j][k]; out[i][j] = t; } } } // https://fgiesen.wordpress.com/2012/08/31/frustum-planes-from-the-projection-matrix/ static void compute_frustum(void) { int i; GLdouble mv[4][4],proj[4][4], mvproj[4][4]; glGetDoublev(GL_MODELVIEW_MATRIX , mv[0]); glGetDoublev(GL_PROJECTION_MATRIX, proj[0]); matd_mul(mvproj, proj, mv); for (i=0; i < 4; ++i) { (&frustum[0].x)[i] = (float) (mvproj[3][i] + mvproj[0][i]); (&frustum[1].x)[i] = (float) (mvproj[3][i] - mvproj[0][i]); (&frustum[2].x)[i] = (float) (mvproj[3][i] + mvproj[1][i]); (&frustum[3].x)[i] = (float) (mvproj[3][i] - mvproj[1][i]); (&frustum[4].x)[i] = (float) (mvproj[3][i] + mvproj[2][i]); (&frustum[5].x)[i] = (float) (mvproj[3][i] - mvproj[2][i]); } } static int test_plane(plane *p, float x0, float y0, float z0, float x1, float y1, float z1) { // return false if the box is entirely behind the plane float d=0; assert(x0 <= x1 && y0 <= y1 && z0 <= z1); if (p->x > 0) d += x1*p->x; else d += x0*p->x; if (p->y > 0) d += y1*p->y; else d += y0*p->y; if (p->z > 0) d += z1*p->z; else d += z0*p->z; return d + p->w >= 0; } static int is_box_in_frustum(float *bmin, float *bmax) { int i; for (i=0; i < 5; ++i) if (!test_plane(&frustum[i], bmin[0], bmin[1], bmin[2], bmax[0], bmax[1], bmax[2])) return 0; return 1; } #ifdef SHORTVIEW int view_dist_in_chunks = 50; #else int view_dist_in_chunks = 80; #endif float compute_priority(int cx, int cy, float x, float y) { float distx, disty, dist2; distx = (cx*16+8) - x; disty = (cy*16+8) - y; dist2 = distx*distx + disty*disty; return view_dist_in_chunks*view_dist_in_chunks * 16 * 16 - dist2; } int chunk_locations, chunks_considered, chunks_in_frustum; int quads_considered, quads_rendered; int chunk_storage_rendered, chunk_storage_considered, chunk_storage_total; int update_frustum = 1; #ifdef SHORTVIEW int max_chunk_storage = 450 << 20; int min_chunk_storage = 350 << 20; #else int max_chunk_storage = 900 << 20; int min_chunk_storage = 800 << 20; #endif float min_priority = -500; // this really wants to be in unit space, not squared space int num_meshes_uploaded; void update_meshes_from_render_thread(void) { int i; for (i=0; i < num_mesh_workers; ++i) { mesh_worker *mw = &mesh_data[i]; if (mw->state == WSTATE_mesh_ready) { upload_mesh_data(&mw->rm); ++num_meshes_uploaded; mw->state = WSTATE_idle; } } } int num_threads_active; float chunk_server_activity; void render_caves(float campos[3]) { float x = campos[0], y = campos[1]; int qchunk_x, qchunk_y; int cam_x, cam_y; int i,j, rad; compute_frustum(); chunk_locations = chunks_considered = chunks_in_frustum = 0; quads_considered = quads_rendered = 0; chunk_storage_total = chunk_storage_considered = chunk_storage_rendered = 0; cam_x = (int) floor(x+0.5); cam_y = (int) floor(y+0.5); qchunk_x = (((int) floor(x)+16) >> 5) << 1; qchunk_y = (((int) floor(y)+16) >> 5) << 1; glEnable(GL_ALPHA_TEST); glAlphaFunc(GL_GREATER, 0.5); stbglUseProgram(main_prog); setup_uniforms(campos); // set uniforms to default values inefficiently glActiveTextureARB(GL_TEXTURE2_ARB); stbglEnableVertexAttribArray(0); num_meshes_uploaded = 0; update_meshes_from_render_thread(); // traverse all in-range chunks and analyze them for (j=-view_dist_in_chunks; j <= view_dist_in_chunks; j += 2) { for (i=-view_dist_in_chunks; i <= view_dist_in_chunks; i += 2) { float priority; int cx = qchunk_x + i; int cy = qchunk_y + j; priority = compute_priority(cx, cy, x, y); if (priority >= min_priority) { int slot_x = (cx>>1) & (CACHED_MESH_NUM_X-1); int slot_y = (cy>>1) & (CACHED_MESH_NUM_Y-1); chunk_mesh *cm = &cached_chunk_mesh[slot_y][slot_x]; ++chunk_locations; if (cm->state == STATE_valid && priority >= 0) { // check if chunk pos actually matches if (cm->chunk_x != cx || cm->chunk_y != cy) { // we have a stale chunk we need to recreate free_chunk(slot_x, slot_y); // it probably will have already gotten freed, but just in case } } if (cm->state == STATE_invalid) { cm->chunk_x = cx; cm->chunk_y = cy; cm->state = STATE_needed; } cm->priority = priority; } } } // draw front-to-back for (rad = 0; rad <= view_dist_in_chunks; rad += 2) { for (j=-rad; j <= rad; j += 2) { // if j is +- rad, then iterate i through all values // if j isn't +-rad, then i should be only -rad & rad int step = 2; if (abs(j) != rad) step = 2*rad; for (i=-rad; i <= rad; i += step) { int cx = qchunk_x + i; int cy = qchunk_y + j; int slot_x = (cx>>1) & (CACHED_MESH_NUM_X-1); int slot_y = (cy>>1) & (CACHED_MESH_NUM_Y-1); chunk_mesh *cm = &cached_chunk_mesh[slot_y][slot_x]; if (cm->state == STATE_valid && cm->priority >= 0) { ++chunks_considered; quads_considered += cm->num_quads; if (is_box_in_frustum(cm->bounds[0], cm->bounds[1])) { ++chunks_in_frustum; // @TODO if in range stbglUniform3fv(uniform_loc[STBVOX_UNIFORM_transform], 3, cm->transform[0]); glBindBufferARB(GL_ARRAY_BUFFER_ARB, cm->vbuf); glVertexAttribIPointer(0, 1, GL_UNSIGNED_INT, 4, (void*) 0); glBindTexture(GL_TEXTURE_BUFFER_ARB, cm->fbuf_tex); glDrawArrays(GL_QUADS, 0, cm->num_quads*4); quads_rendered += cm->num_quads; chunk_storage_rendered += cm->vbuf_size + cm->fbuf_size; } chunk_storage_considered += cm->vbuf_size + cm->fbuf_size; } } } } stbglDisableVertexAttribArray(0); glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0); glActiveTextureARB(GL_TEXTURE0_ARB); stbglUseProgram(0); num_meshes_started = 0; { #define MAX_QUEUE 8 float highest_priority[MAX_QUEUE]; int highest_i[MAX_QUEUE], highest_j[MAX_QUEUE]; float lowest_priority = view_dist_in_chunks * view_dist_in_chunks * 16 * 16.0f; int lowest_i = -1, lowest_j = -1; for (i=0; i < MAX_QUEUE; ++i) { highest_priority[i] = min_priority; highest_i[i] = -1; highest_j[i] = -1; } for (j=0; j < CACHED_MESH_NUM_Y; ++j) { for (i=0; i < CACHED_MESH_NUM_X; ++i) { chunk_mesh *cm = &cached_chunk_mesh[j][i]; if (cm->state == STATE_valid) { cm->priority = compute_priority(cm->chunk_x, cm->chunk_y, x, y); chunk_storage_total += cm->vbuf_size + cm->fbuf_size; if (cm->priority < lowest_priority) { lowest_priority = cm->priority; lowest_i = i; lowest_j = j; } } if (cm->state == STATE_needed) { cm->priority = compute_priority(cm->chunk_x, cm->chunk_y, x, y); if (cm->priority < min_priority) cm->state = STATE_invalid; else if (cm->priority > highest_priority[0]) { int k; highest_priority[0] = cm->priority; highest_i[0] = i; highest_j[0] = j; // bubble this up to right place for (k=0; k < MAX_QUEUE-1; ++k) { if (highest_priority[k] > highest_priority[k+1]) { highest_priority[k] = highest_priority[k+1]; highest_priority[k+1] = cm->priority; highest_i[k] = highest_i[k+1]; highest_i[k+1] = i; highest_j[k] = highest_j[k+1]; highest_j[k+1] = j; } else { break; } } } } } } // I couldn't find any straightforward logic that avoids // the hysteresis problem of continually creating & freeing // a block on the margin, so I just don't free a block until // it's out of range, but this doesn't actually correctly // handle when the cache is too small for the given range if (chunk_storage_total >= min_chunk_storage && lowest_i >= 0) { if (cached_chunk_mesh[lowest_j][lowest_i].priority < -1200) // -1000? 0? free_chunk(lowest_i, lowest_j); } if (chunk_storage_total < max_chunk_storage && highest_i[0] >= 0) { for (j=MAX_QUEUE-1; j >= 0; --j) { if (highest_j[0] >= 0) { chunk_mesh *cm = &cached_chunk_mesh[highest_j[j]][highest_i[j]]; if (request_chunk(cm->chunk_x, cm->chunk_y)) { cm->state = STATE_requested; } else { // if we couldn't queue this one, skip the remainder break; } } } } } update_meshes_from_render_thread(); num_threads_active = 0; for (i=0; i < num_mesh_workers; ++i) { num_threads_active += (mesh_data[i].state == WSTATE_running); } } // Raw data for Q&A: // // 26% parsing & loading minecraft files (4/5ths of which is zlib decode) // 39% building mesh from stb input format // 18% converting from minecraft blocks to stb blocks // 9% reordering from minecraft axis order to stb axis order // 7% uploading vertex buffer to OpenGL