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nothings-stb/tests/caveview/cave_render.c

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// This file takes renders vertex buffers and manages
// threads that invoke mesh building (found in cave_mesher.c)
#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 <math.h>
//#define SHORTVIEW
// renderer maintains GL meshes, draws them
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; y<TEX_SIZE; ++y)
for (x=0; x<TEX_SIZE; ++x) {
texture[y][x] = (color + (stb_rand()&0x1f1f1f))|0xff000000;
}
}
void build_overlay_texture(int n)
{
int x,y;
uint32 color = stb_rand();
if (color & 16)
color = 0xff000000;
else
color = 0xffffffff;
for (y=0; y<TEX_SIZE; ++y)
for (x=0; x<TEX_SIZE; ++x) {
texture[y][x] = 0;
}
for (y=0; y < TEX_SIZE/8; ++y) {
for (x=0; x < TEX_SIZE; ++x) {
texture[y][x] = color;
texture[TEX_SIZE-1-y][x] = color;
texture[x][y] = color;
texture[x][TEX_SIZE-1-y] = color;
}
}
}
// view radius of about 1024 = 2048 columns / 32 columns-per-mesh = 2^11 / 2^5 = 64x64
// so we need bigger than 64x64 so we can precache, which means we have to be
// non-power-of-two, or we have to be pretty huge
#define CACHED_MESH_NUM_X 128
#define CACHED_MESH_NUM_Y 128
chunk_mesh cached_chunk_mesh[CACHED_MESH_NUM_Y][CACHED_MESH_NUM_X];
void free_chunk(int slot_x, int slot_y)
{
chunk_mesh *cm = &cached_chunk_mesh[slot_y][slot_x];
if (cm->state == 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;
}
}
}
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;
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
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