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v4k-git-backup/engine/split/v4k_ai.c

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// AI framework
// - rlyeh, public domain.
//
// [src] original A-star code by @mmozeiko (PD) - https://gist.github.com/mmozeiko/68f0a8459ef2f98bcd879158011cc275
// [src] original swarm/boids code by @Cultrarius (UNLICENSE) - https://github.com/Cultrarius/Swarmz
// boids/swarm -----------------------------------------------------------------
vec3 rnd3() { // random uniform
float theta = randf() * C_PI * 2;
float r = sqrt(randf());
float z = sqrt(1.0f - r * r) * (randf() > 0.5f ? -1.0f : 1.0f);
return vec3(r * cos(theta), r * sin(theta), z);
}
int less3(vec3 *lhs, vec3 *rhs) {
if(lhs->x != rhs->x) return lhs->x - rhs->x;
if(lhs->y != rhs->y) return lhs->y - rhs->y;
if(lhs->z != rhs->z) return lhs->z - rhs->z;
return 0;
}
uint64_t hash3(vec3 *v) {
uint64_t h1 = hash_flt(v->x);
uint64_t h2 = hash_flt(v->y);
uint64_t h3 = hash_flt(v->z);
return (h1 * 31 + h2) * 31 + h3;
}
vec3 clamplen3(vec3 v, float length) {
return len3(v) <= length ? v : scale3(norm3(v), length);
}
float transform_distance(float distance, SWARM_DISTANCE type) {
float quad;
/**/ if (type == SWARM_DISTANCE_LINEAR) return distance;
else if (type == SWARM_DISTANCE_QUADRATIC) return distance * distance;
else if (type == SWARM_DISTANCE_INVERSE_LINEAR) return distance == 0 ? 0 : 1 / distance;
else if (type == SWARM_DISTANCE_INVERSE_QUADRATIC) return (quad = distance * distance), (quad == 0 ? 0 : 1 / quad);
return distance; // throw exception instead?
}
typedef struct nearby_boid_t {
boid_t *boid;
vec3 direction;
float distance;
} nearby_boid_t;
static
vec3 get_voxel_for_boid(float perception_radius, const boid_t *b) { // quantize position
float r = absf(perception_radius);
return vec3( (int)(b->position.x / r), (int)(b->position.y / r), (int)(b->position.z / r) );
}
static
void check_voxel_for_boids(float perception_radius, float blindspot_angledeg_compare_value, array(boid_t*) voxel_cached, array(nearby_boid_t) *result, const vec3 voxelPos, const boid_t *b) {
for each_array_ptr(voxel_cached, const boid_t*, test) {
vec3 p1 = b->position;
vec3 p2 = (*test)->position;
vec3 vec = sub3(p2, p1);
float distance = len3(vec);
float compare_value = 0;
float l1 = len3(vec);
float l2 = len3(b->velocity);
if (l1 != 0 && l2 != 0) {
compare_value = dot3(neg3(b->velocity), vec) / (l1 * l2);
}
if ((&b) != test && distance <= perception_radius && (blindspot_angledeg_compare_value > compare_value || len3(b->velocity) == 0)) {
nearby_boid_t nb;
nb.boid = (boid_t*)*test;
nb.distance = distance;
nb.direction = vec;
array_push(*result, nb);
}
}
}
static
array(nearby_boid_t) get_nearby_boids(const swarm_t *self, const boid_t *b) {
array(nearby_boid_t) result = 0;
array_reserve(result, array_count(self->boids));
vec3 voxelPos = get_voxel_for_boid(self->perception_radius, b);
voxelPos.x -= 1;
voxelPos.y -= 1;
voxelPos.z -= 1;
for (int x = 0; x < 3; x++) {
for (int y = 0; y < 3; y++) {
for (int z = 0; z < 3; z++) {
array(boid_t*) *found = map_find(self->voxel_cache_, &voxelPos);
if( found ) check_voxel_for_boids(self->perception_radius, self->blindspot_angledeg_compare_value_, *found, &result, voxelPos, b);
voxelPos.z++;
}
voxelPos.z -= 3;
voxelPos.y++;
}
voxelPos.y -= 3;
voxelPos.x++;
}
return result;
}
static
void update_boid(swarm_t *self, boid_t *b) {
vec3 separation_sum = {0};
vec3 heading_sum = {0};
vec3 position_sum = {0};
vec3 po = b->position;
array(nearby_boid_t) nearby = get_nearby_boids(self, b); // @leak
for each_array_ptr(nearby, nearby_boid_t, closeboid_t) {
if (closeboid_t->distance == 0) {
separation_sum = add3(separation_sum, scale3(rnd3(), 1000)); //addscale3
}
else {
float separation_factor = transform_distance(closeboid_t->distance, self->separation_type);
separation_sum = add3(separation_sum, scale3(neg3(closeboid_t->direction), separation_factor)); // addscale3
}
heading_sum = add3(heading_sum, closeboid_t->boid->velocity); // inc3
position_sum = add3(position_sum, closeboid_t->boid->position); // inc3
}
vec3 steering_target = b->position;
float target_distance = -1;
for( int i = 0, end = array_count(self->steering_targets); i < end; ++i ) {
vec3 *target = &self->steering_targets[i];
float distance = transform_distance(len3(sub3(*target,b->position)), self->steering_target_type);
if (target_distance < 0 || distance < target_distance) {
steering_target = *target;
target_distance = distance;
}
}
int nearby_size = array_count(nearby);
// Separation: steer to avoid crowding local flockmates
vec3 separation = nearby_size > 0 ? scale3(separation_sum, 1.f / nearby_size) : separation_sum;
// Alignment: steer towards the average heading of local flockmates
vec3 alignment = nearby_size > 0 ? scale3(heading_sum, 1.f / nearby_size) : heading_sum;
// Cohesion: steer to move toward the average position of local flockmates
vec3 avgposition = nearby_size > 0 ? scale3(position_sum, 1.f / nearby_size) : b->position;
vec3 cohesion = sub3(avgposition, b->position);
// Steering: steer towards the nearest target location (like a moth to the light)
vec3 steering = scale3(norm3(sub3(steering_target, b->position)), target_distance);
// calculate boid acceleration
vec3 acceleration;
acceleration = scale3(separation, self->separation_weight);
acceleration = add3(acceleration, scale3(alignment, self->alignment_weight));
acceleration = add3(acceleration, scale3(cohesion, self->cohesion_weight));
acceleration = add3(acceleration, scale3(steering, self->steering_weight));
b->acceleration = clamplen3(acceleration, self->max_acceleration);
}
swarm_t swarm() {
swarm_t self = {0};
self.boids = NULL;
self.perception_radius = 3; // 30
self.separation_weight = 0.1; // 1
self.separation_type = SWARM_DISTANCE_INVERSE_QUADRATIC;
self.alignment_weight = 0.1; // 1
self.cohesion_weight = 0.1; // 1
self.steering_weight = 0.1; // 0.1
// array_push(self.steering_targets, vec3(0,0,0));
self.steering_target_type = SWARM_DISTANCE_LINEAR;
self.blindspot_angledeg = 2; // 20
self.max_acceleration = 1; // 10;
self.max_velocity = 2; // 20;
self.blindspot_angledeg_compare_value_ = 0; // = cos(M_PI * 2 * blindspot_angledeg / 360)
map_init(self.voxel_cache_, less3, hash3);
return self;
}
void swarm_update_acceleration_only(swarm_t *self) {
self->perception_radius += !self->perception_radius; // 0->1
// build voxel cache
map_clear(self->voxel_cache_);
for( int i = 0, end = array_count(self->boids); i < end; ++i ) {
boid_t *b = &(self->boids)[i];
vec3 *key = MALLOC(sizeof(vec3));
*key = get_voxel_for_boid(self->perception_radius, b);
array(boid_t*) *found = map_find_or_add_allocated_key( self->voxel_cache_, key, 0 );
array_push(*found, b);
}
// update all boids
for( int i = 0, end = array_count(self->boids); i < end; ++i ) {
boid_t *b = &(self->boids)[i];
update_boid(self, b);
}
}
void swarm_update_acceleration_and_velocity_only(swarm_t *self, float delta) {
self->blindspot_angledeg_compare_value_ = cosf(C_PI * 2 * self->blindspot_angledeg / 360.0f);
swarm_update_acceleration_only(self);
for( int i = 0, end = array_count(self->boids); i < end; ++i ) {
boid_t *b = &(self->boids)[i];
b->velocity = clamplen3(add3(b->velocity, scale3(b->acceleration, delta)), self->max_velocity);
}
}
void swarm_update(swarm_t *self, float delta) {
swarm_update_acceleration_and_velocity_only(self, delta);
for( int i = 0, end = array_count(self->boids); i < end; ++i ) {
boid_t *b = &(self->boids)[i];
b->prev_position = b->position;
b->position = add3(b->position, scale3(b->velocity, delta));
}
}
int ui_swarm(swarm_t *self) {
const char *distances[] = {
"Linear",
"Inverse Linear",
"Quadratic",
"Inverse Quadratic"
};
int rc = 0;
rc |= ui_float( "Perception Radius", &self->perception_radius);
ui_separator();
rc |= ui_float( "Separation Weight", &self->separation_weight);
rc |= ui_radio( "Separation Type", distances, countof(distances), (int*)&self->separation_type);
ui_separator();
rc |= ui_float( "Alignment Weight", &self->alignment_weight);
rc |= ui_float( "Cohesion Weight", &self->cohesion_weight);
ui_separator();
rc |= ui_float( "Steering Weight", &self->steering_weight);
//array(vec3) steering_targets;
rc |= ui_radio( "Steering Target Type", distances, countof(distances), (int*)&self->steering_target_type);
ui_separator();
rc |= ui_float( "Blindspot Angle", &self->blindspot_angledeg);
rc |= ui_float( "Max Acceleration", &self->max_acceleration);
rc |= ui_float( "Max Velocity", &self->max_velocity);
return rc;
}
// pathfinding -----------------------------------------------------------------
static
int pathfind_astar(int width, int height, const unsigned* map, vec2i src, vec2i dst, vec2i* path, size_t maxpath) {
#define ALLOW_DIAGONAL_MOVEMENT 1
#if ALLOW_DIAGONAL_MOVEMENT
#define ASTAR_DIR_COUNT 8
#else
#define ASTAR_DIR_COUNT 4
#endif
static const vec2i dir[ASTAR_DIR_COUNT] =
{
{ 1, 0 },
{ 0, 1 },
{ -1, 0 },
{ 0, -1 },
#if ALLOW_DIAGONAL_MOVEMENT
{ 1, 1 },
{ 1, -1 },
{ -1, 1 },
{ -1, -1 },
#endif
};
#define ASTAR_POS_TYPE vec2i
#define ASTAR_POS_START src
#define ASTAR_POS_FINISH dst
#define ASTAR_POS_INDEX(p) ((p).y * width + (p).x)
#define ASTAR_MAX_INDEX (width * height)
#define ASTAR_INDEX_POS(p, i) \
do { \
(p).x = (i) % width; \
(p).y = (i) / width; \
} while (0)
#define ASTAR_POS_EQUAL(a, b) ((a).x == (b).x && (a).y == (b).y)
#define ASTAR_MAP_IS_FREE(p) ((p).y >= 0 && (p).y < height && (p).x >= 0 && (p).x < width && (char)map[(p).y * width + (p).x] == 0)
#define ASTAR_NEXT_POS(p, i) \
do { \
(p).x += dir[i].x; \
(p).y += dir[i].y; \
} while (0)
#define ASTAR_PREV_POS(p, i) \
do { \
(p).x -= dir[i].x; \
(p).y -= dir[i].y; \
} while (0)
#define ASTAR_GET_COST(a, b) (abs((a).x - (b).x) + abs((a).y - (b).y))
#if ALLOW_DIAGONAL_MOVEMENT
#define ASTAR_EXTRA_COST(i) (i < 4 ? 5 : 7) // 7/5 is approx sqrt(2)
#define ASTAR_COST_MUL 5
#endif
size_t path_count = 0;
#define ASTAR_PATH(p) if (path_count < maxpath) path[path_count++] = p
// tempwork memory, not thread-safe.
#define ASTAR_TEMP_SIZE (ASTAR_MAX_INDEX * (sizeof(unsigned)*2) + sizeof(unsigned)*4) // (16<<20)
#define ASTAR_TEMP temp
static array(char) ASTAR_TEMP; do_once array_resize(ASTAR_TEMP, ASTAR_TEMP_SIZE);
// #if 1 "astar.h"
{
// generic A* pathfinding
//
// INTERFACE
//
// mandatory macros
#ifndef ASTAR_POS_TYPE
#error ASTAR_POS_TYPE should specify position type
#endif
#ifndef ASTAR_POS_START
#error ASTAR_POS_START should specify start position
#endif
#ifndef ASTAR_POS_FINISH
#error ASTAR_POS_FINISH should specify finish position
#endif
#ifndef ASTAR_POS_INDEX
#error ASTAR_POS_INDEX(p) should specify macro to map position to index
#endif
#ifndef ASTAR_MAX_INDEX
#error ASTAR_MAX_INDEX should specify max count of indices the position can map to
#endif
#ifndef ASTAR_INDEX_POS
#error ASTAR_INDEX_POS(i) should specify macro to map index to position
#endif
#ifndef ASTAR_POS_EQUAL
#error ASTAR_POS_EQUAL(a, b) should specify macro to compare if two positions are the same
#endif
#ifndef ASTAR_MAP_IS_FREE
#error ASTAR_MAP_IS_FREE(p) should specify macro to check if map at position p is free
#endif
#ifndef ASTAR_NEXT_POS
#error ASTAR_NEXT_POS(p, i) should specify macro to get next position in specific direction
#endif
#ifndef ASTAR_PREV_POS
#error ASTAR_PREV_POS(p, i) should specify macro to get previous position from specific direction
#endif
#ifndef ASTAR_DIR_COUNT
#error ASTAR_DIR_COUNT should specify possible direction count
#endif
#ifndef ASTAR_GET_COST
#error ASTAR_GET_COST(a, b) should specify macro to get get cost between two positions
#endif
#ifndef ASTAR_PATH
#error ASTAR_PATH(p) should specify macro that will be invoked on each position for path (in reverse order), including start/finish positions
#endif
#if !defined(ASTAR_TEMP) || !defined(ASTAR_TEMP_SIZE)
#error ASTAR_TEMP and ASTAR_TEMP_SIZE should specify variable & size for temporary memory (should be at least ASTAR_MAX_INDEX * 4 + extra)
#endif
// optional macros
// adds extra cost for specific direction (useful for increasing cost for diagonal movements)
#ifndef ASTAR_EXTRA_COST
#define ASTAR_EXTRA_COST(i) 1
#endif
// multiplier for adding cost values (current_cost + mul * new_cost) - useful when using extra cost for diagonal movements
#ifndef ASTAR_COST_MUL
#define ASTAR_COST_MUL 1
#endif
//
// IMPLEMENTATION
//
#if ASTAR_DIR_COUNT <= 4
#define ASTAR_DIR_BITS 2
#elif ASTAR_DIR_COUNT <= 8
#define ASTAR_DIR_BITS 3
#elif ASTAR_DIR_COUNT <= 16
#define ASTAR_DIR_BITS 4
#elif ASTAR_DIR_COUNT <= 32
#define ASTAR_DIR_BITS 5
#elif ASTAR_DIR_COUNT <= 64
#define ASTAR_DIR_BITS 6
#else
#error Too many elements for ASTAR_DIR_COUNT, 64 is max
#endif
#define ASTAR_COST_BITS (32 - 1 - ASTAR_DIR_BITS)
#define ASTAR_HEAP_SWAP(a, b) \
do { \
heapnode t = heap[a]; \
heap[a] = heap[b]; \
heap[b] = t; \
} while (0) \
#define ASTAR_HEAP_PUSH(idx, c) \
do { \
heap[heap_count].index = idx; \
heap[heap_count].cost = c; \
int i = heap_count++; \
int p = (i - 1) / 2; \
while (i != 0 && heap[p].cost > heap[i].cost) \
{ \
ASTAR_HEAP_SWAP(i, p); \
i = p; \
p = (i - 1) / 2; \
} \
} while (0)
#define ASTAR_HEAP_POP() \
do { \
heap[0] = heap[--heap_count]; \
int i = 0; \
for (;;) \
{ \
int l = 2 * i + 1; \
int r = 2 * i + 2; \
int s = i; \
if (l < heap_count && heap[l].cost < heap[i].cost) s = l; \
if (r < heap_count && heap[r].cost < heap[s].cost) s = r; \
if (s == i) break; \
ASTAR_HEAP_SWAP(i, s); \
i = s; \
} \
} while (0)
typedef union {
struct {
unsigned int cost : ASTAR_COST_BITS;
unsigned int dir : ASTAR_DIR_BITS;
unsigned int visited : 1;
};
unsigned int all;
} node;
typedef struct {
unsigned int index;
unsigned int cost;
} heapnode;
if (ASTAR_TEMP_SIZE >= sizeof(node) * ASTAR_MAX_INDEX + sizeof(heapnode))
{
node* nodes = (node*)ASTAR_TEMP;
for (unsigned int i = 0; i < ASTAR_MAX_INDEX; i++)
{
nodes[i].all = 0;
}
heapnode* heap = (heapnode*)((char*)ASTAR_TEMP + sizeof(node) * ASTAR_MAX_INDEX);
unsigned int heap_max = (ASTAR_TEMP_SIZE - sizeof(node) * ASTAR_MAX_INDEX) / sizeof(heapnode);
int heap_count = 0;
ASTAR_POS_TYPE p = ASTAR_POS_START;
unsigned int nindex = ASTAR_POS_INDEX(p);
node* n = nodes + nindex;
n->cost = 0;
n->visited = 1;
ASTAR_HEAP_PUSH(nindex, ASTAR_GET_COST(p, ASTAR_POS_FINISH));
int found = 0;
while (heap_count != 0)
{
nindex = heap[0].index;
n = nodes + nindex;
ASTAR_HEAP_POP();
ASTAR_INDEX_POS(p, nindex);
if (ASTAR_POS_EQUAL(p, ASTAR_POS_FINISH))
{
found = 1;
break;
}
n->visited = 1;
for (unsigned int i = 0; i < ASTAR_DIR_COUNT; i++)
{
ASTAR_POS_TYPE next = p;
ASTAR_NEXT_POS(next, i);
if (ASTAR_MAP_IS_FREE(next))
{
unsigned int nnext_index = ASTAR_POS_INDEX(next);
node* nnext = nodes + nnext_index;
unsigned int cost = n->cost + ASTAR_EXTRA_COST(i);
if (nnext->visited == 0 || cost < nnext->cost)
{
nnext->cost = cost;
nnext->dir = i;
nnext->visited = 1;
if (heap_count == heap_max)
{
// out of memory
goto bail;
}
unsigned int new_cost = cost + ASTAR_COST_MUL * ASTAR_GET_COST(next, ASTAR_POS_FINISH);
ASTAR_HEAP_PUSH(nnext_index, new_cost);
}
}
}
}
bail:
if (found)
{
ASTAR_PATH(p);
while (!ASTAR_POS_EQUAL(p, ASTAR_POS_START))
{
ASTAR_PREV_POS(p, n->dir);
n = nodes + ASTAR_POS_INDEX(p);
ASTAR_PATH(p);
}
}
}
else
{
// not enough temp memory
}
#undef ASTAR_POS_TYPE
#undef ASTAR_POS_START
#undef ASTAR_POS_FINISH
#undef ASTAR_POS_INDEX
#undef ASTAR_MAX_INDEX
#undef ASTAR_INDEX_POS
#undef ASTAR_POS_EQUAL
#undef ASTAR_MAP_IS_FREE
#undef ASTAR_NEXT_POS
#undef ASTAR_PREV_POS
#undef ASTAR_DIR_COUNT
#undef ASTAR_GET_COST
#undef ASTAR_EXTRA_COST
#undef ASTAR_COST_MUL
#undef ASTAR_PATH
#undef ASTAR_TEMP
#undef ASTAR_TEMP_SIZE
#undef ASTAR_COST_BITS
#undef ASTAR_DIR_BITS
#undef ASTAR_HEAP_SWAP
#undef ASTAR_HEAP_PUSH
#undef ASTAR_HEAP_POP
}
// #endif "astar.h"
return path_count;
}
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