diff options
Diffstat (limited to 'src/modules/swarm')
| -rw-r--r-- | src/modules/swarm/Makefile.am | 3 | ||||
| -rw-r--r-- | src/modules/swarm/swarm.c | 278 |
2 files changed, 281 insertions, 0 deletions
diff --git a/src/modules/swarm/Makefile.am b/src/modules/swarm/Makefile.am new file mode 100644 index 0000000..327aee8 --- /dev/null +++ b/src/modules/swarm/Makefile.am @@ -0,0 +1,3 @@ +noinst_LIBRARIES = libswarm.a +libswarm_a_SOURCES = swarm.c +libswarm_a_CPPFLAGS = -I@top_srcdir@/src -I@top_srcdir@/src/libs diff --git a/src/modules/swarm/swarm.c b/src/modules/swarm/swarm.c new file mode 100644 index 0000000..4ebd79e --- /dev/null +++ b/src/modules/swarm/swarm.c @@ -0,0 +1,278 @@ +/* + * Copyright (C) 2021 - Vito Caputo - <vcaputo@pengaru.com> + * + * This program is free software: you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 3 as published + * by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +/* this implements a very simplified "boids" inspired particles swarm + * http://www.red3d.com/cwr/boids/ + * https://en.wikipedia.org/wiki/Boids + * https://en.wikipedia.org/wiki/Swarm_intelligence + */ + +#include <stdlib.h> +#include <unistd.h> +#include <math.h> + +#include "fb.h" +#include "rototiller.h" + +#define SWARM_SIZE (32 * 1024) +#define SWARM_ZCONST 4.f + +typedef struct v3f_t { + float x, y, z; +} v3f_t; + +typedef struct v2f_t { + float x, y; +} v2f_t; + +typedef struct boid_t { + v3f_t position; + v3f_t direction; + float velocity; +} boid_t; + +typedef struct swarm_context_t { + v3f_t color; + float ztweak; + boid_t boids[]; +} swarm_context_t; + + +static inline float randf(float min, float max) +{ + return ((float)rand() / (float)RAND_MAX) * (max - min) + min; +} + + +static inline void v3f_rand(v3f_t *v, float min, float max) +{ + v->x = randf(min, max); + v->y = randf(min, max); + v->z = randf(min, max); +} + + +static inline v3f_t v3f_add(v3f_t a, v3f_t b) +{ + return (v3f_t){ + .x = a.x + b.x, + .y = a.y + b.y, + .z = a.z + b.z, + }; +} + + +static inline v3f_t v3f_sub(v3f_t a, v3f_t b) +{ + return (v3f_t){ + .x = a.x - b.x, + .y = a.y - b.y, + .z = a.z - b.z, + }; +} + + +static inline v3f_t v3f_mult_scalar(v3f_t v, float scalar) +{ + return (v3f_t){ + .x = v.x * scalar, + .y = v.y * scalar, + .z = v.z * scalar, + }; +} + + +static inline float v3f_len(v3f_t v) +{ + return sqrtf(v.x * v.x + v.y * v.y + v.z * v.z); +} + + +static inline void v3f_normalize(v3f_t *v) +{ + float l = 1.f / v3f_len(*v); + + v->x *= l; + v->y *= l; + v->z *= l; +} + + +static v3f_t v3f_lerp(v3f_t a, v3f_t b, float t) +{ + return (v3f_t){ + .x = (b.x - a.x) * t + a.x, + .y = (b.y - a.y) * t + a.y, + .z = (b.z - a.z) * t + a.z, + }; +} + + +static void boid_randomize(boid_t *boid) +{ + v3f_rand(&boid->position, -1.f, 1.f); + v3f_rand(&boid->direction, -1.f, 1.f); + v3f_normalize(&boid->direction); + boid->velocity = randf(.05f, .2f); +} + + +/* convert a color into a packed, 32-bit rgb pixel value (taken from libs/ray/ray_color.h) */ +static inline uint32_t color_to_uint32(v3f_t color) { + uint32_t pixel; + + if (color.x > 1.0f) color.x = 1.0f; + if (color.y > 1.0f) color.y = 1.0f; + if (color.z > 1.0f) color.z = 1.0f; + + if (color.x < .0f) color.x = .0f; + if (color.y < .0f) color.y = .0f; + if (color.z < .0f) color.z = .0f; + + pixel = (uint32_t)(color.x * 255.0f); + pixel <<= 8; + pixel |= (uint32_t)(color.y * 255.0f); + pixel <<= 8; + pixel |= (uint32_t)(color.z * 255.0f); + + return pixel; +} + + +static void * swarm_create_context(unsigned ticks, unsigned num_cpus) +{ + swarm_context_t *ctxt; + + ctxt = calloc(1, sizeof(swarm_context_t) + sizeof(*(ctxt->boids)) * SWARM_SIZE); + if (!ctxt) + return NULL; + + for (unsigned i = 0; i < SWARM_SIZE; i++) + boid_randomize(&ctxt->boids[i]); + + return ctxt; +} + + +static void swarm_destroy_context(void *context) +{ + swarm_context_t *ctxt = context; + + free(ctxt); +} + + +static void swarm_update(swarm_context_t *ctxt, unsigned ticks) +{ + v3f_t avg_direction = {}; + float avg_velocity = 0.f; + v3f_t avg_center = {}; + float wleader, wcenter, wdirection; + + { /* [0] = leader */ + float r = (float)ticks * ((cosf((float)ticks * .0001f) * .5f + .5f) * .1f); + + ctxt->boids[0].position.x = cosf(r); + ctxt->boids[0].position.y = sinf(r); + ctxt->boids[0].position.z = cosf(r * 2.f); + } + + /* characterize the current swarm */ + for (unsigned i = 0; i < SWARM_SIZE; i++) { + boid_t *b = &ctxt->boids[i]; + + avg_center = v3f_add(avg_center, b->position); + avg_direction = v3f_add(avg_direction, b->direction); + avg_velocity += b->velocity; + } + + avg_velocity *= (1.f / (float)SWARM_SIZE); + avg_center = v3f_mult_scalar(avg_center, (1.f / (float)SWARM_SIZE)); + avg_direction = v3f_mult_scalar(avg_direction, (1.f / (float)SWARM_SIZE)); + v3f_normalize(&avg_direction); + + /* vary weights */ + wleader = cosf((float)ticks * .001f) * .5f + .5f; + wcenter = cosf((float)ticks * .0005f) * .5f + .5f; + wdirection = sinf((float)ticks * .003f) * .5f + .5f; + + /* update the followers in relation to leader and swarm itself */ + for (unsigned i = 1; i < SWARM_SIZE; i++) { + boid_t *b = &ctxt->boids[i]; + v3f_t to_leader = v3f_sub(ctxt->boids[0].position, b->position); + v3f_t to_center = v3f_sub(avg_center, b->position); + + v3f_normalize(&to_leader); + b->direction = v3f_lerp(b->direction, to_leader, wleader * .1f); + v3f_normalize(&b->direction); + b->direction = v3f_lerp(b->direction, to_center, wcenter * .1f); + v3f_normalize(&b->direction); + b->direction = v3f_lerp(b->direction, avg_direction, wdirection * .05f); + v3f_normalize(&b->direction); + + b->position = v3f_add(b->position, v3f_mult_scalar(b->direction, b->velocity)); + } + + /* color the swarm according to the current weights */ + ctxt->color.x = wleader; + ctxt->color.y = wcenter; + ctxt->color.z = wdirection; + + /* this zooms out a bit when the swarm loosens up, gauged by low weights */ + ctxt->ztweak = (1.8f - v3f_len(ctxt->color)) * 4.f; +} + + +static void swarm_render_fragment(void *context, unsigned ticks, unsigned cpu, fb_fragment_t *fragment) +{ + swarm_context_t *ctxt = context; + + swarm_update(ctxt, ticks); + + fb_fragment_zero(fragment); + + { + float fw = fragment->frame_width, fh = fragment->frame_height; + uint32_t color = color_to_uint32(ctxt->color); + + fw *= .5f; + fh *= .5f; + + for (unsigned i = 0; i < SWARM_SIZE; i++) { + boid_t *b = &ctxt->boids[i]; + v2f_t nc; + + nc.x = b->position.x / (b->position.z + SWARM_ZCONST + ctxt->ztweak); + nc.y = b->position.y / (b->position.z + SWARM_ZCONST + ctxt->ztweak); + + nc.x = nc.x * fw + fw; + nc.y = nc.y * fh + fh; + + fb_fragment_put_pixel_checked(fragment, nc.x, nc.y, color); + } + } +} + + +rototiller_module_t swarm_module = { + .create_context = swarm_create_context, + .destroy_context = swarm_destroy_context, + .render_fragment = swarm_render_fragment, + .name = "swarm", + .description = "\"Boids\"-inspired particle swarm in 3D", + .author = "Vito Caputo <vcaputo@pengaru.com>", + .license = "GPLv3", +}; |