fix massive oversight

src/boid-list.cpp

@@ -3,7 +3,7 @@
 #include "boid-list.hpp"
 
 static BoidsListNodeIterator boid_list_get_iterator(BoidsListNode *node, uint16_t count) {
-	return { .node = node, .i = 0, .count = count };
+	return { .count = count, .i = 0, .node = node  };
 }
 
 static bool boid_list_iterator_next(BoidsListNodeIterator *iterator, uint16_t *value) {
@@ -26,7 +26,7 @@ static void boid_list_append(MemoryArena *arena, BoidsListNode *node, uint16_t *
 	int left_count = *count;
 	BoidsListNode *prev = node;
 	BoidsListNode *curr = node;
-	while (left_count > BOIDS_PER_NODE && curr) {
+	while (left_count >= BOIDS_PER_NODE && curr) {
 		prev = curr;
 		curr = curr->next;
 		left_count -= BOIDS_PER_NODE;
@@ -38,7 +38,7 @@ static void boid_list_append(MemoryArena *arena, BoidsListNode *node, uint16_t *
 		prev->next = curr;
 	}
 
-	prev->boid_ids[left_count] = new_boid;
+	curr->boid_ids[left_count] = new_boid;
 	(*count)++;
 }
 

src/boid-list.hpp

@@ -2,17 +2,17 @@
 
 #include "memory-arena.hpp"
 
-#define BOIDS_PER_NODE 32
+#define BOIDS_PER_NODE 128
 
 struct BoidsListNode {
-	uint16_t boid_ids[BOIDS_PER_NODE];
 	BoidsListNode *next;
+	uint16_t boid_ids[BOIDS_PER_NODE];
 };
 
 struct BoidsListNodeIterator {
-	BoidsListNode *node;
-	int i;
 	uint16_t count;
+	int i;
+	BoidsListNode *node;
 };
 
 static BoidsListNodeIterator boid_list_get_iterator(BoidsListNode *node, uint16_t count);

src/boid-playground.hpp

@@ -37,12 +37,12 @@ struct World {
 	std::vector<Obstacle> obstacles;
 
 	MemoryArena frame_arena;
-	float view_radius = 15;
+	float view_radius = 10;
 	float view_angle = PI*1.5;
-	float min_speed = 30;
-	float max_speed = 50;
-	float max_steer_speed = 100;
-	float separation_radius = 10;
+	float min_speed = 10;
+	float max_speed = 40;
+	float max_steer_speed = 200;
+	float separation_radius = 4;
 
 	float alignment_strength = 1;
 	float cohesion_strength = 1;
@@ -58,7 +58,7 @@ struct World {
 };
 
 struct Visuals {
-	float boid_edge_size = 8;
+	float boid_edge_size = 5;
 
 	Color boid_color = BLACK;
 	Color bg_color = RAYWHITE;

src/main.cpp

@@ -12,7 +12,7 @@
 #include "raygui.h"
 
 #define RPROF_IMPLEMENTATION
-#define RPROF_STUB_OUT
+// #define RPROF_STUB_OUT
 #include "rprof.h"
 
 #include "boid-playground.hpp"
@@ -247,25 +247,32 @@ static void world_update(World *world, float dt) {
 		Boid *boid = &boids[i];
 		int chunk_x = boid->pos.x / chunk_size;
 		int chunk_y = boid->pos.y / chunk_size;
+
+		BoidsListNode *node = chunks[chunk_y][chunk_x];
+		uint16_t *count = &chunk_boid_counts[chunk_y][chunk_x];
+		boid_list_append(&world->frame_arena, node, count, i);
 	}
 	RPROF_STOP();
 
 	RPROF_START("Calc dot products and ranges (chunked)");
 	for (int y = 0; y < chunks_high; y++) {
-		for (int x = 0; x < chunks_high; x++) {
+		for (int x = 0; x < chunks_wide; x++) {
 			BoidsListNode *chunk = chunks[y][x];
 			size_t chunk_boid_count = chunk_boid_counts[y][x];
+			if (chunk_boid_count == 0) continue;
 
 			for (int oy = -1; oy <= 1; oy++) {
-				int chunk_y = x + oy;
+				int chunk_y = y + oy;
 				if (chunk_y < 0 || chunk_y >= chunks_high) continue;
 
 				for (int ox = -1; ox <= 1; ox++) {
-					int chunk_x = y + ox;
+					int chunk_x = x + ox;
 					if (chunk_x < 0 || chunk_x >= chunks_wide) continue;
 
 					BoidsListNode *neighbour_chunk = chunks[chunk_y][chunk_x];
 					size_t neighbour_chunk_boid_count = chunk_boid_counts[chunk_y][chunk_x];
+					if (neighbour_chunk_boid_count == 0) continue;
+
 
 					uint16_t boid1;
 					BoidsListNodeIterator it1 = boid_list_get_iterator(chunk, chunk_boid_count);
@@ -284,6 +291,7 @@ static void world_update(World *world, float dt) {
 	}
 	RPROF_STOP();
 
+
 	RPROF_START("Apply forces");
 	for (int i = 0; i < boid_count; i++) {
 		Boid *boid = &world->boids[i];
@@ -510,7 +518,7 @@ static void ui_draw(World *world, Visuals *visuals, UI *ui) {
 		GuiSlider(next_in_layout(&layout, 100, 15), NULL, "View radius", &world->view_radius, 2.5, 150);
 		GuiSlider(next_in_layout(&layout, 100, 15), NULL, "View angle", &world->view_angle, 0, 2*PI);
 
-		gui_valuebox_float(next_in_layout(&layout, 50, 15, 60), "Min speed", &world->min_speed, 0, world->max_speed, &ui->min_speed_edit);
+		gui_valuebox_float(next_in_layout(&layout, 50, 15, 60), "Min speed", &world->min_speed, 0, 1000, &ui->min_speed_edit);
 		gui_valuebox_float(next_in_layout(&layout, 50, 15, 60), "Max speed", &world->max_speed, 0, 1000, &ui->max_speed_edit);
 		gui_valuebox_float(next_in_layout(&layout, 50, 15, 60), "Steer speed", &world->max_steer_speed, 0, 1000, &ui->steer_speed_edit);
 
@@ -604,12 +612,15 @@ int main() {
 	world_init(&g_world, screen_width, screen_height);
 
 	float border = g_world.collision_avoidance_distance;
-	for (int i = 0; i < MAX_BOIDS; i++) {
+	for (int i = 0; i < 20000; i++) {
 		Boid boid;
 		boid_rand_init(&g_world, &boid, border);
 		g_world.boids.push_back(boid);
 	}
 
+	// g_world.boids.push_back({ .pos = { 800, 105 }});
+	// g_world.boids.push_back({ .pos = { 800, 110 }});
+
 #ifdef __EMSCRIPTEN__
 	emscripten_set_main_loop(UpdateDrawFrame, 0, 1);
 #else