A fast and simple zig native ECS.
Builds against zig 0.14.0
git clone --recursive https://github.com/linuxy/coyote-ecs.git
To build:
- zig build
A more complete example: coyote-snake
Benchmark: coyote-bunnies
Define your components in a container
const std = @import("std");
const ecs = @import("coyote-ecs");
const World = ecs.World;
const Cast = ecs.Cast;
const Systems = ecs.Systems;
//Container name is configured in ECS constants
pub const Components = struct {
pub const Apple = struct {
color: u32 = 0,
ripe: bool = false,
harvested: bool = false,
};
pub const Orange = struct {
color: u32 = 0,
ripe: bool = false,
harvested: bool = false,
};
pub const Pear = struct {
color: u32 = 0,
ripe: bool = false,
harvested: bool = false,
};
};Create some entities and components in a world
pub fn main() !void {
//Create a world
var world = try World.create();
defer world.deinit();
//Create an entity
var anOrange = try world.entities.create();
var anApple = try world.entities.create();
var aPear = try world.entities.create();
std.log.info("Created an Orange ID: {}", .{anOrange.id});
//Create a unique component
var orangeComponent = try world.components.create(Components.Orange);
var appleComponent = try world.components.create(Components.Apple);
//Attach and assign a component. Do not use an anonymous struct.
try anOrange.attach(orangeComponent, Components.Orange{.color = 0, .ripe = false, .harvested = false});
try anApple.attach(appleComponent, Components.Apple{.color = 0, .ripe = false, .harvested = false});
_ = try aPear.addComponent(Components.Pear{.color = 1, .ripe = false, .harvested = false});
//Create 50k entities and attach 50k unique components
var i: usize = 0;
while(i < 50000) : (i += 1) {
var anEntity = try world.entities.create();
var anOrangeComponent = try world.components.create(Components.Orange);
try anEntity.attach(anOrangeComponent, Components.Orange{.color = 1, .ripe = false, .harvested = false});
}
//Filter components by type
var it = world.components.iteratorFilter(Components.Orange);
i = 0;
while(it.next()) |_| : (i += 1) {
//...
}
std.log.info("Orange components: {}", .{i});
//Filter entities by type
var it2 = world.entities.iteratorFilter(Components.Apple);
i = 0;
while(it2.next()) |_| : (i += 1) {
//...
}
std.log.info("Apple entities: {}", .{i});
if(aPear.getOneComponent(Components.Pear) != null)
std.log.info("Pear entities: >= 1", .{})
else
std.log.info("Pear entities: 0", .{});
try Systems.run(Grow, .{world});
try Systems.run(Harvest, .{world});
try Systems.run(Raze, .{world});
std.log.info("Entities: {}", .{world.entities.count()});
std.log.info("Components: {}", .{world.components.count()});
}Create some systems
pub fn Grow(world: *World) void {
var it = world.components.iterator();
var i: u32 = 0;
while(it.next()) |component| : (i += 1) {
if(component.is(Components.Orange)) {
try component.set(Components.Orange, .{.ripe = true});
}
if(component.is(Components.Apple)) {
try component.set(Components.Apple, .{.ripe = true});
}
if(component.is(Components.Pear)) {
try component.set(Components.Pear, .{.ripe = true});
}
//Fruits fall from the tree
component.detach();
}
std.log.info("Fruits grown: {}", .{i});
}
pub fn Harvest(world: *World) void {
var it = world.components.iterator();
var i: u32 = 0;
while(it.next()) |component| {
if(component.is(Components.Orange)) {
if(Cast(Components.Orange, component).ripe == true) {
try component.set(Components.Orange, .{.harvested = true});
i += 1;
}
}
if(component.is(Components.Apple)) {
if(Cast(Components.Apple, component).ripe == true) {
try component.set(Components.Apple, .{.harvested = true});
i += 1;
}
}
if(component.is(Components.Pear)) {
if(Cast(Components.Pear, component).ripe == true) {
try component.set(Components.Pear, .{.harvested = true});
i += 1;
}
}
component.destroy();
}
world.components.gc();
std.log.info("Fruits harvested: {}", .{i});
}
pub fn Raze(world: *World) void {
var it = world.entities.iterator();
var i: u32 = 0;
while(it.next()) |entity| {
entity.destroy();
i += 1;
}
std.log.info("Entities destroyed: {}", .{i});
}With C bindings
#include <stddef.h>
#include <stdio.h>
#include "../include/coyote.h"
typedef struct apple {
int color;
int ripe;
int harvested;
} apple;
typedef struct orange {
int color;
int ripe;
int harvested;
} orange;
typedef struct pear {
int color;
int ripe;
int harvested;
} pear;
static const coyote_type t_apple = COYOTE_MAKE_TYPE(0, apple);
static const coyote_type t_orange = COYOTE_MAKE_TYPE(1, orange);
static const coyote_type t_pear = COYOTE_MAKE_TYPE(2, pear);
int main(void) {
world world = coyote_world_create();
if(world != 0)
printf("Created world @%d\n", world);
else
printf("World creation failed.\n");
entity e_apple = coyote_entity_create(world);
entity e_orange = coyote_entity_create(world);
entity e_pear = coyote_entity_create(world);
component c_apple = coyote_component_create(world, t_apple);
component c_orange = coyote_component_create(world, t_orange);
component c_pear = coyote_component_create(world, t_pear);
printf("Created an apple component @%d\n", c_apple);
printf("Created an orange component @%d\n", c_orange);
printf("Created an pear component @%d\n", c_pear);
iterator it = coyote_components_iterator_filter(world, t_orange);
component next = coyote_components_iterator_filter_next(it);
if(next)
printf("Another orange component @%d\n", c_orange);
else
printf("NOT another orange component @%d\n", c_orange);
if(coyote_component_is(c_orange, t_orange))
printf("Component is an orange @%d\n", c_orange);
else
printf("Component is NOT an orange @%d\n", c_orange);
coyote_entity_attach(e_apple, c_apple, t_apple);
//Assignment must happen after attach, TODO: Change?
apple* a1 = coyote_component_get(c_apple); a1->color = 255; a1->ripe = 0; a1->harvested = 0;
printf("Got and assigned an apple component @%d\n", a1);
coyote_entity_detach(e_apple, c_apple);
coyote_component_destroy(c_apple);
coyote_entity_destroy(e_apple);
coyote_entity_destroy(e_pear);
printf("Number of entities: %d == 1\n", coyote_entities_count(world));
printf("Number of components: %d == 3\n", coyote_components_count(world));
coyote_world_destroy(world);
printf("World destroyed.\n");
return 0;
}