Awesome
V ecs is an Entity component System library for V that have a simplistic yet powerful design
What is ecs :
ECS is a programming pattern that is mostly used in games
- E: Entities which are in most cases just an id
- C: Component and thay are simple structs
- S: Systems and they are functions that use or change compenents
Usage :
V ecs have a very simple desing you basically have to create a struct and a function that use the data in that struct Here is an example
import gg
import gx
import mohamedlt.vecs as ecs
const (
win_width = 600
win_height = 300
)
struct App {
mut:
gg &gg.Context
image gg.Image
// the world object is what makes everthing work
world ecs.World
}
// a Position Component
struct Pos {
ecs.Comp
mut:
x f32
y f32
}
// a Color Component
struct Color {
ecs.Comp
color gx.Color
}
// A Resource Can be anything from pictures to simple data
struct Number{
ecs.Resource
val int
}
fn main() {
mut app := &App{
gg: 0
}
// add entity takes a list of the component you need in it
app.world.add_entity([Pos{x:0,y:20},Color{color:gx.gray}])
// add system takes a function name and a list of compenets that must be in an entity to apply this system to
app.world.add_system(app.draw,[Pos{},Color{}])
// same as above but just gives a mut entity
app.world.add_system_mut(frame,[Pos{},Color{}])
// add resource to the world
app.world.add_resource(Number{val:2,name:'numb'})
app.gg = gg.new_context(
bg_color: gx.white
width: win_width
height: win_height
create_window: true
window_title: 'Rectangles'
frame_fn: update
user_data:app
)
app.gg.run()
}
fn update(mut app App){
// world.step needs to be called every frame or whenever you want to update the world
app.world.step()
}
// any system needs to accept a mut entity or an unmut one and a ResourceManger
fn(app &App) draw(e ecs.Entity,mut r ecs.ResourceManger){
app.gg.begin()
// Entity.get_comp return the component of that entity
p := e.get_comp<Pos>()or {panic("")}
c:= e.get_comp<Color>()or {panic("")}
// ResourceManger.get_resource takes a resource name and returns it
speed := r.get_resource<Number>('numb')or {panic("")}
println(speed.val)
app.gg.draw_rect_filled(p.x,p.y,20,20,c.color)
app.gg.end()
}
// this is a system that takes a mut entity and moves it
fn frame(mut e ecs.Entity,mut r ecs.ResourceManger){
mut pos := e.get_comp<Pos>() or {panic('')}
pos.x++
}
Notes:
- A compenet must embed ecs.Comp or have a active field
- A Resource must embed ecs.Resource or have a name field