README

README.md

@@ -1,3 +1,48 @@
+[![License: Apache 2.0](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](LICENSE-APACHE)
+[![Wally]()]()
+
 Just an ECS
 
-jecs provides
+jecs is a stupidly fast Entity Component System (ECS). 
+
+- Process tens of thousands of entities with ease every frame
+- Zero-dependency Luau package
+- Optimized for column-major operations
+- Cache friendly archetype/SoA storage 
+
+### Example
+
+```lua
+local world = Jecs.World.new()
+
+local player = world:entity() 
+local opponent = world:entity()
+
+-- Notice how components are just entities
+local Health = world:entity() 
+local Damage = world:entity()
+local Position = world:entity()
+
+world:add(player, Health, 100)
+world:add(player, Damage, 8)
+world:add(player, Position, Vector3.new(0, 5, 0))
+
+world:add(opponent, Health, 100)
+world:add(opponent, Damage, 21)
+world:add(opponent, Position, Vector3.new(0, 5, 3))
+
+for playerId, playerPosition, health in world:query(Position, Health) do 
+    local totalDamage = 0
+    for _, opponentPosition, damage in world:query(Position, Damage) do 
+        if (playerPosition - opponentPosition).Magnitude < 5  then 
+            totalDamage += damage
+        end
+    end
+
+    world:add(playerId, Health, health - totalDamage)  
+end
+
+assert(world:get(playerId, Health) == 79)
+assert(world:get(opponentId, Health) == 92)
+
+```