Starting entities, components, and levels

entity/entity.go

@@ -0,0 +1,43 @@
+package entity
+
+type Entity struct {
+
+	// Byte 1: Generation; Byte 2: Flags; Bytes 3-8: Index
+	ID    uint64
+	Comps []Comp
+}
+
+type Comp interface {
+	Name() string
+}
+
+func AddComp(e *Entity, c Comp) {
+	e.Comps = append(e.Comps, c)
+}
+
+func GetComp[T Comp](e *Entity) (out T) {
+
+	for i := 0; i < len(e.Comps); i++ {
+
+		comp, ok := e.Comps[i].(T)
+		if ok {
+			return comp
+		}
+	}
+
+	return out
+}
+
+func GetAllCompOfType[T Comp](e *Entity) (out []T) {
+
+	out = []T{}
+	for i := 0; i < len(e.Comps); i++ {
+
+		comp, ok := e.Comps[i].(T)
+		if ok {
+			out = append(out, comp)
+		}
+	}
+
+	return out
+}

entity/registry.go

@@ -0,0 +1,35 @@
+package entity
+
+import "github.com/bloeys/nmage/assert"
+
+type Registry struct {
+	EntityCount uint64
+	Entities    []Entity
+}
+
+func (r *Registry) NewEntity() *Entity {
+
+	assert.T(r.EntityCount < uint64(len(r.Entities)), "Can not add more entities to registry because it is full")
+
+	for i := 0; i < len(r.Entities); i++ {
+
+		// @TODO: Implement generational indices
+		e := &r.Entities[i]
+		if e.ID == 0 {
+			r.EntityCount++
+			e.ID = uint64(i) + 1
+
+			assert.T(e.ID != 0, "Entity ID must not be zero")
+			return e
+		}
+	}
+
+	panic("failed to create new entity because we did not find a free spot in the registry. Why did the assert not go off?")
+}
+
+func NewRegistry(size uint32) *Registry {
+	assert.T(size > 0, "Registry size must be more than zero")
+	return &Registry{
+		Entities: make([]Entity, size),
+	}
+}

go.mod

@@ -1,6 +1,6 @@
 module github.com/bloeys/nmage
 
-go 1.17
+go 1.18
 
 require github.com/veandco/go-sdl2 v0.4.10
 

go.sum

@@ -1,15 +1,11 @@
 github.com/bloeys/assimp-go v0.4.2 h1:ArVK74BCFcTO/rCGj2NgZG9xtbjnJdEn5npIeJx1Z04=
 github.com/bloeys/assimp-go v0.4.2/go.mod h1:my3yRxT7CfOztmvi+0svmwbaqw0KFrxaHxncoyaEIP0=
-github.com/bloeys/gglm v0.3.1 h1:Sy9upW7SBsBfDXrSmEhid3aQ+7J7itej+upwcxOnPMQ=
-github.com/bloeys/gglm v0.3.1/go.mod h1:qwJQ0WzV191wAMwlGicbfbChbKoSedMk7gFFX6GnyOk=
 github.com/bloeys/gglm v0.41.10 h1:R9FMiI+VQVXAI+vDwCB7z9xqzy5VAR1657u8TQTDNKA=
 github.com/bloeys/gglm v0.41.10/go.mod h1:qwJQ0WzV191wAMwlGicbfbChbKoSedMk7gFFX6GnyOk=
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/go-gl/gl v0.0.0-20211025173605-bda47ffaa784 h1:1Zi56D0LNfvkzM+BdoxKryvUEdyWO7LP8oRT+oSYJW0=
 github.com/go-gl/gl v0.0.0-20211025173605-bda47ffaa784/go.mod h1:9YTyiznxEY1fVinfM7RvRcjRHbw2xLBJ3AAGIT0I4Nw=
-github.com/inkyblackness/imgui-go/v4 v4.3.0 h1:iyAzqWXq/dG5+6ckDPhGivtrIo6AywGQMvENKzun04s=
-github.com/inkyblackness/imgui-go/v4 v4.3.0/go.mod h1:g8SAGtOYUP7rYaOB2AsVKCEHmPMDmJKgt4z6d+flhb0=
 github.com/inkyblackness/imgui-go/v4 v4.5.0 h1:iUon7q0Hr0c0/Gc2V6bTP7Anu9WH7H26dI7JkPBmMEA=
 github.com/inkyblackness/imgui-go/v4 v4.5.0/go.mod h1:g8SAGtOYUP7rYaOB2AsVKCEHmPMDmJKgt4z6d+flhb0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=

level/level.go

@@ -0,0 +1,20 @@
+package level
+
+import (
+	"github.com/bloeys/nmage/assert"
+	"github.com/bloeys/nmage/entity"
+)
+
+type Level struct {
+	*entity.Registry
+	Name string
+}
+
+func NewLevel(name string, maxEntities uint32) *Level {
+
+	assert.T(name != "", "Level name can not be empty")
+	return &Level{
+		Name:     name,
+		Registry: entity.NewRegistry(maxEntities),
+	}
+}

main.go

@@ -20,7 +20,9 @@ import (
 )
 
 // @Todo:
-// Entities and components
+// Complete entity registry (e.g. HasEntity, GetEntity, Generational Indices etc...)
+// Helper functions to update active entities
+
 // Integrate physx
 // Create VAO struct independent from VBO to support multi-VBO use cases (e.g. instancing)
 // Renderer batching
@@ -50,8 +52,51 @@ type OurGame struct {
 	ImGUIInfo nmageimgui.ImguiInfo
 }
 
+// type TransformComp struct {
+// 	Pos   *gglm.Vec3
+// 	Rot   *gglm.Quat
+// 	Scale *gglm.Vec3
+// }
+
+// func (t TransformComp) Name() string {
+// 	return "Transform Component"
+// }
+
+// func Test() {
+
+// 	lvl := level.NewLevel("test level", 1000)
+// 	e := lvl.Registry.NewEntity()
+
+// 	trComp := entity.GetComp[*TransformComp](e)
+// 	fmt.Println("Got comp 1:", trComp)
+
+// 	e.Comps = append(e.Comps, &TransformComp{
+// 		Pos:   gglm.NewVec3(0, 0, 0),
+// 		Rot:   gglm.NewQuatEulerXYZ(0, 0, 0),
+// 		Scale: gglm.NewVec3(0, 0, 0),
+// 	}, &TransformComp{
+// 		Pos:   gglm.NewVec3(0, 0, 0),
+// 		Rot:   gglm.NewQuatEulerXYZ(0, 0, 0),
+// 		Scale: gglm.NewVec3(1, 1, 1),
+// 	})
+
+// 	trComp = entity.GetComp[*TransformComp](e)
+// 	fmt.Println("Got comp 2:", trComp)
+
+// 	trComps := entity.GetAllCompOfType[*TransformComp](e)
+// 	fmt.Printf("Got comp 3: %+v, %+v\n", trComps[0], trComps[1])
+
+// 	fmt.Printf("Entity: %+v\n", e)
+// 	fmt.Printf("Entity: %+v\n", lvl.Registry.NewEntity())
+// 	fmt.Printf("Entity: %+v\n", lvl.Registry.NewEntity())
+// 	fmt.Printf("Entity: %+v\n", lvl.Registry.NewEntity())
+// }
+
 func main() {
 
+	// Test()
+	// return
+
 	//Init engine
 	err := engine.Init()
 	if err != nil {