Re-add IndexBufCount

.github/workflows/build-nmage.yml

@@ -1,22 +1,28 @@
 name: build-nmage
+
 on:
   create:
   workflow_dispatch:
 
 jobs:
   build-nmage-macos:
-    runs-on: macos-10.15
+    runs-on: macos-12
     steps:
-      - name: Install golang 1.17
-        uses: actions/setup-go@v2
+    
+      - name: Install golang 1.18
+        uses: actions/setup-go@v3
         with:
-          go-version: '^1.17'
+          go-version: '^1.18'
+
       - name: Install assimp-go dylib
         run: sudo mkdir -p /usr/local/lib && sudo wget https://github.com/bloeys/assimp-go/releases/download/v0.4.2/libassimp_darwin_amd64.dylib -O /usr/local/lib/libassimp.5.dylib
+
       - name: Install SDL2
         run: brew install sdl2{,_image,_mixer,_ttf,_gfx} pkg-config
+
       - name: Clone nmage
         run: git clone https://github.com/bloeys/nmage
+
       - name: build nmage
         working-directory: nmage
         run: go build .

README.md

@@ -1,6 +1,6 @@
 # nMage
 
-[![build](https://github.com/bloeys/nmage/actions/workflows/run-nmage.yml/badge.svg)](https://github.com/bloeys/nmage/actions/workflows/run-nmage.yml)
+[![build](https://github.com/bloeys/nmage/actions/workflows/build-nmage.yml/badge.svg)](https://github.com/bloeys/nmage/actions/workflows/build-nmage.yml)
 
 nMage is a (hopefully!) high performance 3D Game Engine written in Go being developed [live](https://twitch.tv/bloeys), with recordings posted on [YouTube](https://www.youtube.com/channel/UCCf4qyNGPVwpj1HYFGahs_A).
 

assert/assert.go

@@ -5,8 +5,9 @@ import (
 	"github.com/bloeys/nmage/logging"
 )
 
-func T(check bool, msg string) {
+func T(check bool, msg string, args ...any) {
+
 	if consts.Debug && !check {
-		logging.ErrLog.Panicln("Assert failed:", msg)
+		logging.ErrLog.Panicf("Assert failed: "+msg, args...)
 	}
 }

assets/assets.go

@@ -1,8 +1,8 @@
 package assets
 
 var (
-	Textures     map[uint32]Texture = make(map[uint32]Texture)
-	TexturePaths map[string]uint32  = make(map[string]uint32)
+	Textures     = make(map[uint32]Texture)
+	TexturePaths = make(map[string]uint32)
 )
 
 func AddTextureToCache(t Texture) {

assets/textures.go

@@ -2,10 +2,15 @@ package assets
 
 import (
 	"bytes"
+	"fmt"
 	"image"
 	"image/color"
+	"image/jpeg"
 	"image/png"
+	"io"
 	"os"
+	"path"
+	"strings"
 	"unsafe"
 
 	"github.com/go-gl/gl/v4.1-core/gl"
@@ -30,6 +35,18 @@ type TextureLoadOptions struct {
 	TryLoadFromCache bool
 	WriteToCache     bool
 	GenMipMaps       bool
+	KeepPixelsInMem  bool
+}
+
+type Cubemap struct {
+	// These only exists for textures loaded from disk
+	RightPath string
+	LeftPath  string
+	TopPath   string
+	BotPath   string
+	FrontPath string
+	BackPath  string
+	TexID     uint32
 }
 
 func LoadTexturePNG(file string, loadOptions *TextureLoadOptions) (Texture, error) {
@@ -57,27 +74,9 @@ func LoadTexturePNG(file string, loadOptions *TextureLoadOptions) (Texture, erro
 
 	tex := Texture{
 		Path: file,
-		Width:  int32(img.Bounds().Dx()),
-		Height: int32(img.Bounds().Dy()),
-		Pixels: make([]byte, img.Bounds().Dx()*img.Bounds().Dy()*4),
 	}
 
-	//NOTE: Load bottom left to top right because this is the texture coordinate system used by OpenGL
-	//NOTE: We only support 8-bit channels (32-bit colors) for now
-	i := 0
-	for y := img.Bounds().Dy() - 1; y >= 0; y-- {
-		for x := 0; x < img.Bounds().Dx(); x++ {
-
-			c := color.NRGBAModel.Convert(img.At(x, y)).(color.NRGBA)
-
-			tex.Pixels[i] = c.R
-			tex.Pixels[i+1] = c.G
-			tex.Pixels[i+2] = c.B
-			tex.Pixels[i+3] = c.A
-
-			i += 4
-		}
-	}
+	tex.Pixels, tex.Width, tex.Height = pixelsFromNrgbaPng(img)
 
 	//Prepare opengl stuff
 	gl.GenTextures(1, &tex.TexID)
@@ -100,37 +99,21 @@ func LoadTexturePNG(file string, loadOptions *TextureLoadOptions) (Texture, erro
 		AddTextureToCache(tex)
 	}
 
+	if !loadOptions.KeepPixelsInMem {
+		tex.Pixels = nil
+	}
+
 	return tex, nil
 }
 
-func LoadTextureInMemImg(img image.Image, loadOptions *TextureLoadOptions) (Texture, error) {
+func LoadTextureInMemPngImg(img image.Image, loadOptions *TextureLoadOptions) (Texture, error) {
 
 	if loadOptions == nil {
 		loadOptions = &TextureLoadOptions{}
 	}
 
-	tex := Texture{
-		Width:  int32(img.Bounds().Dx()),
-		Height: int32(img.Bounds().Dy()),
-		Pixels: make([]byte, img.Bounds().Dx()*img.Bounds().Dy()*4),
-	}
-
-	//NOTE: Load bottom left to top right because this is the texture coordinate system used by OpenGL
-	//NOTE: We only support 8-bit channels (32-bit colors) for now
-	i := 0
-	for y := img.Bounds().Dy() - 1; y >= 0; y-- {
-		for x := 0; x < img.Bounds().Dx(); x++ {
-
-			c := color.NRGBAModel.Convert(img.At(x, y)).(color.NRGBA)
-
-			tex.Pixels[i] = c.R
-			tex.Pixels[i+1] = c.G
-			tex.Pixels[i+2] = c.B
-			tex.Pixels[i+3] = c.A
-
-			i += 4
-		}
-	}
+	tex := Texture{}
+	tex.Pixels, tex.Width, tex.Height = pixelsFromNrgbaPng(img)
 
 	//Prepare opengl stuff
 	gl.GenTextures(1, &tex.TexID)
@@ -153,5 +136,173 @@ func LoadTextureInMemImg(img image.Image, loadOptions *TextureLoadOptions) (Text
 		AddTextureToCache(tex)
 	}
 
+	if !loadOptions.KeepPixelsInMem {
+		tex.Pixels = nil
+	}
+
 	return tex, nil
 }
+
+func LoadTextureJpeg(file string, loadOptions *TextureLoadOptions) (Texture, error) {
+
+	if loadOptions == nil {
+		loadOptions = &TextureLoadOptions{}
+	}
+
+	if loadOptions.TryLoadFromCache {
+		if tex, ok := GetTextureFromCachePath(file); ok {
+			return tex, nil
+		}
+	}
+
+	//Load from disk
+	fileBytes, err := os.ReadFile(file)
+	if err != nil {
+		return Texture{}, err
+	}
+
+	img, err := jpeg.Decode(bytes.NewReader(fileBytes))
+	if err != nil {
+		return Texture{}, err
+	}
+
+	tex := Texture{
+		Path: file,
+	}
+
+	tex.Pixels, tex.Width, tex.Height = pixelsFromNrgbaPng(img)
+
+	//Prepare opengl stuff
+	gl.GenTextures(1, &tex.TexID)
+	gl.BindTexture(gl.TEXTURE_2D, tex.TexID)
+
+	// set the texture wrapping/filtering options (on the currently bound texture object)
+	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.REPEAT)
+	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.REPEAT)
+	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
+	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
+
+	// load and generate the texture
+	gl.TexImage2D(gl.TEXTURE_2D, 0, gl.RGBA8, tex.Width, tex.Height, 0, gl.RGBA, gl.UNSIGNED_BYTE, unsafe.Pointer(&tex.Pixels[0]))
+
+	if loadOptions.GenMipMaps {
+		gl.GenerateMipmap(tex.TexID)
+	}
+
+	if loadOptions.WriteToCache {
+		AddTextureToCache(tex)
+	}
+
+	if !loadOptions.KeepPixelsInMem {
+		tex.Pixels = nil
+	}
+
+	return tex, nil
+}
+
+func pixelsFromNrgbaPng(img image.Image) (pixels []byte, width, height int32) {
+
+	//NOTE: Load bottom left to top right because this is the texture coordinate system used by OpenGL
+	//NOTE: We only support 8-bit channels (32-bit colors) for now
+	i := 0
+	width, height = int32(img.Bounds().Dx()), int32(img.Bounds().Dy())
+	pixels = make([]byte, img.Bounds().Dx()*img.Bounds().Dy()*4)
+	for y := img.Bounds().Dy() - 1; y >= 0; y-- {
+		for x := 0; x < img.Bounds().Dx(); x++ {
+
+			c := color.NRGBAModel.Convert(img.At(x, y)).(color.NRGBA)
+
+			pixels[i] = c.R
+			pixels[i+1] = c.G
+			pixels[i+2] = c.B
+			pixels[i+3] = c.A
+
+			i += 4
+		}
+	}
+
+	return pixels, width, height
+}
+
+func pixelsFromNrgbaJpg(img image.Image) (pixels []byte, width, height int32) {
+
+	//NOTE: Load bottom left to top right because this is the texture coordinate system used by OpenGL
+	//NOTE: We only support 8-bit channels (32-bit colors) for now
+	i := 0
+	width, height = int32(img.Bounds().Dx()), int32(img.Bounds().Dy())
+	pixels = make([]byte, img.Bounds().Dx()*img.Bounds().Dy()*4)
+	for y := img.Bounds().Dy() - 1; y >= 0; y-- {
+		for x := 0; x < img.Bounds().Dx(); x++ {
+
+			c := color.NRGBAModel.Convert(img.At(x, y)).(color.NRGBA)
+
+			pixels[i] = c.R
+			pixels[i+1] = c.G
+			pixels[i+2] = c.B
+			pixels[i+3] = c.A
+
+			i += 4
+		}
+	}
+
+	return pixels, width, height
+}
+
+func LoadCubemapTextures(rightTex, leftTex, topTex, botTex, frontTex, backTex string) (Cubemap, error) {
+
+	var imgDecoder func(r io.Reader) (image.Image, error)
+	var pixelDecoder func(image.Image) ([]byte, int32, int32)
+	ext := strings.ToLower(path.Ext(rightTex))
+	if ext == ".jpg" || ext == ".jpeg" {
+		imgDecoder = jpeg.Decode
+		pixelDecoder = pixelsFromNrgbaJpg
+	} else if ext == ".png" {
+		imgDecoder = png.Decode
+		pixelDecoder = pixelsFromNrgbaPng
+	} else {
+		return Cubemap{}, fmt.Errorf("unknown image extension: %s. Expected one of: .jpg, .jpeg, .png", ext)
+	}
+
+	cmap := Cubemap{
+		RightPath: rightTex,
+		LeftPath:  leftTex,
+		TopPath:   topTex,
+		BotPath:   botTex,
+		FrontPath: frontTex,
+		BackPath:  backTex,
+	}
+
+	gl.GenTextures(1, &cmap.TexID)
+	gl.BindTexture(gl.TEXTURE_CUBE_MAP, cmap.TexID)
+
+	// The order here matters
+	texturePaths := []string{rightTex, leftTex, topTex, botTex, frontTex, backTex}
+	for i := uint32(0); i < uint32(len(texturePaths)); i++ {
+
+		fPath := texturePaths[i]
+
+		//Load from disk
+		fileBytes, err := os.ReadFile(fPath)
+		if err != nil {
+			return Cubemap{}, err
+		}
+
+		img, err := imgDecoder(bytes.NewReader(fileBytes))
+		if err != nil {
+			return Cubemap{}, err
+		}
+
+		pixels, width, height := pixelDecoder(img)
+
+		gl.TexImage2D(uint32(gl.TEXTURE_CUBE_MAP_POSITIVE_X)+i, 0, gl.RGBA8, int32(width), int32(height), 0, gl.RGBA, gl.UNSIGNED_BYTE, unsafe.Pointer(&pixels[0]))
+	}
+
+	// set the texture wrapping/filtering options (on the currently bound texture object)
+	gl.TexParameteri(gl.TEXTURE_CUBE_MAP, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
+	gl.TexParameteri(gl.TEXTURE_CUBE_MAP, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
+	gl.TexParameteri(gl.TEXTURE_CUBE_MAP, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
+	gl.TexParameteri(gl.TEXTURE_CUBE_MAP, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
+	gl.TexParameteri(gl.TEXTURE_CUBE_MAP, gl.TEXTURE_WRAP_R, gl.CLAMP_TO_EDGE)
+
+	return cmap, nil
+}

buffers/buffers.go

@@ -11,7 +11,10 @@ type Buffer struct {
 	BufID uint32
 	// IndexBufID is the ID of the index/element buffer
 	IndexBufID uint32
+	// IndexBufCount is the number of elements in the index buffer
+	// Updated on SetIndexBufData
 	IndexBufCount int32
+	// IndexBufCount int32
 	Stride int32
 
 	layout []Element
@@ -101,7 +104,7 @@ func (b *Buffer) SetLayout(layout ...Element) {
 
 	for i := 0; i < len(layout); i++ {
 		gl.EnableVertexAttribArray(uint32(i))
-		gl.VertexAttribPointer(uint32(i), layout[i].ElementType.CompCount(), layout[i].ElementType.GLType(), false, b.Stride, gl.PtrOffset(layout[i].Offset))
+		gl.VertexAttribPointerWithOffset(uint32(i), layout[i].ElementType.CompCount(), layout[i].ElementType.GLType(), false, b.Stride, uintptr(layout[i].Offset))
 	}
 
 	b.UnBind()

engine/engine.go

@@ -112,7 +112,7 @@ func Init() error {
 
 func initSDL() error {
 
-	err := sdl.Init(sdl.INIT_EVERYTHING)
+	err := sdl.Init(sdl.INIT_TIMER | sdl.INIT_VIDEO)
 	if err != nil {
 		return err
 	}

engine/game.go

@@ -23,19 +23,26 @@ type Game interface {
 func Run(g Game, w *Window, ui nmageimgui.ImguiInfo) {
 
 	isRunning = true
+
+	// Run init with an active Imgui frame to allow init full imgui access
+	timing.FrameStarted()
+	w.handleInputs()
+
+	width, height := w.SDLWin.GetSize()
+	ui.FrameStart(float32(width), float32(height))
+
 	g.Init()
 
-	//Simulate an imgui frame during init so any imgui calls are allowed within init
-	tempWidth, tempHeight := w.SDLWin.GetSize()
-	tempFBWidth, tempFBHeight := w.SDLWin.GLGetDrawableSize()
-	ui.FrameStart(float32(tempWidth), float32(tempHeight))
-	ui.Render(float32(tempWidth), float32(tempHeight), tempFBWidth, tempFBHeight)
+	fbWidth, fbHeight := w.SDLWin.GLGetDrawableSize()
+	ui.Render(float32(width), float32(height), fbWidth, fbHeight)
+
+	timing.FrameEnded()
 
 	for isRunning {
 
 		//PERF: Cache these
-		width, height := w.SDLWin.GetSize()
-		fbWidth, fbHeight := w.SDLWin.GLGetDrawableSize()
+		width, height = w.SDLWin.GetSize()
+		fbWidth, fbHeight = w.SDLWin.GLGetDrawableSize()
 
 		timing.FrameStarted()
 		w.handleInputs()
@@ -43,7 +50,7 @@ func Run(g Game, w *Window, ui nmageimgui.ImguiInfo) {
 
 		g.Update()
 
-		gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
+		gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT | gl.STENCIL_BUFFER_BIT)
 		g.Render()
 		ui.Render(float32(width), float32(height), fbWidth, fbHeight)
 		w.SDLWin.GLSwap()

entity/base_comp.go

@@ -0,0 +1,27 @@
+package entity
+
+import "github.com/bloeys/nmage/assert"
+
+var _ Comp = &BaseComp{}
+
+type BaseComp struct {
+	Entity *Entity
+}
+
+func (b *BaseComp) base() {
+}
+
+func (b *BaseComp) Init(parent *Entity) {
+	assert.T(parent != nil, "Component was initialized with a nil parent. That is not allowed.")
+	b.Entity = parent
+}
+
+func (b *BaseComp) Name() string {
+	return "Base Component"
+}
+
+func (b *BaseComp) Update() {
+}
+
+func (b *BaseComp) Destroy() {
+}

entity/comp.go

@@ -0,0 +1,62 @@
+package entity
+
+import "github.com/bloeys/nmage/assert"
+
+type Comp interface {
+	// This ensures that implementors of the Comp interface
+	// always embed BaseComp
+	base()
+
+	Name() string
+	Init(parent *Entity)
+	Update()
+	Destroy()
+}
+
+func AddComp[T Comp](e *Entity, c T) {
+
+	assert.T(!HasComp[T](e), "Entity with id '%v' already has component of type '%T'", e.ID, c)
+
+	e.Comps = append(e.Comps, c)
+	c.Init(e)
+}
+
+func HasComp[T Comp](e *Entity) bool {
+
+	for i := 0; i < len(e.Comps); i++ {
+
+		_, ok := e.Comps[i].(T)
+		if ok {
+			return true
+		}
+	}
+
+	return false
+}
+
+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
+}
+
+// DestroyComp calls Destroy on the component and then removes it from the entities component list
+func DestroyComp[T Comp](e *Entity) {
+
+	for i := 0; i < len(e.Comps); i++ {
+
+		comp, ok := e.Comps[i].(T)
+		if ok {
+			comp.Destroy()
+			e.Comps = append(e.Comps[:i], e.Comps[i+1:]...)
+			return
+		}
+	}
+}

entity/entity.go

@@ -3,9 +3,8 @@ package entity
 type EntityFlag byte
 
 const (
-	EntityFlag_Unknown EntityFlag = 0
-	EntityFlag_Dead    EntityFlag = 1 << (iota - 1)
-	EntityFlag_Alive
+	EntityFlag_None  EntityFlag = 0
+	EntityFlag_Alive EntityFlag = 1 << (iota - 1)
 )
 
 const (
@@ -14,64 +13,37 @@ const (
 	IndexBitMask        = 0x00_00_FFFF_FFFF_FFFF
 )
 
+type EntityHandle uint64
+
 type Entity struct {
 
 	// Byte 1: Generation; Byte 2: Flags; Bytes 3-8: Index
-	ID    uint64
+	ID    EntityHandle
 	Comps []Comp
 }
 
-func GetGeneration(id uint64) byte {
+func (e *Entity) HasFlag(ef EntityFlag) bool {
+	return GetFlags(e.ID)&ef > 0
+}
+
+func (e *Entity) UpdateAllComps() {
+	for i := 0; i < len(e.Comps); i++ {
+		e.Comps[i].Update()
+	}
+}
+
+func GetGeneration(id EntityHandle) byte {
 	return byte(id >> GenerationShiftBits)
 }
 
-func GetFlags(id uint64) byte {
-	return byte(id >> FlagsShiftBits)
+func GetFlags(id EntityHandle) EntityFlag {
+	return EntityFlag(id >> FlagsShiftBits)
 }
 
-func GetIndex(id uint64) uint64 {
-	return id & IndexBitMask
+func GetIndex(id EntityHandle) uint64 {
+	return uint64(id & IndexBitMask)
 }
 
-func (e *Entity) HasFlag(ef EntityFlag) bool {
-	return GetFlags(e.ID)&byte(ef) > 0
-}
-
-func NewEntityId(generation, flags byte, index uint64) uint64 {
-	return index | (uint64(generation) << GenerationShiftBits) | (uint64(flags) << FlagsShiftBits)
-}
-
-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
+func NewEntityId(generation byte, flags EntityFlag, index uint64) EntityHandle {
+	return EntityHandle(index | (uint64(generation) << GenerationShiftBits) | (uint64(flags) << FlagsShiftBits))
 }

entity/registry.go

@@ -4,6 +4,12 @@ import (
 	"github.com/bloeys/nmage/assert"
 )
 
+var (
+	// The number of slots required to be in the free list before the free list
+	// is used for creating new entries
+	FreeListUsageThreshold uint32 = 20
+)
+
 type freeListitem struct {
 	EntityIndex uint64
 	nextFree    *freeListitem
@@ -12,7 +18,9 @@ type freeListitem struct {
 type Registry struct {
 	EntityCount uint64
 	Entities    []Entity
+
 	FreeList     *freeListitem
+	FreeListSize uint32
 }
 
 func (r *Registry) NewEntity() *Entity {
@@ -22,17 +30,18 @@ func (r *Registry) NewEntity() *Entity {
 	entityToUseIndex := uint64(0)
 	var entityToUse *Entity = nil
 
-	if r.FreeList != nil {
+	if r.FreeList != nil && r.FreeListSize > FreeListUsageThreshold {
 
 		entityToUseIndex = r.FreeList.EntityIndex
 		entityToUse = &r.Entities[entityToUseIndex]
 		r.FreeList = r.FreeList.nextFree
+		r.FreeListSize--
 	} else {
 
 		for i := 0; i < len(r.Entities); i++ {
 
 			e := &r.Entities[i]
-			if GetFlags(e.ID) != byte(EntityFlag_Unknown) && !e.HasFlag(EntityFlag_Dead) {
+			if e.HasFlag(EntityFlag_Alive) {
 				continue
 			}
 
@@ -47,12 +56,12 @@ func (r *Registry) NewEntity() *Entity {
 	}
 
 	r.EntityCount++
-	entityToUse.ID = NewEntityId(GetGeneration(entityToUse.ID)+1, byte(EntityFlag_Alive), entityToUseIndex)
+	entityToUse.ID = NewEntityId(GetGeneration(entityToUse.ID)+1, EntityFlag_Alive, entityToUseIndex)
 	assert.T(entityToUse.ID != 0, "Entity ID must not be zero")
 	return entityToUse
 }
 
-func (r *Registry) GetEntity(id uint64) *Entity {
+func (r *Registry) GetEntity(id EntityHandle) *Entity {
 
 	index := GetIndex(id)
 	gen := GetGeneration(id)
@@ -67,23 +76,29 @@ func (r *Registry) GetEntity(id uint64) *Entity {
 	return e
 }
 
-func (r *Registry) FreeEntity(id uint64) {
+// FreeEntity calls Destroy on all the entities components, resets the component list, resets the entity flags, then ads this entity to the free list
+func (r *Registry) FreeEntity(id EntityHandle) {
 
 	e := r.GetEntity(id)
 	if e == nil {
 		return
 	}
 
+	for i := 0; i < len(e.Comps); i++ {
+		e.Comps[i].Destroy()
+	}
+
 	r.EntityCount--
 	eIndex := GetIndex(e.ID)
 
 	e.Comps = []Comp{}
-	e.ID = NewEntityId(GetGeneration(e.ID), byte(EntityFlag_Dead), eIndex)
+	e.ID = NewEntityId(GetGeneration(e.ID), EntityFlag_None, eIndex)
 
 	r.FreeList = &freeListitem{
 		EntityIndex: eIndex,
 		nextFree:    r.FreeList,
 	}
+	r.FreeListSize++
 }
 
 func NewRegistry(size uint32) *Registry {

go.mod

@@ -8,6 +8,6 @@ require github.com/go-gl/gl v0.0.0-20211210172815-726fda9656d6
 
 require (
 	github.com/bloeys/assimp-go v0.4.4
-	github.com/bloeys/gglm v0.42.0
+	github.com/bloeys/gglm v0.43.0
 	github.com/inkyblackness/imgui-go/v4 v4.6.0
 )

go.sum

@@ -1,7 +1,7 @@
 github.com/bloeys/assimp-go v0.4.4 h1:Yn5e/RpE0Oes0YMBy8O7KkwAO4R/RpgrZPJCt08dVIU=
 github.com/bloeys/assimp-go v0.4.4/go.mod h1:my3yRxT7CfOztmvi+0svmwbaqw0KFrxaHxncoyaEIP0=
-github.com/bloeys/gglm v0.42.0 h1:UAUFGTaZv3dpZ0YSIQVum3bdeCZgNmx965VLnD2v11k=
-github.com/bloeys/gglm v0.42.0/go.mod h1:qwJQ0WzV191wAMwlGicbfbChbKoSedMk7gFFX6GnyOk=
+github.com/bloeys/gglm v0.43.0 h1:ZpOghR3PHfpkigTDh+FqxLsF0gN8CD6s/bWoei6LyxI=
+github.com/bloeys/gglm v0.43.0/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 v0.0.0-20211210172815-726fda9656d6 h1:zDw5v7qm4yH7N8C8uWd+8Ii9rROdgWxQuGoJ9WDXxfk=

main.go

@@ -3,7 +3,6 @@ package main
 import (
 	"fmt"
 
-	"github.com/bloeys/assimp-go/asig"
 	"github.com/bloeys/gglm/gglm"
 	"github.com/bloeys/nmage/assets"
 	"github.com/bloeys/nmage/camera"
@@ -17,14 +16,12 @@ import (
 	"github.com/bloeys/nmage/renderer/rend3dgl"
 	"github.com/bloeys/nmage/timing"
 	nmageimgui "github.com/bloeys/nmage/ui/imgui"
+	"github.com/go-gl/gl/v4.1-core/gl"
 	"github.com/inkyblackness/imgui-go/v4"
 	"github.com/veandco/go-sdl2/sdl"
 )
 
 // @Todo:
-// 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
@@ -48,12 +45,21 @@ var (
 	cam   *camera.Camera
 
 	simpleMat *materials.Material
+	skyboxMat *materials.Material
+
+	chairMesh  *meshes.Mesh
 	cubeMesh   *meshes.Mesh
+	skyboxMesh *meshes.Mesh
 
 	cubeModelMat = gglm.NewTrMatId()
 
 	lightPos1   = gglm.NewVec3(-2, 0, 2)
 	lightColor1 = gglm.NewVec3(1, 1, 1)
+
+	debugDepthMat        *materials.Material
+	debugDrawDepthBuffer bool
+
+	skyboxCmap assets.Cubemap
 )
 
 type OurGame struct {
@@ -62,12 +68,14 @@ type OurGame struct {
 }
 
 type TransformComp struct {
+	entity.BaseComp
+
 	Pos   *gglm.Vec3
 	Rot   *gglm.Quat
 	Scale *gglm.Vec3
 }
 
-func (t TransformComp) Name() string {
+func (t *TransformComp) Name() string {
 	return "Transform Component"
 }
 
@@ -77,23 +85,15 @@ func Test() {
 	e1 := lvl.Registry.NewEntity()
 
 	trComp := entity.GetComp[*TransformComp](e1)
-	fmt.Println("Got comp 1:", trComp)
+	fmt.Println("Get comp before adding any:", trComp)
 
-	e1.Comps = append(e1.Comps, &TransformComp{
+	entity.AddComp(e1, &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](e1)
-	fmt.Println("Got comp 2:", trComp)
-
-	trComps := entity.GetAllCompOfType[*TransformComp](e1)
-	fmt.Printf("Got comp 3: %+v, %+v\n", trComps[0], trComps[1])
+	fmt.Println("Get transform comp:", trComp)
 
 	fmt.Printf("Entity: %+v\n", e1)
 	fmt.Printf("Entity: %+v\n", lvl.Registry.NewEntity())
@@ -142,38 +142,60 @@ func (g *OurGame) handleWindowEvents(e sdl.Event) {
 			cam.Update()
 
 			simpleMat.SetUnifMat4("projMat", &cam.ProjMat)
+			debugDepthMat.SetUnifMat4("projMat", &cam.ProjMat)
 		}
 	}
 }
 
 func (g *OurGame) Init() {
 
+	var err error
+
 	//Create materials
-	simpleMat = materials.NewMaterial("Simple Mat", "./res/shaders/simple.glsl")
+	simpleMat = materials.NewMaterial("Simple mat", "./res/shaders/simple.glsl")
+	debugDepthMat = materials.NewMaterial("Debug depth mat", "./res/shaders/debug-depth.glsl")
+	skyboxMat = materials.NewMaterial("Skybox mat", "./res/shaders/skybox.glsl")
 
 	//Load meshes
-	var err error
-	cubeMesh, err = meshes.NewMesh("Cube", "./res/models/tex-cube.fbx", asig.PostProcess(0))
+	cubeMesh, err = meshes.NewMesh("Cube", "./res/models/tex-cube.fbx", 0)
 	if err != nil {
-		logging.ErrLog.Fatalln("Failed to load cube mesh. Err: ", err)
+		logging.ErrLog.Fatalln("Failed to load mesh. Err: ", err)
+	}
+
+	chairMesh, err = meshes.NewMesh("Chair", "./res/models/chair.fbx", 0)
+	if err != nil {
+		logging.ErrLog.Fatalln("Failed to load mesh. Err: ", err)
+	}
+
+	skyboxMesh, err = meshes.NewMesh("Skybox", "./res/models/skybox-cube.obj", 0)
+	if err != nil {
+		logging.ErrLog.Fatalln("Failed to load mesh. Err: ", err)
 	}
 
 	//Load textures
-	tex, err := assets.LoadTexturePNG("./res/textures/Low poly planet.png", nil)
+	tex, err := assets.LoadTexturePNG("./res/textures/pallete-endesga-64-1x.png", nil)
 	if err != nil {
 		logging.ErrLog.Fatalln("Failed to load texture. Err: ", err)
 	}
 
-	//Configure material
+	skyboxCmap, err = assets.LoadCubemapTextures(
+		"./res/textures/sb-right.jpg", "./res/textures/sb-left.jpg",
+		"./res/textures/sb-top.jpg", "./res/textures/sb-bottom.jpg",
+		"./res/textures/sb-front.jpg", "./res/textures/sb-back.jpg",
+	)
+	if err != nil {
+		logging.ErrLog.Fatalln("Failed to load cubemap. Err: ", err)
+	}
+
+	// Configure materials
 	simpleMat.DiffuseTex = tex.TexID
 
 	//Movement, scale and rotation
 	translationMat := gglm.NewTranslationMat(gglm.NewVec3(0, 0, 0))
-	scaleMat := gglm.NewScaleMat(gglm.NewVec3(0.25, 0.25, 0.25))
-	rotMat := gglm.NewRotMat(gglm.NewQuatEuler(gglm.NewVec3(0, 0, 0).AsRad()))
+	scaleMat := gglm.NewScaleMat(gglm.NewVec3(1, 1, 1))
+	rotMat := gglm.NewRotMat(gglm.NewQuatEuler(gglm.NewVec3(-90, -90, 0).AsRad()))
 
 	cubeModelMat.Mul(translationMat.Mul(rotMat.Mul(scaleMat)))
-	simpleMat.SetUnifMat4("modelMat", &cubeModelMat.Mat4)
 
 	// Camera
 	winWidth, winHeight := g.Win.SDLWin.GetSize()
@@ -181,11 +203,12 @@ func (g *OurGame) Init() {
 		gglm.NewVec3(0, 0, 10),
 		gglm.NewVec3(0, 0, -1),
 		gglm.NewVec3(0, 1, 0),
-		0.1, 20,
+		0.1, 200,
 		45*gglm.Deg2Rad,
 		float32(winWidth)/float32(winHeight),
 	)
 	simpleMat.SetUnifMat4("projMat", &cam.ProjMat)
+	debugDepthMat.SetUnifMat4("projMat", &cam.ProjMat)
 
 	updateViewMat()
 
@@ -194,21 +217,6 @@ func (g *OurGame) Init() {
 	simpleMat.SetUnifVec3("lightColor1", lightColor1)
 }
 
-// @TODO: Add this to gglm
-// func vecRotByQuat(v *gglm.Vec3, q *gglm.Quat) *gglm.Vec3 {
-
-// 	// Reference: https://gamedev.stackexchange.com/questions/28395/rotating-vector3-by-a-quaternion
-// 	qVec := gglm.NewVec3(q.X(), q.Y(), q.Z())
-
-// 	rotatedVec := qVec.Clone().Scale(2 * gglm.DotVec3(v, qVec))
-
-// 	t1 := q.W()*q.W() - gglm.DotVec3(qVec, qVec)
-// 	rotatedVec.Add(v.Clone().Scale(t1))
-
-// 	rotatedVec.Add(gglm.Cross(qVec, v).Scale(2 * q.W()))
-// 	return rotatedVec
-// }
-
 func (g *OurGame) Update() {
 
 	if input.IsQuitClicked() || input.KeyClicked(sdl.K_ESCAPE) {
@@ -221,7 +229,6 @@ func (g *OurGame) Update() {
 	//Rotating cubes
 	if input.KeyDown(sdl.K_SPACE) {
 		cubeModelMat.Rotate(10*timing.DT()*gglm.Deg2Rad, gglm.NewVec3(1, 1, 1).Normalize())
-		simpleMat.SetUnifMat4("modelMat", &cubeModelMat.Mat4)
 	}
 
 	if imgui.DragFloat3("Cam Pos", &cam.Pos.Data) {
@@ -231,15 +238,25 @@ func (g *OurGame) Update() {
 		updateViewMat()
 	}
 
+	if imgui.DragFloat3("Light Pos 1", &lightPos1.Data) {
+		simpleMat.SetUnifVec3("lightPos1", lightPos1)
+	}
+
+	if imgui.DragFloat3("Light Color 1", &lightColor1.Data) {
+		simpleMat.SetUnifVec3("lightColor1", lightColor1)
+	}
+
 	if input.KeyClicked(sdl.K_F4) {
 		fmt.Printf("Pos: %s; Forward: %s; |Forward|: %f\n", cam.Pos.String(), cam.Forward.String(), cam.Forward.Mag())
 	}
+
+	g.Win.SDLWin.SetTitle(fmt.Sprint("nMage (", timing.GetAvgFPS(), " fps)"))
 }
 
 func (g *OurGame) updateCameraLookAround() {
 
 	mouseX, mouseY := input.GetMouseMotion()
-	if mouseX == 0 && mouseY == 0 {
+	if (mouseX == 0 && mouseY == 0) || !input.MouseDown(sdl.BUTTON_RIGHT) {
 		return
 	}
 
@@ -266,21 +283,26 @@ func (g *OurGame) updateCameraPos() {
 
 	update := false
 
+	var camSpeedScale float32 = 1.0
+	if input.KeyDown(sdl.K_LSHIFT) {
+		camSpeedScale = 2
+	}
+
 	// Forward and backward
 	if input.KeyDown(sdl.K_w) {
-		cam.Pos.Add(cam.Forward.Clone().Scale(camSpeed * timing.DT()))
+		cam.Pos.Add(cam.Forward.Clone().Scale(camSpeed * camSpeedScale * timing.DT()))
 		update = true
 	} else if input.KeyDown(sdl.K_s) {
-		cam.Pos.Add(cam.Forward.Clone().Scale(-camSpeed * timing.DT()))
+		cam.Pos.Add(cam.Forward.Clone().Scale(-camSpeed * camSpeedScale * timing.DT()))
 		update = true
 	}
 
 	// Left and right
 	if input.KeyDown(sdl.K_d) {
-		cam.Pos.Add(gglm.Cross(&cam.Forward, &cam.WorldUp).Normalize().Scale(camSpeed * timing.DT()))
+		cam.Pos.Add(gglm.Cross(&cam.Forward, &cam.WorldUp).Normalize().Scale(camSpeed * camSpeedScale * timing.DT()))
 		update = true
 	} else if input.KeyDown(sdl.K_a) {
-		cam.Pos.Add(gglm.Cross(&cam.Forward, &cam.WorldUp).Normalize().Scale(-camSpeed * timing.DT()))
+		cam.Pos.Add(gglm.Cross(&cam.Forward, &cam.WorldUp).Normalize().Scale(-camSpeed * camSpeedScale * timing.DT()))
 		update = true
 	}
 
@@ -291,18 +313,54 @@ func (g *OurGame) updateCameraPos() {
 
 func (g *OurGame) Render() {
 
-	tempModelMat := cubeModelMat.Clone()
+	matToUse := simpleMat
+	imgui.Checkbox("Debug depth buffer", &debugDrawDepthBuffer)
+	if debugDrawDepthBuffer {
+		matToUse = debugDepthMat
+	}
 
-	rowSize := 100
+	tempModelMatrix := cubeModelMat.Clone()
+	window.Rend.Draw(chairMesh, tempModelMatrix, matToUse)
+
+	rowSize := 1
 	for y := 0; y < rowSize; y++ {
 		for x := 0; x < rowSize; x++ {
-			tempModelMat.Translate(gglm.NewVec3(-1, 0, 0))
-			window.Rend.Draw(cubeMesh, tempModelMat, simpleMat)
+			tempModelMatrix.Translate(gglm.NewVec3(-6, 0, 0))
+			window.Rend.Draw(cubeMesh, tempModelMatrix, matToUse)
 		}
-		tempModelMat.Translate(gglm.NewVec3(float32(rowSize), -1, 0))
+		tempModelMatrix.Translate(gglm.NewVec3(float32(rowSize), -1, 0))
 	}
 
-	g.Win.SDLWin.SetTitle(fmt.Sprint("nMage (", timing.GetAvgFPS(), " fps)"))
+	g.DrawSkybox()
+}
+
+func (g *OurGame) DrawSkybox() {
+
+	gl.Disable(gl.CULL_FACE)
+	gl.DepthFunc(gl.LEQUAL)
+	skyboxMesh.Buf.Bind()
+	skyboxMat.Bind()
+	gl.ActiveTexture(gl.TEXTURE0)
+	gl.BindTexture(gl.TEXTURE_CUBE_MAP, skyboxCmap.TexID)
+
+	viewMat := cam.ViewMat.Clone()
+	viewMat.Set(0, 3, 0)
+	viewMat.Set(1, 3, 0)
+	viewMat.Set(2, 3, 0)
+	viewMat.Set(3, 0, 0)
+	viewMat.Set(3, 1, 0)
+	viewMat.Set(3, 2, 0)
+	viewMat.Set(3, 3, 0)
+
+	skyboxMat.SetUnifMat4("viewMat", viewMat)
+	skyboxMat.SetUnifMat4("projMat", &cam.ProjMat)
+	// window.Rend.Draw(cubeMesh, gglm.NewTrMatId(), skyboxMat)
+	for i := 0; i < len(skyboxMesh.SubMeshes); i++ {
+		gl.DrawElementsBaseVertexWithOffset(gl.TRIANGLES, skyboxMesh.SubMeshes[i].IndexCount, gl.UNSIGNED_INT, uintptr(skyboxMesh.SubMeshes[i].BaseIndex), skyboxMesh.SubMeshes[i].BaseVertex)
+	}
+
+	gl.DepthFunc(gl.LESS)
+	gl.Enable(gl.CULL_FACE)
 }
 
 func (g *OurGame) FrameEnd() {
@@ -315,4 +373,5 @@ func (g *OurGame) DeInit() {
 func updateViewMat() {
 	cam.Update()
 	simpleMat.SetUnifMat4("viewMat", &cam.ViewMat)
+	debugDepthMat.SetUnifMat4("viewMat", &cam.ViewMat)
 }

meshes/mesh.go

@@ -10,9 +10,16 @@ import (
 	"github.com/bloeys/nmage/buffers"
 )
 
+type SubMesh struct {
+	BaseVertex int32
+	BaseIndex  uint32
+	IndexCount int32
+}
+
 type Mesh struct {
 	Name      string
 	Buf       buffers.Buffer
+	SubMeshes []SubMesh
 }
 
 func NewMesh(name, modelPath string, postProcessFlags asig.PostProcess) (*Mesh, error) {
@@ -27,32 +34,68 @@ func NewMesh(name, modelPath string, postProcessFlags asig.PostProcess) (*Mesh,
 		return nil, errors.New("No meshes found in file: " + modelPath)
 	}
 
-	mesh := &Mesh{Name: name}
-	sceneMesh := scene.Meshes[0]
-	mesh.Buf = buffers.NewBuffer()
+	mesh := &Mesh{
+		Name:      name,
+		Buf:       buffers.NewBuffer(),
+		SubMeshes: make([]SubMesh, 0, 1),
+	}
+
+	// Initial sizes assuming one submesh that has vertex pos+normals+texCoords, and 3 indices per face
+	var vertexBufData []float32 = make([]float32, 0, len(scene.Meshes[0].Vertices)*3*3*2)
+	var indexBufData []uint32 = make([]uint32, 0, len(scene.Meshes[0].Faces)*3)
+
+	for i := 0; i < len(scene.Meshes); i++ {
+
+		sceneMesh := scene.Meshes[i]
 
 		if len(sceneMesh.TexCoords[0]) == 0 {
 			sceneMesh.TexCoords[0] = make([]gglm.Vec3, len(sceneMesh.Vertices))
+			println("Zeroing tex coords for submesh", i)
 		}
 
 		layoutToUse := []buffers.Element{{ElementType: buffers.DataTypeVec3}, {ElementType: buffers.DataTypeVec3}, {ElementType: buffers.DataTypeVec2}}
-
 		if len(sceneMesh.ColorSets) > 0 && len(sceneMesh.ColorSets[0]) > 0 {
 			layoutToUse = append(layoutToUse, buffers.Element{ElementType: buffers.DataTypeVec4})
 		}
+
+		if i == 0 {
 			mesh.Buf.SetLayout(layoutToUse...)
+		} else {
+
+			// @NOTE: Require that all submeshes have the same vertex buffer layout
+			firstSubmeshLayout := mesh.Buf.GetLayout()
+			assert.T(len(firstSubmeshLayout) == len(layoutToUse), fmt.Sprintf("Vertex layout of submesh %d does not equal vertex layout of the first submesh. Original layout: %v; This layout: %v", i, firstSubmeshLayout, layoutToUse))
+
+			for i := 0; i < len(firstSubmeshLayout); i++ {
+				if firstSubmeshLayout[i].ElementType != layoutToUse[i].ElementType {
+					panic(fmt.Sprintf("Vertex layout of submesh %d does not equal vertex layout of the first submesh. Original layout: %v; This layout: %v", i, firstSubmeshLayout, layoutToUse))
+				}
+			}
+		}
 
-	var values []float32
 		arrs := []arrToInterleave{{V3s: sceneMesh.Vertices}, {V3s: sceneMesh.Normals}, {V2s: v3sToV2s(sceneMesh.TexCoords[0])}}
-
 		if len(sceneMesh.ColorSets) > 0 && len(sceneMesh.ColorSets[0]) > 0 {
 			arrs = append(arrs, arrToInterleave{V4s: sceneMesh.ColorSets[0]})
 		}
 
-	values = interleave(arrs...)
+		indices := flattenFaces(sceneMesh.Faces)
+		mesh.SubMeshes = append(mesh.SubMeshes, SubMesh{
 
-	mesh.Buf.SetData(values)
-	mesh.Buf.SetIndexBufData(flattenFaces(sceneMesh.Faces))
+			// Index of the vertex to start from (e.g. if index buffer says use vertex 5, and BaseVertex=3, the vertex used will be vertex 8)
+			BaseVertex: int32(len(vertexBufData)*4) / mesh.Buf.Stride,
+			// Which index (in the index buffer) to start from
+			BaseIndex: uint32(len(indexBufData)),
+			// How many indices in this submesh
+			IndexCount: int32(len(indices)),
+		})
+
+		vertexBufData = append(vertexBufData, interleave(arrs...)...)
+		indexBufData = append(indexBufData, indices...)
+	}
+
+	// fmt.Printf("!!! Vertex count: %d; Submeshes: %+v\n", len(vertexBufData)*4/int(mesh.Buf.Stride), mesh.SubMeshes)
+	mesh.Buf.SetData(vertexBufData)
+	mesh.Buf.SetIndexBufData(indexBufData)
 	return mesh, nil
 }
 

renderer/rend3dgl/rend3dgl.go

@@ -28,7 +28,10 @@ func (r3d *Rend3DGL) Draw(mesh *meshes.Mesh, trMat *gglm.TrMat, mat *materials.M
 	}
 
 	mat.SetUnifMat4("modelMat", &trMat.Mat4)
-	gl.DrawElements(gl.TRIANGLES, mesh.Buf.IndexBufCount, gl.UNSIGNED_INT, gl.PtrOffset(0))
+
+	for i := 0; i < len(mesh.SubMeshes); i++ {
+		gl.DrawElementsBaseVertexWithOffset(gl.TRIANGLES, mesh.SubMeshes[i].IndexCount, gl.UNSIGNED_INT, uintptr(mesh.SubMeshes[i].BaseIndex), mesh.SubMeshes[i].BaseVertex)
+	}
 }
 
 func (r3d *Rend3DGL) FrameEnd() {

res/models/obj.obj

@@ -1,46 +0,0 @@
-# Blender v2.92.0 OBJ File: ''
-# www.blender.org
-mtllib obj.mtl
-o Cube
-v 2.275618 1.000000 0.349413
-v 3.520138 -1.000000 0.102233
-v 2.275618 1.000000 0.752820
-v 3.520138 -1.000000 1.000000
-v 0.244520 1.000000 0.349413
-v -1.000000 -1.000000 0.102233
-v 0.244520 1.000000 0.752820
-v -1.000000 -1.000000 1.000000
-vt 0.806168 0.568832
-vt 0.693832 0.681168
-vt 0.693832 0.568832
-vt 0.375000 1.000000
-vt 0.375000 0.750000
-vt 0.375000 0.000000
-vt 0.625000 0.250000
-vt 0.375000 0.250000
-vt 0.375000 0.500000
-vt 0.125000 0.750000
-vt 0.125000 0.500000
-vt 0.806168 0.681168
-vt 0.625000 0.931168
-vt 0.625000 0.068832
-vn 0.0000 1.0000 0.0000
-vn 0.0000 0.1227 0.9924
-vn -0.8490 0.5283 0.0000
-vn 0.0000 -1.0000 0.0000
-vn 0.8490 0.5283 0.0000
-vn 0.0000 0.1227 -0.9924
-usemtl Material
-s off
-f 5/1/1 3/2/1 1/3/1
-f 3/2/2 8/4/2 4/5/2
-f 8/6/3 5/7/3 6/8/3
-f 2/9/4 8/10/4 6/11/4
-f 1/3/5 4/5/5 2/9/5
-f 5/7/6 2/9/6 6/8/6
-f 5/1/1 7/12/1 3/2/1
-f 3/2/2 7/13/2 8/4/2
-f 8/6/3 7/14/3 5/7/3
-f 2/9/4 4/5/4 8/10/4
-f 1/3/5 3/2/5 4/5/5
-f 5/7/6 1/3/6 2/9/6

res/models/skybox-cube.obj

@@ -0,0 +1,38 @@
+# Blender v2.92.0 OBJ File: 'chair.blend'
+# www.blender.org
+o Cube.002_Cube.005
+v -1.000000 -1.000000 1.000000
+v -1.000000 1.000000 1.000000
+v -1.000000 -1.000000 -1.000000
+v -1.000000 1.000000 -1.000000
+v 1.000000 -1.000000 1.000000
+v 1.000000 1.000000 1.000000
+v 1.000000 -1.000000 -1.000000
+v 1.000000 1.000000 -1.000000
+vt 0.375000 0.000000
+vt 0.625000 0.000000
+vt 0.625000 0.250000
+vt 0.375000 0.250000
+vt 0.625000 0.500000
+vt 0.375000 0.500000
+vt 0.625000 0.750000
+vt 0.375000 0.750000
+vt 0.625000 1.000000
+vt 0.375000 1.000000
+vt 0.125000 0.500000
+vt 0.125000 0.750000
+vt 0.875000 0.500000
+vt 0.875000 0.750000
+vn -1.0000 0.0000 0.0000
+vn 0.0000 0.0000 -1.0000
+vn 1.0000 0.0000 0.0000
+vn 0.0000 0.0000 1.0000
+vn 0.0000 -1.0000 0.0000
+vn 0.0000 1.0000 0.0000
+s off
+f 1/1/1 2/2/1 4/3/1 3/4/1
+f 3/4/2 4/3/2 8/5/2 7/6/2
+f 7/6/3 8/5/3 6/7/3 5/8/3
+f 5/8/4 6/7/4 2/9/4 1/10/4
+f 3/11/5 7/6/5 5/8/5 1/12/5
+f 8/5/6 4/13/6 2/14/6 6/7/6

res/shaders/debug-depth.glsl

@@ -0,0 +1,52 @@
+//shader:vertex
+#version 410
+
+layout(location=0) in vec3 vertPosIn;
+layout(location=1) in vec3 vertNormalIn;
+layout(location=2) in vec2 vertUV0In;
+layout(location=3) in vec3 vertColorIn;
+
+out vec3 vertNormal;
+out vec2 vertUV0;
+out vec3 vertColor;
+out vec3 fragPos;
+
+//MVP = Model View Projection
+uniform mat4 modelMat;
+uniform mat4 viewMat;
+uniform mat4 projMat;
+
+void main()
+{
+    vertNormal = mat3(transpose(inverse(modelMat))) * vertNormalIn;
+    vertUV0 = vertUV0In;
+    vertColor = vertColorIn;
+    fragPos = vec3(modelMat * vec4(vertPosIn, 1.0));
+
+    gl_Position = projMat * viewMat * modelMat * vec4(vertPosIn, 1.0);
+}
+
+//shader:fragment
+#version 410
+
+in vec3 vertColor;
+in vec3 vertNormal;
+in vec2 vertUV0;
+in vec3 fragPos;
+
+out vec4 fragColor;
+
+uniform float near = 0.1;
+uniform float far  = 200.0;
+  
+float LinearizeDepth(float depth) 
+{
+    float z = depth * 2.0 - 1.0; // back to NDC 
+    return (2.0 * near * far) / (far + near - z * (far - near));	
+}
+
+void main()
+{
+    float depth = LinearizeDepth(gl_FragCoord.z) / far;
+    fragColor = vec4(vec3(depth), 1.0);
+} 

res/shaders/simple.glsl

@@ -29,7 +29,7 @@ void main()
 //shader:fragment
 #version 410
 
-uniform float ambientStrength = 0.1;
+uniform float ambientStrength = 0;
 uniform vec3 ambientLightColor = vec3(1, 1, 1);
 
 uniform vec3 lightPos1;

res/shaders/skybox.glsl

@@ -0,0 +1,33 @@
+//shader:vertex
+#version 410
+
+layout(location=0) in vec3 vertPosIn;
+layout(location=1) in vec3 vertNormalIn;
+layout(location=2) in vec2 vertUV0In;
+layout(location=3) in vec3 vertColorIn;
+
+out vec3 vertUV0;
+
+uniform mat4 viewMat;
+uniform mat4 projMat;
+
+void main()
+{
+    vertUV0 = vec3(vertPosIn.x, vertPosIn.y, -vertPosIn.z);
+    vec4 pos = projMat * viewMat * vec4(vertPosIn, 1.0);
+    gl_Position = pos.xyww;
+}
+
+//shader:fragment
+#version 410
+
+in vec3 vertUV0;
+
+out vec4 fragColor;
+
+uniform samplerCube skybox;
+
+void main()
+{
+    fragColor = texture(skybox, vertUV0);
+}