Simplify the game interface

engine/engine.go

@@ -3,6 +3,7 @@ package engine
 import (
 	"runtime"
 
+	"github.com/bloeys/nmage/asserts"
 	"github.com/bloeys/nmage/input"
 	"github.com/bloeys/nmage/renderer"
 	"github.com/bloeys/nmage/timing"
@@ -11,6 +12,10 @@ import (
 	"github.com/veandco/go-sdl2/sdl"
 )
 
+var (
+	isInited = false
+)
+
 type Window struct {
 	SDLWin         *sdl.Window
 	GlCtx          sdl.GLContext
@@ -96,6 +101,8 @@ func (w *Window) Destroy() error {
 
 func Init() error {
 
+	isInited = true
+
 	runtime.LockOSThread()
 	timing.Init()
 	err := initSDL()
@@ -139,6 +146,7 @@ func CreateOpenGLWindowCentered(title string, width, height int32, flags WindowF
 
 func createWindow(title string, x, y, width, height int32, flags WindowFlags, rend renderer.Render) (*Window, error) {
 
+	asserts.T(isInited, "engine.Init was not called!")
 	if x == -1 && y == -1 {
 		x = sdl.WINDOWPOS_CENTERED
 		y = sdl.WINDOWPOS_CENTERED
@@ -186,6 +194,8 @@ func initOpenGL() error {
 }
 
 func SetVSync(enabled bool) {
+	asserts.T(isInited, "engine.Init was not called!")
+
 	if enabled {
 		sdl.GLSetSwapInterval(1)
 	} else {

engine/game.go

@@ -6,37 +6,32 @@ import (
 	"github.com/go-gl/gl/v4.1-core/gl"
 )
 
+var (
+	isRunning = false
+)
+
 type Game interface {
 	Init()
-	Start()
 
-	FrameStart()
 	Update()
 	Render()
 	FrameEnd()
-	ShouldRun() bool
 
-	GetWindow() *Window
-	GetImGUI() nmageimgui.ImguiInfo
-
-	Deinit()
+	DeInit()
 }
 
-func Run(g Game) {
-
-	w := g.GetWindow()
-	ui := g.GetImGUI()
+func Run(g Game, w *Window, ui nmageimgui.ImguiInfo) {
 
+	isRunning = true
 	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))
-	g.Start()
 	ui.Render(float32(tempWidth), float32(tempHeight), tempFBWidth, tempFBHeight)
 
-	for g.ShouldRun() {
+	for isRunning {
 
 		//PERF: Cache these
 		width, height := w.SDLWin.GetSize()
@@ -46,8 +41,6 @@ func Run(g Game) {
 		w.handleInputs()
 		ui.FrameStart(float32(width), float32(height))
 
-		g.FrameStart()
-
 		g.Update()
 
 		gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
@@ -60,5 +53,9 @@ func Run(g Game) {
 		timing.FrameEnded()
 	}
 
-	g.Deinit()
+	g.DeInit()
+}
+
+func Quit() {
+	isRunning = false
 }

main.go

@@ -22,6 +22,11 @@ import (
 // need to rebind the texutre if the texture (or any material values) change between draw calls
 // DT handling for when it is zero is wrong! (Gives 1000 DT)
 
+//nMage TODO:
+//	* Allow texture loading without cache
+//	* Move SetAttribute away from material struct
+//	* Create VAO struct independent from VBO to support multi-VBO use cases (e.g. instancing)
+
 //TODO: Tasks:
 // Build simple game
 // Integrate physx
@@ -39,8 +44,7 @@ import (
 // Material system editor with fields automatically extracted from the shader
 
 var (
-	isRunning bool = true
-	window    *engine.Window
+	window *engine.Window
 
 	simpleMat *materials.Material
 	cubeMesh  *meshes.Mesh
@@ -57,7 +61,6 @@ var (
 type OurGame struct {
 	Win       *engine.Window
 	ImGUIInfo nmageimgui.ImguiInfo
-	Quitting  bool
 }
 
 func (g *OurGame) Init() {
@@ -102,16 +105,10 @@ func (g *OurGame) Init() {
 	simpleMat.SetUnifVec3("lightColor1", lightColor1)
 }
 
-func (g *OurGame) Start() {
-}
-
-func (g *OurGame) FrameStart() {
-}
-
 func (g *OurGame) Update() {
 
 	if input.IsQuitClicked() {
-		g.Quitting = true
+		engine.Quit()
 	}
 
 	winWidth, winHeight := g.Win.SDLWin.GetSize()
@@ -167,25 +164,13 @@ func (g *OurGame) Render() {
 		tempModelMat.Translate(gglm.NewVec3(float32(rowSize), -1, 0))
 	}
 
-	g.GetWindow().SDLWin.SetTitle(fmt.Sprint("nMage (", timing.GetAvgFPS(), " fps)"))
+	g.Win.SDLWin.SetTitle(fmt.Sprint("nMage (", timing.GetAvgFPS(), " fps)"))
 }
 
 func (g *OurGame) FrameEnd() {
 }
 
-func (g *OurGame) ShouldRun() bool {
-	return !g.Quitting
-}
-
-func (g *OurGame) GetWindow() *engine.Window {
-	return g.Win
-}
-
-func (g *OurGame) GetImGUI() nmageimgui.ImguiInfo {
-	return g.ImGUIInfo
-}
-
-func (g *OurGame) Deinit() {
+func (g *OurGame) DeInit() {
 	g.Win.Destroy()
 }
 
@@ -211,8 +196,7 @@ func main() {
 		ImGUIInfo: nmageimgui.NewImGUI(),
 	}
 
-	engine.Run(game)
-	return
+	engine.Run(game, window, game.ImGUIInfo)
 }
 
 func updateViewMat() {