FPS camera with pitch and yaw

camera/camera.go

@@ -38,7 +38,7 @@ type Camera struct {
 // Should be called whenever a camera parameter changes
 func (c *Camera) Update() {
 
-	c.ViewMat = gglm.LookAt(&c.Pos, c.Pos.Clone().Add(&c.Forward), &c.WorldUp).Mat4
+	c.ViewMat = gglm.LookAtRH(&c.Pos, c.Pos.Clone().Add(&c.Forward), &c.WorldUp).Mat4
 
 	if c.Type == Type_Perspective {
 		c.ProjMat = *gglm.Perspective(c.Fov, c.AspectRatio, c.NearClip, c.FarClip)
@@ -47,9 +47,15 @@ func (c *Camera) Update() {
 	}
 }
 
-func (c *Camera) LookAt(forward, worldUp *gglm.Vec3) {
+// UpdateRotation calculates a new forward vector and then calls camera.Update()
-	c.Forward = *forward
+func (c *Camera) UpdateRotation(pitch, yaw float32) {
-	c.WorldUp = *worldUp
+
+	dir := gglm.NewVec3(
+		gglm.Cos32(yaw)*gglm.Cos32(pitch),
+		gglm.Sin32(pitch),
+		gglm.Sin32(yaw)*gglm.Cos32(pitch),
+	)
+	c.Forward = *dir.Normalize()
 	c.Update()
 }
 

go.mod

@@ -2,12 +2,12 @@ module github.com/bloeys/nmage
 
 go 1.18
 
-require github.com/veandco/go-sdl2 v0.4.10
+require github.com/veandco/go-sdl2 v0.4.25
 
-require github.com/go-gl/gl v0.0.0-20211025173605-bda47ffaa784
+require github.com/go-gl/gl v0.0.0-20211210172815-726fda9656d6
 
 require (
 	github.com/bloeys/assimp-go v0.4.2
-	github.com/bloeys/gglm v0.41.10
+	github.com/bloeys/gglm v0.42.0
-	github.com/inkyblackness/imgui-go/v4 v4.5.0
+	github.com/inkyblackness/imgui-go/v4 v4.6.0
 )

go.sum

@@ -1,17 +1,17 @@
 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 v0.41.10 h1:R9FMiI+VQVXAI+vDwCB7z9xqzy5VAR1657u8TQTDNKA=
+github.com/bloeys/gglm v0.42.0 h1:UAUFGTaZv3dpZ0YSIQVum3bdeCZgNmx965VLnD2v11k=
-github.com/bloeys/gglm v0.41.10/go.mod h1:qwJQ0WzV191wAMwlGicbfbChbKoSedMk7gFFX6GnyOk=
+github.com/bloeys/gglm v0.42.0/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 v0.0.0-20211025173605-bda47ffaa784 h1:1Zi56D0LNfvkzM+BdoxKryvUEdyWO7LP8oRT+oSYJW0=
+github.com/go-gl/gl v0.0.0-20211210172815-726fda9656d6 h1:zDw5v7qm4yH7N8C8uWd+8Ii9rROdgWxQuGoJ9WDXxfk=
-github.com/go-gl/gl v0.0.0-20211025173605-bda47ffaa784/go.mod h1:9YTyiznxEY1fVinfM7RvRcjRHbw2xLBJ3AAGIT0I4Nw=
+github.com/go-gl/gl v0.0.0-20211210172815-726fda9656d6/go.mod h1:9YTyiznxEY1fVinfM7RvRcjRHbw2xLBJ3AAGIT0I4Nw=
-github.com/inkyblackness/imgui-go/v4 v4.5.0 h1:iUon7q0Hr0c0/Gc2V6bTP7Anu9WH7H26dI7JkPBmMEA=
+github.com/inkyblackness/imgui-go/v4 v4.6.0 h1:ShcnXEYl80+xREGBY9OpGWePA6FfJChY9Varsm+3jjE=
-github.com/inkyblackness/imgui-go/v4 v4.5.0/go.mod h1:g8SAGtOYUP7rYaOB2AsVKCEHmPMDmJKgt4z6d+flhb0=
+github.com/inkyblackness/imgui-go/v4 v4.6.0/go.mod h1:g8SAGtOYUP7rYaOB2AsVKCEHmPMDmJKgt4z6d+flhb0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
-github.com/veandco/go-sdl2 v0.4.10 h1:8QoD2bhWl7SbQDflIAUYWfl9Vq+mT8/boJFAUzAScgY=
+github.com/veandco/go-sdl2 v0.4.25 h1:J5ac3KKOccp/0xGJA1PaNYKPUcZm19IxhDGs8lJofPI=
-github.com/veandco/go-sdl2 v0.4.10/go.mod h1:OROqMhHD43nT4/i9crJukyVecjPNYYuCofep6SNiAjY=
+github.com/veandco/go-sdl2 v0.4.25/go.mod h1:OROqMhHD43nT4/i9crJukyVecjPNYYuCofep6SNiAjY=

main.go

@@ -36,20 +36,23 @@ import (
 // Material system editor with fields automatically extracted from the shader
 
 const (
-	camSpeed float32 = 15
+	camSpeed         = 15
+	mouseSensitivity = 0.5
 )
 
 var (
 	window *engine.Window
 
-	cam *camera.Camera
+	pitch float32 = 0
+	yaw   float32 = -90
+	cam   *camera.Camera
 
 	simpleMat *materials.Material
 	cubeMesh  *meshes.Mesh
 
 	cubeModelMat = gglm.NewTrMatId()
 
-	lightPos1   = gglm.NewVec3(2, 2, 0)
+	lightPos1   = gglm.NewVec3(-2, 0, 2)
 	lightColor1 = gglm.NewVec3(1, 1, 1)
 )
 
@@ -175,8 +178,8 @@ func (g *OurGame) Init() {
 	// Camera
 	winWidth, winHeight := g.Win.SDLWin.GetSize()
 	cam = camera.NewPerspective(
-		gglm.NewVec3(0, 0, -10),
+		gglm.NewVec3(0, 0, 10),
-		gglm.NewVec3(0, 0, 1),
+		gglm.NewVec3(0, 0, -1),
 		gglm.NewVec3(0, 1, 0),
 		0.1, 20,
 		45*gglm.Deg2Rad,
@@ -192,36 +195,28 @@ func (g *OurGame) Init() {
 
 }
 
+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) {
 		engine.Quit()
 	}
 
-	//Camera movement
+	g.updateCameraLookAround()
-	if input.KeyDown(sdl.K_w) {
+	g.updateCameraPos()
-		cam.Pos.Add(cam.WorldUp.Clone().Scale(camSpeed * timing.DT()))
-		updateViewMat()
-	} else if input.KeyDown(sdl.K_s) {
-		cam.Pos.Sub(cam.WorldUp.Clone().Scale(camSpeed * timing.DT()))
-		updateViewMat()
-	}
-
-	if input.KeyDown(sdl.K_d) {
-		cam.Pos.Add(gglm.Cross(&cam.WorldUp, &cam.Forward).Scale(camSpeed * timing.DT()))
-		updateViewMat()
-	} else if input.KeyDown(sdl.K_a) {
-		cam.Pos.Sub(gglm.Cross(&cam.WorldUp, &cam.Forward).Scale(camSpeed * timing.DT()))
-		updateViewMat()
-	}
-
-	if input.GetMouseWheelYNorm() > 0 {
-		cam.Pos.Add(&cam.Forward)
-		updateViewMat()
-	} else if input.GetMouseWheelYNorm() < 0 {
-		cam.Pos.Sub(&cam.Forward)
-		updateViewMat()
-	}
 
 	//Rotating cubes
 	if input.KeyDown(sdl.K_SPACE) {
@@ -229,10 +224,68 @@ func (g *OurGame) Update() {
 		simpleMat.SetUnifMat4("modelMat", &cubeModelMat.Mat4)
 	}
 
-	imgui.DragFloat3("Cam Pos", &cam.Pos.Data)
+	if imgui.DragFloat3("Cam Pos", &cam.Pos.Data) {
+		updateViewMat()
+	}
+	if imgui.DragFloat3("Cam Forward", &cam.Forward.Data) {
+		updateViewMat()
+	}
 
 	if input.KeyClicked(sdl.K_F4) {
-		fmt.Printf("Pos: %s; Forward: %s; Forward*WorldUp: %s\n", cam.Pos.String(), cam.Forward.String(), gglm.Cross(&cam.Forward, &cam.WorldUp))
+		fmt.Printf("Pos: %s; Forward: %s; |Forward|: %f\n", cam.Pos.String(), cam.Forward.String(), cam.Forward.Mag())
+	}
+}
+
+func (g *OurGame) updateCameraLookAround() {
+
+	mouseX, mouseY := input.GetMouseMotion()
+	if mouseX == 0 && mouseY == 0 {
+		return
+	}
+
+	// Yaw
+	yaw += float32(mouseX) * mouseSensitivity * timing.DT()
+
+	// Pitch
+	pitch += float32(-mouseY) * mouseSensitivity * timing.DT()
+	if pitch > 89.0 {
+		pitch = 89.0
+	}
+
+	if pitch < -89.0 {
+		pitch = -89.0
+	}
+
+	// Update cam forward
+	cam.UpdateRotation(pitch, yaw)
+
+	updateViewMat()
+}
+
+func (g *OurGame) updateCameraPos() {
+
+	update := false
+
+	// Forward and backward
+	if input.KeyDown(sdl.K_w) {
+		cam.Pos.Add(cam.Forward.Clone().Scale(camSpeed * timing.DT()))
+		update = true
+	} else if input.KeyDown(sdl.K_s) {
+		cam.Pos.Add(cam.Forward.Clone().Scale(-camSpeed * 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()))
+		update = true
+	} else if input.KeyDown(sdl.K_a) {
+		cam.Pos.Add(gglm.Cross(&cam.Forward, &cam.WorldUp).Normalize().Scale(-camSpeed * timing.DT()))
+		update = true
+	}
+
+	if update {
+		updateViewMat()
 	}
 }