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Zoom shake feature + noise types (#7)
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@setanarut
setanarut authored Sep 29, 2024
1 parent 262a5df commit fbea332
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Showing 4 changed files with 78 additions and 55 deletions.
125 changes: 73 additions & 52 deletions camera.go
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Original file line number Diff line number Diff line change
Expand Up @@ -5,7 +5,7 @@ import (
"math"

"github.com/hajimehoshi/ebiten/v2"
"github.com/ojrac/opensimplex-go"
"github.com/setanarut/fastnoise"
)

// Camera object
Expand All @@ -20,13 +20,12 @@ type Camera struct {
LerpSpeed float64

// Camera shake options
ShakeOptions CameraShakeOptions
ShakeOptions *CameraShakeOptions

// private
drawOptions *ebiten.DrawImageOptions
rotation, actualRotation, delta, tick, trauma, w, h float64
tempTarget, centerOffset, topLeft, traumaOffset vec2
noise opensimplex.Noise
drawOptions *ebiten.DrawImageOptions
angle, actualAngle, tickSpeed, tick, trauma, w, h, zoomFactorShake float64
tempTarget, centerOffset, topLeft, traumaOffset vec2
}

// NewCamera returns new Camera
Expand All @@ -38,28 +37,45 @@ func NewCamera(lookAtX, lookAtY, w, h float64) *Camera {
LerpSpeed: 0.1,
ShakeOptions: DefaultCameraShakeOptions(),
// private
w: w,
h: h,
rotation: 0,
trauma: 0,
drawOptions: &ebiten.DrawImageOptions{},
centerOffset: vec2{-(w * 0.5), -(h * 0.5)},
traumaOffset: vec2{},
topLeft: vec2{},
tempTarget: vec2{},
noise: opensimplex.New(1),
delta: 1.0 / 60.0,
tick: 0,
w: w,
h: h,
angle: 0,
zoomFactorShake: 1.0,
trauma: 0,
drawOptions: &ebiten.DrawImageOptions{},
centerOffset: vec2{-(w * 0.5), -(h * 0.5)},
traumaOffset: vec2{},
topLeft: vec2{},
tempTarget: vec2{},
tickSpeed: 1.0 / 60.0,
tick: 0,
}

c.LookAt(lookAtX, lookAtY)
c.tempTarget = target
return c
}

func DefaultCameraShakeOptions() *CameraShakeOptions {
opt := &CameraShakeOptions{
Noise: fastnoise.New[float64](),
MaxX: 10.0,
MaxY: 10.0,
MaxAngle: 0.05, // 5 degree
MaxZoomFactor: 0.1,
Decay: 0.666,
TimeScale: 10,
}
opt.Noise.Frequency = 0.5
return opt
}

// LookAt aligns the midpoint of the camera viewport to the target.
// Use this function only once in Update() and change only the TargetX TargetY variables
func (cam *Camera) LookAt(targetX, targetY float64) {

target := vec2{targetX, targetY}

if cam.Lerp {
cam.tempTarget = cam.tempTarget.Lerp(target, cam.LerpSpeed)
cam.topLeft = cam.tempTarget
Expand All @@ -68,22 +84,37 @@ func (cam *Camera) LookAt(targetX, targetY float64) {
}

if cam.trauma > 0 {

var shake = math.Pow(cam.trauma, 2)
cam.traumaOffset.X = cam.noise.Eval3(cam.tick*cam.ShakeOptions.TimeScale, 0, 0) * cam.ShakeOptions.ShakeSizeX * shake
cam.traumaOffset.Y = cam.noise.Eval3(0, cam.tick*cam.ShakeOptions.TimeScale, 0) * cam.ShakeOptions.ShakeSizeY * shake
cam.actualRotation = cam.noise.Eval3(0, 0, cam.tick*cam.ShakeOptions.TimeScale) * cam.ShakeOptions.MaxShakeAngle * shake
cam.trauma = clamp(cam.trauma-(cam.delta*cam.ShakeOptions.Decay), 0, 1)
} else {
cam.actualRotation = 0.0

noiseValueX := cam.ShakeOptions.Noise.GetNoise3D(cam.tick*cam.ShakeOptions.TimeScale, 0, 0)
noiseValueY := cam.ShakeOptions.Noise.GetNoise3D(0, cam.tick*cam.ShakeOptions.TimeScale, 0)
noiseValueAngle := cam.ShakeOptions.Noise.GetNoise3D(0, 0, cam.tick*cam.ShakeOptions.TimeScale)

cam.traumaOffset.X = noiseValueX * cam.ShakeOptions.MaxX * shake
cam.traumaOffset.Y = noiseValueY * cam.ShakeOptions.MaxY * shake
cam.actualAngle = noiseValueAngle * cam.ShakeOptions.MaxAngle * shake

noiseValueZoom := cam.ShakeOptions.Noise.GetNoise3D(cam.tick*cam.ShakeOptions.TimeScale+300, 0, 0)
cam.zoomFactorShake = (noiseValueZoom * cam.ShakeOptions.MaxZoomFactor * shake)
cam.zoomFactorShake *= cam.ZoomFactor
cam.zoomFactorShake += cam.ZoomFactor

cam.trauma = clamp(cam.trauma-(cam.tickSpeed*cam.ShakeOptions.Decay), 0, 1)

} else {
cam.actualAngle = 0.0
cam.zoomFactorShake = cam.ZoomFactor
}

// offset
cam.actualRotation += cam.rotation
cam.actualAngle += cam.angle
cam.topLeft = cam.topLeft.Add(cam.traumaOffset)
cam.topLeft = cam.topLeft.Add(cam.centerOffset)
cam.tick += cam.delta
if cam.tick > 60000 {

// tick
cam.tick += cam.tickSpeed
if cam.tick > 1000000 {
cam.tick = 0
}
}
Expand All @@ -106,17 +137,17 @@ func (cam *Camera) Target() (X float64, Y float64) {

// ActualAngle returns camera rotation angle (including the angle of trauma shaking.). The unit is radian.
func (cam *Camera) ActualAngle() (angle float64) {
return cam.actualRotation
return cam.actualAngle
}

// Angle returns camera rotation angle (The angle of trauma shake is not included.). The unit is radian.
func (cam *Camera) Angle() (angle float64) {
return cam.rotation
return cam.angle
}

// SetAngle sets rotation. The unit is radian.
func (cam *Camera) SetAngle(angle float64) {
cam.rotation = angle
cam.angle = angle
}

// Width returns width of the camera
Expand All @@ -137,15 +168,15 @@ func (cam *Camera) SetSize(w, h float64) {

// Reset resets rotation and zoom factor to zero
func (cam *Camera) Reset() {
cam.rotation, cam.ZoomFactor = 0.0, 1.0
cam.angle, cam.ZoomFactor, cam.zoomFactorShake = 0.0, 1.0, 1.0
}

// String returns camera values as string
func (cam *Camera) String() string {
x, y := cam.Target()
return fmt.Sprintf(
"TargetX: %.1f\nTargetY: %.1f\nCam Rotation: %.1f\nZoom factor: %.2f\nLerp: %v",
x, y, cam.ActualAngle(), cam.ZoomFactor, cam.Lerp,
x, y, cam.ActualAngle(), cam.zoomFactorShake, cam.Lerp,
)
}

Expand All @@ -167,8 +198,8 @@ func (cam *Camera) ScreenToWorld(screenX, screenY int) (worldX float64, worldY f
func (cam *Camera) ApplyCameraTransform(geoM *ebiten.GeoM) {
geoM.Translate(-cam.topLeft.X, -cam.topLeft.Y) // camera movement
geoM.Translate(cam.centerOffset.X, cam.centerOffset.Y) // rotate and scale from center.
geoM.Rotate(cam.actualRotation) // rotate
geoM.Scale(cam.ZoomFactor, cam.ZoomFactor) // apply zoom factor
geoM.Rotate(cam.actualAngle) // rotate
geoM.Scale(cam.zoomFactorShake, cam.zoomFactorShake) // apply zoom factor
geoM.Translate(math.Abs(cam.centerOffset.X), math.Abs(cam.centerOffset.Y)) // restore center translation
}

Expand All @@ -181,22 +212,12 @@ func (cam *Camera) Draw(worldObject *ebiten.Image, worldObjectOps *ebiten.DrawIm
}

type CameraShakeOptions struct {
TimeScale float64
// Max shake angle (radians)
MaxShakeAngle float64
ShakeSizeX float64
ShakeSizeY float64
Decay float64
}

func DefaultCameraShakeOptions() CameraShakeOptions {

return CameraShakeOptions{
ShakeSizeX: 150.0,
ShakeSizeY: 150.0,
MaxShakeAngle: 0.5235987756, // 30 degree
TimeScale: 16,
Decay: 0.333,
}

// Noise generator for noise types and settings.
Noise *fastnoise.State[float64]
MaxX float64 // Maximum X-axis shake. 0 means disabled
MaxY float64 // Maximum Y-axis shake. 0 means disabled
MaxAngle float64 // Max shake angle (radians). 0 means disabled
MaxZoomFactor float64 // Zoom factor strength [1-0]. 0 means disabled
TimeScale float64 // Noise time domain speed
Decay float64 // Decay for trauma
}
4 changes: 2 additions & 2 deletions examples/demo/main.go
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Original file line number Diff line number Diff line change
Expand Up @@ -23,7 +23,7 @@ var (
| Key | Action |
| ------------ | -------------------------- |
| WASD | Move camera |
| T | Add 0.6 Trauma |
| T | Add 1.0 Trauma |
| E/Q | Zoom in/out |
| Tab | Look at random position |
| ArrowUp/Down | Zoom 2x |
Expand Down Expand Up @@ -53,7 +53,7 @@ func (g *Game) Update() error {
cam.Lerp = !cam.Lerp
}
if inpututil.IsKeyJustPressed(ebiten.KeyT) {
cam.AddTrauma(0.6)
cam.AddTrauma(1.0)
}

if inpututil.IsKeyJustPressed(ebiten.KeyArrowUp) {
Expand Down
2 changes: 1 addition & 1 deletion go.mod
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Original file line number Diff line number Diff line change
Expand Up @@ -4,14 +4,14 @@ go 1.23.1

require (
github.com/hajimehoshi/ebiten/v2 v2.8.0
github.com/ojrac/opensimplex-go v1.0.2
)

require (
github.com/ebitengine/gomobile v0.0.0-20240911145611-4856209ac325 // indirect
github.com/ebitengine/hideconsole v1.0.0 // indirect
github.com/ebitengine/purego v0.8.0 // indirect
github.com/jezek/xgb v1.1.1 // indirect
github.com/setanarut/fastnoise v1.1.1
golang.org/x/sync v0.8.0 // indirect
golang.org/x/sys v0.25.0 // indirect
)
Expand Down
2 changes: 2 additions & 0 deletions go.sum
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Original file line number Diff line number Diff line change
Expand Up @@ -10,6 +10,8 @@ github.com/jezek/xgb v1.1.1 h1:bE/r8ZZtSv7l9gk6nU0mYx51aXrvnyb44892TwSaqS4=
github.com/jezek/xgb v1.1.1/go.mod h1:nrhwO0FX/enq75I7Y7G8iN1ubpSGZEiA3v9e9GyRFlk=
github.com/ojrac/opensimplex-go v1.0.2 h1:l4vs0D+JCakcu5OV0kJ99oEaWJfggSc9jiLpxaWvSzs=
github.com/ojrac/opensimplex-go v1.0.2/go.mod h1:NwbXFFbXcdGgIFdiA7/REME+7n/lOf1TuEbLiZYOWnM=
github.com/setanarut/fastnoise v1.1.1 h1:cD9gUjY9GMxVab+B7AY09j2GAHMdiKzchDE5z6dQ7eE=
github.com/setanarut/fastnoise v1.1.1/go.mod h1:74vG3/RcPPcNi2M0riHJXQp9/+eTSh0rnQ/0WTEY6SU=
golang.org/x/image v0.20.0 h1:7cVCUjQwfL18gyBJOmYvptfSHS8Fb3YUDtfLIZ7Nbpw=
golang.org/x/image v0.20.0/go.mod h1:0a88To4CYVBAHp5FXJm8o7QbUl37Vd85ply1vyD8auM=
golang.org/x/sync v0.8.0 h1:3NFvSEYkUoMifnESzZl15y791HH1qU2xm6eCJU5ZPXQ=
Expand Down

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