FEATURE: Removed fancy physics which didnt work on web and added a simple drag and drop mechanic to its place

src/game/capybara.go

@@ -73,7 +73,7 @@ func (c *Capybara) Draw(screen *ebiten.Image, level uint32) {
 
 	op := &ebiten.DrawImageOptions{}
 	capybaraBounds := c.Sprite.Img.Bounds()
-	scale := float64(screen.Bounds().Dx()) / float64(capybaraBounds.Dx()) / 2.5
+	scale := float64(screen.Bounds().Dx()) / float64(capybaraBounds.Dx()) / 2.0
 	c.Sprite.Scale = scale
 	op.GeoM.Scale(
 		scale+c.Sprite.Animation.Squish,

src/game/game.go

@@ -44,6 +44,8 @@ type Game struct {
 	FontFace            font.Face
 	PassiveIncomeTicker int
 	Screen              *ebiten.Image
+	TouchIDs            []ebiten.TouchID
+	Strokes             map[*Stroke]struct{}
 	Capybara            *Capybara
 	Background          *Sprite
 	MandarinRain        *MandarinRain
@@ -74,6 +76,8 @@ func NewGame() Game {
 			DPI:     72,
 			Hinting: font.HintingVertical,
 		}),
+		TouchIDs:            nil,
+		Strokes:             map[*Stroke]struct{}{},
 		PassiveIncomeTicker: 0,
 		MandarinRain:        NewMandarinRain(3, 8),
 	}
@@ -165,6 +169,30 @@ func (g *Game) Update() error {
 		g.MandarinRain = NewMandarinRain(3, 8)
 	}
 
+	if inpututil.IsMouseButtonJustPressed(ebiten.MouseButtonLeft) && g.MandarinRain.InProgress {
+		physical := g.MandarinRain.PhysicalAt(ebiten.CursorPosition())
+		if physical != nil {
+			s := NewStroke(&MouseStrokeSource{}, physical)
+			g.Strokes[s] = struct{}{}
+		}
+	}
+
+	g.TouchIDs = inpututil.AppendJustPressedTouchIDs(g.TouchIDs[:0])
+	for _, id := range g.TouchIDs {
+		physical := g.MandarinRain.PhysicalAt(ebiten.TouchPosition(id))
+		if physical != nil {
+			s := NewStroke(&TouchStrokeSource{id}, physical)
+			g.Strokes[s] = struct{}{}
+		}
+	}
+
+	for s := range g.Strokes {
+		s.Update(g)
+		if !s.Physical().Sprite.Dragged {
+			delete(g.Strokes, s)
+		}
+	}
+
 	return nil
 }
 

src/game/mandarinRain.go

@@ -22,7 +22,6 @@ import (
 	"math/rand"
 
 	"github.com/hajimehoshi/ebiten/v2"
-	"github.com/hajimehoshi/ebiten/v2/inpututil"
 )
 
 type MandarinRain struct {
@@ -35,12 +34,10 @@ type MandarinRain struct {
 	mandarinsInBox       uint16
 	boxFull              bool
 	mandarinCountRange   [2]uint16
-	// screenBounds         image.Rectangle
 }
 
 func NewMandarinRain(from uint16, to uint16) *MandarinRain {
 	rain := MandarinRain{}
-	// rain.screenBounds = WindowBounds()
 	rain.InProgress = false
 	rain.mandarinInitialCount = uint16(rand.Int31n(int32(to-from)) + int32(from))
 	rain.mandarinCountRange = [2]uint16{from, to}
@@ -59,6 +56,20 @@ func NewMandarinRain(from uint16, to uint16) *MandarinRain {
 	return &rain
 }
 
+func (mr *MandarinRain) PhysicalAt(x int, y int) *Physical {
+	for _, orange := range mr.Mandarins {
+		if orange.Sprite.IsIn(x, y) {
+			return orange
+		}
+	}
+
+	if mr.MandarinBox.Sprite.IsIn(x, y) {
+		return mr.MandarinBox
+	}
+
+	return nil
+}
+
 func (mr *MandarinRain) Run(game *Game) {
 	if mr.InProgress {
 		return
@@ -79,41 +90,12 @@ func (mr *MandarinRain) Run(game *Game) {
 }
 
 func (mr *MandarinRain) Update(game *Game) {
-	cPosX, cPosY := ebiten.CursorPosition()
-	var tPosX int = 0
-	var tPosY int = 0
-	if len(ebiten.AppendTouchIDs(nil)) != 0 {
-		tPosX, tPosY = ebiten.TouchPosition(ebiten.AppendTouchIDs(nil)[0])
-	}
-
 	// Oranges
 	temp := mr.Mandarins[:0]
 	for _, orange := range mr.Mandarins {
 		orange.Acceleration.Vx = 0.0
 		orange.Acceleration.Vy = 9.81 / orange.Mass
 
-		if ebiten.IsMouseButtonPressed(ebiten.MouseButtonLeft) &&
-			orange.InVicinity(float64(cPosX), float64(cPosY), 75.0) {
-			difference := newVec2f(
-				(float64(cPosX-orange.Sprite.RealBounds().Dx()/2)-orange.Sprite.X)*4.5,
-				(float64(cPosY-orange.Sprite.RealBounds().Dy()/2)-orange.Sprite.Y)*4.5,
-			)
-
-			orange.Acceleration.Vx = difference.Vx / orange.Mass
-			orange.Acceleration.Vy = difference.Vy / orange.Mass
-		} else if len(inpututil.AppendJustPressedTouchIDs(nil)) != 0 &&
-			orange.InVicinity(float64(tPosX), float64(tPosY), 75.0) {
-
-			tPosX, tPosY := ebiten.TouchPosition(ebiten.AppendTouchIDs(nil)[0])
-			difference := newVec2f(
-				(float64(tPosX-orange.Sprite.RealBounds().Dx()/2)-orange.Sprite.X)*4.5,
-				(float64(tPosY-orange.Sprite.RealBounds().Dy()/2)-orange.Sprite.Y)*4.5,
-			)
-
-			orange.Acceleration.Vx = difference.Vx / orange.Mass
-			orange.Acceleration.Vy = difference.Vy / orange.Mass
-		}
-
 		orange.Velocity.Vx = orange.Velocity.Vx + orange.Acceleration.Vx*0.05
 		orange.Velocity.Vy = orange.Velocity.Vy + orange.Acceleration.Vy*0.05
 
@@ -166,28 +148,6 @@ func (mr *MandarinRain) Update(game *Game) {
 	mr.MandarinBox.Acceleration.Vx = 0.0
 	mr.MandarinBox.Acceleration.Vy = 9.81 / mr.MandarinBox.Mass
 
-	if ebiten.IsMouseButtonPressed(ebiten.MouseButtonLeft) &&
-		mr.MandarinBox.InVicinity(float64(cPosX), float64(cPosY), 75.0) {
-		difference := newVec2f(
-			(float64(cPosX-mr.MandarinBox.Sprite.RealBounds().Dx()/2)-mr.MandarinBox.Sprite.X)*3.5,
-			(float64(cPosY-mr.MandarinBox.Sprite.RealBounds().Dy()/2)-mr.MandarinBox.Sprite.Y)*3.5,
-		)
-
-		mr.MandarinBox.Acceleration.Vx = difference.Vx / mr.MandarinBox.Mass
-		mr.MandarinBox.Acceleration.Vy = difference.Vy / mr.MandarinBox.Mass
-	} else if len(inpututil.AppendJustPressedTouchIDs(nil)) != 0 &&
-		mr.MandarinBox.InVicinity(float64(tPosX), float64(tPosY), 75.0) {
-
-		tPosX, tPosY := ebiten.TouchPosition(ebiten.AppendTouchIDs(nil)[0])
-		difference := newVec2f(
-			(float64(tPosX-mr.MandarinBox.Sprite.RealBounds().Dx()/2)-mr.MandarinBox.Sprite.X)*3.5,
-			(float64(tPosY-mr.MandarinBox.Sprite.RealBounds().Dy()/2)-mr.MandarinBox.Sprite.Y)*3.5,
-		)
-
-		mr.MandarinBox.Acceleration.Vx = difference.Vx / mr.MandarinBox.Mass
-		mr.MandarinBox.Acceleration.Vy = difference.Vy / mr.MandarinBox.Mass
-	}
-
 	mr.MandarinBox.Velocity.Vx = mr.MandarinBox.Velocity.Vx + mr.MandarinBox.Acceleration.Vx*0.05
 	mr.MandarinBox.Velocity.Vy = mr.MandarinBox.Velocity.Vy + mr.MandarinBox.Acceleration.Vy*0.05
 

src/game/sprite.go

@@ -38,6 +38,7 @@ type Sprite struct {
 	Y         float64
 	Animation AnimationData
 	Scale     float64
+	Dragged   bool
 }
 
 func NewSprite(img image.Image) *Sprite {
@@ -51,6 +52,7 @@ func NewSprite(img image.Image) *Sprite {
 			BounceDirectionFlag: false,
 		},
 		Scale:   1.0,
+		Dragged: false,
 	}
 }
 

src/game/stroke.go

@@ -0,0 +1,80 @@
+package game
+
+import (
+	"github.com/hajimehoshi/ebiten/v2"
+	"github.com/hajimehoshi/ebiten/v2/inpututil"
+)
+
+type StrokeSource interface {
+	Position() (int, int)
+	IsJustReleased() bool
+}
+
+type MouseStrokeSource struct{}
+
+func (m *MouseStrokeSource) Position() (int, int) {
+	return ebiten.CursorPosition()
+}
+
+func (m *MouseStrokeSource) IsJustReleased() bool {
+	return inpututil.IsMouseButtonJustReleased(ebiten.MouseButtonLeft)
+}
+
+type TouchStrokeSource struct {
+	ID ebiten.TouchID
+}
+
+func (t *TouchStrokeSource) Position() (int, int) {
+	return ebiten.TouchPosition(t.ID)
+}
+
+func (t *TouchStrokeSource) IsJustReleased() bool {
+	return inpututil.IsTouchJustReleased(t.ID)
+}
+
+type Stroke struct {
+	source   StrokeSource
+	offsetX  float64
+	offsetY  float64
+	physical *Physical
+}
+
+func NewStroke(source StrokeSource, physical *Physical) *Stroke {
+	physical.Sprite.Dragged = true
+	x, y := source.Position()
+	return &Stroke{
+		source:   source,
+		offsetX:  float64(x) - physical.Sprite.X,
+		offsetY:  float64(y) - physical.Sprite.Y,
+		physical: physical,
+	}
+}
+
+func (s *Stroke) Update(game *Game) {
+	if !s.physical.Sprite.Dragged {
+		return
+	}
+
+	// xp, yp := s.source.Position()
+	// difference := newVec2f(
+	// 	(float64(xp-s.physical.Sprite.RealBounds().Dx()/2)-s.physical.Sprite.X)*3.5,
+	// 	(float64(yp-s.physical.Sprite.RealBounds().Dy()/2)-s.physical.Sprite.Y)*3.5,
+	// )
+
+	// s.physical.Acceleration.Vx = difference.Vx / s.physical.Mass
+	// s.physical.Acceleration.Vy = difference.Vy / s.physical.Mass
+
+	if s.source.IsJustReleased() {
+		s.physical.Sprite.Dragged = false
+		return
+	}
+
+	ix, iy := s.source.Position()
+	x := float64(ix) - s.offsetX
+	y := float64(iy) - s.offsetY
+	s.physical.Sprite.MoveTo(x, y, game.Screen)
+}
+
+func (s *Stroke) Physical() *Physical {
+	return s.physical
+}

src/main.go

@@ -36,7 +36,7 @@ import (
 	"github.com/hajimehoshi/ebiten/v2"
 )
 
-const Version string = "v0.1.1-release"
+const Version string = "v0.1.2-release"
 
 var (
 	silent    *bool = flag.Bool("silent", false, "Set to true in order to discard all logging")