internal/uidriver/glfw: Add WheelDelta

examples/wheel/main.go

@@ -43,7 +43,7 @@ type Game struct {
 }
 
 func (g *Game) Update() error {
-	dx, dy := ebiten.Wheel()
+	dx, dy := ebiten.WheelDelta()
 	g.x += dx
 	g.y += dy
 	return nil

input.go

@@ -106,6 +106,10 @@ func Wheel() (xoff, yoff float64) {
 	return uiDriver().Input().Wheel()
 }
 
+func WheelDelta() (xoff, yoff float64) {
+	return uiDriver().Input().WheelDelta()
+}
+
 // IsMouseButtonPressed returns a boolean indicating whether mouseButton is pressed.
 //
 // If you want to know whether the mouseButton started being pressed in the current frame,

internal/driver/input.go

@@ -37,4 +37,5 @@ type Input interface {
 	StandardGamepadButtonValue(id GamepadID, button StandardGamepadButton) float64
 	TouchPosition(id TouchID) (x, y int)
 	Wheel() (xoff, yoff float64)
+	WheelDelta() (xoff, yoff float64)
 }

internal/uidriver/glfw/input.go

@@ -260,6 +260,16 @@ func (i *Input) Wheel() (xoff, yoff float64) {
 	return i.scrollX, i.scrollY
 }
 
+func (i *Input) WheelDelta() (xoff, yoff float64) {
+	if !i.ui.isRunning() {
+		return 0, 0
+	}
+
+	i.ui.m.RLock()
+	defer i.ui.m.RUnlock()
+	return i.scrollX * wheelFactor, i.scrollY * wheelFactor
+}
+
 var glfwMouseButtonToMouseButton = map[glfw.MouseButton]driver.MouseButton{
 	glfw.MouseButtonLeft:   driver.MouseButtonLeft,
 	glfw.MouseButtonRight:  driver.MouseButtonRight,

internal/uidriver/glfw/ui_darwin.go

@@ -194,3 +194,5 @@ func (u *UserInterface) adjustViewSize() {
 
 func initializeWindowAfterCreation(w *glfw.Window) {
 }
+
+const wheelFactor = 10

internal/uidriver/glfw/ui_unix.go

@@ -179,3 +179,5 @@ func initializeWindowAfterCreation(w *glfw.Window) {
 	// Apparently the window state is inconsistent just after the window is created, but we are not sure.
 	// For more details, see the discussion in #1829.
 }
+
+const wheelFactor = 53

internal/uidriver/glfw/ui_windows.go

@@ -193,3 +193,5 @@ func (u *UserInterface) adjustViewSize() {
 
 func initializeWindowAfterCreation(w *glfw.Window) {
 }
+
+const wheelFactor = 120

internal/uidriver/js/input_js.go

@@ -245,6 +245,10 @@ func (i *Input) Wheel() (xoff, yoff float64) {
 	return i.wheelX, i.wheelY
 }
 
+func (i *Input) WheelDelta() (xoff, yoff float64) {
+	return i.wheelX, i.wheelY
+}
+
 func (i *Input) keyDown(code js.Value) {
 	if i.keyPressed == nil {
 		i.keyPressed = map[int]bool{}

internal/uidriver/mobile/input.go

@@ -195,6 +195,10 @@ func (i *Input) Wheel() (xoff, yoff float64) {
 	return 0, 0
 }
 
+func (i *Input) WheelDelta() (xoff, yoff float64) {
+	return 0, 0
+}
+
 func (i *Input) IsMouseButtonPressed(key driver.MouseButton) bool {
 	return false
 }