Correctly handle imgui mouse/keyboard capture

engine/engine.go

@@ -15,6 +15,10 @@ import (
 
 var (
 	isInited = false
+
+	isSdlButtonLeftDown   = false
+	isSdlButtonMiddleDown = false
+	isSdlButtonRightDown  = false
 )
 
 type Window struct {
@@ -29,7 +33,9 @@ func (w *Window) handleInputs() {
 	input.EventLoopStart()
 	imIo := imgui.CurrentIO()
 
-	// @TODO: Would be nice to have imgui package process its own events via a callback instead of it being part of engine code
+	imguiCaptureMouse := imIo.WantCaptureMouse()
+	imguiCaptureKeyboard := imIo.WantCaptureKeyboard()
+
 	for event := sdl.PollEvent(); event != nil; event = sdl.PollEvent() {
 
 		//Fire callbacks
@@ -42,14 +48,18 @@ func (w *Window) handleInputs() {
 
 		case *sdl.MouseWheelEvent:
 
+			if !imguiCaptureMouse {
 				input.HandleMouseWheelEvent(e)
+			}
 
-			xDelta, yDelta := input.GetMouseWheelMotion()
+			imIo.AddMouseWheelDelta(float32(e.X), float32(e.Y))
-			imIo.AddMouseWheelDelta(float32(xDelta), float32(yDelta))
 
 		case *sdl.KeyboardEvent:
 
+			if !imguiCaptureKeyboard {
 				input.HandleKeyboardEvent(e)
+			}
+
 			imIo.AddKeyEvent(nmageimgui.SdlScancodeToImGuiKey(e.Keysym.Scancode), e.Type == sdl.KEYDOWN)
 
 			// Send modifier key updates to imgui
@@ -73,12 +83,29 @@ func (w *Window) handleInputs() {
 			imIo.AddInputCharactersUTF8(e.GetText())
 
 		case *sdl.MouseButtonEvent:
+
+			if !imguiCaptureMouse {
 				input.HandleMouseBtnEvent(e)
+			}
+
+			isPressed := e.State == sdl.PRESSED
+
+			if e.Button == sdl.BUTTON_LEFT {
+				isSdlButtonLeftDown = isPressed
+			} else if e.Button == sdl.BUTTON_MIDDLE {
+				isSdlButtonMiddleDown = isPressed
+			} else if e.Button == sdl.BUTTON_RIGHT {
+				isSdlButtonRightDown = isPressed
+			}
 
 		case *sdl.MouseMotionEvent:
+
+			if !imguiCaptureMouse {
 				input.HandleMouseMotionEvent(e)
+			}
 
 		case *sdl.WindowEvent:
+
 			if e.Event == sdl.WINDOWEVENT_SIZE_CHANGED {
 				w.handleWindowResize()
 			}
@@ -92,9 +119,9 @@ func (w *Window) handleInputs() {
 	x, y, _ := sdl.GetMouseState()
 	imIo.SetMousePos(imgui.Vec2{X: float32(x), Y: float32(y)})
 
-	imIo.SetMouseButtonDown(0, input.MouseDown(sdl.BUTTON_LEFT))
+	imIo.SetMouseButtonDown(0, isSdlButtonLeftDown)
-	imIo.SetMouseButtonDown(1, input.MouseDown(sdl.BUTTON_RIGHT))
+	imIo.SetMouseButtonDown(1, isSdlButtonRightDown)
-	imIo.SetMouseButtonDown(2, input.MouseDown(sdl.BUTTON_MIDDLE))
+	imIo.SetMouseButtonDown(2, isSdlButtonMiddleDown)
 }
 
 func (w *Window) handleWindowResize() {

input/input.go

@@ -31,8 +31,8 @@ type mouseWheelState struct {
 }
 
 var (
-	keyMap        = make(map[sdl.Keycode]*keyState)
+	keyMap        = make(map[sdl.Keycode]keyState)
-	mouseBtnMap   = make(map[int]*mouseBtnState)
+	mouseBtnMap   = make(map[int]mouseBtnState)
 	mouseMotion   = mouseMotionState{}
 	mouseWheel    = mouseWheelState{}
 	quitRequested bool
@@ -70,29 +70,31 @@ func IsQuitClicked() bool {
 
 func HandleKeyboardEvent(e *sdl.KeyboardEvent) {
 
-	ks := keyMap[e.Keysym.Sym]
+	ks, ok := keyMap[e.Keysym.Sym]
-	if ks == nil {
+	if !ok {
-		ks = &keyState{Key: e.Keysym.Sym}
+		ks = keyState{Key: e.Keysym.Sym}
-		keyMap[ks.Key] = ks
 	}
 
 	ks.State = int(e.State)
 	ks.IsPressedThisFrame = e.State == sdl.PRESSED && e.Repeat == 0
 	ks.IsReleasedThisFrame = e.State == sdl.RELEASED && e.Repeat == 0
+
+	keyMap[ks.Key] = ks
 }
 
 func HandleMouseBtnEvent(e *sdl.MouseButtonEvent) {
 
-	mb := mouseBtnMap[int(e.Button)]
+	mb, ok := mouseBtnMap[int(e.Button)]
-	if mb == nil {
+	if !ok {
-		mb = &mouseBtnState{Btn: int(e.Button)}
+		mb = mouseBtnState{Btn: int(e.Button)}
-		mouseBtnMap[int(e.Button)] = mb
 	}
 
 	mb.State = int(e.State)
 	mb.IsDoubleClicked = e.Clicks == 2 && e.State == sdl.PRESSED
 	mb.IsPressedThisFrame = e.State == sdl.PRESSED
 	mb.IsReleasedThisFrame = e.State == sdl.RELEASED
+
+	mouseBtnMap[int(e.Button)] = mb
 }
 
 func HandleMouseMotionEvent(e *sdl.MouseMotionEvent) {
@@ -167,8 +169,8 @@ func GetMouseWheelYNorm() int32 {
 
 func KeyClicked(kc sdl.Keycode) bool {
 
-	ks := keyMap[kc]
+	ks, ok := keyMap[kc]
-	if ks == nil {
+	if !ok {
 		return false
 	}
 
@@ -177,8 +179,8 @@ func KeyClicked(kc sdl.Keycode) bool {
 
 func KeyReleased(kc sdl.Keycode) bool {
 
-	ks := keyMap[kc]
+	ks, ok := keyMap[kc]
-	if ks == nil {
+	if !ok {
 		return false
 	}
 
@@ -187,8 +189,8 @@ func KeyReleased(kc sdl.Keycode) bool {
 
 func KeyDown(kc sdl.Keycode) bool {
 
-	ks := keyMap[kc]
+	ks, ok := keyMap[kc]
-	if ks == nil {
+	if !ok {
 		return false
 	}
 
@@ -197,8 +199,8 @@ func KeyDown(kc sdl.Keycode) bool {
 
 func KeyUp(kc sdl.Keycode) bool {
 
-	ks := keyMap[kc]
+	ks, ok := keyMap[kc]
-	if ks == nil {
+	if !ok {
 		return true
 	}
 
@@ -207,8 +209,8 @@ func KeyUp(kc sdl.Keycode) bool {
 
 func MouseClicked(mb int) bool {
 
-	btn := mouseBtnMap[mb]
+	btn, ok := mouseBtnMap[mb]
-	if btn == nil {
+	if !ok {
 		return false
 	}
 
@@ -217,8 +219,8 @@ func MouseClicked(mb int) bool {
 
 func MouseDoubleClicked(mb int) bool {
 
-	btn := mouseBtnMap[mb]
+	btn, ok := mouseBtnMap[mb]
-	if btn == nil {
+	if !ok {
 		return false
 	}
 
@@ -226,8 +228,8 @@ func MouseDoubleClicked(mb int) bool {
 }
 
 func MouseReleased(mb int) bool {
-	btn := mouseBtnMap[mb]
+	btn, ok := mouseBtnMap[mb]
-	if btn == nil {
+	if !ok {
 		return false
 	}
 
@@ -236,8 +238,8 @@ func MouseReleased(mb int) bool {
 
 func MouseDown(mb int) bool {
 
-	btn := mouseBtnMap[mb]
+	btn, ok := mouseBtnMap[mb]
-	if btn == nil {
+	if !ok {
 		return false
 	}
 
@@ -246,8 +248,8 @@ func MouseDown(mb int) bool {
 
 func MouseUp(mb int) bool {
 
-	btn := mouseBtnMap[mb]
+	btn, ok := mouseBtnMap[mb]
-	if btn == nil {
+	if !ok {
 		return true
 	}