From 038765b2b081b43b815c879d59fa15202ca29356 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jean-Andr=C3=A9=20Santoni?= <jean.andre.santoni@gmail.com>
Date: Mon, 25 Oct 2021 10:20:15 +0700
Subject: [PATCH] Mouse support (#469)

---
 input/input.go       | 23 +++++++++++++++++++++++
 libretro/libretro.go | 17 ++++++++++++++++-
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/input/input.go b/input/input.go
index 5e221b9f..22ce36cf 100644
--- a/input/input.go
+++ b/input/input.go
@@ -32,6 +32,9 @@ var (
 	NewAnalogState AnalogStates // analog input state for the current frame
 )
 
+var oldMouseX float64
+var oldMouseY float64
+
 // Hot keys
 const (
 	// ActionMenuToggle toggles the menu UI
@@ -190,5 +193,25 @@ func State(port uint, device uint32, index uint, id uint) int16 {
 		return NewAnalogState[port][index][id]
 	}
 
+	if device == lr.DeviceMouse {
+		x, y := vid.Window.GetCursorPos()
+		if id == uint(lr.DeviceIDMouseX) {
+			d := x - oldMouseX
+			oldMouseX = x
+			return int16(d)
+		}
+		if id == uint(lr.DeviceIDMouseY) {
+			d := y - oldMouseY
+			oldMouseY = y
+			return int16(d)
+		}
+		if id == uint(lr.DeviceIDMouseLeft) && vid.Window.GetMouseButton(glfw.MouseButton1) == glfw.Press {
+			return 1
+		}
+		if id == uint(lr.DeviceIDMouseRight) && vid.Window.GetMouseButton(glfw.MouseButton2) == glfw.Press {
+			return 1
+		}
+	}
+
 	return 0
 }
diff --git a/libretro/libretro.go b/libretro/libretro.go
index 32f15248..381ce7f5 100644
--- a/libretro/libretro.go
+++ b/libretro/libretro.go
@@ -295,7 +295,7 @@ const (
 	DeviceIDJoypadMask = uint32(C.RETRO_DEVICE_ID_JOYPAD_MASK)
 )
 
-// Index / Id values for ANALOG device.
+// Index / Id values for analog device
 const (
 	DeviceIndexAnalogLeft   = uint32(C.RETRO_DEVICE_INDEX_ANALOG_LEFT)
 	DeviceIndexAnalogRight  = uint32(C.RETRO_DEVICE_INDEX_ANALOG_RIGHT)
@@ -304,6 +304,21 @@ const (
 	DeviceIDAnalogY         = uint32(C.RETRO_DEVICE_ID_ANALOG_Y)
 )
 
+// ID values for the mouse device
+const (
+	DeviceIDMouseX              = uint32(C.RETRO_DEVICE_ID_MOUSE_X)
+	DeviceIDMouseY              = uint32(C.RETRO_DEVICE_ID_MOUSE_Y)
+	DeviceIDMouseLeft           = uint32(C.RETRO_DEVICE_ID_MOUSE_LEFT)
+	DeviceIDMouseRight          = uint32(C.RETRO_DEVICE_ID_MOUSE_RIGHT)
+	DeviceIDMouseWheelUp        = uint32(C.RETRO_DEVICE_ID_MOUSE_WHEELUP)
+	DeviceIDMouseWheelDown      = uint32(C.RETRO_DEVICE_ID_MOUSE_WHEELDOWN)
+	DeviceIDMouseMiddle         = uint32(C.RETRO_DEVICE_ID_MOUSE_MIDDLE)
+	DeviceIDMouseHorizWheelUp   = uint32(C.RETRO_DEVICE_ID_MOUSE_HORIZ_WHEELUP)
+	DeviceIDMouseHorizWheelDown = uint32(C.RETRO_DEVICE_ID_MOUSE_HORIZ_WHEELDOWN)
+	DeviceIDMouseButton4        = uint32(C.RETRO_DEVICE_ID_MOUSE_BUTTON_4)
+	DeviceIDMouseButton5        = uint32(C.RETRO_DEVICE_ID_MOUSE_BUTTON_5)
+)
+
 // Environment callback API. See libretro.h for details
 const (
 	EnvironmentSetRotation                      = uint32(C.RETRO_ENVIRONMENT_SET_ROTATION)