Fix missing slider joystick handling on Windows

platform/windows/joypad_windows.cpp

@@ -172,6 +172,7 @@ bool JoypadWindows::setup_dinput_joypad(const DIDEVICEINSTANCE *instance) {
 	sprintf_s(uid, "%04x%04x%04x%04x%04x%04x%04x%04x", type, 0, vendor, 0, product, 0, version, 0);
 
 	id_to_change = joypad_count;
+	slider_count = 0;
 
 	joy->di_joy->SetDataFormat(&c_dfDIJoystick2);
 	joy->di_joy->SetCooperativeLevel(*hWnd, DISCL_FOREGROUND);
@@ -206,9 +207,12 @@ void JoypadWindows::setup_joypad_object(const DIDEVICEOBJECTINSTANCE *ob, int p_
 			ofs = DIJOFS_RY;
 		else if (ob->guidType == GUID_RzAxis)
 			ofs = DIJOFS_RZ;
-		else if (ob->guidType == GUID_Slider)
-			ofs = DIJOFS_SLIDER(0);
-		else
+		else if (ob->guidType == GUID_Slider) {
+			if (slider_count < 2) {
+				ofs = DIJOFS_SLIDER(slider_count);
+				slider_count++;
+			}
+		} else
 			return;
 		prop_range.diph.dwSize = sizeof(DIPROPRANGE);
 		prop_range.diph.dwHeaderSize = sizeof(DIPROPHEADER);
@@ -388,9 +392,9 @@ void JoypadWindows::process_joypads() {
 		}
 
 		// on mingw, these constants are not constants
-		int count = 6;
-		unsigned int axes[] = { DIJOFS_X, DIJOFS_Y, DIJOFS_Z, DIJOFS_RX, DIJOFS_RY, DIJOFS_RZ };
-		int values[] = { js.lX, js.lY, js.lZ, js.lRx, js.lRy, js.lRz };
+		int count = 8;
+		unsigned int axes[] = { DIJOFS_X, DIJOFS_Y, DIJOFS_Z, DIJOFS_RX, DIJOFS_RY, DIJOFS_RZ, DIJOFS_SLIDER(0), DIJOFS_SLIDER(1) };
+		int values[] = { js.lX, js.lY, js.lZ, js.lRx, js.lRy, js.lRz, js.rglSlider[0], js.rglSlider[1] };
 
 		for (int j = 0; j < joy->joy_axis.size(); j++) {
 			for (int k = 0; k < count; k++) {

platform/windows/joypad_windows.h

@@ -118,6 +118,7 @@ private:
 	Input *input;
 
 	int id_to_change;
+	int slider_count;
 	int joypad_count;
 	bool attached_joypads[JOYPADS_MAX];
 	dinput_gamepad d_joypads[JOYPADS_MAX];