Index: ps/trunk/source/gui/ObjectTypes/CSlider.cpp
===================================================================
--- ps/trunk/source/gui/ObjectTypes/CSlider.cpp	(revision 26212)
+++ ps/trunk/source/gui/ObjectTypes/CSlider.cpp	(revision 26213)
@@ -1,127 +1,131 @@
-/* Copyright (C) 2021 Wildfire Games.
+/* Copyright (C) 2022 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation, either version 2 of the License, or
  * (at your option) any later version.
  *
  * 0 A.D. is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 #include "precompiled.h"
 
 #include "CSlider.h"
 
 #include "gui/CGUI.h"
 #include "maths/MathUtil.h"
 
 const CStr CSlider::EventNameValueChange = "ValueChange";
 
 CSlider::CSlider(CGUI& pGUI)
 	: IGUIObject(pGUI),
 	  IGUIButtonBehavior(*static_cast<IGUIObject*>(this)),
 	  m_ButtonSide(this, "button_width"),
 	  m_MaxValue(this, "max_value"),
 	  m_MinValue(this, "min_value"),
 	  m_Sprite(this, "sprite"),
 	  m_SpriteDisabled(this, "sprite_disabled"),
 	  m_SpriteBar(this, "sprite_bar"),
 	  m_SpriteBarDisabled(this, "sprite_bar_disabled"),
 	  m_Value(this, "value")
 {
 	m_Value.Set(Clamp<float>(m_Value, m_MinValue, m_MaxValue), false);
 }
 
 CSlider::~CSlider()
 {
 }
 
 void CSlider::ResetStates()
 {
 	IGUIObject::ResetStates();
 	IGUIButtonBehavior::ResetStates();
 }
 
 float CSlider::GetSliderRatio() const
 {
 	return (m_MaxValue - m_MinValue) / (m_CachedActualSize.GetWidth() - m_ButtonSide);
 }
 
 void CSlider::IncrementallyChangeValue(const float difference)
 {
 	m_Value.Set(Clamp<float>(m_Value + difference, m_MinValue, m_MaxValue), true);
 	UpdateValue();
 }
 
 void CSlider::HandleMessage(SGUIMessage& Message)
 {
 	IGUIObject::HandleMessage(Message);
 	IGUIButtonBehavior::HandleMessage(Message);
 
 	switch (Message.type)
 	{
 	/*
 	case GUIM_SETTINGS_UPDATED:
 	{
 		m_Value.Set(Clamp<float>(m_Value, m_MinValue, m_MaxValue), true);
 		break;
 	}
 	*/
 	case GUIM_MOUSE_WHEEL_DOWN:
 	{
 		if (m_Pressed)
 			break;
 		IncrementallyChangeValue(-0.01f);
 		break;
 	}
 	case GUIM_MOUSE_WHEEL_UP:
 	{
 		if (m_Pressed)
 			break;
 		IncrementallyChangeValue(0.01f);
 		break;
 	}
 	case GUIM_MOUSE_PRESS_LEFT:
 		FALLTHROUGH;
 	case GUIM_MOUSE_MOTION:
 	{
 		if (m_Pressed)
 		{
 			m_Mouse = m_pGUI.GetMousePos();
 			IncrementallyChangeValue((m_Mouse.X - GetButtonRect().CenterPoint().X) * GetSliderRatio());
 		}
 		break;
 	}
 	default:
 		break;
 	}
 }
 
 void CSlider::Draw(CCanvas2D& canvas)
 {
 	CRect sliderLine(m_CachedActualSize);
 	sliderLine.left += m_ButtonSide / 2.0f;
 	sliderLine.right -= m_ButtonSide / 2.0f;
 	m_pGUI.DrawSprite(IsEnabled() ? m_SpriteBar : m_SpriteBarDisabled, canvas, sliderLine);
 	m_pGUI.DrawSprite(IsEnabled() ? m_Sprite : m_SpriteDisabled, canvas, GetButtonRect());
 }
 
 void CSlider::UpdateValue()
 {
 	ScriptEvent(EventNameValueChange);
 }
 
 CRect CSlider::GetButtonRect() const
 {
-	float ratio = m_MaxValue > m_MinValue ? (m_Value - m_MinValue) / (m_MaxValue - m_MinValue) : 0.0f;
+	// Even if the value is incorrect it doesn't make sense to draw it outside
+	// of the element bounds. Because that value might be set intentionally in the
+	// config for debug purposes.
+	const float value = Clamp<float>(m_Value, m_MinValue, m_MaxValue);
+	float ratio = m_MaxValue > m_MinValue ? (value - m_MinValue) / (m_MaxValue - m_MinValue) : 0.0f;
 	float x = m_CachedActualSize.left + ratio * (m_CachedActualSize.GetWidth() - m_ButtonSide);
 	float y = m_CachedActualSize.top + (m_CachedActualSize.GetHeight() - m_ButtonSide) / 2.0;
 	return CRect(x, y, x + m_ButtonSide, y + m_ButtonSide);
 }