Add LightOffset property to allow light sources to origin from locations other than the object center.

docs/sdk/script/fn/SetLightRange.xml

@@ -24,6 +24,7 @@
       </params>
     </syntax>
     <desc>Sets the light reach of the object. When a clonk is added to the crew via <funclink>MakeCrewMember</funclink>, a light is added automatically with the default range of 300 and a fadeout of 80.</desc>
+    <remark>A local offset for the light center can be defined by setting the object property LightRange to an array with two elements for X- and Y-offset respectively.</remark>
     <examples>
       <example>
         <code>func ControlUse(object clonk)
@@ -34,6 +35,15 @@
 }</code>
         <text>Confused the acid phile with the eye drops, did ya?</text>
       </example>
+      <example>
+        <code>func Construction()
+{
+	SetLightRange(100, 100);
+	this.LightRange = [0,-100];
+	return true;
+}</code>
+        <text>Script for a lamp post. A light coming from 100 pixel above the object center is enabled when the object is created.</text>
+      </example>
     </examples>
     <related>
       <funclink>SetPlrView</funclink>

src/landscape/fow/C4FoWLight.cpp

@@ -96,8 +96,16 @@ void C4FoWLight::SetColor(uint32_t iValue)
 
 void C4FoWLight::Update(C4Rect Rec)
 {
-	// Update position from object. Clear if we moved in any way
+	// Update position from object.
 	int32_t iNX = fixtoi(pObj->fix_x), iNY = fixtoi(pObj->fix_y);
+	// position may be affected by LightOffset property
+	C4ValueArray *light_offset = pObj->GetPropertyArray(P_LightOffset);
+	if (light_offset)
+	{
+		iNX += light_offset->GetItem(0).getInt();
+		iNY += light_offset->GetItem(1).getInt();
+	}
+	// Clear if we moved in any way
 	if (iNX != iX || iNY != iY)
 	{
 		for(size_t i = 0; i < sections.size(); ++i )

src/script/C4StringTable.cpp

@@ -236,6 +236,7 @@ C4StringTable::C4StringTable()
 	P[P_Equalizer_Mid2_Width] = "Equalizer_Mid2_Width";
 	P[P_Equalizer_High_Gain] = "Equalizer_High_Gain";
 	P[P_Equalizer_High_Cutoff] = "Equalizer_High_Cutoff";
+	P[P_LightOffset] = "LightOffset";
 	P[DFA_WALK] = "WALK";
 	P[DFA_FLIGHT] = "FLIGHT";
 	P[DFA_KNEEL] = "KNEEL";

src/script/C4StringTable.h

@@ -438,6 +438,7 @@ enum C4PropertyName
 	P_Equalizer_Mid2_Width,
 	P_Equalizer_High_Gain,
 	P_Equalizer_High_Cutoff,
+	P_LightOffset,
 // Default Action Procedures
 	DFA_WALK,
 	DFA_FLIGHT,