dynamically assigned render lights

lightarray.cpp

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+/*
+This Source Code Form is subject to the
+terms of the Mozilla Public License, v.
+2.0. If a copy of the MPL was not
+distributed with this file, You can
+obtain one at
+http://mozilla.org/MPL/2.0/.
+*/
+
+/*
+    MaSzyna EU07 locomotive simulator
+    Copyright (C) 2001-2004  Marcin Wozniak and others
+
+*/
+
+#include "stdafx.h"
+#include "lightarray.h"
+#include "dynobj.h"
+
+void
+light_array::insert( TDynamicObject const *Owner ) {
+
+    // we're only storing lights for locos, which have two sets of lights, front and rear
+    // for a more generic role this function would have to be tweaked to add vehicle type-specific light combinations
+    data.emplace_back( Owner, 0 );
+    data.emplace_back( Owner, 1 );
+}
+
+void
+light_array::remove( TDynamicObject const *Owner ) {
+
+    data.erase(
+        std::remove_if(
+            data.begin(),
+            data.end(),
+            [=]( light_record const &light ){ return light.owner == Owner; } ),
+        data.end() );
+}
+
+// updates records in the collection
+void
+light_array::update() {
+
+    for( auto &light : data ) {
+        // update light parameters to match current data of the owner
+        if( light.index == 0 ) {
+            // front light set
+            light.position = light.owner->GetPosition() + ( light.owner->VectorFront() * light.owner->GetLength() * 0.45 );
+            light.direction = light.owner->VectorFront();
+        }
+        else {
+            // rear light set
+            light.position = light.owner->GetPosition() - ( light.owner->VectorFront() * light.owner->GetLength() * 0.45 );
+            light.direction = light.owner->VectorFront();
+            light.direction.x = -light.direction.x;
+            light.direction.z = -light.direction.z;
+        }
+        // determine intensity of this light set
+        if( true == light.owner->MoverParameters->Battery ) {
+            // with battery on, the intensity depends on the state of activated switches
+            auto const &lightbits = light.owner->iLights[ light.index ];
+            light.count = 0 +
+                ( ( lightbits & 1 ) ? 1 : 0 ) +
+                ( ( lightbits & 4 ) ? 1 : 0 ) +
+                ( ( lightbits & 16 ) ? 1 : 0 );
+
+            light.intensity = 0.15f * light.count; // TODO: intensity can be affected further by dim switch or other factors
+        }
+        else {
+            // with battery off the lights are off
+            light.intensity = 0.0f;
+            light.count = 0;
+        }
+    }
+}