Fixed|Renderer: Crash when drawing particles (jXCCP)

Ensure that the active set of generators is known when beginning
rendering of a map.

A crash occurred because the generators were set too late; the
renderer was trying to mark which generators are visible before
knowing which map's generators to use.

doomsday/client/include/render/rend_particle.h

@@ -23,10 +23,6 @@
 
 #include "world/p_particle.h"
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 void Rend_ParticleRegister(void);
 
 /**
@@ -68,8 +64,4 @@ void Rend_RenderParticles(void);
  */
 void Rend_RenderGenerators(void);
 
-#ifdef __cplusplus
-} // extern "C"
-#endif
-
 #endif // LIBDENG_RENDER_PARTICLE_H

doomsday/client/src/render/rend_particle.cpp

@@ -230,7 +230,22 @@ void Rend_ParticleReleaseExtraTextures()
 
 void Rend_ParticleInitForNewFrame()
 {
+    // Which set of generators are we using for this frame?
+    if(App_World().hasMap())
+    {
+        /**
+         * @todo If rendering multiple maps per frame, this would have to be
+         * set from the map rendering function. -jk
+         */
+        gens = &App_World().map().generators();
+    }
+    else
+    {
+        gens = 0;
+    }
+
     if(!useParticles) return;
+
     // Clear all visibility flags.
     de::zap(visiblePtcGens);
 }
@@ -872,8 +887,6 @@ void Rend_RenderParticles()
     if(!useParticles) return;
     if(!App_World().hasMap()) return;
 
-    gens = &App_World().map().generators();
-
     // No visible particles at all?
     if(!listVisibleParticles()) return;
 
@@ -957,8 +970,6 @@ void Rend_RenderGenerators()
     if(!devDrawGenerators) return;
     if(!App_World().hasMap()) return;
 
-    gens = &App_World().map().generators();
-
     glDisable(GL_DEPTH_TEST);
 
     float eye[3] = { vOrigin[VX], vOrigin[VZ], vOrigin[VY] };