Allow configurable exhuast particle, fixes #2878

src/karts/kart_gfx.cpp

@@ -111,14 +111,24 @@ KartGFX::KartGFX(const AbstractKart *kart, bool is_day)
     addEffect(KGFX_NITRO2,      "nitro.xml",       rear_nitro_left,  true );
     addEffect(KGFX_NITROSMOKE1, "nitro-smoke.xml", rear_nitro_left,  false);
     addEffect(KGFX_NITROSMOKE2, "nitro-smoke.xml", rear_nitro_right, false);
-    addEffect(KGFX_EXHAUST1,    "kart_exhaust.xml",rear_nitro_right, false );
-    addEffect(KGFX_EXHAUST2,    "kart_exhaust.xml",rear_nitro_left,  false );
     addEffect(KGFX_ZIPPER,      "zipper_fire.xml", rear_center,      true );
     addEffect(KGFX_TERRAIN,     "smoke.xml",       Vec3(0, 0, 0),    false);
     addEffect(KGFX_SKID1L,      "skid1.xml",       rear_left,        true );
     addEffect(KGFX_SKID1R,      "skid1.xml",       rear_right,       true );
     addEffect(KGFX_SKID2L,      "skid2.xml",       rear_left,        true );
     addEffect(KGFX_SKID2R,      "skid2.xml",       rear_right,       true );
+    if (!kart->getKartModel()->getExhaustXML().empty())
+    {
+        const std::string& ex = kart->getKartModel()->getExhaustXML();
+        addEffect(KGFX_EXHAUST1, ex, rear_nitro_right, false);
+        addEffect(KGFX_EXHAUST2, ex, rear_nitro_left, false);
+    }
+    else
+    {
+        m_all_emitters.push_back(NULL);
+        m_all_emitters.push_back(NULL);
+    }
+
 }   // KartGFX
 
 // ----------------------------------------------------------------------------

src/karts/kart_gfx.hpp

@@ -49,8 +49,6 @@ public:
                        KGFX_NITRO2,
                        KGFX_NITROSMOKE1,
                        KGFX_NITROSMOKE2,
-                       KGFX_EXHAUST1,
-                       KGFX_EXHAUST2,
                        KGFX_ZIPPER,
                        KGFX_TERRAIN,
                        KGFX_SKIDL,
@@ -59,6 +57,8 @@ public:
                        KGFX_SKID1R = KGFX_SKIDR,
                        KGFX_SKID2L,
                        KGFX_SKID2R,
+                       KGFX_EXHAUST1,
+                       KGFX_EXHAUST2,
                        KGFX_COUNT};
 
 private:

src/karts/kart_model.cpp

@@ -215,6 +215,10 @@ void KartModel::loadInfo(const XMLNode &node)
         }
     }
 
+    if (const XMLNode* exhaust = node.getNode("exhaust"))
+    {
+        exhaust->get("file", &m_exhaust_xml);
+    }
 }   // loadInfo
 
 // ----------------------------------------------------------------------------
@@ -336,6 +340,7 @@ KartModel* KartModel::makeCopy(KartRenderType krt)
     km->m_render_info           = new RenderInfo();
     km->m_inverse_bone_matrices = m_inverse_bone_matrices;
     km->m_version               = m_version;
+    km->m_exhaust_xml           = m_exhaust_xml;
     km->m_render_info->setKartModelRenderInfo(krt);
 
     km->m_nitro_emitter_position[0] = m_nitro_emitter_position[0];
@@ -1206,6 +1211,12 @@ void KartModel::toggleHeadlights(bool on)
 }   // toggleHeadlights
 
 //-----------------------------------------------------------------------------
+/** Called when a kart is load. this will load all the inverse bone matrices
+ *  for each bone in straight frame. The location, rotation and scale in
+ *  kart.xml for attachments (speedweighted objects, headlight, hat...) are in
+ *  object space, so if you use a inverse bone matrix * that matrix, it will be
+ *  relative to the bone, and you can use the result to set parent.
+ */
 void KartModel::initInverseBoneMatrices()
 {
     if (m_version < 3)

src/karts/kart_model.hpp

@@ -310,16 +310,27 @@ private:
     /** Pointer to the kart object belonging to this kart model. */
     AbstractKart* m_kart;
 
+    /** Tell the render type of this kart model, either colorized (red / blue now)
+     *  or transparent (ghost kart). */
     KartRenderType m_krt;
 
+    /** For our engine to get the desired hue / saturation for colorization. */
     RenderInfo* m_render_info;
 
+    /** True if this kart model can be colorization in red / blue (now only
+     *  used in soccer mode). */
     bool m_support_colorization;
 
+    /** Used to cache inverse bone matrices for each bone in straight frame
+     *  for attachment. */
     std::unordered_map<std::string, core::matrix4> m_inverse_bone_matrices;
 
+    /** Version of kart model (in kart.xml).  */
     unsigned m_version;
 
+    /** Exhaust particle file (xml) for the kart, empty if disabled.  */
+    std::string m_exhaust_xml;
+
     // ------------------------------------------------------------------------
     void initInverseBoneMatrices();
     // ------------------------------------------------------------------------
@@ -444,6 +455,8 @@ public:
     // ------------------------------------------------------------------------
     const core::matrix4&
                       getInverseBoneMatrix(const std::string& bone_name) const;
+    // ------------------------------------------------------------------------
+    const std::string& getExhaustXML() const          { return m_exhaust_xml; }
 
 };   // KartModel
 #endif