Initial commit

1 files changed, 1531 insertions, 0 deletions

diff --git a/src/cgame/cg_trails.c b/src/cgame/cg_trails.c
new file mode 100644
index 0000000..05f5ef5
--- /dev/null
+++ b/src/cgame/cg_trails.c
@@ -0,0 +1,1531 @@
+/*
+===========================================================================
+Copyright (C) 2000-2009 Darklegion Development
+
+This file is part of Tremulous.
+
+Tremulous 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.
+
+Tremulous 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 Tremulous; if not, write to the Free Software
+Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+===========================================================================
+*/
+
+// cg_trails.c -- the trail system
+
+
+#include "cg_local.h"
+
+static baseTrailSystem_t  baseTrailSystems[ MAX_BASETRAIL_SYSTEMS ];
+static baseTrailBeam_t    baseTrailBeams[ MAX_BASETRAIL_BEAMS ];
+static int                numBaseTrailSystems = 0;
+static int                numBaseTrailBeams = 0;
+
+static trailSystem_t      trailSystems[ MAX_TRAIL_SYSTEMS ];
+static trailBeam_t        trailBeams[ MAX_TRAIL_BEAMS ];
+
+/*
+===============
+CG_CalculateBeamNodeProperties
+
+Fills in trailBeamNode_t.textureCoord
+===============
+*/
+static void CG_CalculateBeamNodeProperties( trailBeam_t *tb )
+{
+  trailBeamNode_t *i = NULL;
+  trailSystem_t   *ts;
+  baseTrailBeam_t *btb;
+  float           nodeDistances[ MAX_TRAIL_BEAM_NODES ];
+  float           totalDistance = 0.0f, position = 0.0f;
+  int             j, numNodes = 0;
+  float           TCRange, widthRange, alphaRange;
+  vec3_t          colorRange;
+  float           fadeAlpha = 1.0f;
+
+  if( !tb || !tb->nodes )
+    return;
+
+  ts = tb->parent;
+  btb = tb->class;
+
+  if( ts->destroyTime > 0 && btb->fadeOutTime )
+  {
+    fadeAlpha -= (float)( cg.time - ts->destroyTime ) / btb->fadeOutTime;
+
+    if( fadeAlpha < 0.0f )
+      fadeAlpha = 0.0f;
+  }
+
+  TCRange = tb->class->backTextureCoord -
+    tb->class->frontTextureCoord;
+  widthRange = tb->class->backWidth -
+    tb->class->frontWidth;
+  alphaRange = tb->class->backAlpha -
+    tb->class->frontAlpha;
+  VectorSubtract( tb->class->backColor,
+      tb->class->frontColor, colorRange );
+
+  for( i = tb->nodes; i && i->next; i = i->next )
+  {
+    nodeDistances[ numNodes++ ] =
+      Distance( i->position, i->next->position );
+  }
+
+  for( j = 0; j < numNodes; j++ )
+    totalDistance += nodeDistances[ j ];
+
+  for( j = 0, i = tb->nodes; i; i = i->next, j++ )
+  {
+    if( tb->class->textureType == TBTT_STRETCH )
+    {
+      i->textureCoord = tb->class->frontTextureCoord +
+        ( ( position / totalDistance ) * TCRange );
+    }
+    else if( tb->class->textureType == TBTT_REPEAT )
+    {
+      if( tb->class->clampToBack )
+        i->textureCoord = ( totalDistance - position ) /
+          tb->class->repeatLength;
+      else
+        i->textureCoord = position / tb->class->repeatLength;
+    }
+
+    i->halfWidth = ( tb->class->frontWidth +
+      ( ( position / totalDistance ) * widthRange ) ) / 2.0f;
+    i->alpha = (byte)( (float)0xFF * ( tb->class->frontAlpha +
+      ( ( position / totalDistance ) * alphaRange ) ) * fadeAlpha );
+    VectorMA( tb->class->frontColor, ( position / totalDistance ),
+        colorRange, i->color );
+
+    position += nodeDistances[ j ];
+  }
+}
+
+/*
+===============
+CG_LightVertex
+
+Lights a particular vertex
+===============
+*/
+static void CG_LightVertex( vec3_t point, byte alpha, byte *rgba )
+{
+  int     i;
+  vec3_t  alight, dlight, lightdir;
+
+  trap_R_LightForPoint( point, alight, dlight, lightdir );
+  for( i = 0; i <= 2; i++ )
+    rgba[ i ] = (int)alight[ i ];
+
+  rgba[ 3 ] = alpha;
+}
+
+/*
+===============
+CG_RenderBeam
+
+Renders a beam
+===============
+*/
+static void CG_RenderBeam( trailBeam_t *tb )
+{
+  trailBeamNode_t   *i = NULL;
+  trailBeamNode_t   *prev = NULL;
+  trailBeamNode_t   *next = NULL;
+  vec3_t            up;
+  polyVert_t        verts[ ( MAX_TRAIL_BEAM_NODES - 1 ) * 4 ];
+  int               numVerts = 0;
+  baseTrailBeam_t   *btb;
+  trailSystem_t     *ts;
+  baseTrailSystem_t *bts;
+
+  if( !tb || !tb->nodes )
+    return;
+
+  btb = tb->class;
+  ts = tb->parent;
+  bts = ts->class;
+
+  if( bts->thirdPersonOnly &&
+      ( CG_AttachmentCentNum( &ts->frontAttachment ) == cg.snap->ps.clientNum ||
+        CG_AttachmentCentNum( &ts->backAttachment ) == cg.snap->ps.clientNum ) &&
+      !cg.renderingThirdPerson )
+    return;
+
+  CG_CalculateBeamNodeProperties( tb );
+
+  i = tb->nodes;
+
+  do
+  {
+    prev = i->prev;
+    next = i->next;
+
+    if( prev && next )
+    {
+      //this node has two neighbours
+      GetPerpendicularViewVector( cg.refdef.vieworg, next->position, prev->position, up );
+    }
+    else if( !prev && next )
+    {
+      //this is the front
+      GetPerpendicularViewVector( cg.refdef.vieworg, next->position, i->position, up );
+    }
+    else if( prev && !next )
+    {
+      //this is the back
+      GetPerpendicularViewVector( cg.refdef.vieworg, i->position, prev->position, up );
+    }
+    else
+      break;
+
+    if( prev )
+    {
+      VectorMA( i->position, i->halfWidth, up, verts[ numVerts ].xyz );
+      verts[ numVerts ].st[ 0 ] = i->textureCoord;
+      verts[ numVerts ].st[ 1 ] = 1.0f;
+
+      if( btb->realLight )
+        CG_LightVertex( verts[ numVerts ].xyz, i->alpha, verts[ numVerts ].modulate );
+      else
+      {
+        VectorCopy( i->color, verts[ numVerts ].modulate );
+        verts[ numVerts ].modulate[ 3 ] = i->alpha;
+      }
+
+      numVerts++;
+
+      VectorMA( i->position, -i->halfWidth, up, verts[ numVerts ].xyz );
+      verts[ numVerts ].st[ 0 ] = i->textureCoord;
+      verts[ numVerts ].st[ 1 ] = 0.0f;
+
+      if( btb->realLight )
+        CG_LightVertex( verts[ numVerts ].xyz, i->alpha, verts[ numVerts ].modulate );
+      else
+      {
+        VectorCopy( i->color, verts[ numVerts ].modulate );
+        verts[ numVerts ].modulate[ 3 ] = i->alpha;
+      }
+
+      numVerts++;
+    }
+
+    if( next )
+    {
+      VectorMA( i->position, -i->halfWidth, up, verts[ numVerts ].xyz );
+      verts[ numVerts ].st[ 0 ] = i->textureCoord;
+      verts[ numVerts ].st[ 1 ] = 0.0f;
+
+      if( btb->realLight )
+        CG_LightVertex( verts[ numVerts ].xyz, i->alpha, verts[ numVerts ].modulate );
+      else
+      {
+        VectorCopy( i->color, verts[ numVerts ].modulate );
+        verts[ numVerts ].modulate[ 3 ] = i->alpha;
+      }
+
+      numVerts++;
+
+      VectorMA( i->position, i->halfWidth, up, verts[ numVerts ].xyz );
+      verts[ numVerts ].st[ 0 ] = i->textureCoord;
+      verts[ numVerts ].st[ 1 ] = 1.0f;
+
+      if( btb->realLight )
+        CG_LightVertex( verts[ numVerts ].xyz, i->alpha, verts[ numVerts ].modulate );
+      else
+      {
+        VectorCopy( i->color, verts[ numVerts ].modulate );
+        verts[ numVerts ].modulate[ 3 ] = i->alpha;
+      }
+
+      numVerts++;
+    }
+
+    i = i->next;
+  } while( i );
+
+  trap_R_AddPolysToScene( tb->class->shader, 4, &verts[ 0 ], numVerts / 4 );
+}
+
+/*
+===============
+CG_AllocateBeamNode
+
+Allocates a trailBeamNode_t from a trailBeam_t's nodePool
+===============
+*/
+static trailBeamNode_t *CG_AllocateBeamNode( trailBeam_t *tb )
+{
+  baseTrailBeam_t *btb = tb->class;
+  int             i;
+  trailBeamNode_t *tbn;
+
+  for( i = 0; i < MAX_TRAIL_BEAM_NODES; i++ )
+  {
+    tbn = &tb->nodePool[ i ];
+    if( !tbn->used )
+    {
+      tbn->timeLeft = btb->segmentTime;
+      tbn->prev = NULL;
+      tbn->next = NULL;
+      tbn->used = qtrue;
+      return tbn;
+    }
+  }
+
+  // no space left
+  return NULL;
+}
+
+/*
+===============
+CG_DestroyBeamNode
+
+Removes a node from a beam
+Returns the new head
+===============
+*/
+static trailBeamNode_t *CG_DestroyBeamNode( trailBeamNode_t *tbn )
+{
+  trailBeamNode_t *newHead = NULL;
+
+  if( tbn->prev )
+  {
+    if( tbn->next )
+    {
+      // node is in the middle
+      tbn->prev->next = tbn->next;
+      tbn->next->prev = tbn->prev;
+    }
+    else // node is at the back
+      tbn->prev->next = NULL;
+
+    // find the new head (shouldn't have changed)
+    newHead = tbn->prev;
+
+    while( newHead->prev )
+      newHead = newHead->prev;
+  }
+  else if( tbn->next )
+  {
+    //node is at the front
+    tbn->next->prev = NULL;
+    newHead = tbn->next;
+  }
+
+  tbn->prev = NULL;
+  tbn->next = NULL;
+  tbn->used = qfalse;
+
+  return newHead;
+}
+
+/*
+===============
+CG_FindLastBeamNode
+
+Returns the last beam node in a beam
+===============
+*/
+static trailBeamNode_t *CG_FindLastBeamNode( trailBeam_t *tb )
+{
+  trailBeamNode_t *i = tb->nodes;
+
+  while( i && i->next )
+    i = i->next;
+
+  return i;
+}
+
+/*
+===============
+CG_CountBeamNodes
+
+Returns the number of nodes in a beam
+===============
+*/
+static int CG_CountBeamNodes( trailBeam_t *tb )
+{
+  trailBeamNode_t *i = tb->nodes;
+  int             numNodes = 0;
+
+  while( i )
+  {
+    numNodes++;
+    i = i->next;
+  }
+
+  return numNodes;
+}
+
+/*
+===============
+CG_PrependBeamNode
+
+Prepend a new beam node to the front of a beam
+Returns the new node
+===============
+*/
+static trailBeamNode_t *CG_PrependBeamNode( trailBeam_t *tb )
+{
+  trailBeamNode_t *i;
+
+  if( tb->nodes )
+  {
+    // prepend another node
+    i = CG_AllocateBeamNode( tb );
+
+    if( i )
+    {
+      i->next = tb->nodes;
+      tb->nodes->prev = i;
+      tb->nodes = i;
+    }
+  }
+  else //add first node
+  {
+    i = CG_AllocateBeamNode( tb );
+
+    if( i )
+      tb->nodes = i;
+  }
+
+  return i;
+}
+
+/*
+===============
+CG_AppendBeamNode
+
+Append a new beam node to the back of a beam
+Returns the new node
+===============
+*/
+static trailBeamNode_t *CG_AppendBeamNode( trailBeam_t *tb )
+{
+  trailBeamNode_t *last, *i;
+
+  if( tb->nodes )
+  {
+    // append another node
+    last = CG_FindLastBeamNode( tb );
+    i = CG_AllocateBeamNode( tb );
+
+    if( i )
+    {
+      last->next = i;
+      i->prev = last;
+      i->next = NULL;
+    }
+  }
+  else //add first node
+  {
+    i = CG_AllocateBeamNode( tb );
+
+    if( i )
+      tb->nodes = i;
+  }
+
+  return i;
+}
+
+/*
+===============
+CG_ApplyJitters
+===============
+*/
+static void CG_ApplyJitters( trailBeam_t *tb )
+{
+  trailBeamNode_t *i = NULL;
+  int             j;
+  baseTrailBeam_t *btb;
+  trailSystem_t   *ts;
+  trailBeamNode_t *start;
+  trailBeamNode_t *end;
+
+  if( !tb || !tb->nodes )
+    return;
+
+  btb = tb->class;
+  ts = tb->parent;
+
+  for( j = 0; j < btb->numJitters; j++ )
+  {
+    if( tb->nextJitterTimes[ j ] <= cg.time )
+    {
+      for( i = tb->nodes; i; i = i->next )
+      {
+        i->jitters[ j ][ 0 ] = ( crandom( ) * btb->jitters[ j ].magnitude );
+        i->jitters[ j ][ 1 ] = ( crandom( ) * btb->jitters[ j ].magnitude );
+      }
+
+      tb->nextJitterTimes[ j ] = cg.time + btb->jitters[ j ].period;
+    }
+  }
+
+  start = tb->nodes;
+  end = CG_FindLastBeamNode( tb );
+
+  if( !btb->jitterAttachments )
+  {
+    if( CG_Attached( &ts->frontAttachment ) && start->next )
+      start = start->next;
+
+    if( CG_Attached( &ts->backAttachment ) && end->prev )
+      end = end->prev;
+  }
+
+  for( i = start; i; i = i->next )
+  {
+    vec3_t          forward, right, up;
+    trailBeamNode_t *prev;
+    trailBeamNode_t *next;
+    float           upJitter = 0.0f, rightJitter = 0.0f;
+
+    prev = i->prev;
+    next = i->next;
+
+    if( prev && next )
+    {
+      //this node has two neighbours
+      GetPerpendicularViewVector( cg.refdef.vieworg, next->position, prev->position, up );
+      VectorSubtract( next->position, prev->position, forward );
+    }
+    else if( !prev && next )
+    {
+      //this is the front
+      GetPerpendicularViewVector( cg.refdef.vieworg, next->position, i->position, up );
+      VectorSubtract( next->position, i->position, forward );
+    }
+    else if( prev && !next )
+    {
+      //this is the back
+      GetPerpendicularViewVector( cg.refdef.vieworg, i->position, prev->position, up );
+      VectorSubtract( i->position, prev->position, forward );
+    }
+
+    VectorNormalize( forward );
+    CrossProduct( forward, up, right );
+    VectorNormalize( right );
+
+    for( j = 0; j < btb->numJitters; j++ )
+    {
+      upJitter += i->jitters[ j ][ 0 ];
+      rightJitter += i->jitters[ j ][ 1 ];
+    }
+
+    VectorMA( i->position, upJitter, up, i->position );
+    VectorMA( i->position, rightJitter, right, i->position );
+
+    if( i == end )
+      break;
+  }
+}
+
+/*
+===============
+CG_UpdateBeam
+
+Updates a beam
+===============
+*/
+static void CG_UpdateBeam( trailBeam_t *tb )
+{
+  baseTrailBeam_t *btb;
+  trailSystem_t   *ts;
+  trailBeamNode_t *i;
+  int             deltaTime;
+  int             nodesToAdd;
+  int             j;
+  int             numNodes;
+
+  if( !tb )
+    return;
+
+  btb = tb->class;
+  ts = tb->parent;
+
+  deltaTime = cg.time - tb->lastEvalTime;
+  tb->lastEvalTime = cg.time;
+
+  // first make sure this beam has enough nodes
+  if( ts->destroyTime <= 0 || btb->fadeOutTime > 0 )
+  {
+    nodesToAdd = btb->numSegments - CG_CountBeamNodes( tb ) + 1;
+
+    while( nodesToAdd-- )
+    {
+      i = CG_AppendBeamNode( tb );
+
+      if( !tb->nodes->next && CG_Attached( &ts->frontAttachment ) )
+      {
+        // this is the first node to be added
+        if( !CG_AttachmentPoint( &ts->frontAttachment, i->refPosition ) )
+          CG_DestroyTrailSystem( &ts );
+      }
+      else
+        VectorCopy( i->prev->refPosition, i->refPosition );
+    }
+  }
+
+  numNodes = CG_CountBeamNodes( tb );
+
+  for( i = tb->nodes; i; i = i->next )
+    VectorCopy( i->refPosition, i->position );
+
+  if( CG_Attached( &ts->frontAttachment ) && CG_Attached( &ts->backAttachment ) )
+  {
+    // beam between two attachments
+    vec3_t dir, front, back;
+
+    if( ts->destroyTime > 0 && ( cg.time - ts->destroyTime ) >= btb->fadeOutTime )
+    {
+      tb->valid = qfalse;
+      return;
+    }
+
+    if( !CG_AttachmentPoint( &ts->frontAttachment, front ) )
+      CG_DestroyTrailSystem( &ts );
+
+    if( !CG_AttachmentPoint( &ts->backAttachment, back ) )
+      CG_DestroyTrailSystem( &ts );
+
+    VectorSubtract( back, front, dir );
+
+    for( j = 0, i = tb->nodes; i; i = i->next, j++ )
+    {
+      float scale = (float)j / (float)( numNodes - 1 );
+
+      VectorMA( front, scale, dir, i->position );
+    }
+  }
+  else if( CG_Attached( &ts->frontAttachment ) )
+  {
+    // beam from one attachment
+
+    // cull the trail tail
+    i = CG_FindLastBeamNode( tb );
+
+    if( i && i->timeLeft >= 0 )
+    {
+      i->timeLeft -= deltaTime;
+
+      if( i->timeLeft < 0 )
+      {
+        tb->nodes = CG_DestroyBeamNode( i );
+
+        if( !tb->nodes )
+        {
+          tb->valid = qfalse;
+          return;
+        }
+
+        // if the ts has been destroyed, stop creating new nodes
+        if( ts->destroyTime <= 0 )
+          CG_PrependBeamNode( tb );
+      }
+      else if( i->timeLeft >= 0 && i->prev )
+      {
+        vec3_t  dir;
+        float   length;
+
+        VectorSubtract( i->refPosition, i->prev->refPosition, dir );
+        length = VectorNormalize( dir ) *
+          ( (float)i->timeLeft / (float)tb->class->segmentTime );
+
+        VectorMA( i->prev->refPosition, length, dir, i->position );
+      }
+    }
+
+    if( tb->nodes )
+    {
+      if( !CG_AttachmentPoint( &ts->frontAttachment, tb->nodes->refPosition ) )
+        CG_DestroyTrailSystem( &ts );
+
+      VectorCopy( tb->nodes->refPosition, tb->nodes->position );
+    }
+  }
+
+  CG_ApplyJitters( tb );
+}
+
+/*
+===============
+CG_ParseTrailBeamColor
+===============
+*/
+static qboolean CG_ParseTrailBeamColor( byte *c, char **text_p )
+{
+  char  *token;
+  int   i;
+
+  for( i = 0; i <= 2; i++ )
+  {
+    token = COM_Parse( text_p );
+
+    if( !Q_stricmp( token, "" ) )
+      return qfalse;
+
+    c[ i ] = (int)( (float)0xFF * atof_neg( token, qfalse ) );
+  }
+
+  return qtrue;
+}
+
+/*
+===============
+CG_ParseTrailBeam
+
+Parse a trail beam
+===============
+*/
+static qboolean CG_ParseTrailBeam( baseTrailBeam_t *btb, char **text_p )
+{
+  char  *token;
+
+  // read optional parameters
+  while( 1 )
+  {
+    token = COM_Parse( text_p );
+
+    if( !Q_stricmp( token, "" ) )
+      return qfalse;
+
+    if( !Q_stricmp( token, "segments" ) )
+    {
+      token = COM_Parse( text_p );
+      if( !Q_stricmp( token, "" ) )
+        break;
+
+      btb->numSegments = atoi_neg( token, qfalse );
+
+      if( btb->numSegments >= MAX_TRAIL_BEAM_NODES )
+      {
+        btb->numSegments = MAX_TRAIL_BEAM_NODES - 1;
+        CG_Printf( S_COLOR_YELLOW "WARNING: too many segments in trail beam\n" );
+      }
+      continue;
+    }
+    else if( !Q_stricmp( token, "width" ) )
+    {
+      token = COM_Parse( text_p );
+      if( !Q_stricmp( token, "" ) )
+        break;
+
+      btb->frontWidth = atof_neg( token, qfalse );
+
+      token = COM_Parse( text_p );
+      if( !Q_stricmp( token, "" ) )
+        break;
+
+      if( !Q_stricmp( token, "-" ) )
+        btb->backWidth = btb->frontWidth;
+      else
+        btb->backWidth = atof_neg( token, qfalse );
+      continue;
+    }
+    else if( !Q_stricmp( token, "alpha" ) )
+    {
+      token = COM_Parse( text_p );
+      if( !Q_stricmp( token, "" ) )
+        break;
+
+      btb->frontAlpha = atof_neg( token, qfalse );
+
+      token = COM_Parse( text_p );
+      if( !Q_stricmp( token, "" ) )
+        break;
+
+      if( !Q_stricmp( token, "-" ) )
+        btb->backAlpha = btb->frontAlpha;
+      else
+        btb->backAlpha = atof_neg( token, qfalse );
+      continue;
+    }
+    else if( !Q_stricmp( token, "color" ) )
+    {
+      token = COM_Parse( text_p );
+      if( !Q_stricmp( token, "" ) )
+        break;
+
+      if( !Q_stricmp( token, "{" ) )
+      {
+        if( !CG_ParseTrailBeamColor( btb->frontColor, text_p ) )
+          break;
+
+        token = COM_Parse( text_p );
+        if( Q_stricmp( token, "}" ) )
+        {
+          CG_Printf( S_COLOR_RED "ERROR: missing '}'\n" );
+          break;
+        }
+
+        token = COM_Parse( text_p );
+        if( !Q_stricmp( token, "" ) )
+          break;
+
+        if( !Q_stricmp( token, "-" ) )
+        {
+          btb->backColor[ 0 ] = btb->frontColor[ 0 ];
+          btb->backColor[ 1 ] = btb->frontColor[ 1 ];
+          btb->backColor[ 2 ] = btb->frontColor[ 2 ];
+        }
+        else if( !Q_stricmp( token, "{" ) )
+        {
+          if( !CG_ParseTrailBeamColor( btb->backColor, text_p ) )
+            break;
+
+          token = COM_Parse( text_p );
+          if( Q_stricmp( token, "}" ) )
+          {
+            CG_Printf( S_COLOR_RED "ERROR: missing '}'\n" );
+            break;
+          }
+        }
+        else
+        {
+          CG_Printf( S_COLOR_RED "ERROR: missing '{'\n" );
+          break;
+        }
+      }
+      else
+      {
+        CG_Printf( S_COLOR_RED "ERROR: missing '{'\n" );
+        break;
+      }
+
+      continue;
+    }
+    else if( !Q_stricmp( token, "segmentTime" ) )
+    {
+      token = COM_Parse( text_p );
+      if( !Q_stricmp( token, "" ) )
+        break;
+
+      btb->segmentTime = atoi_neg( token, qfalse );
+      continue;
+    }
+    else if( !Q_stricmp( token, "fadeOutTime" ) )
+    {
+      token = COM_Parse( text_p );
+      if( !Q_stricmp( token, "" ) )
+        break;
+
+      btb->fadeOutTime = atoi_neg( token, qfalse );
+      continue;
+    }
+    else if( !Q_stricmp( token, "shader" ) )
+    {
+      token = COM_Parse( text_p );
+      if( !Q_stricmp( token, "" ) )
+        break;
+
+      Q_strncpyz( btb->shaderName, token, MAX_QPATH );
+
+      continue;
+    }
+    else if( !Q_stricmp( token, "textureType" ) )
+    {
+      token = COM_Parse( text_p );
+      if( !Q_stricmp( token, "" ) )
+        break;
+
+      if( !Q_stricmp( token, "stretch" ) )
+      {
+        btb->textureType = TBTT_STRETCH;
+
+        token = COM_Parse( text_p );
+        if( !Q_stricmp( token, "" ) )
+          break;
+
+        btb->frontTextureCoord = atof_neg( token, qfalse );
+
+        token = COM_Parse( text_p );
+        if( !Q_stricmp( token, "" ) )
+          break;
+
+        btb->backTextureCoord = atof_neg( token, qfalse );
+      }
+      else if( !Q_stricmp( token, "repeat" ) )
+      {
+        btb->textureType = TBTT_REPEAT;
+
+        token = COM_Parse( text_p );
+        if( !Q_stricmp( token, "" ) )
+          break;
+
+        if( !Q_stricmp( token, "front" ) )
+          btb->clampToBack = qfalse;
+        else if( !Q_stricmp( token, "back" ) )
+          btb->clampToBack = qtrue;
+        else
+        {
+          CG_Printf( S_COLOR_RED "ERROR: unknown textureType clamp \"%s\"\n", token );
+          break;
+        }
+
+        token = COM_Parse( text_p );
+        if( !Q_stricmp( token, "" ) )
+          break;
+
+        btb->repeatLength = atof_neg( token, qfalse );
+      }
+      else
+      {
+        CG_Printf( S_COLOR_RED "ERROR: unknown textureType \"%s\"\n", token );
+        break;
+      }
+
+      continue;
+    }
+    else if( !Q_stricmp( token, "realLight" ) )
+    {
+      btb->realLight = qtrue;
+
+      continue;
+    }
+    else if( !Q_stricmp( token, "jitter" ) )
+    {
+      if( btb->numJitters == MAX_TRAIL_BEAM_JITTERS )
+      {
+        CG_Printf( S_COLOR_RED "ERROR: too many jitters\n", token );
+        break;
+      }
+
+      token = COM_Parse( text_p );
+      if( !Q_stricmp( token, "" ) )
+        break;
+
+      btb->jitters[ btb->numJitters ].magnitude = atof_neg( token, qfalse );
+
+      token = COM_Parse( text_p );
+      if( !Q_stricmp( token, "" ) )
+        break;
+
+      btb->jitters[ btb->numJitters ].period = atoi_neg( token, qfalse );
+
+      btb->numJitters++;
+
+      continue;
+    }
+    else if( !Q_stricmp( token, "jitterAttachments" ) )
+    {
+      btb->jitterAttachments = qtrue;
+
+      continue;
+    }
+    else if( !Q_stricmp( token, "}" ) )
+      return qtrue; //reached the end of this trail beam
+    else
+    {
+      CG_Printf( S_COLOR_RED "ERROR: unknown token '%s' in trail beam\n", token );
+      return qfalse;
+    }
+  }
+
+  return qfalse;
+}
+
+/*
+===============
+CG_InitialiseBaseTrailBeam
+===============
+*/
+static void CG_InitialiseBaseTrailBeam( baseTrailBeam_t *btb )
+{
+  memset( btb, 0, sizeof( baseTrailBeam_t ) );
+
+  btb->numSegments = 1;
+  btb->frontWidth = btb->backWidth = 1.0f;
+  btb->frontAlpha = btb->backAlpha = 1.0f;
+  memset( btb->frontColor, 0xFF, sizeof( btb->frontColor ) );
+  memset( btb->backColor, 0xFF, sizeof( btb->backColor ) );
+
+  btb->segmentTime = 100;
+
+  btb->textureType = TBTT_STRETCH;
+  btb->frontTextureCoord = 0.0f;
+  btb->backTextureCoord = 1.0f;
+}
+
+/*
+===============
+CG_ParseTrailSystem
+
+Parse a trail system section
+===============
+*/
+static qboolean CG_ParseTrailSystem( baseTrailSystem_t *bts, char **text_p, const char *name )
+{
+  char *token;
+
+  // read optional parameters
+  while( 1 )
+  {
+    token = COM_Parse( text_p );
+
+    if( !Q_stricmp( token, "" ) )
+      return qfalse;
+
+    if( !Q_stricmp( token, "{" ) )
+    {
+      CG_InitialiseBaseTrailBeam( &baseTrailBeams[ numBaseTrailBeams ] );
+
+      if( !CG_ParseTrailBeam( &baseTrailBeams[ numBaseTrailBeams ], text_p ) )
+      {
+        CG_Printf( S_COLOR_RED "ERROR: failed to parse trail beam\n" );
+        return qfalse;
+      }
+
+      if( bts->numBeams == MAX_BEAMS_PER_SYSTEM )
+      {
+        CG_Printf( S_COLOR_RED "ERROR: trail system has > %d beams\n", MAX_BEAMS_PER_SYSTEM );
+        return qfalse;
+      }
+      else if( numBaseTrailBeams == MAX_BASETRAIL_BEAMS )
+      {
+        CG_Printf( S_COLOR_RED "ERROR: maximum number of trail beams (%d) reached\n",
+            MAX_BASETRAIL_BEAMS );
+        return qfalse;
+      }
+      else
+      {
+        //start parsing beams again
+        bts->beams[ bts->numBeams ] = &baseTrailBeams[ numBaseTrailBeams ];
+        bts->numBeams++;
+        numBaseTrailBeams++;
+      }
+      continue;
+    }
+    else if( !Q_stricmp( token, "thirdPersonOnly" ) )
+      bts->thirdPersonOnly = qtrue;
+    else if( !Q_stricmp( token, "lifeTime" ) )
+    {
+      token = COM_Parse( text_p );
+      if( !Q_stricmp( token, "" ) )
+        break;
+
+      bts->lifeTime = atoi_neg( token, qfalse );
+      continue;
+    }
+    else if( !Q_stricmp( token, "beam" ) ) //acceptable text
+      continue;
+    else if( !Q_stricmp( token, "}" ) )
+    {
+      if( cg_debugTrails.integer >= 1 )
+        CG_Printf( "Parsed trail system %s\n", name );
+
+      return qtrue; //reached the end of this trail system
+    }
+    else
+    {
+      CG_Printf( S_COLOR_RED "ERROR: unknown token '%s' in trail system %s\n", token, bts->name );
+      return qfalse;
+    }
+  }
+
+  return qfalse;
+}
+
+/*
+===============
+CG_ParseTrailFile
+
+Load the trail systems from a trail file
+===============
+*/
+static qboolean CG_ParseTrailFile( const char *fileName )
+{
+  char          *text_p;
+  int           i;
+  int           len;
+  char          *token;
+  char          text[ 32000 ];
+  char          tsName[ MAX_QPATH ];
+  qboolean      tsNameSet = qfalse;
+  fileHandle_t  f;
+
+  // load the file
+  len = trap_FS_FOpenFile( fileName, &f, FS_READ );
+  if( len <= 0 )
+    return qfalse;
+
+  if( len == 0 || len >= sizeof( text ) - 1 )
+  {
+    trap_FS_FCloseFile( f );
+    CG_Printf( S_COLOR_RED "ERROR: trail file %s is %s\n", fileName,
+      len == 0 ? "empty" : "too long" );
+    return qfalse;
+  }
+
+  trap_FS_Read( text, len, f );
+  text[ len ] = 0;
+  trap_FS_FCloseFile( f );
+
+  // parse the text
+  text_p = text;
+
+  // read optional parameters
+  while( 1 )
+  {
+    token = COM_Parse( &text_p );
+
+    if( !Q_stricmp( token, "" ) )
+      break;
+
+    if( !Q_stricmp( token, "{" ) )
+    {
+      if( tsNameSet )
+      {
+        //check for name space clashes
+        for( i = 0; i < numBaseTrailSystems; i++ )
+        {
+          if( !Q_stricmp( baseTrailSystems[ i ].name, tsName ) )
+          {
+            CG_Printf( S_COLOR_RED "ERROR: a trail system is already named %s\n", tsName );
+            return qfalse;
+          }
+        }
+
+        Q_strncpyz( baseTrailSystems[ numBaseTrailSystems ].name, tsName, MAX_QPATH );
+
+        if( !CG_ParseTrailSystem( &baseTrailSystems[ numBaseTrailSystems ], &text_p, tsName ) )
+        {
+          CG_Printf( S_COLOR_RED "ERROR: %s: failed to parse trail system %s\n", fileName, tsName );
+          return qfalse;
+        }
+
+        //start parsing trail systems again
+        tsNameSet = qfalse;
+
+        if( numBaseTrailSystems == MAX_BASETRAIL_SYSTEMS )
+        {
+          CG_Printf( S_COLOR_RED "ERROR: maximum number of trail systems (%d) reached\n",
+              MAX_BASETRAIL_SYSTEMS );
+          return qfalse;
+        }
+        else
+          numBaseTrailSystems++;
+
+        continue;
+      }
+      else
+      {
+        CG_Printf( S_COLOR_RED "ERROR: unamed trail system\n" );
+        return qfalse;
+      }
+    }
+
+    if( !tsNameSet )
+    {
+      Q_strncpyz( tsName, token, sizeof( tsName ) );
+      tsNameSet = qtrue;
+    }
+    else
+    {
+      CG_Printf( S_COLOR_RED "ERROR: trail system already named\n" );
+      return qfalse;
+    }
+  }
+
+  return qtrue;
+}
+
+/*
+===============
+CG_LoadTrailSystems
+
+Load trail system templates
+===============
+*/
+void CG_LoadTrailSystems( void )
+{
+  int   i, numFiles, fileLen;
+  char  fileList[ MAX_TRAIL_FILES * MAX_QPATH ];
+  char  fileName[ MAX_QPATH ];
+  char  *filePtr;
+
+  //clear out the old
+  numBaseTrailSystems = 0;
+  numBaseTrailBeams = 0;
+
+  for( i = 0; i < MAX_BASETRAIL_SYSTEMS; i++ )
+  {
+    baseTrailSystem_t  *bts = &baseTrailSystems[ i ];
+    memset( bts, 0, sizeof( baseTrailSystem_t ) );
+  }
+
+  for( i = 0; i < MAX_BASETRAIL_BEAMS; i++ )
+  {
+    baseTrailBeam_t  *btb = &baseTrailBeams[ i ];
+    memset( btb, 0, sizeof( baseTrailBeam_t ) );
+  }
+
+  //and bring in the new
+  numFiles = trap_FS_GetFileList( "scripts", ".trail",
+      fileList, MAX_TRAIL_FILES * MAX_QPATH );
+  filePtr = fileList;
+
+  for( i = 0; i < numFiles; i++, filePtr += fileLen + 1 )
+  {
+    fileLen = strlen( filePtr );
+    strcpy( fileName, "scripts/" );
+    strcat( fileName, filePtr );
+    CG_Printf( "...loading '%s'\n", fileName );
+    CG_ParseTrailFile( fileName );
+  }
+}
+
+/*
+===============
+CG_RegisterTrailSystem
+
+Load the media that a trail system needs
+===============
+*/
+qhandle_t CG_RegisterTrailSystem( char *name )
+{
+  int               i, j;
+  baseTrailSystem_t *bts;
+  baseTrailBeam_t   *btb;
+
+  for( i = 0; i < MAX_BASETRAIL_SYSTEMS; i++ )
+  {
+    bts = &baseTrailSystems[ i ];
+
+    if( !Q_stricmp( bts->name, name ) )
+    {
+      //already registered
+      if( bts->registered )
+        return i + 1;
+
+      for( j = 0; j < bts->numBeams; j++ )
+      {
+        btb = bts->beams[ j ];
+
+        btb->shader = trap_R_RegisterShader( btb->shaderName );
+      }
+
+      if( cg_debugTrails.integer >= 1 )
+        CG_Printf( "Registered trail system %s\n", name );
+
+      bts->registered = qtrue;
+
+      //avoid returning 0
+      return i + 1;
+    }
+  }
+
+  CG_Printf( S_COLOR_RED "ERROR: failed to register trail system %s\n", name );
+  return 0;
+}
+
+
+/*
+===============
+CG_SpawnNewTrailBeam
+
+Allocate a new trail beam
+===============
+*/
+static trailBeam_t *CG_SpawnNewTrailBeam( baseTrailBeam_t *btb,
+    trailSystem_t *parent )
+{
+  int           i;
+  trailBeam_t   *tb = NULL;
+  trailSystem_t *ts = parent;
+
+  for( i = 0; i < MAX_TRAIL_BEAMS; i++ )
+  {
+    tb = &trailBeams[ i ];
+
+    if( !tb->valid )
+    {
+      memset( tb, 0, sizeof( trailBeam_t ) );
+
+      //found a free slot
+      tb->class = btb;
+      tb->parent = ts;
+
+      tb->valid = qtrue;
+
+      if( cg_debugTrails.integer >= 1 )
+        CG_Printf( "TB %s created\n", ts->class->name );
+
+      return tb;
+    }
+  }
+
+  if( cg_debugTrails.integer >= 1 )
+    CG_Printf( "MAX_TRAIL_BEAMS\n" );
+
+  return NULL;
+}
+
+
+/*
+===============
+CG_SpawnNewTrailSystem
+
+Spawns a new trail system
+===============
+*/
+trailSystem_t *CG_SpawnNewTrailSystem( qhandle_t psHandle )
+{
+  int               i, j;
+  trailSystem_t     *ts = NULL;
+  baseTrailSystem_t *bts = &baseTrailSystems[ psHandle - 1 ];
+
+  if( !bts->registered )
+  {
+    CG_Printf( S_COLOR_RED "ERROR: a trail system has not been registered yet\n" );
+    return NULL;
+  }
+
+  for( i = 0; i < MAX_TRAIL_SYSTEMS; i++ )
+  {
+    ts = &trailSystems[ i ];
+
+    if( !ts->valid )
+    {
+      memset( ts, 0, sizeof( trailSystem_t ) );
+
+      //found a free slot
+      ts->class = bts;
+
+      ts->valid = qtrue;
+      ts->destroyTime = -1;
+      ts->birthTime = cg.time;
+      
+      for( j = 0; j < bts->numBeams; j++ )
+        CG_SpawnNewTrailBeam( bts->beams[ j ], ts );
+
+      if( cg_debugTrails.integer >= 1 )
+        CG_Printf( "TS %s created\n", bts->name );
+
+      return ts;
+    }
+  }
+
+  if( cg_debugTrails.integer >= 1 )
+    CG_Printf( "MAX_TRAIL_SYSTEMS\n" );
+
+  return NULL;
+}
+
+/*
+===============
+CG_DestroyTrailSystem
+
+Destroy a trail system
+===============
+*/
+void CG_DestroyTrailSystem( trailSystem_t **ts )
+{
+  (*ts)->destroyTime = cg.time;
+
+  if( CG_Attached( &(*ts)->frontAttachment ) &&
+      !CG_Attached( &(*ts)->backAttachment ) )
+  {
+    vec3_t v;
+
+    // attach the trail head to a static point
+    CG_AttachmentPoint( &(*ts)->frontAttachment, v );
+    CG_SetAttachmentPoint( &(*ts)->frontAttachment, v );
+    CG_AttachToPoint( &(*ts)->frontAttachment );
+
+    (*ts)->frontAttachment.centValid = qfalse; // a bit naughty
+  }
+
+  ts = NULL;
+}
+
+/*
+===============
+CG_IsTrailSystemValid
+
+Test a trail system for validity
+===============
+*/
+qboolean CG_IsTrailSystemValid( trailSystem_t **ts )
+{
+  if( *ts == NULL || ( *ts && !(*ts)->valid ) )
+  {
+    if( *ts && !(*ts)->valid )
+      *ts = NULL;
+
+    return qfalse;
+  }
+
+  return qtrue;
+}
+
+/*
+===============
+CG_GarbageCollectTrailSystems
+
+Destroy inactive trail systems
+===============
+*/
+static void CG_GarbageCollectTrailSystems( void )
+{
+  int           i, j, count;
+  trailSystem_t *ts;
+  trailBeam_t   *tb;
+  int           centNum;
+
+  for( i = 0; i < MAX_TRAIL_SYSTEMS; i++ )
+  {
+    ts = &trailSystems[ i ];
+    count = 0;
+
+    //don't bother checking already invalid systems
+    if( !ts->valid )
+      continue;
+
+    for( j = 0; j < MAX_TRAIL_BEAMS; j++ )
+    {
+      tb = &trailBeams[ j ];
+
+      if( tb->valid && tb->parent == ts )
+        count++;
+    }
+
+    if( !count )
+      ts->valid = qfalse;
+
+    //check systems where the parent cent has left the PVS
+    //( local player entity is always valid )
+    if( ( centNum = CG_AttachmentCentNum( &ts->frontAttachment ) ) >= 0 &&
+        centNum != cg.snap->ps.clientNum )
+    {
+      trailSystem_t *tempTS = ts;
+
+      if( !cg_entities[ centNum ].valid )
+        CG_DestroyTrailSystem( &tempTS );
+    }
+
+    if( ( centNum = CG_AttachmentCentNum( &ts->backAttachment ) ) >= 0 &&
+        centNum != cg.snap->ps.clientNum )
+    {
+      trailSystem_t *tempTS = ts;
+
+      if( !cg_entities[ centNum ].valid )
+        CG_DestroyTrailSystem( &tempTS );
+    }
+
+    // lifetime expired
+    if( ts->destroyTime <= 0 && ts->class->lifeTime &&
+        ts->birthTime + ts->class->lifeTime < cg.time )
+    {
+      trailSystem_t *tempTS = ts;
+
+      CG_DestroyTrailSystem( &tempTS );
+      if( cg_debugTrails.integer >= 1 )
+        CG_Printf( "TS %s expired (born %d, lives %d, now %d)\n",
+                   ts->class->name, ts->birthTime, ts->class->lifeTime,
+                   cg.time );
+    }
+
+    if( cg_debugTrails.integer >= 1 && !ts->valid )
+      CG_Printf( "TS %s garbage collected\n", ts->class->name );
+  }
+}
+
+/*
+===============
+CG_AddTrails
+
+Add trails to the scene
+===============
+*/
+void CG_AddTrails( void )
+{
+  int           i;
+  trailBeam_t   *tb;
+  int           numTS = 0, numTB = 0;
+
+  //remove expired trail systems
+  CG_GarbageCollectTrailSystems( );
+
+  for( i = 0; i < MAX_TRAIL_BEAMS; i++ )
+  {
+    tb = &trailBeams[ i ];
+
+    if( tb->valid )
+    {
+      CG_UpdateBeam( tb );
+      CG_RenderBeam( tb );
+    }
+  }
+
+  if( cg_debugTrails.integer >= 2 )
+  {
+    for( i = 0; i < MAX_TRAIL_SYSTEMS; i++ )
+      if( trailSystems[ i ].valid )
+        numTS++;
+
+    for( i = 0; i < MAX_TRAIL_BEAMS; i++ )
+      if( trailBeams[ i ].valid )
+        numTB++;
+
+    CG_Printf( "TS: %d  TB: %d\n", numTS, numTB );
+  }
+}
+
+static trailSystem_t  *testTS;
+static qhandle_t      testTSHandle;
+
+/*
+===============
+CG_DestroyTestTS_f
+
+Destroy the test a trail system
+===============
+*/
+void CG_DestroyTestTS_f( void )
+{
+  if( CG_IsTrailSystemValid( &testTS ) )
+    CG_DestroyTrailSystem( &testTS );
+}
+
+/*
+===============
+CG_TestTS_f
+
+Test a trail system
+===============
+*/
+void CG_TestTS_f( void )
+{
+  char tsName[ MAX_QPATH ];
+
+  if( trap_Argc( ) < 2 )
+    return;
+
+  Q_strncpyz( tsName, CG_Argv( 1 ), MAX_QPATH );
+  testTSHandle = CG_RegisterTrailSystem( tsName );
+
+  if( testTSHandle )
+  {
+    CG_DestroyTestTS_f( );
+
+    testTS = CG_SpawnNewTrailSystem( testTSHandle );
+
+    if( CG_IsTrailSystemValid( &testTS ) )
+    {
+      CG_SetAttachmentCent( &testTS->frontAttachment, &cg_entities[ 0 ] );
+      CG_AttachToCent( &testTS->frontAttachment );
+    }
+  }
+}