Refactor: Moved line of sight test algorithm into GameMap

doomsday/engine/api/dd_share.h

@@ -257,7 +257,7 @@ enum {
 
     // Non-integer/special values for Set/Get
     DD_TRANSLATIONTABLES_ADDRESS,
-    DD_TRACE_ADDRESS, ///< divline 'trace' used by PathTraverse.
+    DD_TRACE_ADDRESS, ///< obsolete divline 'trace' used by PathTraverse.
     DD_SPRITE_REPLACEMENT, ///< Sprite <-> model replacement.
     DD_ACTION_LINK, ///< State action routine addresses.
     DD_MAP_NAME,
@@ -283,10 +283,10 @@ enum {
     DD_XGFUNC_LINK, ///< XG line classes
     DD_SHARED_FIXED_TRIGGER_OBSOLETE, ///< obsolete
     DD_GAMETIC,
-    DD_OPENRANGE,
-    DD_OPENTOP,
-    DD_OPENBOTTOM,
-    DD_LOWFLOOR,
+    DD_OPENRANGE, ///< obsolete
+    DD_OPENTOP, ///< obsolete
+    DD_OPENBOTTOM, ///< obsolete
+    DD_LOWFLOOR, ///< obsolete
     DD_CPLAYER_THRUST_MUL_OBSOLETE, ///< obsolete
     DD_GRAVITY,
     DD_PSPRITE_OFFSET_X, ///< 10x
@@ -873,7 +873,20 @@ typedef struct intercept_s {
 
 typedef int (*traverser_t) (const intercept_t* intercept, void* paramaters);
 
-#define NO_INDEX            0xffffffff
+/**
+ * A simple POD data structure for representing line trace openings.
+ */
+typedef struct {
+    /// Top and bottom z of the opening.
+    float top, bottom;
+
+    /// Distance from top to bottom.
+    float range;
+
+    /// Z height of the lowest Plane at the opening on the X|Y axis.
+    /// @todo Does not belong here?
+    float lowFloor;
+} TraceOpening;
 
 //------------------------------------------------------------------------
 //

doomsday/engine/api/doomsday.def

@@ -1,6 +1,6 @@
 ; Doomsday Engine API (Routines exported from Doomsday.exe).
 ;
-; Highest ordinal is currently: --> 827 <--
+; Highest ordinal is currently: --> 829 <--
 ; Other free ordinals: none
 
 NAME                            "DOOMSDAY"
@@ -446,7 +446,9 @@ EXPORTS
     P_MakeDivline               @61 NONAME
     P_PointOnDivlineSide        @62 NONAME
     P_InterceptVector           @63 NONAME
-    P_LineOpening               @64 NONAME
+    P_TraceLOS                  @829 NONAME
+    P_TraceOpening              @828 NONAME
+    P_SetTraceOpening           @64 NONAME
     P_SubsectorAtPointXY        @102 NONAME
     P_MobjsBoxIterator          @346 NONAME
     P_LinesBoxIterator          @435 NONAME

doomsday/engine/api/doomsday.h

@@ -422,7 +422,10 @@ boolean ClMobj_LocalActionsEnabled(struct mobj_s* mo);
     void            P_MakeDivline(struct linedef_s* li, divline_t* dl);
     int             P_PointOnDivlineSide(float x, float y, const divline_t* line);
     float           P_InterceptVector(divline_t* v2, divline_t* v1);
-    void            P_LineOpening(struct linedef_s* linedef);
+
+    const divline_t* P_TraceLOS(void);
+    TraceOpening*   P_TraceOpening(void);
+    void            P_SetTraceOpening(struct linedef_s* linedef);
 
     struct subsector_s* P_SubsectorAtPointXY(float x, float y);
 

doomsday/engine/portable/include/gamemap.h

@@ -73,6 +73,11 @@ typedef struct gamemap_s {
 
     float globalGravity; // Gravity for the current map.
     int ambientLightLevel; // Ambient lightlevel for the current map.
+
+    /// Current LOS trace state.
+    /// @todo Refactor to support concurrent traces.
+    TraceOpening traceOpening;
+    divline_t traceLOS;
 } GameMap;
 
 /**
@@ -86,6 +91,31 @@ const char* GameMap_OldUniqueId(GameMap* map);
 
 void GameMap_Bounds(GameMap* map, float* min, float* max);
 
+/**
+ * Retrieve an immutable copy of the LOS trace line.
+ *
+ * @param map  GameMap instance.
+ */
+const divline_t* GameMap_TraceLOS(GameMap* map);
+
+/**
+ * Retrieve an immutable copy of the LOS TraceOpening state.
+ *
+ * @param map  GameMap instance.
+ */
+const TraceOpening* GameMap_TraceOpening(GameMap* map);
+
+/**
+ * Update the TraceOpening state for according to the opening defined by the
+ * inner-minimal planes heights which intercept @a linedef
+ *
+ * If @a lineDef is not owned by the map this is a no-op.
+ *
+ * @param map  GameMap instance.
+ * @param lineDef  LineDef to configure the opening for.
+ */
+void GameMap_SetTraceOpening(GameMap* map, linedef_t* lineDef);
+
 /**
  * Retrieve the map-global ambient light level.
  *

doomsday/engine/portable/include/p_maputil.h

@@ -37,9 +37,6 @@
 #define IS_SECTOR_LINKED(mo)    ((mo)->sPrev != NULL)
 #define IS_BLOCK_LINKED(mo)     ((mo)->bNext != NULL)
 
-extern float  opentop, openbottom, openrange, lowfloor;
-extern divline_t traceLOS;
-
 float           P_AccurateDistanceFixed(fixed_t dx, fixed_t dy);
 float           P_AccurateDistance(float dx, float dy);
 float           P_ApproxDistance(float dx, float dy);
@@ -72,7 +69,26 @@ float           P_InterceptVector(const divline_t* v2, const divline_t* v1);
 int             P_PointOnDivLineSidef(fvertex_t *pnt, fdivline_t *dline);
 float           P_FloatInterceptVertex(fvertex_t *start, fvertex_t *end,
                                        fdivline_t *fdiv, fvertex_t *inter);
-void            P_LineOpening(linedef_t* linedef);
+
+/**
+ * Retrieve an immutable copy of the LOS trace line for the CURRENT map.
+ *
+ * @note Always returns a valid divline_t even if there is no current map.
+ */
+const divline_t* P_TraceLOS(void);
+
+/**
+ * Retrieve an immutable copy of the TraceOpening state for the CURRENT map.
+ *
+ * @note Always returns a valid TraceOpening even if there is no current map.
+ */
+const TraceOpening* P_TraceOpening(void);
+
+/**
+ * Update the TraceOpening state for the CURRENT map according to the opening
+ * defined by the inner-minimal planes heights which intercept @a linedef
+ */
+void P_SetTraceOpening(linedef_t* linedef);
 
 /**
  * Determine the BSP leaf (subsector) on the back side of the BS partition that
@@ -154,4 +170,8 @@ int P_PathTraverse2(float const from[2], float const to[2], int flags, traverser
  */
 int P_PathXYTraverse(float fromX, float fromY, float toX, float toY, int flags, traverser_t callback);
 int P_PathXYTraverse2(float fromX, float fromY, float toX, float toY, int flags, traverser_t callback, void* paramaters);
+
+boolean P_CheckLineSight(const float from[3], const float to[3], float bottomSlope,
+    float topSlope, int flags);
+
 #endif

doomsday/engine/portable/include/p_sight.h

@@ -1,35 +1,41 @@
-/**\file
- *\section License
- * License: GPL
- * Online License Link: http://www.gnu.org/licenses/gpl.html
- *
- *\author Copyright © 2003-2012 Jaakko Keränen <jaakko.keranen@iki.fi>
- *\author Copyright © 2006-2012 Daniel Swanson <danij@dengine.net>
+/**
+ * @file p_sight.h
+ * Gamemap Line of Sight Testing. @ingroup map
  *
- * This program 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.
+ * @authors Copyright © 2003-2012 Jaakko Keränen <jaakko.keranen@iki.fi>
+ * @authors Copyright © 2006-2012 Daniel Swanson <danij@dengine.net>
  *
- * This program 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.
+ * @par License
+ * GPL: http://www.gnu.org/licenses/gpl.html
  *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin St, Fifth Floor,
- * Boston, MA  02110-1301  USA
+ * <small>This program 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. This program 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 this program; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA</small>
  */
 
-/**
- * de_play.h: Line of Sight Testing
- */
+#ifndef LIBDENG_MAP_GAMEMAP_SIGHT_H
+#define LIBDENG_MAP_GAMEMAP_SIGHT_H
 
-#ifndef __DOOMSDAY_PLAY_SIGHT_H__
-#define __DOOMSDAY_PLAY_SIGHT_H__
+#include "gamemap.h"
 
-boolean         P_CheckLineSight(const float from[3], const float to[3],
-                                 float bottomSlope, float topSlope, int flags);
+/**
+ * Traces a line of sight.
+ *
+ * @param from          World position, trace origin coordinates.
+ * @param to            World position, trace target coordinates.
+ * @param flags         Line Sight Flags (LS_*) @see lineSightFlags
+ *
+ * @return              @c true if the traverser function returns @c true
+ *                      for all visited lines.
+ */
+boolean GameMap_CheckLineSight(GameMap* map, const float from[3], const float to[3],
+    float bottomSlope, float topSlope, int flags);
 
-#endif
+#endif /// LIBDENG_MAP_GAMEMAP_SIGHT_H

doomsday/engine/portable/src/dam_main.c

@@ -523,12 +523,14 @@ boolean DAM_AttemptMapLoad(const Uri* uri)
         Z_FreeTags(PU_MAP, PU_PURGELEVEL - 1);
 
         if(mapCache && dam->cachedMapFound)
-        {   // Attempt to load the cached map data.
+        {
+            // Attempt to load the cached map data.
             if(loadMap(&map, dam))
                 loadedOK = true;
         }
         else
-        {   // Try a JIT conversion with the help of a plugin.
+        {
+            // Try a JIT conversion with the help of a plugin.
             if(convertMap(&map, dam))
                 loadedOK = true;
         }

doomsday/engine/portable/src/dd_main.c

@@ -2089,6 +2089,7 @@ void DD_SetInteger(int ddvalue, int parm)
 void* DD_GetVariable(int ddvalue)
 {
     static uint valueU;
+    static float valueF;
 
     switch(ddvalue)
     {
@@ -2128,7 +2129,8 @@ void* DD_GetVariable(int ddvalue)
         return &valueU;
 
     case DD_TRACE_ADDRESS:
-        return &traceLOS;
+        /// @fixme Do not cast away const.
+        return (void*)P_TraceLOS();
 
     case DD_TRANSLATIONTABLES_ADDRESS:
         return translationTables;
@@ -2223,25 +2225,33 @@ void* DD_GetVariable(int ddvalue)
     case DD_GAMETIC: {
         static timespan_t       fracTic;
         fracTic = gameTime * TICSPERSEC;
-        return &fracTic;
-      }
-    case DD_OPENRANGE:
-        return &openrange;
+        return &fracTic; }
+
+    case DD_OPENRANGE: {
+        const TraceOpening* open = P_TraceOpening();
+        valueF = open->range;
+        return &valueF; }
 
-    case DD_OPENTOP:
-        return &opentop;
+    case DD_OPENTOP: {
+        const TraceOpening* open = P_TraceOpening();
+        valueF = open->top;
+        return &valueF; }
 
-    case DD_OPENBOTTOM:
-        return &openbottom;
+    case DD_OPENBOTTOM: {
+        const TraceOpening* open = P_TraceOpening();
+        valueF = open->bottom;
+        return &valueF; }
 
-    case DD_LOWFLOOR:
-        return &lowfloor;
+    case DD_LOWFLOOR: {
+        const TraceOpening* open = P_TraceOpening();
+        valueF = open->lowFloor;
+        return &valueF; }
 
     case DD_NUMLUMPS: {
         static int count;
         count = F_LumpCount();
-        return &count;
-      }
+        return &count; }
+
     default: break;
     }