add direct vertical aiming (from Crispy Doom) (#1105)

* add direct vertical aiming (from Crispy Doom)

* add comment

src/info.h

@@ -1524,6 +1524,8 @@ typedef struct
     int bloodcolor;   // [FG] colored blood and gibs
     // DEHEXTRA
     mobjtype_t droppeditem; // mobj to drop after death
+    // [crispy] height of the spawnstate's first sprite in pixels
+    int	actualheight;
 } mobjinfo_t;
 
 #define NO_ALTSPEED -1

src/m_menu.c

@@ -4057,6 +4057,7 @@ enum {
   gen3_title2,
   gen3_hangsolid,
   gen3_blockmapfix,
+  gen3_verticalaim,
   gen3_pistolstart,
   gen3_end2,
 };
@@ -4248,6 +4249,9 @@ setup_menu_t gen_settings3[] = { // General Settings screen3
   {"Improved Hit Detection", S_YESNO|S_STRICT|S_CRITICAL, m_null, M_X,
    M_Y + gen3_blockmapfix*M_SPC, {"blockmapfix"}},
 
+  {"Direct Vertical Aiming", S_YESNO|S_STRICT|S_CRITICAL, m_null, M_X,
+   M_Y + gen3_verticalaim*M_SPC, {"direct_vertical_aiming"}},
+
   {"Pistol Start", S_YESNO|S_STRICT|S_CRITICAL, m_null, M_X,
    M_Y + gen3_pistolstart*M_SPC, {"pistolstart"}},
 

src/m_misc.c

@@ -620,6 +620,13 @@ default_t defaults[] = {
     "1 to enable blockmap bug fix"
   },
 
+  {
+    "direct_vertical_aiming",
+    (config_t *) &direct_vertical_aiming, NULL,
+    {0}, {0,1}, number, ss_gen, wad_no,
+    "1 to enable direct vertical aiming"
+  },
+
   {
     "pistolstart",
     (config_t *) &default_pistolstart, (config_t *) &pistolstart,

src/p_map.c

@@ -564,9 +564,14 @@ static boolean PIT_CheckThing(mobj_t *thing) // killough 3/26/98: make static
   if (tmthing->flags & MF_MISSILE || (tmthing->flags & MF_BOUNCES &&
 				      !(tmthing->flags & MF_SOLID)))
     {
+      // [crispy] mobj or actual sprite height
+      const fixed_t thingheight = (tmthing->target && tmthing->target->player &&
+        CRITICAL(direct_vertical_aiming)) ?
+        thing->info->actualheight : thing->height;
+
       // see if it went over / under
 
-      if (tmthing->z > thing->z + thing->height)
+      if (tmthing->z > thing->z + thingheight)
 	return true;    // overhead
 
       if (tmthing->z+tmthing->height < thing->z)
@@ -1565,6 +1570,29 @@ static boolean PTR_ShootTraverse(intercept_t *in)
 	      return false;
 	}
 
+      // [crispy] check if the pullet puff's z-coordinate is below or above
+      // its spawning sector's floor or ceiling, respectively, and move its
+      // coordinates to the point where the trajectory hits the plane
+      if (CRITICAL(direct_vertical_aiming) && aimslope)
+      {
+        const int lineside = P_PointOnLineSide(x, y, li);
+        int side;
+
+        if ((side = li->sidenum[lineside]) != NO_INDEX)
+        {
+          const sector_t *const sector = sides[side].sector;
+
+          if (z < sector->floorheight ||
+             (z > sector->ceilingheight && sector->ceilingpic != skyflatnum))
+          {
+            z = BETWEEN(sector->floorheight, sector->ceilingheight, z);
+            frac = FixedDiv(z - shootz, FixedMul(aimslope, attackrange));
+            x = trace.x + FixedMul (trace.dx, frac);
+            y = trace.y + FixedMul (trace.dy, frac);
+          }
+        }
+      }
+
       // Spawn bullet puffs.
 
       P_SpawnPuff (x,y,z);
@@ -1586,7 +1614,12 @@ static boolean PTR_ShootTraverse(intercept_t *in)
   // check angles to see if the thing can be aimed at
 
   dist = FixedMul (attackrange, in->frac);
-  thingtopslope = FixedDiv (th->z+th->height - shootz , dist);
+  {
+  // [crispy] mobj or actual sprite height
+  const fixed_t thingheight = (shootthing->player && CRITICAL(direct_vertical_aiming)) ?
+                th->info->actualheight : th->height;
+  thingtopslope = FixedDiv (th->z+thingheight - shootz , dist);
+  }
 
   if (thingtopslope < aimslope)
     return true;  // shot over the thing

src/p_mobj.c

@@ -35,9 +35,12 @@
 #include "g_game.h"
 #include "p_inter.h"
 #include "v_video.h"
+#include "m_swap.h"
+#include "w_wad.h"
 
 // [FG] colored blood and gibs
 boolean colored_blood;
+boolean direct_vertical_aiming;
 
 //
 // P_SetMobjState
@@ -873,6 +876,29 @@ mobj_t *P_SpawnMobj(fixed_t x, fixed_t y, fixed_t z, mobjtype_t type)
       mobj->intflags &= ~MIF_FLIP;
   }
 
+  // [crispy] height of the spawnstate's first sprite in pixels
+  if (!info->actualheight)
+  {
+    const spritedef_t *const sprdef = &sprites[mobj->sprite];
+
+    if (!sprdef->numframes || !(mobj->flags & (MF_SOLID|MF_SHOOTABLE)))
+    {
+      info->actualheight = info->height;
+    }
+    else
+    {
+      spriteframe_t *sprframe;
+      int lump;
+      patch_t *patch;
+
+      sprframe = &sprdef->spriteframes[mobj->frame & FF_FRAMEMASK];
+      lump = sprframe->lump[0];
+      patch = W_CacheLumpNum(lump + firstspritelump, PU_CACHE);
+
+      info->actualheight = SHORT(patch->height) << FRACBITS;
+    }
+  }
+
   P_AddThinker(&mobj->thinker);
 
   return mobj;
@@ -1448,6 +1474,11 @@ mobj_t* P_SpawnPlayerMissile(mobj_t* source,mobjtype_t type)
     {
       // killough 8/2/98: prefer autoaiming at enemies
       int mask = demo_version < 203 ? 0 : MF_FRIEND;
+      if (CRITICAL(direct_vertical_aiming))
+      {
+        slope = PLAYER_SLOPE(source->player);
+      }
+      else
       do
 	{
 	  slope = P_AimLineAttack(source, an, 16*64*FRACUNIT, mask);

src/p_mobj.h

@@ -416,6 +416,9 @@ extern int iquetail;
 // [FG] colored blood and gibs
 extern boolean colored_blood;
 
+#define PLAYER_SLOPE(a)	((((a)->lookdir / MLOOKUNIT) << FRACBITS) / 173) // angle to fixed approximation
+extern boolean direct_vertical_aiming;
+
 mobj_t *P_SubstNullMobj(mobj_t *mobj);
 void    P_RespawnSpecials(void);
 mobj_t  *P_SpawnMobj(fixed_t x, fixed_t y, fixed_t z, mobjtype_t type);

src/p_pspr.c

@@ -786,6 +786,11 @@ void A_FireOldBFG(player_t *player, pspdef_t *psp)
 	  // killough 8/2/98: make autoaiming prefer enemies
 	  int mask = MF_FRIEND;
 	  fixed_t slope;
+	  if (CRITICAL(direct_vertical_aiming))
+	  {
+	    slope = PLAYER_SLOPE(mo->player);
+	  }
+	  else
 	  do
 	    {
 	      slope = P_AimLineAttack(mo, an, 16*64*FRACUNIT, mask);
@@ -851,6 +856,11 @@ static void P_BulletSlope(mobj_t *mo)
   // killough 8/2/98: make autoaiming prefer enemies
   int mask = demo_version < 203 ? 0 : MF_FRIEND;
 
+  if (CRITICAL(direct_vertical_aiming))
+  {
+    bulletslope = PLAYER_SLOPE(mo->player);
+  }
+  else
   do
     {
       bulletslope = P_AimLineAttack(mo, an, 16*64*FRACUNIT, mask);