Exported Trace() interface to ZScript

src/p_trace.cpp

@@ -42,6 +42,7 @@
 #include "p_spec.h"
 #include "g_levellocals.h"
 #include "p_terrain.h"
+#include "vm.h"
 
 //==========================================================================
 //
@@ -948,3 +949,76 @@ static bool EditTraceResult (uint32_t flags, FTraceResults &res)
 	}
 	return true;
 }
+
+//==========================================================================
+//
+//  [ZZ] here go the methods for the ZScript interface
+//
+//==========================================================================
+IMPLEMENT_CLASS(DTracer, false, false)
+DEFINE_FIELD_X(Tracer, DTracer, Results)
+
+// define TraceResults fields
+DEFINE_FIELD_NAMED_X(TraceResults, FTraceResults, Sector, Sec)
+DEFINE_FIELD_X(TraceResults, FTraceResults, HitTexture)
+DEFINE_FIELD_X(TraceResults, FTraceResults, HitPos)
+DEFINE_FIELD_X(TraceResults, FTraceResults, HitVector)
+DEFINE_FIELD_X(TraceResults, FTraceResults, SrcFromTarget)
+DEFINE_FIELD_X(TraceResults, FTraceResults, SrcAngleFromTarget)
+DEFINE_FIELD_X(TraceResults, FTraceResults, Distance)
+DEFINE_FIELD_X(TraceResults, FTraceResults, Fraction)
+DEFINE_FIELD_NAMED_X(TraceResults, FTraceResults, Actor, Thing)
+DEFINE_FIELD_NAMED_X(TraceResults, FTraceResults, Line, Linedef)
+DEFINE_FIELD_X(TraceResults, FTraceResults, Side)
+DEFINE_FIELD_X(TraceResults, FTraceResults, Tier)
+DEFINE_FIELD_X(TraceResults, FTraceResults, unlinked)
+DEFINE_FIELD_X(TraceResults, FTraceResults, HitType)
+DEFINE_FIELD_X(TraceResults, FTraceResults, CrossedWater)
+DEFINE_FIELD_X(TraceResults, FTraceResults, CrossedWaterPos)
+DEFINE_FIELD_X(TraceResults, FTraceResults, Crossed3DWater)
+DEFINE_FIELD_X(TraceResults, FTraceResults, Crossed3DWaterPos)
+
+DEFINE_ACTION_FUNCTION(DTracer, Trace)
+{
+	PARAM_SELF_PROLOGUE(DTracer);
+	/*bool Trace(const DVector3 &start, sector_t *sector, const DVector3 &direction, double maxDist,
+	ActorFlags ActorMask, uint32_t WallMask, AActor *ignore, FTraceResults &res, uint32_t traceFlags = 0,
+	ETraceStatus(*callback)(FTraceResults &res, void *) = NULL, void *callbackdata = NULL);*/
+	PARAM_FLOAT(start_x);
+	PARAM_FLOAT(start_y);
+	PARAM_FLOAT(start_z);
+	PARAM_POINTER(sector, sector_t);
+	PARAM_FLOAT(direction_x);
+	PARAM_FLOAT(direction_y);
+	PARAM_FLOAT(direction_z);
+	PARAM_FLOAT(maxDist);
+	// actor flags and wall flags are not supported due to how flags are implemented on the ZScript side.
+	// say thanks to oversimplifying the user API.
+	PARAM_INT(traceFlags);
+
+	// Trace(vector3 start, Sector sector, vector3 direction, double maxDist, ETraceFlags traceFlags)
+	bool res = Trace(DVector3(start_x, start_y, start_z), sector, DVector3(direction_x, direction_y, direction_z), maxDist,
+					 (ActorFlag)0xFFFFFFFF, 0xFFFFFFFF, nullptr, self->Results, traceFlags, &DTracer::TraceCallback, self);
+	ACTION_RETURN_BOOL(res);
+}
+
+ETraceStatus DTracer::TraceCallback(FTraceResults& res, void* pthis)
+{
+	DTracer* self = (DTracer*)pthis;
+	// "res" here should refer to self->Results anyway.
+	return self->CallZScriptCallback();
+}
+
+ETraceStatus DTracer::CallZScriptCallback()
+{
+	IFVIRTUAL(DTracer, TraceCallback)
+	{
+		int status;
+		VMReturn results[1] = { &status };
+		VMValue params[1] = { (DTracer*)this };
+		VMCall(func, params, 1, results, 1);
+		return (ETraceStatus)status;
+	}
+
+	return TRACE_Stop;
+}

src/p_trace.h

@@ -112,4 +112,14 @@ bool Trace(const DVector3 &start, sector_t *sector, const DVector3 &direction, d
 	ActorFlags ActorMask, uint32_t WallMask, AActor *ignore, FTraceResults &res, uint32_t traceFlags = 0,
 	ETraceStatus(*callback)(FTraceResults &res, void *) = NULL, void *callbackdata = NULL);
 
+// [ZZ] this is the object that's used for ZScript
+class DTracer : public DObject
+{
+	DECLARE_CLASS(DTracer, DObject)
+public:
+	FTraceResults Results;
+	static ETraceStatus TraceCallback(FTraceResults& res, void* pthis);
+	ETraceStatus CallZScriptCallback();
+};
+
 #endif //__P_TRACE_H__

wadsrc/static/zscript/base.txt

@@ -460,6 +460,87 @@ class BlockLinesIterator : Object native
 	native bool Next();
 }
 
+enum ETraceStatus
+{
+	TRACE_Stop,		// stop the trace, returning this hit
+	TRACE_Continue,		// continue the trace, returning this hit if there are none further along
+	TRACE_Skip,		// continue the trace; do not return this hit
+	TRACE_Abort		// stop the trace, returning no hits
+}
+
+enum ETraceFlags
+{
+	TRACE_NoSky		= 1,	// Hitting the sky returns TRACE_HitNone
+	TRACE_PCross		= 2,	// Trigger SPAC_PCROSS lines
+	TRACE_Impact		= 4,	// Trigger SPAC_IMPACT lines
+	TRACE_PortalRestrict	= 8,	// Cannot go through portals without a static link offset.
+	TRACE_ReportPortals	= 16	// Report any portal crossing to the TraceCallback
+}
+
+
+enum ETraceResult
+{
+	TRACE_HitNone,
+	TRACE_HitFloor,
+	TRACE_HitCeiling,
+	TRACE_HitWall,
+	TRACE_HitActor,
+	TRACE_CrossingPortal
+}
+
+enum ELineTier
+{
+	TIER_Middle,
+	TIER_Upper,
+	TIER_Lower,
+	TIER_FFloor
+}
+
+struct TraceResults native
+{
+	native Sector Sec; // originally called "Sector". cannot be named like this in ZScript.
+	native TextureID HitTexture;
+	native vector3 HitPos;
+	native vector3 HitVector;
+	native vector3 SrcFromTarget;
+	native double SrcAngleFromTarget;
+
+	native double Distance;
+	native double Fraction;
+
+	native Actor Thing;		// valid if hit an actor. // originally called "Actor".
+
+	native Line Linedef;		// valid if hit a line // originally called "Line".
+	native uint8 Side;
+	native uint8 Tier;		// see Tracer.ELineTier
+	native bool unlinked;		// passed through a portal without static offset.
+
+	native ETraceResult HitType;
+	// F3DFloor *ffloor;
+
+	native Sector CrossedWater;		// For Boom-style, Transfer_Heights-based deep water
+	native vector3 CrossedWaterPos;	// remember the position so that we can use it for spawning the splash
+	native Sector Crossed3DWater;		// For 3D floor-based deep water
+	native vector3 Crossed3DWaterPos;
+}
+
+class Tracer : Object native
+{
+	native @TraceResults Results;
+	native bool Trace(vector3 start, Sector sec, vector3 direction, double maxDist, ETraceFlags traceFlags);
+
+	virtual ETraceStatus TraceCallback()
+	{
+		// Normally you would examine Results.HitType (for ETraceResult), and determine either:
+		//  - stop tracing and return the entity that was found (return TRACE_Stop)
+		//  - ignore some object, like noclip, e.g. only count solid walls and floors, and ignore actors (return TRACE_Skip)
+		//  - find last object of some type (return TRACE_Continue)
+		//  - stop tracing entirely and assume we found nothing (return TRACE_Abort)
+		// TRACE_Abort and TRACE_Continue are of limited use in scripting.
+
+		return TRACE_Stop; // default callback returns first hit, whatever it is.
+	}
+}
 
 struct DropItem native
 {