Add extension: DP_SV_MODELFLAGS_AS_EFFECTS

[qbism]

About- The DP_SV_MODELFLAGS_AS_EFFECTS extension provides a way to override model flags within qc. Model flags are baked-in the mdl, and vanilla Quake does not expose the flags to qc. For more info, search DP source code for "modelflags"

Disclaimer- The cut-and-paste code shown here may need to be adapted to your particular engine, which will already be heavily modded. This tutorial only applies to engines that already have the extensions system built-in, AND a network protocol that can write extended effects up to 32 bits.

Background- Pick-up item models are compiled with a flag set called EF_ROTATE to automatically make them spin around slowly. But vanilla Quake does not provide a way to bestow this rotation on any arbitrary entity from qc. An example would be a vwep model that doubles as a pick-up model. This was my original need, but the idea can be expanded to all model flags with DP_SV_MODELFLAGS_AS_EFFECTS.

Let's get messy- First back up your code!

Crack open the header file where entity effects are defined, typically server.h, and add:

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#define EF_NOMODELFLAGS         8388608      // indicates the model's .effects should be ignored (allows overriding them)
#define EF_ROCKET            16777216   // leave a trail
#define EF_GRENADE            33554432   // leave a trail
#define EF_GIB               67108864   // leave a trail
#define EF_ROTATE            134217728   // rotate (bonus items)
#define EF_TRACER            268435456   // green split trail
#define EF_ZOMGIB            536870912   // small blood trail
#define EF_TRACER2            1073741824   // orange split trail + rotate
#define EF_TRACER3            0x80000000   // purple trail


Rename defines starting with EF_ in model.h to MF_

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 #define   MF_ROCKET   1         // leave a trail
#define   MF_GRENADE   2         // leave a trail
#define   MF_GIB      4         // leave a trail
#define   MF_ROTATE   8         // rotate (bonus items)
#define   MF_TRACER   16         // green split trail
#define   MF_ZOMGIB   32         // small blood trail
#define   MF_TRACER2   64         // orange split trail + rotate
#define   MF_TRACER3   128         // purple trail

In render.h in typedef stuct entity_s add

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int                  modelflags;

In model.c change

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mod->flags = LittleLong (pinmodel->flags);

to this

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   i = LittleLong (pinmodel->flags);
   mod->flags = ((i & 255) << 24) | (i & 0x00FFFF00);

Just before the section of cl_main.c that processes model flag effects like EF_ROTATE add

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      if (!(ent->effects & 0xFF800000))  //qbism based on DP model flags
         ent->effects |= ent->model->flags;

and replace occurrences of ent->model->flags with ent->effects.
This conditional is using model flag overrides if they exist in ent->effects. Otherwise it uses the flags as read from the mdl.

Open sv_main.c and be careful where you stick the following, engines vary greatly here. Also maybe this could be written more concisely. Just prior to comparison of entity effects to baseline add

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      if ((val = GetEdictFieldValue(ent, "modelflags")))
      {
         i= (unsigned int)ent->v.effects;
         i |= ((unsigned int)val->_float & 0xff) << 24;
         ent->v.effects = i;
      }

Head to pr_cmds.c, add this extension to the list:

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char *pr_extensions[] =
{
// add the extension names here, syntax: "extensionname",
   "DP_SV_MODELFLAGS_AS_EFFECTS  ",

That's the gist of it, engine side.

qc source changes- In defs.qc in field definitions, add

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.float       modelflags;

Scroll further down to built-in functions and add

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float(string ext) dp_checkextension = #99;

It may already be somwhere as frik_checkextension.

Tack this to the effect definitions in defs.qc

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float EF_NOMODELFLAGS = 8388608; // ignore any effects in a model file and substitute your own
float MF_ROCKET  =   1; // leave a trail
float MF_GRENADE =   2; // leave a trail
float MF_GIB     =   4; // leave a trail
float MF_ROTATE  =   8; // rotate (bonus items)
float MF_TRACER  =  16; // green split trail
float MF_ZOMGIB  =  32; // small blood trail
float MF_TRACER2 =  64; // orange split trail
float MF_TRACER3 = 128; // purple trail

Example to set a flag-

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self.modelflags = MF_ROTATE;

[Sajt]

What you were looking for is probably DP_SV_MODELFLAGS_AS_EFFECTS. It adds a field, .modelflags, which uses the same flag values as mdl flags. There is only one .effects flag added, EF_NOMODELFLAGS, which cancels the original .mdl flags.

[qbism]

That would be a more flexible way to go, and I'm going to try it. Does any other engine but DP have it?

Searching DP for "modelflags" brings out the starting points.