Abstract over con_var layout changes from OE to NE

This doesn't allow us to support OE in and of itself but is part of the
groundwork necessary to do so in the future.

1 files changed, 39 insertions, 13 deletions

diff --git a/src/con_.h b/src/con_.h
index b491aad..c2c0cce 100644
--- a/src/con_.h
+++ b/src/con_.h
@@ -117,9 +117,7 @@ struct con_cmd { // ConCommand in engine
 	bool has_complcb : 1, use_newcb : 1, use_newcmdiface : 1;
 };
 
-struct con_var { // ConVar in engine
-	struct con_cmdbase base;
-	void **vtable_iconvar; // IConVar in engine (pure virtual)
+struct con_var_common {
 	struct con_var *parent;
 	const char *defaultval;
 	char *strval;
@@ -131,8 +129,19 @@ struct con_var { // ConVar in engine
 	float minval;
 	bool hasmax; // just sticking to sdk position
 	float maxval;
+};
+
+struct con_var { // ConVar in engine
+	struct con_cmdbase base;
+	union {
+		struct con_var_common v1;
+		struct {
+			void **vtable_iconvar; // IConVar in engine (pure virtual)
+			struct con_var_common v2;
+		};
+	};
 	/*
-	 * Our quickly-chucked-in optional callback - doesn't match the engine!!
+	 * Our quickly-chucked-in optional callback - doesn't match the engine ABI!
 	 * Also has to be manually set in code, although that's probably fine anyway
 	 * as it's common to only want a cvar to do something if the feature
 	 * succesfully init-ed.
@@ -143,13 +152,27 @@ struct con_var { // ConVar in engine
 /* The change callback used in most branches of Source. Takes an IConVar :) */
 typedef void (*con_varcb)(void *v, const char *, float);
 
+
+/* Returns a registered variable with the given name, or null if not found. */
+struct con_var *con_findvar(const char *name);
+
+/* Returns a registered command with the given name, or null if not found. */
+struct con_cmd *con_findcmd(const char *name);
+
+/*
+ * Returns a pointer to the common (i.e. middle) part of a ConVar struct, the
+ * offset of which varies by engine version. This sub-struct contains
+ * essentially all the actual cvar-specific data.
+ */
+static inline struct con_var_common *con_getvarcommon(struct con_var *v) {
+	return &v->v2;
+}
+
 /*
  * These functions get and set the values of console variables in a
  * neatly-abstracted manner. Note: cvar values are always strings internally -
  * numerical values are just interpretations of the underlying value.
  */
-struct con_var *con_findvar(const char *name);
-struct con_cmd *con_findcmd(const char *name);
 const char *con_getvarstr(const struct con_var *v);
 float con_getvarf(const struct con_var *v);
 int con_getvari(const struct con_var *v);
@@ -236,13 +259,16 @@ extern struct _con_vtab_iconvar_wrap {
 			.name = "" #name_, .help = "" desc, .flags = (flags_) \
 		}, \
 		.vtable_iconvar = _con_vtab_iconvar, \
-		.parent = &_cvar_##name_, /* bizarre, but how the engine does it */ \
-		.defaultval = _Generic(value, char *: value, int: #value, \
-				double: #value), \
-		.strlen = sizeof(_Generic(value, char *: value, default: #value)), \
-		.fval = _Generic(value, char *: 0, int: value, double: value), \
-		.ival = _Generic(value, char *: 0, int: value, double: (int)value), \
-		.hasmin = hasmin_, .minval = (min), .hasmax = hasmax_, .maxval = (max) \
+		.v2 = { \
+			.parent = &_cvar_##name_, /* bizarre, but how the engine does it */ \
+			.defaultval = _Generic(value, char *: value, int: #value, \
+					double: #value), \
+			.strlen = sizeof(_Generic(value, char *: value, default: #value)), \
+			.fval = _Generic(value, char *: 0, int: value, double: value), \
+			.ival = _Generic(value, char *: 0, int: value, double: (int)value), \
+			.hasmin = hasmin_, .minval = (min), \
+			.hasmax = hasmax_, .maxval = (max) \
+		} \
 	}; \
 	struct con_var *name_ = &_cvar_##name_;