Feature: New spawns style "random" (#106)

* Add `rog.inc`

- ROG is an include file which allows you to generate random valid origins around the map. It could be used to create random player spawns or in Battle Royale mods(PUBG/Fortnite) to spawn the floor loot/drop crates/llamas, etc.

* redm_spawns: add `random` spawn preset

* ConVar `redm_spawn_preset` hot change support

* CvarChange_redm_spawn_preset: rework api usage

* better ConVar desc

cstrike/addons/amxmodx/configs/redm/gamemode_deathmatch.json

@@ -57,7 +57,10 @@
         // Minimum distance to the enemy to enable spawn checks.
         "redm_randomspawn_dist": "1500",
 
-        // Name of the spawn manager
+        /* Name of the spawn manager style.
+        `none`,
+        `preset`,
+        `random` - (beta) */
         "redm_spawn_preset": "preset",
 
     // ReDM: Features

cstrike/addons/amxmodx/scripting/ReDeathmatch/ReDM_spawn_manager.inc

@@ -20,12 +20,22 @@ SpawnManager_Init() {
         redm_spawn_preset,
         charsmax(redm_spawn_preset)
     )
+    hook_cvar_change(get_cvar_pointer("redm_spawn_preset"), "CvarChange_redm_spawn_preset")
 
     RegisterHookChain(RG_CSGameRules_GetPlayerSpawnSpot, "CSGameRules_GetPlayerSpawnSpot", .post = false)
 
     redm_setstyle(redm_spawn_preset)
 }
 
+public CvarChange_redm_spawn_preset(const cvar, const oldValue[], const value[]) {
+    new bool: result = redm_setstyle(value)
+    if (result)
+        return
+
+    set_pcvar_string(cvar, oldValue)
+    LogMessageEx(Warning, "CvarChange_redm_spawn_preset: Spawn preset style `%s` not found!", value)
+}
+
 public CSGameRules_GetPlayerSpawnSpot(const player) {
     if (!IsActive())
         return HC_CONTINUE

cstrike/addons/amxmodx/scripting/include/redm.inc

@@ -70,8 +70,11 @@ native redm_addstyle(const name[], const function[])
 /**
  * Sets the current spawn style handler by name.
  * The handler registered to this name will be called after every spawn.
+ * 
+ * @param name     Style preset name.
+ * @return         True if the style has been set, otherwise false.
  */
-native redm_setstyle(const name[])
+native bool: redm_setstyle(const name[])
 
 /**
  * Returns the current style ID.