vk: make `vk_debug_log` a command, not a cvar

This makes it easily switchable at any point in time.

Still not sure how to properly manage log verbosity cvars:
- cvars are loaded after initialization and map load, so we can't really
  depend on saved cvar values.
- reloading cvars each frame cancels `-vkverboselogs` arg that is
  supposed to work around the above limitation

ref/vk/TODO.md

@@ -1,3 +1,12 @@
+# 2023-11-07 E326
+- [x] list supported arguments for `rt_debug_display_only` cvar
+- [x] make vk_debug_log a command
+- [ ] remove stvecs from patches -- not used, inconvenient
+- [ ] patch texture coordinates by matrices
+    - [ ] add support for matrices to mapents
+    - [ ] convert old direct scale/offset patches to matrices and check that they work
+    - [ ] remove old direct scale/offset patches
+
 # 2023-11-06 E325
 - [x] fix material asserts and inherit
 - [x] fixup -vkverboselogs

ref/vk/vk_core.c

@@ -701,7 +701,6 @@ qboolean R_VkInit( void )
 	vk_core.rtx = false;
 
 	VK_LoadCvars();
-	VK_LogsReadCvar();
 
 	// Force extremely verbose logs at startup.
 	// This is instrumental in some investigations, because the usual "vk_debug_log" cvar is not set

ref/vk/vk_cvar.c

@@ -1,6 +1,7 @@
 #include "vk_cvar.h"
 #include "vk_common.h"
 #include "vk_core.h"
+#include "vk_logs.h"
 
 #define NONEXTERN_CVAR(cvar) cvar_t *cvar;
 DECLARE_CVAR(NONEXTERN_CVAR)
@@ -8,6 +9,13 @@ DECLARE_CVAR(NONEXTERN_CVAR)
 
 DEFINE_ENGINE_SHARED_CVAR_LIST()
 
+static void setDebugLog( void ) {
+	const int argc = gEngine.Cmd_Argc();
+	const char *const modules = argc > 1 ? gEngine.Cmd_Argv(1) : "";
+	gEngine.Cvar_Set("vk_debug_log_", modules);
+	R_LogSetVerboseModules( modules );
+}
+
 void VK_LoadCvars( void )
 {
 #define gEngfuncs gEngine // ...
@@ -20,7 +28,9 @@ void VK_LoadCvars( void )
 	rt_force_disable = gEngine.Cvar_Get( "rt_force_disable", "0", FCVAR_GLCONFIG, "Force disable Ray Tracing" );
 	vk_device_target_id = gEngine.Cvar_Get( "vk_device_target_id", "", FCVAR_GLCONFIG, "Selected video device id" );
 
-	vk_debug_log = gEngine.Cvar_Get("vk_debug_log", "", FCVAR_GLCONFIG, "List of modules to enable debug logs for");
+	vk_debug_log = gEngine.Cvar_Get("vk_debug_log_", "", FCVAR_GLCONFIG | FCVAR_READ_ONLY, "");
+
+	gEngine.Cmd_AddCommand("vk_debug_log", setDebugLog, "Set modules to enable debug logs for");
 }
 
 void VK_LoadCvarsAfterInit( void )

ref/vk/vk_logs.c

@@ -20,9 +20,8 @@ static const struct log_pair_t {
 	{"sprite", LogModule_Sprite},
 };
 
-void VK_LogsReadCvar(void) {
+void R_LogSetVerboseModules( const char *p ) {
 	g_log_debug_bits = 0;
-	const char *p = vk_debug_log->string;
 	while (*p) {
 		const char *next = Q_strchrnul(p, ',');
 		const const_string_view_t name = {p, next - p};
@@ -31,6 +30,7 @@ void VK_LogsReadCvar(void) {
 		for (int i = 0; i < COUNTOF(g_log_module_pairs); ++i) {
 			const struct log_pair_t *const pair = g_log_module_pairs + i;
 			if (stringViewCmp(name, pair->name) == 0) {
+				gEngine.Con_Reportf("Enabling verbose logs for module \"%.*s\"\n", name.len, name.s);
 				bit = pair->bit;
 				break;
 			}

ref/vk/vk_logs.h

@@ -77,5 +77,4 @@ extern uint32_t g_log_debug_bits;
 		++called; \
 	} while(0)
 
-// Read debug-enabled modules from cvar
-void VK_LogsReadCvar(void);
+void R_LogSetVerboseModules( const char *modules );