mat: load materials from multiple sources; abs paths

- look for materials in:
  - pbr/materials.mat
  - pbr/models/materials.mat
  - pbr/wadname.wad/materials.mat
  - pbr/maps/mapname.bsp/materials.mat

- all paths are relative to their materials.mat, except for ones that begin with '/', which are relative to `pbr` dir

pbr dir should be placed in modname dir, e.g. 'valve'

#155

ref_vk/vk_materials.c

@@ -33,17 +33,10 @@ static int findTextureNamedLike( const char *texture_name ) {
 
 	return tex_id ? tex_id : -1;
 }
-static int loadTextureF( const char *fmt, ... ) {
-	int tex_id = 0;
-	char buffer[1024];
-	va_list argptr;
 
-	va_start( argptr, fmt );
-	vsnprintf( buffer, sizeof buffer, fmt, argptr );
-	va_end( argptr );
-
-	tex_id = VK_LoadTexture( buffer, NULL, 0, 0);
-	gEngine.Con_Reportf("Loading texture %s => %d\n", buffer, tex_id);
+static int loadTexture( const char *filename ) {
+	const int tex_id = VK_LoadTexture( filename, NULL, 0, 0);
+	gEngine.Con_Reportf("Loading texture %s => %d\n", filename, tex_id);
 	return tex_id ? tex_id : -1;
 }
 
@@ -61,6 +54,8 @@ static void loadMaterialsFromFile( const char *filename ) {
 	};
 	int current_material_index = -1;
 
+	gEngine.Con_Reportf("Loading materials from %s\n", filename);
+
 	if ( !data )
 		return;
 
@@ -104,33 +99,55 @@ static void loadMaterialsFromFile( const char *filename ) {
 
 		if (Q_stricmp(key, "for") == 0) {
 			current_material_index = findTextureNamedLike(value);
-		} else if (Q_stricmp(key, "basecolor_map") == 0) {
-			if ((current_material.base_color = loadTextureF("%.*s%s", path_end - path_begin, path_begin, value)) < 0) {
-				gEngine.Con_Printf(S_ERROR "Failed to load basecolor_map texture %s\n", value);
-			}
-		} else if (Q_stricmp(key, "normal_map") == 0) {
-			if ((current_material.normalmap = loadTextureF("%.*s%s", path_end - path_begin, path_begin, value)) < 0) {
-				gEngine.Con_Printf(S_ERROR "Failed to load normal_map texture %s\n", value);
-				current_material.normalmap = 0;
-			}
-		} else if (Q_stricmp(key, "metal_map") == 0) {
-			if ((current_material.metalness = loadTextureF("%.*s%s", path_end - path_begin, path_begin, value)) < 0) {
-				gEngine.Con_Printf(S_ERROR "Failed to load metal_map texture %s\n", value);
-				current_material.metalness = tglob.blackTexture;
-			}
-		} else if (Q_stricmp(key, "roughness_map") == 0) {
-			if ((current_material.roughness = loadTextureF("%.*s%s", path_end - path_begin, path_begin, value)) < 0) {
-				gEngine.Con_Printf(S_ERROR "Failed to load roughness_map texture %s\n", value);
-				current_material.roughness = tglob.whiteTexture;
-			}
 		} else {
-			gEngine.Con_Printf(S_ERROR "Unknown material key %s\n", key);
+			char texture_path[256];
+			int *tex_id_dest;
+			int tex_id = loadTexture(texture_path);
+			if (Q_stricmp(key, "basecolor_map") == 0) {
+				tex_id_dest = &current_material.base_color;
+			} else if (Q_stricmp(key, "normal_map") == 0) {
+				tex_id_dest = &current_material.normalmap;
+			} else if (Q_stricmp(key, "metal_map") == 0) {
+				tex_id_dest = &current_material.metalness;
+			} else if (Q_stricmp(key, "roughness_map") == 0) {
+				tex_id_dest = &current_material.roughness;
+			} else {
+				gEngine.Con_Printf(S_ERROR "Unknown material key %s\n", key);
+				continue;
+			}
+
+			if (value[0] == '/') {
+				// Path relative to valve/pbr dir
+				Q_snprintf(texture_path, sizeof(texture_path), "pbr%s", value);
+			} else {
+				// Path relative to current material.mat file
+				Q_snprintf(texture_path, sizeof(texture_path), "%.*s%s", path_end - path_begin, path_begin, value);
+			}
+
+			tex_id = loadTexture(texture_path);
+			if (tex_id < 0) {
+				gEngine.Con_Printf(S_ERROR "Failed to load texture \"%s\" for key \"%s\"\n", value, key);
+				continue;
+			}
+
+			*tex_id_dest = tex_id;
 		}
 	}
 
 	Mem_Free( data );
 }
 
+static void loadMaterialsFromFileF( const char *fmt, ... ) {
+	char buffer[256];
+	va_list argptr;
+
+	va_start( argptr, fmt );
+	vsnprintf( buffer, sizeof buffer, fmt, argptr );
+	va_end( argptr );
+
+	loadMaterialsFromFile( buffer );
+}
+
 void XVK_ReloadMaterials( void ) {
 	for (int i = 0; i < MAX_TEXTURES; ++i) {
 		xvk_material_t *const mat = g_materials.materials + i;
@@ -149,7 +166,21 @@ void XVK_ReloadMaterials( void ) {
 	}
 
 	loadMaterialsFromFile( "pbr/materials.mat" );
-	// TODO map-specific
+	loadMaterialsFromFile( "pbr/models/materials.mat" );
+
+	{
+		const char *wad = g_map_entities.wadlist;
+		for (; *wad;) {
+			const char *const wad_end = Q_strchr(wad, ';');
+			loadMaterialsFromFileF("pbr/%.*s/materials.mat", wad_end - wad, wad);
+			wad = wad_end + 1;
+		}
+	}
+
+	{
+		const model_t *map = gEngine.pfnGetModelByIndex( 1 );
+		loadMaterialsFromFileF("pbr/%s/materials.mat", map->name);
+	}
 }
 
 xvk_material_t* XVK_GetMaterialForTextureIndex( int tex_index ) {