From 206de278b3c812cafb85c14cdc83e83c77943d30 Mon Sep 17 00:00:00 2001
From: dashodanger <none@none.com>
Date: Mon, 24 Jun 2024 15:23:12 -0600
Subject: [PATCH] First pass of string work

---
 source/bsp.cc        |  4 +--
 source/bsp.h         |  4 +--
 source/bsp_level.cc  |  8 ++++-
 source/bsp_node.cc   |  4 +++
 source/csg_doom.cc   |  4 +--
 source/csg_local.h   |  2 --
 source/csg_main.cc   | 28 +++++++--------
 source/csg_main.h    | 20 +++++------
 source/ff_main.cc    | 13 +++----
 source/g_doom.cc     | 14 ++++----
 source/g_doom.h      | 12 +++----
 source/images.h      | 24 ++++++-------
 source/lib_wad.cc    |  8 ++---
 source/lib_wad.h     |  6 ++--
 source/lib_zip.cc    |  4 +--
 source/lib_zip.h     |  4 +--
 source/m_addons.cc   | 54 ++--------------------------
 source/m_addons.h    |  5 ++-
 source/m_cookie.cc   | 53 ++++-----------------------
 source/m_cookie.h    | 18 +++++-----
 source/m_lua.cc      | 62 ++++++++++++--------------------
 source/m_lua.h       | 10 +++---
 source/m_options.cc  |  9 +++--
 source/m_theme.cc    |  4 +--
 source/m_trans.cc    | 41 +++++++++------------
 source/main.cc       |  2 +-
 source/slump.cc      |  2 +-
 source/slump.h       |  4 +--
 source/slump_main.cc |  2 +-
 source/sys_macro.h   |  4 +++
 source/ui_build.cc   |  9 +++--
 source/ui_build.h    |  4 +--
 source/ui_game.cc    |  6 ++--
 source/ui_game.h     |  6 ++--
 source/ui_map.cc     |  2 +-
 source/ui_map.h      |  2 +-
 source/ui_module.cc  | 86 ++++++++++++++++++++++----------------------
 source/ui_module.h   | 74 +++++++++++++++++++-------------------
 source/ui_widgets.cc | 19 +++++-----
 source/ui_widgets.h  | 18 +++++-----
 40 files changed, 269 insertions(+), 386 deletions(-)

diff --git a/source/bsp.cc b/source/bsp.cc
index 1e5298917..448ad1537 100644
--- a/source/bsp.cc
+++ b/source/bsp.cc
@@ -159,7 +159,7 @@ build_result_e BuildFile(buildinfo_t *build_info)
     return BUILD_OK;
 }
 
-void VisitFile(std::string filename, buildinfo_t *build_info)
+static void VisitFile(const std::string &filename, buildinfo_t *build_info)
 {
     LogPrint("\n");
     LogPrint("Building %s\n", filename.c_str());
@@ -308,7 +308,7 @@ void CheckTypeSizes(buildinfo_t *build_info)
     assert_size(raw_vertex_t, 4);
 }
 
-int AJBSP_BuildNodes(std::string filename, buildinfo_t *build_info)
+int AJBSP_BuildNodes(const std::string &filename, buildinfo_t *build_info)
 {
     // need this early, especially for fatal errors in utility/wad code
     ajbsp::SetInfo(build_info);
diff --git a/source/bsp.h b/source/bsp.h
index 5715fb40a..2ab4694b4 100644
--- a/source/bsp.h
+++ b/source/bsp.h
@@ -87,7 +87,7 @@ typedef enum
     BUILD_LumpOverflow
 } build_result_e;
 
-int AJBSP_BuildNodes(std::string filename, buildinfo_t *build_info);
+int AJBSP_BuildNodes(const std::string &filename, buildinfo_t *build_info);
 
 namespace ajbsp
 {
@@ -97,7 +97,7 @@ void SetInfo(buildinfo_t *info);
 
 // attempt to open a wad.  on failure, the FatalError method in the
 // buildinfo_t interface is called.
-void OpenWad(std::string filename);
+void OpenWad(const std::string &filename);
 
 // close a previously opened wad.
 void CloseWad();
diff --git a/source/bsp_level.cc b/source/bsp_level.cc
index 326327df8..88ac3f6d9 100644
--- a/source/bsp_level.cc
+++ b/source/bsp_level.cc
@@ -1220,6 +1220,9 @@ void GetLinedefs()
             num_real_lines++;
 
         line->self_ref = (line->left && line->right && (line->left->sector == line->right->sector));
+
+        if (line->self_ref)
+            line->is_precious = true;
     }
 }
 
@@ -1482,6 +1485,9 @@ void ParseUDMF_Block(ajparse::lexer_c &lex, int cur_type)
             num_real_lines++;
 
         line->self_ref = (line->left && line->right && (line->left->sector == line->right->sector));
+
+        if (line->self_ref)
+            line->is_precious = true;
     }
 }
 
@@ -2817,7 +2823,7 @@ void SetInfo(buildinfo_t *info)
     cur_info = info;
 }
 
-void OpenWad(std::string filename)
+void OpenWad(const std::string &filename)
 {
     cur_wad = Wad_file::Open(filename.c_str(), 'a');
     if (cur_wad == NULL)
diff --git a/source/bsp_node.cc b/source/bsp_node.cc
index 1f0fad75c..a04870e12 100644
--- a/source/bsp_node.cc
+++ b/source/bsp_node.cc
@@ -532,6 +532,10 @@ void EvaluateFastWorker(quadtree_c *tree, seg_t **best_H, seg_t **best_V, int mi
         if (part->linedef == NULL)
             continue;
 
+        /* ignore self-ref and polyobj stuff as partition candidates */
+        if (part->linedef->is_precious)
+            continue;
+
         if (part->pdy == 0)
         {
             // horizontal seg
diff --git a/source/csg_doom.cc b/source/csg_doom.cc
index 9ab59b2fe..7ad491751 100644
--- a/source/csg_doom.cc
+++ b/source/csg_doom.cc
@@ -2268,7 +2268,7 @@ class dummy_line_info_c
     int flags;
 
   public:
-    dummy_line_info_c(std::string _tex, int _special = 0, int _tag = 0, int _flags = 0)
+    dummy_line_info_c(std::string_view _tex, int _special = 0, int _tag = 0, int _flags = 0)
         : tex(_tex), special(_special), tag(_tag), flags(_flags)
     {
     }
@@ -2311,7 +2311,7 @@ class dummy_sector_c
         return (share_count >= DUMMY_MAX_SHARE);
     }
 
-    void AddInfo(std::string &tex, int special, int tag, int flags)
+    void AddInfo(std::string_view tex, int special, int tag, int flags)
     {
         SYS_ASSERT(!isFull());
 
diff --git a/source/csg_local.h b/source/csg_local.h
index 87dc99096..24c4dc2b4 100644
--- a/source/csg_local.h
+++ b/source/csg_local.h
@@ -158,8 +158,6 @@ class region_c
     void ComputeMidPoint();
     void ComputeBounds();
     void ClockwiseSnags(); // requires CalcMidPoint()
-
-    void DebugDump();
 };
 
 class gap_c
diff --git a/source/csg_main.cc b/source/csg_main.cc
index 21da88357..ba3cba251 100644
--- a/source/csg_main.cc
+++ b/source/csg_main.cc
@@ -203,36 +203,36 @@ extern int   q_low_light;
 
 extern void SPOT_FillPolygon(uint8_t content, const int *shape, int count);
 
-void csg_property_set_c::Add(std::string key, std::string value)
+void csg_property_set_c::Add(const std::string &key, std::string_view value)
 {
-    dict[key] = std::string(value);
+    dict[key] = value;
 }
 
-void csg_property_set_c::Remove(std::string key)
+void csg_property_set_c::Remove(const std::string &key)
 {
     dict.erase(key);
 }
 
-std::string csg_property_set_c::getStr(std::string key, std::string def_val) const
+std::string csg_property_set_c::getStr(const std::string &key, std::string_view def_val) const
 {
     std::map<std::string, std::string>::const_iterator PI = dict.find(key);
 
     if (PI == dict.end())
     {
-        return def_val;
+        return std::string(def_val);
     }
 
-    return PI->second.c_str();
+    return PI->second;
 }
 
-double csg_property_set_c::getDouble(std::string key, double def_val) const
+double csg_property_set_c::getDouble(const std::string &key, double def_val) const
 {
     std::string str = getStr(key);
 
     return !str.empty() ? StringToDouble(str) : def_val;
 }
 
-int csg_property_set_c::getInt(std::string key, int def_val) const
+int csg_property_set_c::getInt(const std::string &key, int def_val) const
 {
     std::string str = getStr(key);
 
@@ -649,7 +649,7 @@ csg_entity_c::~csg_entity_c()
 {
 }
 
-bool csg_entity_c::Match(std::string want_name) const
+bool csg_entity_c::Match(std::string_view want_name) const
 {
     return (StringCompare(id, want_name) == 0);
 }
@@ -779,7 +779,7 @@ class brush_quad_node_c
 
   private:
     bool IntersectBrush(const csg_brush_c *B, double x1, double y1, double z1, double x2, double y2, double z2,
-                        std::string mode)
+                        std::string_view mode)
     {
         if (mode[0] == 'v')
         {
@@ -833,7 +833,7 @@ class brush_quad_node_c
     }
 
   public:
-    bool TraceRay(double x1, double y1, double z1, double x2, double y2, double z2, std::string mode)
+    bool TraceRay(double x1, double y1, double z1, double x2, double y2, double z2, std::string_view mode)
     {
         for (unsigned int k = 0; k < brushes.size(); k++)
         {
@@ -1611,7 +1611,7 @@ int CSG_trace_ray(lua_State *L)
     return 1;
 }
 
-bool CSG_TraceRay(double x1, double y1, double z1, double x2, double y2, double z2, std::string mode)
+bool CSG_TraceRay(double x1, double y1, double z1, double x2, double y2, double z2, std::string_view mode)
 {
     SYS_ASSERT(brush_quad_tree);
 
@@ -1644,7 +1644,7 @@ void CSG_spot_processing(int x1, int y1, int x2, int y2, int floor_h)
 
 //------------------------------------------------------------------------
 
-csg_property_set_c *CSG_LookupTexProps(std::string name)
+csg_property_set_c *CSG_LookupTexProps(const std::string &name)
 {
     std::map<std::string, csg_property_set_c *>::iterator TPI;
 
@@ -1672,7 +1672,7 @@ static void CSG_FreeTexProps()
     all_tex_props.clear();
 }
 
-void CSG_LinkBrushToEntity(csg_brush_c *B, std::string link_key)
+void CSG_LinkBrushToEntity(csg_brush_c *B, const std::string &link_key)
 {
     for (unsigned int k = 0; k < all_entities.size(); k++)
     {
diff --git a/source/csg_main.h b/source/csg_main.h
index 0ebb409e7..1f5b0696f 100644
--- a/source/csg_main.h
+++ b/source/csg_main.h
@@ -69,18 +69,16 @@ class csg_property_set_c
     {
     }
 
-    void Add(std::string key, std::string value);
-    void Remove(std::string key);
+    void Add(const std::string &key, std::string_view value);
+    void Remove(const std::string &key);
 
-    std::string getStr(std::string key, std::string def_val = "") const;
+    std::string getStr(const std::string &key, std::string_view def_val = "") const;
 
-    double getDouble(std::string key, double def_val = 0) const;
-    int    getInt(std::string key, int def_val = 0) const;
+    double getDouble(const std::string &key, double def_val = 0) const;
+    int    getInt(const std::string &key, int def_val = 0) const;
 
     void getHexenArgs(uint8_t *arg5) const;
 
-    void DebugDump();
-
   public:
     typedef std::map<std::string, std::string>::iterator iterator;
 
@@ -252,7 +250,7 @@ class csg_entity_c
     csg_entity_c();
     ~csg_entity_c();
 
-    bool Match(std::string want_name) const;
+    bool Match(std::string_view want_name) const;
 };
 
 /***** VARIABLES ****************/
@@ -268,13 +266,13 @@ extern std::string dummy_plane_tex;
 
 void CSG_Main_Free();
 
-bool CSG_TraceRay(double x1, double y1, double z1, double x2, double y2, double z2, std::string mode);
+bool CSG_TraceRay(double x1, double y1, double z1, double x2, double y2, double z2, std::string_view mode);
 
 int CSG_BrushContents(double x, double y, double z, double *liquid_depth = NULL);
 
-csg_property_set_c *CSG_LookupTexProps(std::string name);
+csg_property_set_c *CSG_LookupTexProps(const std::string &name);
 
-void CSG_LinkBrushToEntity(csg_brush_c *B, std::string link_key);
+void CSG_LinkBrushToEntity(csg_brush_c *B, const std::string &link_key);
 
 //--- editor settings ---
 // vi:ts=4:sw=4:noexpandtab
diff --git a/source/ff_main.cc b/source/ff_main.cc
index ff84dd5a8..670990ea4 100644
--- a/source/ff_main.cc
+++ b/source/ff_main.cc
@@ -5,6 +5,7 @@
 #include <string>
 
 #include "ff.h"
+#include "lib_util.h"
 
 extern "C"
 {
@@ -22,32 +23,32 @@ std::string result;
 
 void year()
 {
-    result.append(std::to_string(now.tm_year + 1900));
+    result.append(NumToString(now.tm_year + 1900));
 }
 
 void month()
 {
-    result.append(std::to_string(now.tm_mon + 1));
+    result.append(NumToString(now.tm_mon + 1));
 }
 
 void day()
 {
-    result.append(std::to_string(now.tm_mday));
+    result.append(NumToString(now.tm_mday));
 }
 
 void hour()
 {
-    result.append(std::to_string(now.tm_hour));
+    result.append(NumToString(now.tm_hour));
 }
 
 void minute()
 {
-    result.append(std::to_string(now.tm_min));
+    result.append(NumToString(now.tm_min));
 }
 
 void second()
 {
-    result.append(std::to_string(now.tm_sec));
+    result.append(NumToString(now.tm_sec));
 }
 
 void game()
diff --git a/source/g_doom.cc b/source/g_doom.cc
index 6676e28fb..ace0bdf99 100644
--- a/source/g_doom.cc
+++ b/source/g_doom.cc
@@ -345,7 +345,7 @@ bool BuildNodes(std::string filename)
 
 namespace Doom
 {
-void WriteLump(std::string name, const void *data, uint32_t len)
+void WriteLump(std::string_view name, const void *data, uint32_t len)
 {
     SYS_ASSERT(name.size() <= 8);
 
@@ -363,7 +363,7 @@ void WriteLump(std::string name, const void *data, uint32_t len)
 }
 } // namespace Doom
 
-void Doom::WriteLump(std::string name, qLump_c *lump)
+void Doom::WriteLump(std::string_view name, qLump_c *lump)
 {
     WriteLump(name, lump->GetBuffer(), lump->GetSize());
 }
@@ -429,7 +429,7 @@ static void WriteSections()
 
 } // namespace Doom
 
-void Doom::AddSectionLump(char ch, std::string name, qLump_c *lump)
+void Doom::AddSectionLump(char ch, std::string_view name, qLump_c *lump)
 {
     int k;
     switch (ch)
@@ -459,7 +459,7 @@ void Doom::AddSectionLump(char ch, std::string name, qLump_c *lump)
     sections[k]->push_back(lump);
 }
 
-bool Doom::StartWAD(std::string filename)
+bool Doom::StartWAD(const std::string &filename)
 {
     if (!WAD_OpenWrite(filename))
     {
@@ -562,7 +562,7 @@ int Doom::v094_begin_level(lua_State *L)
     return 0;
 }
 
-void Doom::EndLevel(std::string level_name)
+void Doom::EndLevel(const std::string &level_name)
 {
     // terminate header lump with trailing NUL
     if (header_lump->GetSize() > 0)
@@ -695,7 +695,7 @@ int Doom::v094_add_vertex(lua_State *L)
     return 0;
 }
 
-void Doom::AddSector(int f_h, std::string f_tex, int c_h, std::string c_tex, int light, int special, int tag)
+void Doom::AddSector(int f_h, const std::string &f_tex, int c_h, const std::string &c_tex, int light, int special, int tag)
 {
     if (!UDMF_mode)
     {
@@ -740,7 +740,7 @@ int Doom::v094_add_sector(lua_State *L)
     return 0;
 }
 
-void Doom::AddSidedef(int sector, std::string l_tex, std::string m_tex, std::string u_tex, int x_offset, int y_offset)
+void Doom::AddSidedef(int sector, const std::string &l_tex, const std::string &m_tex, const std::string &u_tex, int x_offset, int y_offset)
 {
     if (!UDMF_mode)
     {
diff --git a/source/g_doom.h b/source/g_doom.h
index 15c598bf7..e0fa8300d 100644
--- a/source/g_doom.h
+++ b/source/g_doom.h
@@ -78,27 +78,27 @@ extern int sub_format;
 
 /***** FUNCTIONS ****************/
 
-bool StartWAD(std::string filename);
+bool StartWAD(const std::string &filename);
 bool EndWAD();
 
 void BeginLevel();
-void EndLevel(std::string level_name);
+void EndLevel(const std::string &level_name);
 
-void WriteLump(std::string name, qLump_c *lump);
+void WriteLump(std::string_view name, qLump_c *lump);
 
 // the section parameter can be:
 //   'P' : patches   //   'F' : flats
 //   'S' : sprites   //   'C' : colormaps (Boom)
 //   'T' : textures (Zdoom)
-void AddSectionLump(char section, std::string name, qLump_c *lump);
+void AddSectionLump(char section, std::string_view name, qLump_c *lump);
 
 void HeaderPrintf(const char *str, ...);
 
 void AddVertex(int x, int y);
 
-void AddSector(int f_h, std::string f_tex, int c_h, std::string c_tex, int light, int special, int tag);
+void AddSector(int f_h, const std::string &f_tex, int c_h, const std::string &c_tex, int light, int special, int tag);
 
-void AddSidedef(int sector, std::string l_tex, std::string m_tex, std::string u_tex, int x_offset, int y_offset);
+void AddSidedef(int sector, const std::string &l_tex, const std::string &m_tex, const std::string &u_tex, int x_offset, int y_offset);
 
 void AddLinedef(int vert1, int vert2, int side1, int side2, int type, int flags, int tag, const uint8_t *args);
 
diff --git a/source/images.h b/source/images.h
index efe9b2efb..4cb8e3f55 100644
--- a/source/images.h
+++ b/source/images.h
@@ -3,7 +3,7 @@
 #pragma once
 
 #ifndef _WIN32
-static const char *obsidian_icon[] = {
+static constexpr char *obsidian_icon[] = {
     "64 64 928 2",
     "  	c #000000",
     ". 	c #010101",
@@ -1065,7 +1065,7 @@ static const char *obsidian_icon[] = {
 #endif
 
 /* XPM */
-static const char *clippy_xpm[] = {
+static constexpr char *clippy_xpm[] = {
     "476 225 956 2",
     "  	c None",
     ". 	c #51514F",
@@ -4164,7 +4164,7 @@ typedef struct
 //
 //------------------------------------------------------------------------
 
-const uint8_t image_data_BOLT[64 * 64] = {
+constexpr uint8_t image_data_BOLT[64 * 64] = {
     70,  70,  70,  70,  68,  68,  68,  68,  68,  68,  68,  52,  63,  68,  68,  70,  68,  68,  68,  68,  68,  68,  70,
     70,  79,  79,  79,  79,  85,  93,  100, 108, 108, 108, 121, 121, 121, 121, 121, 121, 121, 114, 108, 108, 108, 93,
     93,  93,  93,  93,  93,  93,  85,  79,  79,  79,  79,  79,  79,  70,  70,  70,  79,  79,  70,  70,  70,  70,  70,
@@ -4345,7 +4345,7 @@ const uint8_t image_data_BOLT[64 * 64] = {
     108, 100, 100, 100, 100, 93,  85,  85,  85,  85,  85,  79,  79,  79,  79,  79,  79,  79,  79,  79,  79,  70,  70,
     70,  68};
 
-const logo_image_t logo_BOLT = {"BOLT", 64, 64, image_data_BOLT};
+constexpr logo_image_t logo_BOLT = {"BOLT", 64, 64, image_data_BOLT};
 
 //------------------------------------------------------------------------
 //  LOGO Data : "CARVE" image
@@ -4370,7 +4370,7 @@ const logo_image_t logo_BOLT = {"BOLT", 64, 64, image_data_BOLT};
 
 // Same as the RELIEF image for now
 
-const uint8_t image_data_CARVE[64 * 64] = {
+constexpr uint8_t image_data_CARVE[64 * 64] = {
     17,  20,  20,  20,  20,  20,  20,  20,  21,  20,  17,  17,  17,  17,  17,  20,  20,  20,  20,  17,  17,  17,  17,
     17,  17,  20,  20,  20,  17,  17,  17,  21,  20,  20,  20,  20,  20,  24,  17,  17,  20,  17,  17,  20,  17,  31,
     20,  17,  31,  20,  20,  20,  20,  20,  20,  20,  20,  20,  20,  20,  20,  20,  20,  20,  20,  20,  20,  20,  20,
@@ -4551,7 +4551,7 @@ const uint8_t image_data_CARVE[64 * 64] = {
     31,  17,  17,  17,  20,  20,  20,  20,  20,  20,  20,  17,  20,  20,  20,  20,  20,  20,  17,  17,  20,  20,  20,
     20,  20};
 
-const logo_image_t logo_CARVE = {"CARVE", 64, 64, image_data_CARVE};
+constexpr logo_image_t logo_CARVE = {"CARVE", 64, 64, image_data_CARVE};
 
 //------------------------------------------------------------------------
 //  FONT Data : "CWILV"
@@ -4573,7 +4573,7 @@ const logo_image_t logo_CARVE = {"CARVE", 64, 64, image_data_CARVE};
 //
 //------------------------------------------------------------------------
 
-const uint8_t image_data_CWILV[99 * 64] = {
+constexpr uint8_t image_data_CWILV[99 * 64] = {
     0,   0,   0,   0,   1,   1,   0,   0,   0,   0,   0,   0,   1,   1,   1,   0,   0,   0,   0,   0,   0,   1,   1,
     0,   0,   0,   0,   0,   0,   0,   1,   1,   1,   0,   0,   0,   0,   0,   0,   0,   0,   1,   1,   0,   0,   0,
     0,   0,   1,   1,   1,   1,   1,   0,   0,   0,   0,   0,   1,   1,   0,   0,   0,   0,   1,   1,   1,   1,   1,
@@ -4851,7 +4851,7 @@ const uint8_t image_data_CWILV[99 * 64] = {
     0,   1,   1,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   1,   1,   0,
     1,   1,   7,   28,  21,  4,   0,   0,   0,   0,   0};
 
-const logo_image_t font_CWILV = {"CWILV", 99, 64, image_data_CWILV};
+constexpr logo_image_t font_CWILV = {"CWILV", 99, 64, image_data_CWILV};
 
 //------------------------------------------------------------------------
 //  LOGO Data : "PILL" image
@@ -4874,7 +4874,7 @@ const logo_image_t font_CWILV = {"CWILV", 99, 64, image_data_CWILV};
 //
 //------------------------------------------------------------------------
 
-const uint8_t image_data_PILL[128 * 32] = {
+constexpr uint8_t image_data_PILL[128 * 32] = {
     17,  9,   9,   9,   17,  17,  17,  17,  12,  12,  12,  12,  12,  12,  12,  12,  12,  20,  12,  12,  20,  20,  14,
     14,  14,  17,  22,  22,  17,  17,  20,  20,  20,  20,  20,  20,  52,  20,  20,  22,  22,  52,  52,  52,  52,  52,
     22,  20,  52,  52,  52,  52,  52,  52,  52,  52,  52,  52,  52,  52,  52,  52,  52,  52,  52,  52,  52,  52,  52,
@@ -5055,7 +5055,7 @@ const uint8_t image_data_PILL[128 * 32] = {
     20,  20,  17,  17,  17,  17,  20,  20,  20,  20,  20,  12,  12,  12,  12,  12,  20,  12,  12,  12,  12,  5,   5,
     9,   9};
 
-const logo_image_t logo_PILL = {"PILL", 128, 32, image_data_PILL};
+constexpr logo_image_t logo_PILL = {"PILL", 128, 32, image_data_PILL};
 
 //------------------------------------------------------------------------
 //  LOGO Data : "RELIEF" image
@@ -5078,7 +5078,7 @@ const logo_image_t logo_PILL = {"PILL", 128, 32, image_data_PILL};
 //
 //------------------------------------------------------------------------
 
-const uint8_t image_data_RELIEF[64 * 64] = {
+constexpr uint8_t image_data_RELIEF[64 * 64] = {
     17,  20,  20,  20,  20,  20,  20,  20,  21,  20,  17,  17,  17,  17,  17,  20,  20,  20,  20,  17,  17,  17,  17,
     17,  17,  20,  20,  20,  17,  17,  17,  21,  20,  20,  20,  20,  20,  24,  17,  17,  20,  17,  17,  20,  17,  31,
     20,  17,  31,  20,  20,  20,  20,  20,  20,  20,  20,  20,  20,  20,  20,  20,  20,  20,  20,  20,  20,  20,  20,
@@ -5259,4 +5259,4 @@ const uint8_t image_data_RELIEF[64 * 64] = {
     31,  17,  17,  17,  20,  20,  20,  20,  20,  20,  20,  17,  20,  20,  20,  20,  20,  20,  17,  17,  20,  20,  20,
     20,  20};
 
-const logo_image_t logo_RELIEF = {"RELIEF", 64, 64, image_data_RELIEF};
\ No newline at end of file
+constexpr logo_image_t logo_RELIEF = {"RELIEF", 64, 64, image_data_RELIEF};
\ No newline at end of file
diff --git a/source/lib_wad.cc b/source/lib_wad.cc
index d4daf133a..931041d59 100644
--- a/source/lib_wad.cc
+++ b/source/lib_wad.cc
@@ -38,7 +38,7 @@ static PHYSFS_File     *wad_R_fp;
 static raw_wad_header_t wad_R_header;
 static raw_wad_entry_t *wad_R_dir;
 
-bool WAD_OpenRead(std::string filename)
+bool WAD_OpenRead(const std::string &filename)
 {
 
     wad_R_fp = PHYSFS_openRead(filename.c_str());
@@ -198,7 +198,7 @@ static std::list<raw_wad_entry_t> wad_W_directory;
 
 static raw_wad_entry_t wad_W_lump;
 
-bool WAD_OpenWrite(std::string filename)
+bool WAD_OpenWrite(const std::string &filename)
 {
     wad_W_fp = FileOpen(filename, "wb");
 
@@ -267,11 +267,11 @@ void WAD_CloseWrite(void)
     wad_W_directory.clear();
 }
 
-void WAD_NewLump(std::string name)
+void WAD_NewLump(std::string_view name)
 {
     if (name.size() > 8)
     {
-        FatalError("WAD_NewLump: name too long: '%s'\n", name.c_str());
+        FatalError("WAD_NewLump: name too long: '%s'\n", std::string(name).c_str());
     }
 
     memset(&wad_W_lump, 0, sizeof(wad_W_lump));
diff --git a/source/lib_wad.h b/source/lib_wad.h
index 8ba0c5b05..72973860c 100644
--- a/source/lib_wad.h
+++ b/source/lib_wad.h
@@ -27,7 +27,7 @@
 
 #include <string>
 
-bool WAD_OpenRead(std::string filename);
+bool WAD_OpenRead(const std::string &filename);
 void WAD_CloseRead();
 
 int         WAD_NumEntries();
@@ -39,10 +39,10 @@ bool WAD_ReadData(int entry, int offset, int length, void *buffer);
 
 /* WAD writing */
 
-bool WAD_OpenWrite(std::string filename);
+bool WAD_OpenWrite(const std::string &filename);
 void WAD_CloseWrite();
 
-void WAD_NewLump(std::string name);
+void WAD_NewLump(std::string_view name);
 bool WAD_AppendData(const void *data, int length);
 void WAD_FinishLump();
 
diff --git a/source/lib_zip.cc b/source/lib_zip.cc
index 3153037f8..28b9639a0 100644
--- a/source/lib_zip.cc
+++ b/source/lib_zip.cc
@@ -59,7 +59,7 @@ bool ZIPF_OpenWrite(const std::string &filename)
     return true;
 }
 
-bool ZIPF_AddFile(const std::string &filename, std::string directory)
+bool ZIPF_AddFile(const std::string &filename, std::string_view directory)
 {
     if (!zip_writer)
     {
@@ -71,7 +71,7 @@ bool ZIPF_AddFile(const std::string &filename, std::string directory)
 }
 
 // Calling function is responsible for freeing *data
-bool ZIPF_AddMem(std::string name, uint8_t *data, size_t length)
+bool ZIPF_AddMem(const std::string &name, uint8_t *data, size_t length)
 {
     if (!zip_writer)
     {
diff --git a/source/lib_zip.h b/source/lib_zip.h
index c5dbb1f15..061e99142 100644
--- a/source/lib_zip.h
+++ b/source/lib_zip.h
@@ -28,8 +28,8 @@
 /* ZIP writing */
 
 bool ZIPF_OpenWrite(const std::string &filename);
-bool ZIPF_AddFile(const std::string &filename, std::string directory);
-bool ZIPF_AddMem(std::string name, uint8_t *data, size_t length);
+bool ZIPF_AddFile(const std::string &filename, std::string_view directory);
+bool ZIPF_AddMem(const std::string &name, uint8_t *data, size_t length);
 bool ZIPF_CloseWrite();
 
 //--- editor settings ---
diff --git a/source/m_addons.cc b/source/m_addons.cc
index 8af947320..362be4250 100644
--- a/source/m_addons.cc
+++ b/source/m_addons.cc
@@ -103,7 +103,7 @@ bool VFS_AddArchive(std::string filename, bool options_file)
     return true; // Ok
 }
 
-void VFS_InitAddons(std::string search_dir)
+void VFS_InitAddons()
 {
     LogPrint("Initializing VFS...\n");
 
@@ -146,7 +146,7 @@ void VFS_ParseCommandLine()
     LogPrint("DONE\n\n");
 }
 
-void VFS_OptParse(std::string name)
+void VFS_OptParse(const std::string &name)
 {
     // just remember it now
     if (initial_enabled_addons.find(name) == initial_enabled_addons.end())
@@ -269,56 +269,6 @@ void VFS_ScanForAddons()
 
 //----------------------------------------------------------------------
 
-//
-// this is useful to "extract" something out of virtual FS to the real
-// file system so we can use normal stdio file operations on it
-// [ especially a _library_ that uses stdio.h ]
-//
-bool VFS_CopyFile(const char *src_name, const char *dest_name)
-{
-    char buffer[1024];
-
-    PHYSFS_file *src = PHYSFS_openRead(src_name);
-    if (!src)
-    {
-        return false;
-    }
-
-    FILE *dest = FileOpen(dest_name, "wb");
-    if (!dest)
-    {
-        PHYSFS_close(src);
-        return false;
-    }
-
-    bool was_OK = true;
-
-    while (was_OK)
-    {
-        int rlen = (int)(PHYSFS_readBytes(src, buffer, sizeof(buffer)) / sizeof(buffer));
-        if (rlen < 0)
-        {
-            was_OK = false;
-        }
-
-        if (rlen <= 0)
-        {
-            break;
-        }
-
-        int wlen = fwrite(buffer, 1, rlen, dest);
-        if (wlen < rlen || ferror(dest))
-        {
-            was_OK = false;
-        }
-    }
-
-    fclose(dest);
-    PHYSFS_close(src);
-
-    return was_OK;
-}
-
 uint8_t *VFS_LoadFile(const char *filename, int *length)
 {
     *length = 0;
diff --git a/source/m_addons.h b/source/m_addons.h
index d7484ed9f..72920b579 100644
--- a/source/m_addons.h
+++ b/source/m_addons.h
@@ -28,16 +28,15 @@
 #include <string>
 #include <vector>
 
-void VFS_InitAddons(std::string search_dir);
+void VFS_InitAddons();
 void VFS_ParseCommandLine();
 void VFS_ScanForAddons();
 void VFS_ScanForPresets();
 
-void VFS_OptParse(std::string name);
+void VFS_OptParse(const std::string &name);
 void VFS_OptWrite(FILE *fp);
 
 // util functions
-bool     VFS_CopyFile(const char *src_name, const char *dest_name);
 uint8_t *VFS_LoadFile(const char *filename, int *length);
 void     VFS_FreeFile(const uint8_t *mem);
 
diff --git a/source/m_cookie.cc b/source/m_cookie.cc
index 9739bcf40..196bb91e3 100644
--- a/source/m_cookie.cc
+++ b/source/m_cookie.cc
@@ -44,7 +44,7 @@ static std::string active_module;
 
 static bool keep_seed;
 
-static void Cookie_SetValue(std::string name, std::string value)
+static void Cookie_SetValue(std::string name, const std::string &value)
 {
     if (context == cookie_context_e::Load)
     {
@@ -113,7 +113,7 @@ static void Cookie_SetValue(std::string name, std::string value)
     ob_set_config(name, value);
 }
 
-static bool Cookie_ParseLine(std::string buf)
+static bool Cookie_ParseLine(std::string &buf)
 {
     if (buf.find('=') == std::string::npos)
     {
@@ -163,7 +163,7 @@ static bool Cookie_ParseLine(std::string buf)
 
 //----------------------------------------------------------------------
 
-bool Cookie_Load(std::string filename)
+bool Cookie_Load(const std::string &filename)
 {
     context = cookie_context_e::Load;
 
@@ -226,7 +226,7 @@ bool Cookie_Load(std::string filename)
     return true;
 }
 
-bool Cookie_LoadString(std::string str, bool _keep_seed)
+bool Cookie_LoadString(const std::string &str, bool _keep_seed)
 {
     context   = cookie_context_e::Load;
     keep_seed = _keep_seed;
@@ -251,7 +251,7 @@ bool Cookie_LoadString(std::string str, bool _keep_seed)
     return true;
 }
 
-bool Cookie_Save(std::string filename)
+bool Cookie_Save(const std::string &filename)
 {
     context = cookie_context_e::Save;
     setlocale(LC_NUMERIC, "C");
@@ -487,7 +487,7 @@ class RecentFiles_c
         }
     }
 
-    bool get_name(int index, std::string buffer, bool for_menu) const
+    bool get_name(int index, std::string &buffer, bool for_menu) const
     {
         if (index >= size)
         {
@@ -531,7 +531,7 @@ void Recent_Write(FILE *fp)
     recent_configs.write_all(fp, "recent_config");
 }
 
-void Recent_AddFile(int group, std::string filename)
+void Recent_AddFile(int group, const std::string &filename)
 {
     SYS_ASSERT(0 <= group && group < RECG_NUM_GROUPS);
 
@@ -553,44 +553,5 @@ void Recent_AddFile(int group, std::string filename)
     }
 }
 
-void Recent_RemoveFile(int group, std::string filename)
-{
-    SYS_ASSERT(0 <= group && group < RECG_NUM_GROUPS);
-
-    switch (group)
-    {
-    case RECG_Output:
-        recent_wads.remove(filename);
-        break;
-
-    case RECG_Config:
-        recent_configs.remove(filename);
-        break;
-    }
-
-    // push to disk now -- why wait?
-    if (!batch_mode)
-    {
-        Options_Save(options_file);
-    }
-}
-
-bool Recent_GetName(int group, int index, std::string name_buf, bool for_menu)
-{
-    SYS_ASSERT(0 <= group && group < RECG_NUM_GROUPS);
-    SYS_ASSERT(index >= 0);
-
-    switch (group)
-    {
-    case RECG_Output:
-        return recent_wads.get_name(index, name_buf, for_menu);
-
-    case RECG_Config:
-        return recent_configs.get_name(index, name_buf, for_menu);
-    }
-
-    return false;
-}
-
 //--- editor settings ---
 // vi:ts=4:sw=4:noexpandtab
diff --git a/source/m_cookie.h b/source/m_cookie.h
index eebe316c4..d7a24064d 100644
--- a/source/m_cookie.h
+++ b/source/m_cookie.h
@@ -25,20 +25,20 @@
 
 #include <string>
 
-bool Cookie_Load(std::string filename);
-bool Cookie_Save(std::string filename);
+bool Cookie_Load(const std::string &filename);
+bool Cookie_Save(const std::string &filename);
 
-bool Cookie_LoadString(std::string str, bool _keep_seed);
+bool Cookie_LoadString(const std::string &str, bool _keep_seed);
 
 void Cookie_ParseArguments(void);
 
 /* option stuff */
 
 void Parse_Option(const std::string &name, const std::string &value);
-bool Options_Load(std::string filename);
-bool Options_Save(std::string filename);
-bool Theme_Options_Load(std::string filename);
-bool Theme_Options_Save(std::string filename);
+bool Options_Load(const std::string &filename);
+bool Options_Save(const std::string &filename);
+bool Theme_Options_Load(const std::string &filename);
+bool Theme_Options_Save(const std::string &filename);
 
 /* recent file stuff */
 
@@ -54,9 +54,7 @@ typedef enum
 
 } recent_group_e;
 
-void Recent_AddFile(int group, std::string filename);
-void Recent_RemoveFile(int group, std::string filename);
-bool Recent_GetName(int group, int index, std::string name_buf, bool for_menu = false);
+void Recent_AddFile(int group, const std::string &filename);
 
 //--- editor settings ---
 // vi:ts=4:sw=4:noexpandtab
diff --git a/source/m_lua.cc b/source/m_lua.cc
index 19d6f6f32..25a594e05 100644
--- a/source/m_lua.cc
+++ b/source/m_lua.cc
@@ -66,16 +66,16 @@ int gui_format_prefix(lua_State *L)
         format = custom_prefix.c_str();
     }
 
-    const char *result = ff_main(levelcount, game, port, theme, OBSIDIAN_SHORT_VERSION, format.c_str());
+    std::string result = ff_main(levelcount, game, port, theme, OBSIDIAN_SHORT_VERSION, format.c_str());
 
-    if (!result)
+    if (result.empty())
     {
         lua_pushstring(L, "FF_ERROR_"); // Will help people notice issues
         return 1;
     }
     else
     {
-        lua_pushstring(L, result);
+        lua_pushstring(L, result.c_str());
         return 1;
     }
 
@@ -1681,7 +1681,7 @@ static int p_init_lua(lua_State *L)
     return 0;
 }
 
-static bool Script_CallFunc(std::string func_name, int nresult = 0, std::string *params = NULL)
+static bool Script_CallFunc(const std::string &func_name, int nresult = 0, const std::vector<std::string> &params = {})
 {
     // Note: the results of the function will be on the Lua stack
 
@@ -1700,12 +1700,10 @@ static bool Script_CallFunc(std::string func_name, int nresult = 0, std::string
     }
 
     int nargs = 0;
-    if (params)
+    for (const std::string& param : params)
     {
-        for (; !params->empty(); params++, nargs++)
-        {
-            lua_pushstring(LUA_ST, params->c_str());
-        }
+        lua_pushstring(LUA_ST, param.c_str());
+        nargs++;
     }
 
     int status = lua_pcall(LUA_ST, nargs, nresult, -2 - nargs);
@@ -1947,7 +1945,7 @@ void Script_Close()
 // WRAPPERS TO LUA FUNCTIONS
 //------------------------------------------------------------------------
 
-bool ob_set_config(std::string key, std::string value)
+bool ob_set_config(const std::string &key, const std::string &value)
 {
     // See the document 'doc/Config_Flow.txt' for a good
     // description of the flow of configuration values
@@ -1959,16 +1957,10 @@ bool ob_set_config(std::string key, std::string value)
         return false;
     }
 
-    std::string params[3] = {
-        key,
-        value,
-        "",
-    };
-
-    return Script_CallFunc("ob_set_config", 0, &params[0]);
+    return Script_CallFunc("ob_set_config", 0, {key, value});
 }
 
-bool ob_set_mod_option(std::string module, std::string option, std::string value)
+bool ob_set_mod_option(const std::string &module, const std::string &option, const std::string &value)
 {
     if (!has_loaded)
     {
@@ -1976,9 +1968,7 @@ bool ob_set_mod_option(std::string module, std::string option, std::string value
         return false;
     }
 
-    std::string params[4] = {module, option, value, ""};
-
-    return Script_CallFunc("ob_set_mod_option", 0, &params[0]);
+    return Script_CallFunc("ob_set_mod_option", 0, {module, option, value});
 }
 
 bool ob_read_all_config(std::vector<std::string> *lines, bool need_full)
@@ -1991,12 +1981,12 @@ bool ob_read_all_config(std::vector<std::string> *lines, bool need_full)
 
     conf_line_buffer = lines;
 
-    std::string params[2];
+    std::vector<std::string> params;
 
-    params[0] = need_full ? "need_full" : "";
-    params[1] = ""; // end of list
+    if (need_full)
+        params.push_back("need_full");
 
-    bool result = Script_CallFunc("ob_read_all_config", 0, &params[0]);
+    bool result = Script_CallFunc("ob_read_all_config", 0, params);
 
     conf_line_buffer = NULL;
 
@@ -2048,11 +2038,9 @@ std::string ob_game_format()
     return res;
 }
 
-std::string ob_get_param(std::string parameter)
+std::string ob_get_param(const std::string &parameter)
 {
-    std::string params[2] = {parameter, ""};
-
-    if (!Script_CallFunc("ob_get_param", 1, &params[0]))
+    if (!Script_CallFunc("ob_get_param", 1, {parameter}))
     {
         return "";
     }
@@ -2067,9 +2055,7 @@ std::string ob_get_param(std::string parameter)
 
 bool ob_hexen_ceiling_check(int thing_id)
 {
-    std::string params[2] = {NumToString(thing_id), ""};
-
-    if (!Script_CallFunc("ob_hexen_ceiling_check", 1, &params[0]))
+    if (!Script_CallFunc("ob_hexen_ceiling_check", 1, {NumToString(thing_id)}))
     {
         return false;
     }
@@ -2082,11 +2068,9 @@ bool ob_hexen_ceiling_check(int thing_id)
     return StringToInt(param);
 }
 
-bool ob_mod_enabled(std::string module_name)
+bool ob_mod_enabled(const std::string &module_name)
 {
-    std::string params[2] = {module_name, ""};
-
-    if (!Script_CallFunc("ob_mod_enabled", 1, &params[0]))
+    if (!Script_CallFunc("ob_mod_enabled", 1, {module_name}))
     {
         return false;
     }
@@ -2152,11 +2136,9 @@ void ob_print_reference_json()
     }
 }
 
-void ob_invoke_hook(std::string hookname)
+void ob_invoke_hook(const std::string &hookname)
 {
-    std::string params[2] = {hookname, ""};
-
-    if (!Script_CallFunc("ob_invoke_hook", 0, &params[0]))
+    if (!Script_CallFunc("ob_invoke_hook", 0, {hookname}))
     {
         ProgStatus("%s", _("Script Error"));
     }
diff --git a/source/m_lua.h b/source/m_lua.h
index cb7eaa5fe..a35d4463a 100644
--- a/source/m_lua.h
+++ b/source/m_lua.h
@@ -42,15 +42,15 @@ extern color_mapping_t color_mappings[MAX_COLOR_MAPS];
 
 // Wrappers which call Lua functions:
 
-bool ob_set_config(std::string key, std::string value);
-bool ob_set_mod_option(std::string module, std::string option, std::string value);
+bool ob_set_config(const std::string &key, const std::string &value);
+bool ob_set_mod_option(const std::string &module, const std::string &option, const std::string &value);
 
 bool ob_read_all_config(std::vector<std::string> *lines, bool need_full);
 
-std::string ob_get_param(std::string parameter);
-bool        ob_mod_enabled(std::string module_name);
+std::string ob_get_param(const std::string &parameter);
+bool        ob_mod_enabled(const std::string &module_name);
 bool        ob_hexen_ceiling_check(int thing_id);
-void        ob_invoke_hook(std::string hookname);
+void        ob_invoke_hook(const std::string &hookname);
 void        ob_print_reference();
 void        ob_print_reference_json();
 
diff --git a/source/m_options.cc b/source/m_options.cc
index fe011295b..f43db5d0b 100644
--- a/source/m_options.cc
+++ b/source/m_options.cc
@@ -30,6 +30,7 @@
 #include "m_lua.h"
 #include "m_trans.h"
 #include "main.h"
+#include "sys_macro.h"
 
 extern std::string BestDirectory();
 
@@ -145,7 +146,7 @@ static bool Options_ParseLine(const std::string &buf)
     return true;
 }
 
-bool Options_Load(std::string filename)
+bool Options_Load(const std::string &filename)
 {
     FILE *option_fp = FileOpen(filename, "r");
 
@@ -179,7 +180,7 @@ bool Options_Load(std::string filename)
     return true;
 }
 
-bool Options_Save(std::string filename)
+bool Options_Save(const std::string &filename)
 {
     FILE *option_fp = FileOpen(filename, "w");
 
@@ -610,9 +611,7 @@ class UI_OptionsWin : public Fl_Window
 
         default_output_path = dir_name;
         UI_OptionsWin *that = (UI_OptionsWin *)data;
-        std::string    blanker;
-        blanker.append(250, ' ');
-        that->opt_current_output_path->copy_label(blanker.c_str());
+        that->opt_current_output_path->label(BLANKOUT);
         that->opt_current_output_path->redraw_label();
         that->opt_current_output_path->copy_label(
             StringFormat("%s: %s", _("Current Path"), BestDirectory().c_str()).c_str());
diff --git a/source/m_theme.cc b/source/m_theme.cc
index 49cb85bbf..db8a5d367 100644
--- a/source/m_theme.cc
+++ b/source/m_theme.cc
@@ -296,7 +296,7 @@ static bool Theme_Options_ParseLine(std::string buf)
     return true;
 }
 
-bool Theme_Options_Load(std::string filename)
+bool Theme_Options_Load(const std::string &filename)
 {
     FILE *option_fp = FileOpen(filename, "r");
 
@@ -346,7 +346,7 @@ bool Theme_Options_Load(std::string filename)
     return true;
 }
 
-bool Theme_Options_Save(std::string filename)
+bool Theme_Options_Save(const std::string &filename)
 {
     FILE *option_fp = FileOpen(filename, "w");
 
diff --git a/source/m_trans.cc b/source/m_trans.cc
index 5cbdac247..9c9a873f1 100644
--- a/source/m_trans.cc
+++ b/source/m_trans.cc
@@ -49,6 +49,7 @@
 #include <map>
 
 static std::map<std::string, std::string> trans_store;
+static std::map<std::string, std::string>::iterator trans_iter;
 
 // current Options setting
 std::string t_language = _("AUTO");
@@ -395,25 +396,22 @@ std::string t_language = _("AUTO");
 #endif
 #endif
 
-static std::string remove_codeset(std::string langcode)
+static std::string remove_codeset(std::string_view langcode)
 {
-    if (langcode.find('.') != std::string::npos)
-    {
-        auto p = std::find(langcode.begin(), langcode.end(), '.');
-        langcode.resize(p - langcode.begin());
-    }
-
-    return langcode;
+    size_t pos = langcode.find('.');
+    if (pos != std::string_view::npos)
+        return std::string(langcode.substr(0, pos));
+    else
+        return std::string(langcode);
 }
 
-static std::string remove_territory(std::string langcode)
+static std::string remove_territory(std::string_view langcode)
 {
-    if (langcode.find('_') != std::string::npos)
-    {
-        langcode.resize(std::find(langcode.begin(), langcode.end(), '_') - langcode.begin());
-    }
-
-    return langcode;
+    size_t pos = langcode.find('_');
+    if (pos != std::string_view::npos)
+        return std::string(langcode.substr(0, pos));
+    else
+        return std::string(langcode);
 }
 
 /* DETERMINE CURRENT LANGUAGE */
@@ -1162,11 +1160,6 @@ void Trans_SetLanguage()
         path = StringFormat("%s/language/%s.po", install_dir.c_str(), lang_plain.c_str());
     }
 
-    if (!FileExists(path))
-    {
-        FatalError("WTF: %s\n", path.c_str());
-    }
-
     FILE *fp = FileOpen(path, "rb");
     if (!fp)
     {
@@ -1222,13 +1215,11 @@ void Trans_UnInit()
 
 const char *ob_gettext(const char *s)
 {
-    std::map<std::string, std::string>::iterator IT;
-
-    IT = trans_store.find(s);
+    trans_iter = trans_store.find(s);
 
-    if (IT != trans_store.end())
+    if (trans_iter != trans_store.end())
     {
-        return IT->second.c_str();
+        return trans_iter->second.c_str();
     }
 
     return s;
diff --git a/source/main.cc b/source/main.cc
index 14a04b861..b06a5728f 100644
--- a/source/main.cc
+++ b/source/main.cc
@@ -1482,7 +1482,7 @@ softrestart:;
 
     if (main_action != MAIN_SOFT_RESTART)
     {
-        VFS_InitAddons(install_dir);
+        VFS_InitAddons();
 
         if (const int load_arg = argv::Find('l', "load"); load_arg >= 0)
         {
diff --git a/source/slump.cc b/source/slump.cc
index 82cbd156d..70c9fbbbb 100644
--- a/source/slump.cc
+++ b/source/slump.cc
@@ -1342,7 +1342,7 @@ void secretize_config(config *c)
 /* 3. Parse the arglist to get overrides to switches,         */
 /* 4. Read the config for non-switches (flats, themes, etc).  */
 /* 5. Do postproduction defaults and calculations and such.   */
-config *get_config(std::string filename)
+config *get_config(const std::string &filename)
 {
     config *answer;
     int     i;
diff --git a/source/slump.h b/source/slump.h
index 6f1f21392..2bd952bd5 100644
--- a/source/slump.h
+++ b/source/slump.h
@@ -37,7 +37,7 @@
 #include <string>
 #include <vector>
 
-bool slump_main(std::string filename);
+bool slump_main(const std::string &filename);
 
 /* Slump 0.003.02 */
 #define SOURCE_VERSION    (0)
@@ -941,7 +941,7 @@ typedef struct s_config
 /* Lots and lots and lots of functions */
 /* And this isn't even all of 'em! */
 
-config    *get_config(std::string filename);
+config    *get_config(const std::string &filename);
 void       NewLevel(level *l, haa *init_haa, config *c);
 void       DumpLevel(dumphandle dh, config *c, level *l, int episode, int mission, int map);
 void       FreeLevel(level *l);
diff --git a/source/slump_main.cc b/source/slump_main.cc
index 50797825f..2ef210197 100644
--- a/source/slump_main.cc
+++ b/source/slump_main.cc
@@ -63,7 +63,7 @@ void machioize(config *c, float amount)
     }
 }
 
-bool slump_main(std::string filename)
+bool slump_main(const std::string &filename)
 {
 
     /* A stubby but functional main() */
diff --git a/source/sys_macro.h b/source/sys_macro.h
index 93ad2cfa4..a0f725f3f 100644
--- a/source/sys_macro.h
+++ b/source/sys_macro.h
@@ -24,6 +24,10 @@
 #include <math.h>
 #include <stdint.h>
 
+constexpr char *BLANKOUT = "                                                                                           "
+                           "                                                                                           "
+                           "                                                                    ";
+
 // basic constants
 #define OBSIDIAN_MSG_BUF_LEN  2000
 #define OBSIDIAN_DIST_EPSILON (1.0 / 1024.0)
diff --git a/source/ui_build.cc b/source/ui_build.cc
index a5904c58e..264ab2ed0 100644
--- a/source/ui_build.cc
+++ b/source/ui_build.cc
@@ -23,6 +23,7 @@
 #include "m_trans.h"
 #include "main.h"
 #include "sys_assert.h"
+#include "sys_macro.h"
 
 UI_Build::UI_Build(int X, int Y, int W, int H, const char *label) : Fl_Group(X, Y, W, H, label)
 {
@@ -365,7 +366,7 @@ void UI_Build::ParseSteps(const char *names)
     }
 }
 
-int UI_Build::FindStep(std::string name)
+int UI_Build::FindStep(std::string_view name)
 {
     for (int i = 0; i < (int)step_names.size(); i++)
     {
@@ -378,12 +379,10 @@ int UI_Build::FindStep(std::string name)
     return -1; // not found
 }
 
-void UI_Build::AddStatusStep(std::string name)
+void UI_Build::AddStatusStep(const std::string &name)
 {
     // modifies the current status string to show the current step
-    std::string blankout;
-    blankout.append(200, ' ');
-    status->copy_label(blankout.c_str());
+    status->label(BLANKOUT);
     status->copy_label(StringFormat("%s : %s", status_label.c_str(), name.c_str()).c_str());
     status->redraw();
 }
diff --git a/source/ui_build.h b/source/ui_build.h
index 1fd82c5c8..fe8baf1df 100644
--- a/source/ui_build.h
+++ b/source/ui_build.h
@@ -67,12 +67,12 @@ class UI_Build : public Fl_Group
 
     void SetStatus(std::string_view msg);
 
-    void AddStatusStep(std::string name);
+    void AddStatusStep(const std::string &name);
 
   private:
     void resize(int X, int Y, int W, int H);
 
-    int FindStep(std::string name); // -1 if not found
+    int FindStep(std::string_view name); // -1 if not found
 };
 
 //--- editor settings ---
diff --git a/source/ui_game.cc b/source/ui_game.cc
index 6251eff32..4cefb079a 100644
--- a/source/ui_game.cc
+++ b/source/ui_game.cc
@@ -289,7 +289,7 @@ void UI_Game::Locked(bool value)
     }
 }
 
-bool UI_Game::AddChoice(std::string button, std::string id, std::string label)
+bool UI_Game::AddChoice(const std::string &button, const std::string &id, const std::string &label)
 {
     if (!StringCompare(button, "engine"))
     {
@@ -323,7 +323,7 @@ bool UI_Game::AddChoice(std::string button, std::string id, std::string label)
     return false; // unknown button
 }
 
-bool UI_Game::EnableChoice(std::string button, std::string id, bool enable_it)
+bool UI_Game::EnableChoice(const std::string &button, const std::string &id, bool enable_it)
 {
     if (!StringCompare(button, "engine"))
     {
@@ -354,7 +354,7 @@ bool UI_Game::EnableChoice(std::string button, std::string id, bool enable_it)
     return false; // unknown button
 }
 
-bool UI_Game::SetButton(std::string button, std::string id)
+bool UI_Game::SetButton(const std::string &button, const std::string &id)
 {
     if (!StringCompare(button, "engine"))
     {
diff --git a/source/ui_game.h b/source/ui_game.h
index 82c7b88de..48946da06 100644
--- a/source/ui_game.h
+++ b/source/ui_game.h
@@ -53,9 +53,9 @@ class UI_Game : public Fl_Group
     void Locked(bool value);
 
     // these return false if 'button' is not valid
-    bool AddChoice(std::string button, std::string id, std::string label);
-    bool EnableChoice(std::string button, std::string id, bool enable_it);
-    bool SetButton(std::string button, std::string id);
+    bool AddChoice(const std::string &button, const std::string &id, const std::string &label);
+    bool EnableChoice(const std::string &button, const std::string &id, bool enable_it);
+    bool SetButton(const std::string &button, const std::string &id);
 
     void SetAbortButton(bool abort);
 
diff --git a/source/ui_map.cc b/source/ui_map.cc
index 210b76120..18e43c3ce 100644
--- a/source/ui_map.cc
+++ b/source/ui_map.cc
@@ -352,7 +352,7 @@ void UI_MiniMap::DrawEntity(int x, int y, uint8_t r, uint8_t g, uint8_t b)
     RawPixel(x, y + 1, r, g, b);
 }
 
-void UI_MiniMap::GifStart(std::string filename, int delay)
+void UI_MiniMap::GifStart(std::string_view filename, int delay)
 {
     gif_writer = new GifWriter;
     gif_delay  = delay;
diff --git a/source/ui_map.h b/source/ui_map.h
index 37b41834a..00884bd41 100644
--- a/source/ui_map.h
+++ b/source/ui_map.h
@@ -62,7 +62,7 @@ class UI_MiniMap : public Fl_Box
 
     void MapClear();
 
-    void GifStart(std::string filename, int delay);
+    void GifStart(std::string_view filename, int delay);
     void GifFrame();
     void GifFinish();
 
diff --git a/source/ui_module.cc b/source/ui_module.cc
index 6c1513438..f26c22627 100644
--- a/source/ui_module.cc
+++ b/source/ui_module.cc
@@ -32,7 +32,7 @@
 #include "sys_macro.h"
 #include "sys_xoshiro.h"
 
-UI_Module::UI_Module(int X, int Y, int W, int H, std::string id, std::string label, std::string tip, int red, int green,
+UI_Module::UI_Module(int X, int Y, int W, int H, const std::string &id, const std::string &label, const std::string &tip, int red, int green,
                      int blue, bool suboptions)
     : Fl_Group(X, Y, W, H), choice_map(), cur_opt_y(0)
 {
@@ -96,7 +96,7 @@ bool UI_Module::Is_UI() const
     return (!StringCompare(id_name.substr(0, 3), "ui_"));
 }
 
-void UI_Module::AddHeader(std::string opt, std::string label, int gap)
+void UI_Module::AddHeader(const std::string &opt, const std::string &label, int gap)
 {
     int nw = this->parent()->w();
 
@@ -126,7 +126,7 @@ void UI_Module::AddHeader(std::string opt, std::string label, int gap)
     choice_map_header[opt] = rhead;
 }
 
-void UI_Module::AddUrl(std::string opt, std::string label, std::string url, int gap)
+void UI_Module::AddUrl(const std::string &opt, const std::string &label, const std::string &url, int gap)
 {
     int nw = this->parent()->w();
 
@@ -156,8 +156,8 @@ void UI_Module::AddUrl(std::string opt, std::string label, std::string url, int
     choice_map_url[opt] = rurl;
 }
 
-void UI_Module::AddOption(std::string opt, std::string label, std::string tip, std::string longtip, int gap,
-                          std::string randomize_group, std::string default_value)
+void UI_Module::AddOption(const std::string &opt, const std::string &label, const std::string &tip, std::string &longtip, int gap,
+                          const std::string &randomize_group, const std::string &default_value)
 {
     int nw = this->parent()->w();
     //    int nh = kf_h(30);
@@ -221,9 +221,9 @@ void UI_Module::AddOption(std::string opt, std::string label, std::string tip, s
     choice_map[opt] = rch;
 }
 
-void UI_Module::AddSliderOption(std::string opt, std::string label, std::string tip, std::string longtip, int gap,
-                                double min, double max, double inc, std::string units, std::string presets,
-                                std::string nan, std::string randomize_group, std::string default_value)
+void UI_Module::AddSliderOption(const std::string &opt, std::string &label, const std::string &tip, std::string &longtip, int gap,
+                                double min, double max, double inc, const std::string &units, const std::string &presets,
+                                const std::string &nan, const std::string &randomize_group, const std::string &default_value)
 {
     int nw = this->parent()->w();
     //    int nh = kf_h(30);
@@ -408,8 +408,8 @@ void UI_Module::AddSliderOption(std::string opt, std::string label, std::string
     choice_map_slider[opt] = rsl;
 }
 
-void UI_Module::AddButtonOption(std::string opt, std::string label, std::string tip, std::string longtip, int gap,
-                                std::string randomize_group, std::string default_value)
+void UI_Module::AddButtonOption(const std::string &opt, const std::string &label, const std::string &tip, std::string &longtip, int gap,
+                                const std::string &randomize_group, const std::string &default_value)
 {
     int nw = this->parent()->w();
     //    int nh = kf_h(30);
@@ -625,7 +625,7 @@ void UI_Module::randomize_Values(std::vector<std::string> selected_randomize_gro
     }
 }
 
-void UI_Module::AddOptionChoice(std::string option, std::string id, std::string label)
+void UI_Module::AddOptionChoice(const std::string &option, const std::string &id, const std::string &label)
 {
     UI_RChoice *rch = FindOpt(option);
 
@@ -640,7 +640,7 @@ void UI_Module::AddOptionChoice(std::string option, std::string id, std::string
     rch->mod_menu->EnableChoice(id, 1);
 }
 
-bool UI_Module::SetOption(std::string option, std::string value)
+bool UI_Module::SetOption(const std::string &option, const std::string &value)
 {
     UI_RChoice *rch = FindOpt(option);
 
@@ -654,7 +654,7 @@ bool UI_Module::SetOption(std::string option, std::string value)
     return true;
 }
 
-bool UI_Module::SetSliderOption(std::string option, std::string value)
+bool UI_Module::SetSliderOption(const std::string &option, const std::string &value)
 {
     UI_RSlide *rsl = FindSliderOpt(option);
 
@@ -700,7 +700,7 @@ bool UI_Module::SetSliderOption(std::string option, std::string value)
     return true;
 }
 
-bool UI_Module::SetButtonOption(std::string option, int value)
+bool UI_Module::SetButtonOption(const std::string &option, int value)
 {
     UI_RButton *rbt = FindButtonOpt(option);
 
@@ -713,7 +713,7 @@ bool UI_Module::SetButtonOption(std::string option, int value)
     return true;
 }
 
-UI_RChoice *UI_Module::FindOpt(std::string option)
+UI_RChoice *UI_Module::FindOpt(const std::string &option)
 {
     if (choice_map.find(option) == choice_map.end())
     {
@@ -723,7 +723,7 @@ UI_RChoice *UI_Module::FindOpt(std::string option)
     return choice_map[option];
 }
 
-UI_RSlide *UI_Module::FindSliderOpt(std::string option)
+UI_RSlide *UI_Module::FindSliderOpt(const std::string &option)
 {
     if (choice_map_slider.find(option) == choice_map_slider.end())
     {
@@ -733,7 +733,7 @@ UI_RSlide *UI_Module::FindSliderOpt(std::string option)
     return choice_map_slider[option];
 }
 
-UI_RButton *UI_Module::FindButtonOpt(std::string option)
+UI_RButton *UI_Module::FindButtonOpt(const std::string &option)
 {
     if (choice_map_button.find(option) == choice_map_button.end())
     {
@@ -743,7 +743,7 @@ UI_RButton *UI_Module::FindButtonOpt(std::string option)
     return choice_map_button[option];
 }
 
-UI_RHeader *UI_Module::FindHeaderOpt(std::string option)
+UI_RHeader *UI_Module::FindHeaderOpt(const std::string &option)
 {
     if (choice_map_header.find(option) == choice_map_header.end())
     {
@@ -753,7 +753,7 @@ UI_RHeader *UI_Module::FindHeaderOpt(std::string option)
     return choice_map_header[option];
 }
 
-UI_RLink *UI_Module::FindUrlOpt(std::string option)
+UI_RLink *UI_Module::FindUrlOpt(const std::string &option)
 {
     if (choice_map_url.find(option) == choice_map_url.end())
     {
@@ -838,10 +838,9 @@ void UI_Module::callback_PresetCheck(Fl_Widget *w, void *data)
 
     std::string new_label;
 
-    current_slider->unit_label->copy_label(new_label.append(50, ' ').c_str()); // To prevent visual errors with
-                                                                               // labels of different lengths
-    // Check against the preset_choices map
+    current_slider->unit_label->label(BLANKOUT);
 
+    // Check against the preset_choices map
     if (current_slider->preset_choices.count(value) == 1)
     {
         new_label = current_slider->preset_choices[value];
@@ -1047,8 +1046,7 @@ void UI_Module::callback_NanOptions(Fl_Widget *w, void *data)
     if (temp_value > 0)
     {
         std::string new_label;
-        current_slider->unit_label->copy_label(new_label.append(50, ' ').c_str()); // To prevent visual errors with
-                                                                                   // labels of different lengths
+        current_slider->unit_label->label(BLANKOUT);
         new_label = nan_options->text(temp_value);
         current_slider->unit_label->copy_label(new_label.c_str());
         current_slider->prev_button->deactivate();
@@ -1068,7 +1066,7 @@ void UI_Module::callback_NanOptions(Fl_Widget *w, void *data)
 
 //----------------------------------------------------------------
 
-UI_CustomMods::UI_CustomMods(int X, int Y, int W, int H, std::string label) : Fl_Group(X, Y, W, H)
+UI_CustomMods::UI_CustomMods(int X, int Y, int W, int H, const std::string &label) : Fl_Group(X, Y, W, H)
 {
 
     box(FL_FLAT_BOX);
@@ -1120,7 +1118,7 @@ typedef struct
     UI_CustomMods *parent;
 } mod_enable_callback_data_t;
 
-void UI_CustomMods::AddModule(std::string id, std::string label, std::string tip, int red, int green, int blue,
+void UI_CustomMods::AddModule(const std::string &id, const std::string &label, const std::string &tip, int red, int green, int blue,
                               bool suboptions)
 {
     UI_Module *M = new UI_Module(mx, my, mw - 4, kf_h(34), id, label, tip, red, green, blue, suboptions);
@@ -1139,7 +1137,7 @@ void UI_CustomMods::AddModule(std::string id, std::string label, std::string tip
     PositionAll();
 }
 
-bool UI_CustomMods::AddHeader(std::string module, std::string option, std::string label, int gap)
+bool UI_CustomMods::AddHeader(const std::string &module, const std::string &option, const std::string &label, int gap)
 {
     UI_Module *M = FindID(module);
 
@@ -1155,7 +1153,7 @@ bool UI_CustomMods::AddHeader(std::string module, std::string option, std::strin
     return true;
 }
 
-bool UI_CustomMods::AddUrl(std::string module, std::string option, std::string label, std::string url, int gap)
+bool UI_CustomMods::AddUrl(const std::string &module, const std::string &option, const std::string &label, const std::string &url, int gap)
 {
     UI_Module *M = FindID(module);
 
@@ -1171,8 +1169,8 @@ bool UI_CustomMods::AddUrl(std::string module, std::string option, std::string l
     return true;
 }
 
-bool UI_CustomMods::AddOption(std::string module, std::string option, std::string label, std::string tip,
-                              std::string longtip, int gap, std::string randomize_group, std::string default_value)
+bool UI_CustomMods::AddOption(const std::string &module, const std::string &option, const std::string &label, const std::string &tip,
+                              std::string &longtip, int gap, const std::string &randomize_group, const std::string &default_value)
 {
     UI_Module *M = FindID(module);
 
@@ -1188,10 +1186,10 @@ bool UI_CustomMods::AddOption(std::string module, std::string option, std::strin
     return true;
 }
 
-bool UI_CustomMods::AddSliderOption(std::string module, std::string option, std::string label, std::string tip,
-                                    std::string longtip, int gap, double min, double max, double inc, std::string units,
-                                    std::string presets, std::string nan, std::string randomize_group,
-                                    std::string default_value)
+bool UI_CustomMods::AddSliderOption(const std::string &module, const std::string &option, std::string &label, const std::string &tip,
+                                    std::string &longtip, int gap, double min, double max, double inc, const std::string &units,
+                                    const std::string &presets, const std::string &nan, const std::string &randomize_group,
+                                    const std::string &default_value)
 {
     UI_Module *M = FindID(module);
 
@@ -1208,9 +1206,9 @@ bool UI_CustomMods::AddSliderOption(std::string module, std::string option, std:
     return true;
 }
 
-bool UI_CustomMods::AddButtonOption(std::string module, std::string option, std::string label, std::string tip,
-                                    std::string longtip, int gap, std::string randomize_group,
-                                    std::string default_value)
+bool UI_CustomMods::AddButtonOption(const std::string &module, const std::string &option, const std::string &label, const std::string &tip,
+                                    std::string &longtip, int gap, const std::string &randomize_group,
+                                    const std::string &default_value)
 {
     UI_Module *M = FindID(module);
 
@@ -1226,7 +1224,7 @@ bool UI_CustomMods::AddButtonOption(std::string module, std::string option, std:
     return true;
 }
 
-bool UI_CustomMods::AddOptionChoice(std::string module, std::string option, std::string id, std::string label)
+bool UI_CustomMods::AddOptionChoice(const std::string &module, const std::string &option, const std::string &id, const std::string &label)
 {
     UI_Module *M = FindID(module);
 
@@ -1240,7 +1238,7 @@ bool UI_CustomMods::AddOptionChoice(std::string module, std::string option, std:
     return true;
 }
 
-bool UI_CustomMods::ShowModule(std::string id, bool new_shown)
+bool UI_CustomMods::ShowModule(const std::string &id, bool new_shown)
 {
     SYS_ASSERT(!id.empty());
 
@@ -1272,7 +1270,7 @@ bool UI_CustomMods::ShowModule(std::string id, bool new_shown)
     return true;
 }
 
-bool UI_CustomMods::SetOption(std::string module, std::string option, std::string value)
+bool UI_CustomMods::SetOption(const std::string &module, const std::string &option, const std::string &value)
 {
     UI_Module *M = FindID(module);
 
@@ -1284,7 +1282,7 @@ bool UI_CustomMods::SetOption(std::string module, std::string option, std::strin
     return M->SetOption(option, value);
 }
 
-bool UI_CustomMods::SetSliderOption(std::string module, std::string option, std::string value)
+bool UI_CustomMods::SetSliderOption(const std::string &module, const std::string &option, const std::string &value)
 {
     UI_Module *M = FindID(module);
 
@@ -1296,7 +1294,7 @@ bool UI_CustomMods::SetSliderOption(std::string module, std::string option, std:
     return M->SetSliderOption(option, value);
 }
 
-bool UI_CustomMods::SetButtonOption(std::string module, std::string option, int value)
+bool UI_CustomMods::SetButtonOption(const std::string &module, const std::string &option, int value)
 {
     UI_Module *M = FindID(module);
 
@@ -1308,7 +1306,7 @@ bool UI_CustomMods::SetButtonOption(std::string module, std::string option, int
     return M->SetButtonOption(option, value);
 }
 
-bool UI_CustomMods::EnableMod(std::string id, bool enable)
+bool UI_CustomMods::EnableMod(const std::string &id, bool enable)
 {
     SYS_ASSERT(!id.empty());
 
@@ -1777,7 +1775,7 @@ void UI_CustomMods::callback_ModEnable(Fl_Widget *w, void *data)
     ob_set_mod_option(M->id_name, "self", M->mod_button->value() ? "true" : "false");
 }
 
-UI_Module *UI_CustomMods::FindID(std::string id) const
+UI_Module *UI_CustomMods::FindID(const std::string &id) const
 {
     for (int j = 0; j < mod_pack->children(); j++)
     {
diff --git a/source/ui_module.h b/source/ui_module.h
index a50ff1d5f..b9521f89f 100644
--- a/source/ui_module.h
+++ b/source/ui_module.h
@@ -60,31 +60,31 @@ class UI_Module : public Fl_Group
     int cur_opt_y;
 
   public:
-    UI_Module(int X, int Y, int W, int H, std::string id, std::string label, std::string tip, int red, int green,
+    UI_Module(int X, int Y, int W, int H, const std::string &id, const std::string &label, const std::string &tip, int red, int green,
               int blue, bool suboptions);
     virtual ~UI_Module();
 
-    void AddOption(std::string option, std::string label, std::string tip, std::string longtip, int gap,
-                   std::string randomize_group, std::string default_value);
+    void AddOption(const std::string &option, const std::string &label, const std::string &tip, std::string &longtip, int gap,
+                   const std::string &randomize_group, const std::string &default_value);
 
-    void AddHeader(std::string option, std::string label, int gap);
+    void AddHeader(const std::string &option, const std::string &label, int gap);
 
-    void AddUrl(std::string option, std::string label, std::string url, int gap);
+    void AddUrl(const std::string &option, const std::string &label, const std::string &url, int gap);
 
-    void AddSliderOption(std::string option, std::string label, std::string tip, std::string longtip, int gap,
-                         double min, double max, double inc, std::string units, std::string presets, std::string nan,
-                         std::string randomize_group, std::string default_value);
+    void AddSliderOption(const std::string &option, std::string &label, const std::string &tip, std::string &longtip, int gap,
+                         double min, double max, double inc, const std::string &units, const std::string &presets, const std::string &nan,
+                         const std::string &randomize_group, const std::string &default_value);
 
-    void AddButtonOption(std::string opt, std::string label, std::string tip, std::string longtip, int gap,
-                         std::string randomize_group, std::string default_value);
+    void AddButtonOption(const std::string &opt, const std::string &label, const std::string &tip, std::string &longtip, int gap,
+                         const std::string &randomize_group, const std::string &default_value);
 
-    void AddOptionChoice(std::string option, std::string id, std::string label);
+    void AddOptionChoice(const std::string &option, const std::string &id, const std::string &label);
 
-    bool SetOption(std::string option, std::string value);
+    bool SetOption(const std::string &option, const std::string &value);
 
-    bool SetSliderOption(std::string option, std::string value);
+    bool SetSliderOption(const std::string &option, const std::string &value);
 
-    bool SetButtonOption(std::string option, int value);
+    bool SetButtonOption(const std::string &option, int value);
 
     bool Is_UI() const;
 
@@ -95,15 +95,15 @@ class UI_Module : public Fl_Group
 
     void randomize_Values(std::vector<std::string> selected_randomize_groups);
 
-    UI_RChoice *FindOpt(std::string opt);       // const;
+    UI_RChoice *FindOpt(const std::string &opt);       // const;
 
-    UI_RSlide *FindSliderOpt(std::string opt);  // const;
+    UI_RSlide *FindSliderOpt(const std::string &opt);  // const;
 
-    UI_RButton *FindButtonOpt(std::string opt); // const;
+    UI_RButton *FindButtonOpt(const std::string &opt); // const;
 
-    UI_RHeader *FindHeaderOpt(std::string opt); // const;
+    UI_RHeader *FindHeaderOpt(const std::string &opt); // const;
 
-    UI_RLink *FindUrlOpt(std::string opt);      // const;
+    UI_RLink *FindUrlOpt(const std::string &opt);      // const;
 
   protected:
   private:
@@ -139,43 +139,43 @@ class UI_CustomMods : public Fl_Group
     int total_h;
 
   public:
-    UI_CustomMods(int X, int Y, int W, int H, std::string label);
+    UI_CustomMods(int X, int Y, int W, int H, const std::string &label);
     virtual ~UI_CustomMods();
 
   public:
-    void AddModule(std::string id, std::string label, std::string tip, int red, int green, int blue, bool suboptions);
+    void AddModule(const std::string &id, const std::string &label, const std::string &tip, int red, int green, int blue, bool suboptions);
 
     // these return false if module is unknown
-    bool ShowModule(std::string id, bool new_shown);
-    bool EnableMod(std::string id, bool enable);
+    bool ShowModule(const std::string &id, bool new_shown);
+    bool EnableMod(const std::string &id, bool enable);
 
-    bool AddHeader(std::string module, std::string option, std::string label, int gap);
+    bool AddHeader(const std::string &module, const std::string &option, const std::string &label, int gap);
 
-    bool AddUrl(std::string module, std::string option, std::string label, std::string url, int gap);
+    bool AddUrl(const std::string &module, const std::string &option, const std::string &label, const std::string &url, int gap);
 
-    bool AddOption(std::string module, std::string option, std::string label, std::string tip, std::string longtip,
-                   int gap, std::string randomize_group, std::string default_value);
+    bool AddOption(const std::string &module, const std::string &option, const std::string &label, const std::string &tip, std::string &longtip,
+                   int gap, const std::string &randomize_group, const std::string &default_value);
 
-    bool AddSliderOption(std::string module, std::string option, std::string label, std::string tip,
-                         std::string longtip, int gap, double min, double max, double inc, std::string units,
-                         std::string presets, std::string nan, std::string randomize_group, std::string default_value);
+    bool AddSliderOption(const std::string &module, const std::string &option, std::string &label, const std::string &tip,
+                         std::string &longtip, int gap, double min, double max, double inc, const std::string &units,
+                         const std::string &presets, const std::string &nan, const std::string &randomize_group, const std::string &default_value);
 
-    bool AddButtonOption(std::string module, std::string option, std::string label, std::string tip,
-                         std::string longtip, int gap, std::string randomize_group, std::string default_value);
+    bool AddButtonOption(const std::string &module, const std::string &option, const std::string &label, const std::string &tip,
+                         std::string &longtip, int gap, const std::string &randomize_group, const std::string &default_value);
 
-    bool AddOptionChoice(std::string module, std::string option, std::string id, std::string label);
+    bool AddOptionChoice(const std::string &module, const std::string &option, const std::string &id, const std::string &label);
 
-    bool SetOption(std::string module, std::string option, std::string value);
+    bool SetOption(const std::string &module, const std::string &option, const std::string &value);
 
-    bool SetSliderOption(std::string module, std::string option, std::string value);
+    bool SetSliderOption(const std::string &module, const std::string &option, const std::string &value);
 
-    bool SetButtonOption(std::string module, std::string option, int value);
+    bool SetButtonOption(const std::string &module, const std::string &option, int value);
 
     void Locked(bool value);
 
     void SurpriseMe();
 
-    UI_Module *FindID(std::string id) const;
+    UI_Module *FindID(const std::string &id) const;
 
   private:
     void PositionAll(UI_Module *focus = NULL);
diff --git a/source/ui_widgets.cc b/source/ui_widgets.cc
index 7de38de8e..0057d7431 100644
--- a/source/ui_widgets.cc
+++ b/source/ui_widgets.cc
@@ -25,7 +25,7 @@
 #include "main.h"
 #include "sys_assert.h"
 
-choice_data_c::choice_data_c(std::string _id, std::string _label) : enabled(false), mapped(-1), widget(NULL)
+choice_data_c::choice_data_c(std::string_view _id, std::string_view _label) : enabled(false), mapped(-1), widget(NULL)
 {
     if (!_id.empty())
     {
@@ -49,7 +49,7 @@ choice_data_c::~choice_data_c()
 
 //----------------------------------------------------------------
 
-UI_RChoiceMenu::UI_RChoiceMenu(int x, int y, int w, int h, std::string label)
+UI_RChoiceMenu::UI_RChoiceMenu(int x, int y, int w, int h, const std::string &label)
     : UI_CustomMenu(x, y, w, h, label), opt_list()
 {
     visible_focus(0);
@@ -65,7 +65,7 @@ UI_RChoiceMenu::~UI_RChoiceMenu()
     }
 }
 
-void UI_RChoiceMenu::AddChoice(std::string id, std::string label)
+void UI_RChoiceMenu::AddChoice(const std::string &id, const std::string &label)
 {
     choice_data_c *opt = FindID(id);
 
@@ -83,13 +83,10 @@ void UI_RChoiceMenu::AddChoice(std::string id, std::string label)
         opt = new choice_data_c(id, label);
 
         opt_list.push_back(opt);
-
-        // no need to call Recreate() here since new pairs are always
-        // hidden (enabled == false).
     }
 }
 
-bool UI_RChoiceMenu::EnableChoice(std::string id, bool enable_it)
+bool UI_RChoiceMenu::EnableChoice(const std::string &id, bool enable_it)
 {
     SYS_ASSERT(!id.empty());
 
@@ -123,7 +120,7 @@ std::string UI_RChoiceMenu::GetLabel() const
     return P ? P->label : "";
 }
 
-bool UI_RChoiceMenu::ChangeTo(std::string id)
+bool UI_RChoiceMenu::ChangeTo(const std::string &id)
 {
     SYS_ASSERT(!id.empty());
 
@@ -181,7 +178,7 @@ void UI_RChoiceMenu::Recreate()
     value(0);
 }
 
-choice_data_c *UI_RChoiceMenu::FindID(std::string id) const
+choice_data_c *UI_RChoiceMenu::FindID(std::string_view id) const
 {
     for (unsigned int j = 0; j < opt_list.size(); j++)
     {
@@ -344,7 +341,7 @@ UI_RButton::~UI_RButton()
 
 //----------------------------------------------------------------
 
-UI_CustomCheckBox::UI_CustomCheckBox(int x, int y, int w, int h, std::string label)
+UI_CustomCheckBox::UI_CustomCheckBox(int x, int y, int w, int h, const std::string &label)
     : Fl_Check_Button(x, y, w, h, label.empty() ? "" : label.c_str())
 {
     visible_focus(0);
@@ -881,7 +878,7 @@ void UI_ManualEntry::draw()
 
 //----------------------------------------------------------------
 
-UI_CustomMenu::UI_CustomMenu(int x, int y, int w, int h, std::string label)
+UI_CustomMenu::UI_CustomMenu(int x, int y, int w, int h, const std::string &label)
     : Fl_Choice(x, y, w, h, label.empty() ? "" : label.c_str())
 {
     visible_focus(0);
diff --git a/source/ui_widgets.h b/source/ui_widgets.h
index 688042977..8c54cf8ce 100644
--- a/source/ui_widgets.h
+++ b/source/ui_widgets.h
@@ -63,7 +63,7 @@ class choice_data_c
     Fl_Check_Button *widget;
 
   public:
-    choice_data_c(std::string _id, std::string _label);
+    choice_data_c(std::string_view _id, std::string_view _label);
     ~choice_data_c();
 };
 
@@ -152,7 +152,7 @@ class UI_CustomMenu : public Fl_Choice
 {
   private:
   public:
-    UI_CustomMenu(int x, int y, int w, int h, std::string label = "");
+    UI_CustomMenu(int x, int y, int w, int h, const std::string &label = "");
     virtual ~UI_CustomMenu();
 
   private:
@@ -165,19 +165,19 @@ class UI_RChoiceMenu : public UI_CustomMenu
     std::vector<choice_data_c *> opt_list;
 
   public:
-    UI_RChoiceMenu(int x, int y, int w, int h, std::string label = "");
+    UI_RChoiceMenu(int x, int y, int w, int h, const std::string &label = "");
     virtual ~UI_RChoiceMenu();
 
   public:
     // add a new choice to the list.  If a choice with the same 'id'
     // already exists, it is just replaced instead.
     // The choice will begin disabled (shown == false).
-    void AddChoice(std::string id, std::string label);
+    void AddChoice(const std::string &id, const std::string &label);
 
     // finds the option with the given ID, and update its 'enabled'
     // value.  Returns true if successful, or false if no such
     // option exists.  Any change will call Recreate().
-    bool EnableChoice(std::string id, bool enable_it);
+    bool EnableChoice(const std::string &id, bool enable_it);
 
     // get the id string for the currently shown value.
     // Returns the string "none" if there are no choices.
@@ -185,11 +185,11 @@ class UI_RChoiceMenu : public UI_CustomMenu
 
     // change the currently shown value via the new 'id'.
     // If does not exist, returns false and nothing was changed.
-    bool ChangeTo(std::string id);
+    bool ChangeTo(const std::string &id);
 
     std::string GetLabel() const;
 
-    choice_data_c *FindID(std::string id) const;
+    choice_data_c *FindID(std::string_view id) const;
 
   private:
     choice_data_c *FindMapped() const;
@@ -201,8 +201,6 @@ class UI_RChoiceMenu : public UI_CustomMenu
     // first entry.
     void Recreate();
 
-    //    const char *GetLabel() const;  // ????
-
     void GotoPrevious();
     void GotoNext();
 };
@@ -344,7 +342,7 @@ class UI_CustomCheckBox : public Fl_Check_Button
 {
   private:
   public:
-    UI_CustomCheckBox(int x, int y, int w, int h, std::string label = "");
+    UI_CustomCheckBox(int x, int y, int w, int h, const std::string &label = "");
     virtual ~UI_CustomCheckBox();
 
   private: