Screen::Pen: handle COLOR_RESET color values

docs/changelog.txt

@@ -61,6 +61,7 @@ Template for new versions:
 ## Fixes
 - a safety check was added to ``Screen::doSetTile_char`` fur out of bound pen color values
 - ``TextArea`` widget corrected to use ``COLOR_BLACK`` instead of ``COLOR_RESET`` as default background color
+- ``Screen::Pen``: COLOR_RESET from Lua is changed to grey (fg) or black (bg); color values are masked to 4 bits to keep them in the expected range
 
 ## Misc Improvements
 

library/LuaApi.cpp

@@ -22,6 +22,7 @@ must not be misrepresented as being the original software.
 distribution.
 */
 
+#include "ColorText.h"
 #include "Core.h"
 #include "Error.h"
 #include "Internal.h"
@@ -232,14 +233,30 @@ static bool get_bool_field(lua_State *L, bool *pf, int idx, const char *name, bo
     return !nil;
 }
 
+static int8_t mask_pen_color(int8_t color, int8_t default_color) {
+    if (color == COLOR_RESET)
+        color = default_color;
+    return color & 15;
+}
+
+static bool get_color_field(lua_State *L, int8_t *pf, int idx, const char *name, int defval)
+{
+    bool nonnil = get_int_field(L, pf, idx, name, defval); // defval for nil
+    *pf = mask_pen_color(*pf, defval); // defval for COLOR_RESET
+    return nonnil;
+}
+
+static constexpr int8_t DEFAULT_FG = COLOR_GREY;
+static constexpr int8_t DEFAULT_BG = COLOR_BLACK;
+
 static void decode_pen(lua_State *L, Pen &pen, int idx)
 {
     idx = lua_absindex(L, idx);
 
     get_char_field(L, &pen.ch, idx, "ch", 0);
 
-    get_int_field(L, &pen.fg, idx, "fg", 7);
-    get_int_field(L, &pen.bg, idx, "bg", 0);
+    get_color_field(L, &pen.fg, idx, "fg", DEFAULT_FG);
+    get_color_field(L, &pen.bg, idx, "bg", DEFAULT_BG);
 
     lua_getfield(L, idx, "bold");
     if (lua_isnil(L, -1))
@@ -252,8 +269,8 @@ static void decode_pen(lua_State *L, Pen &pen, int idx)
 
     get_int_or_closure_field(L, &pen.tile, idx, "tile", 0);
 
-    bool tcolor = get_int_field(L, &pen.tile_fg, idx, "tile_fg", 7);
-    tcolor = get_int_field(L, &pen.tile_bg, idx, "tile_bg", 0) || tcolor;
+    bool tcolor = get_color_field(L, &pen.tile_fg, idx, "tile_fg", DEFAULT_FG);
+    tcolor = get_color_field(L, &pen.tile_bg, idx, "tile_bg", DEFAULT_BG) || tcolor;
 
     if (tcolor)
         pen.tile_mode = Pen::TileColor;
@@ -672,7 +689,7 @@ void Lua::CheckPen(lua_State *L, Screen::Pen *pen, int index, bool allow_nil, bo
     }
     else if (allow_color && lua_isnumber(L, index))
     {
-        *pen = Pen(0, lua_tointeger(L, index)&15, 0);
+        *pen = Pen(0, mask_pen_color(lua_tointeger(L, index), DEFAULT_FG), 0);
     }
     else
     {
@@ -698,8 +715,8 @@ static int adjust_pen(lua_State *L, bool no_copy)
 
             iidx = -1;
 
-            pen.fg = luaL_optint(L, 2, pen.fg) & 15;
-            pen.bg = luaL_optint(L, 3, pen.bg);
+            pen.fg = mask_pen_color(luaL_optint(L, 2, pen.fg), DEFAULT_FG);
+            pen.bg = mask_pen_color(luaL_optint(L, 3, pen.bg), DEFAULT_BG);
 
             if (!lua_isnil(L, 4))
                 pen.bold = lua_toboolean(L, 4);
@@ -864,15 +881,15 @@ static int dfhack_pen_newindex(lua_State *L)
         lua_pushinteger(L, (unsigned char)pen.ch);
         break;
     case 1:
-        pen.fg = luaL_checkint(L, 3) & 15;
+        pen.fg = mask_pen_color(luaL_checkint(L, 3), DEFAULT_FG);
         lua_pushinteger(L, pen.fg);
         break;
     case 2:
         pen.bold = lua_toboolean(L, 3);
         lua_pushboolean(L, pen.bold);
         break;
     case 3:
-        pen.bg = luaL_checkint(L, 3) & 15;
+        pen.bg = mask_pen_color(luaL_checkint(L, 3), DEFAULT_BG);
         lua_pushinteger(L, pen.bg);
         break;
     case 4:
@@ -891,14 +908,14 @@ static int dfhack_pen_newindex(lua_State *L)
         lua_pushboolean(L, pen.tile_mode == Pen::CharColor);
         break;
     case 6:
-        if (pen.tile_mode != Pen::TileColor) { wipe_tc = true; pen.tile_bg = 0; }
-        pen.tile_fg = luaL_checkint(L, 3) & 15;
+        if (pen.tile_mode != Pen::TileColor) { wipe_tc = true; pen.tile_bg = DEFAULT_BG; }
+        pen.tile_fg = mask_pen_color(luaL_checkint(L, 3), DEFAULT_FG);
         pen.tile_mode = Pen::TileColor;
         lua_pushinteger(L, pen.tile_fg);
         break;
     case 7:
-        if (pen.tile_mode != Pen::TileColor) { wipe_tc = true; pen.tile_fg = 7; }
-        pen.tile_bg = luaL_checkint(L, 3) & 15;
+        if (pen.tile_mode != Pen::TileColor) { wipe_tc = true; pen.tile_fg = DEFAULT_FG; }
+        pen.tile_bg = mask_pen_color(luaL_checkint(L, 3), DEFAULT_BG);
         pen.tile_mode = Pen::TileColor;
         lua_pushinteger(L, pen.tile_bg);
         break;

library/include/modules/Screen.h

@@ -94,26 +94,26 @@ namespace DFHack
             // NOTE: LuaApi.cpp assumes this struct is plain data and has empty destructor
 
             Pen(char ch = 0, int8_t fg = 7, int8_t bg = 0, int tile = 0, bool color_tile = false)
-              : ch(ch), fg(fg&7), bg(bg), bold(!!(fg&8)),
+              : ch(ch), fg(fg&7), bg(bg&15), bold(!!(fg&8)),
                 tile(tile), tile_mode(color_tile ? CharColor : AsIs), tile_fg(0), tile_bg(0)
             {}
             Pen(char ch, int8_t fg, int8_t bg, bool bold, int tile = 0, bool color_tile = false)
-              : ch(ch), fg(fg), bg(bg), bold(bold),
+              : ch(ch), fg(fg&15), bg(bg&15), bold(bold),
                 tile(tile), tile_mode(color_tile ? CharColor : AsIs), tile_fg(0), tile_bg(0)
             {}
             Pen(char ch, int8_t fg, int8_t bg, int tile, int8_t tile_fg, int8_t tile_bg)
-              : ch(ch), fg(fg&7), bg(bg), bold(!!(fg&8)),
-                tile(tile), tile_mode(TileColor), tile_fg(tile_fg), tile_bg(tile_bg)
+              : ch(ch), fg(fg&7), bg(bg&15), bold(!!(fg&8)),
+                tile(tile), tile_mode(TileColor), tile_fg(tile_fg&15), tile_bg(tile_bg&15)
             {}
             Pen(char ch, int8_t fg, int8_t bg, bool bold, int tile, int8_t tile_fg, int8_t tile_bg)
-              : ch(ch), fg(fg), bg(bg), bold(bold),
-                tile(tile), tile_mode(TileColor), tile_fg(tile_fg), tile_bg(tile_bg)
+              : ch(ch), fg(fg&15), bg(bg&15), bold(bold),
+                tile(tile), tile_mode(TileColor), tile_fg(tile_fg&15), tile_bg(tile_bg&15)
             {}
 
             void adjust(int8_t nfg) { fg = nfg&7; bold = !!(nfg&8); }
-            void adjust(int8_t nfg, bool nbold) { fg = nfg; bold = nbold; }
-            void adjust(int8_t nfg, int8_t nbg) { adjust(nfg); bg = nbg; }
-            void adjust(int8_t nfg, bool nbold, int8_t nbg) { adjust(nfg, nbold); bg = nbg; }
+            void adjust(int8_t nfg, bool nbold) { fg = nfg&15; bold = nbold; }
+            void adjust(int8_t nfg, int8_t nbg) { adjust(nfg); bg = nbg&15; }
+            void adjust(int8_t nfg, bool nbold, int8_t nbg) { adjust(nfg, nbold); bg = nbg&15; }
 
             Pen color(int8_t nfg) const { Pen cp(*this); cp.adjust(nfg); return cp; }
             Pen color(int8_t nfg, bool nbold) const { Pen cp(*this); cp.adjust(nfg, nbold); return cp; }

library/modules/Screen.cpp

@@ -480,9 +480,9 @@ bool Screen::drawBorder(const std::string &title)
     if (!gps) return false;
 
     auto dim = getWindowSize();
-    Pen border('\xDB', 8);
-    Pen text(0, 0, 7);
-    Pen signature(0, 0, 8);
+    Pen border('\xDB', COLOR_DARKGREY);
+    Pen text(0, COLOR_BLACK, COLOR_GREY);
+    Pen signature(0, COLOR_BLACK, COLOR_DARKGREY);
 
     for (int x = 0; x < dim.x; x++)
     {
@@ -516,8 +516,8 @@ bool Screen::invalidate()
     return true;
 }
 
-const Pen Screen::Painter::default_pen(0,COLOR_GREY,0);
-const Pen Screen::Painter::default_key_pen(0,COLOR_LIGHTGREEN,0);
+const Pen Screen::Painter::default_pen(0, COLOR_GREY, COLOR_BLACK);
+const Pen Screen::Painter::default_key_pen(0, COLOR_LIGHTGREEN, COLOR_BLACK);
 
 void Screen::Painter::do_paint_string(const std::string &str, const Pen &pen, bool map)
 {