* Replace _cucul_attr_to_ansi8() with a now documented cucul_attr_to_ansi()

function.

caca/driver_conio.c

@@ -107,13 +107,13 @@ static void conio_display(caca_display_t *dp)
         if(n && *chars == CUCUL_MAGIC_FULLWIDTH)
         {
             *screen++ = '[';
-            *screen++ = _cucul_attr_to_ansi8(*attrs++);
+            *screen++ = cucul_attr_to_ansi(*attrs++);
             ch = ']';
             chars++;
             n--;
         }
         *screen++ = ch;
-        *screen++ = _cucul_attr_to_ansi8(*attrs++);
+        *screen++ = cucul_attr_to_ansi(*attrs++);
     }
 #   if defined(SCREENUPDATE_IN_PC_H)
     ScreenUpdate(dp->drv.p->screen);

caca/driver_ncurses.c

@@ -203,7 +203,7 @@ static void ncurses_display(caca_display_t *dp)
         move(y, 0);
         for(x = dp->cv->width; x--; )
         {
-            attrset(dp->drv.p->attr[_cucul_attr_to_ansi8(*attrs++)]);
+            attrset(dp->drv.p->attr[cucul_attr_to_ansi(*attrs++)]);
             ncurses_write_utf32(*chars++);
         }
     }

caca/driver_slang.c

@@ -242,11 +242,11 @@ static void slang_display(caca_display_t *dp)
             else
 #endif
             {
-                SLsmg_set_color(slang_assoc[_cucul_attr_to_ansi8(*attrs++)]);
+                SLsmg_set_color(slang_assoc[cucul_attr_to_ansi(*attrs++)]);
                 slang_write_utf32(ch);
             }
 #else
-            SLsmg_set_color(_cucul_attr_to_ansi8(*attrs++));
+            SLsmg_set_color(cucul_attr_to_ansi(*attrs++));
             slang_write_utf32(ch);
 #endif
         }

caca/driver_vga.c

@@ -125,13 +125,13 @@ static void vga_display(caca_display_t *dp)
         if(n && *chars == CUCUL_MAGIC_FULLWIDTH)
         {
             *screen++ = '[';
-            *screen++ = _cucul_attr_to_ansi8(*attrs++);
+            *screen++ = cucul_attr_to_ansi(*attrs++);
             ch = ']';
             chars++;
             n--;
         }
         *screen++ = ch;
-        *screen++ = _cucul_attr_to_ansi8(*attrs++);
+        *screen++ = cucul_attr_to_ansi(*attrs++);
     }
 }
 

cucul/attr.c

@@ -234,6 +234,32 @@ int cucul_set_color_argb(cucul_canvas_t *cv, unsigned int fg, unsigned int bg)
     return 0;
 }
 
+/** \brief Get DOS ANSI information from attribute.
+ *
+ *  Get the ANSI colour pair for a given attribute. The returned value is
+ *  an 8-bit value whose higher 4 bits are the background colour and lower
+ *  4 bits are the foreground colour.
+ *
+ *  If the attribute has ARGB colours, the nearest colour is used. Special
+ *  attributes such as \e CUCUL_DEFAULT and \e CUCUL_TRANSPARENT are not
+ *  handled and are both replaced with \e CUCUL_LIGHTGRAY for the foreground
+ *  colour and \e CUCUL_BLACK for the background colour.
+ *
+ *  This function never fails. If the attribute value is outside the expected
+ *  32-bit range, higher order bits are simply ignored.
+ *
+ *  \param attr The requested attribute value.
+ *  \return The corresponding DOS ANSI value.
+ */
+unsigned char cucul_attr_to_ansi(unsigned long int attr)
+{
+    uint8_t fg = nearest_ansi((attr >> 4) & 0x3fff);
+    uint8_t bg = nearest_ansi(attr >> 18);
+
+    return (fg < 0x10 ? fg : CUCUL_LIGHTGRAY)
+            | ((bg < 0x10 ? bg : CUCUL_BLACK) << 4);
+}
+
 /** \brief Get ANSI foreground information from attribute.
  *
  *  Get the ANSI foreground colour value for a given attribute. The returned
@@ -336,20 +362,6 @@ static uint8_t nearest_ansi(uint16_t argb14)
     return best;
 }
 
-uint8_t _cucul_attr_to_ansi8(uint32_t attr)
-{
-    uint8_t fg = nearest_ansi((attr >> 4) & 0x3fff);
-    uint8_t bg = nearest_ansi(attr >> 18);
-
-    if(fg == CUCUL_DEFAULT || fg == CUCUL_TRANSPARENT)
-        fg = CUCUL_LIGHTGRAY;
-
-    if(bg == CUCUL_DEFAULT || bg == CUCUL_TRANSPARENT)
-        bg = CUCUL_BLACK;
-
-    return fg | (bg << 4);
-}
-
 uint16_t _cucul_attr_to_rgb12fg(uint32_t attr)
 {
     uint16_t fg = (attr >> 4) & 0x3fff;

cucul/cucul.h

@@ -121,6 +121,7 @@ int cucul_rotate(cucul_canvas_t *);
  *  These functions perform conversions between attribute values.
  *
  *  @{ */
+unsigned char cucul_attr_to_ansi(unsigned long int);
 unsigned char cucul_attr_to_ansi_fg(unsigned long int);
 unsigned char cucul_attr_to_ansi_bg(unsigned long int);
 /*  @} */

cucul/cucul_internals.h

@@ -57,13 +57,10 @@ extern unsigned int _cucul_strlen_utf8(char const *);
 extern char const *_cucul_skip_utf8(char const *, unsigned int);
 
 /* Colour functions */
-uint8_t _cucul_attr_to_ansi8(uint32_t);
-uint8_t _cucul_attr_to_ansi4fg(uint32_t);
-uint8_t _cucul_attr_to_ansi4bg(uint32_t);
-uint16_t _cucul_attr_to_rgb12fg(uint32_t);
-uint16_t _cucul_attr_to_rgb12bg(uint32_t);
-uint32_t _cucul_attr_to_rgb24fg(uint32_t);
-uint32_t _cucul_attr_to_rgb24bg(uint32_t);
-void _cucul_attr_to_argb4(uint32_t, uint8_t[8]);
+extern uint16_t _cucul_attr_to_rgb12fg(uint32_t);
+extern uint16_t _cucul_attr_to_rgb12bg(uint32_t);
+extern uint32_t _cucul_attr_to_rgb24fg(uint32_t);
+extern uint32_t _cucul_attr_to_rgb24bg(uint32_t);
+extern void _cucul_attr_to_argb4(uint32_t, uint8_t[8]);
 
 #endif /* __CUCUL_INTERNALS_H__ */