* Updated documentation of fullwidth-aware functions.

* Fullwidth support in all exporters.

cucul/canvas.c

@@ -53,8 +53,7 @@
  *
  *  The behaviour when printing non-printable characters or invalid UTF-32
  *  characters is undefined. To print a sequence of bytes forming an UTF-8
- *  character instead of an UTF-32 character, use the cucul_putstr() function
- *  instead.
+ *  character instead of an UTF-32 character, use the cucul_putstr() function.
  *
  *  This function never fails.
  *
@@ -132,7 +131,12 @@ int cucul_putchar(cucul_canvas_t *cv, int x, int y, unsigned long int ch)
  *  as a UTF-32 value.
  *
  *  If the coordinates are outside the canvas boundaries, a space (0x20)
- *  is returned. FIXME: explain CUCUL_MAGIC_FULLWIDTH
+ *  is returned.
+ *
+ *  A special exception is when CUCUL_MAGIC_FULLWIDTH is returned. This
+ *  value is guaranteed not to be a valid Unicode character, and indicates
+ *  that the character at the left of the requested one is a fullwidth
+ *  character.
  *
  *  This function never fails.
  *
@@ -270,6 +274,9 @@ int cucul_clear_canvas(cucul_canvas_t *cv)
  *  - \c EINVAL A mask was specified but the mask size and source canvas
  *    size do not match.
  *
+ *  FIXME: this function may corrupt the canvas if fullwidth characters
+ *         appear at odd places.
+ *
  *  \param dst The destination canvas.
  *  \param x X coordinate.
  *  \param y Y coordinate.

cucul/export.c

@@ -224,6 +224,9 @@ static void export_utf8(cucul_canvas_t *cv, cucul_buffer_t *ex)
             uint32_t ch = linechar[x];
             uint8_t fg, bg;
 
+            if(ch == CUCUL_MAGIC_FULLWIDTH)
+                continue;
+
             fg = ((attr & 0xffff) == CUCUL_COLOR_DEFAULT) ?
                      0x10 : palette[_cucul_argb32_to_ansi4fg(attr)];
             bg = ((attr >> 16) == CUCUL_COLOR_TRANSPARENT) ?
@@ -298,6 +301,9 @@ static void export_ansi(cucul_canvas_t *cv, cucul_buffer_t *ex)
             uint8_t bg = palette[_cucul_argb32_to_ansi4bg(lineattr[x])];
             uint32_t ch = linechar[x];
 
+            if(ch == CUCUL_MAGIC_FULLWIDTH)
+                ch = '?';
+
             if(fg != prevfg || bg != prevbg)
             {
                 cur += sprintf(cur, "\033[0;");
@@ -377,7 +383,9 @@ static void export_html(cucul_canvas_t *cv, cucul_buffer_t *ex)
                 x + len < cv->width && lineattr[x + len] == lineattr[x];
                 len++)
             {
-                if(linechar[x + len] <= 0x00000020)
+                if(linechar[x + len] == CUCUL_MAGIC_FULLWIDTH)
+                    ;
+                else if(linechar[x + len] <= 0x00000020)
                     cur += sprintf(cur, "&nbsp;");
                 else if(linechar[x + len] < 0x00000080)
                     cur += sprintf(cur, "%c",
@@ -450,7 +458,9 @@ static void export_html3(cucul_canvas_t *cv, cucul_buffer_t *ex)
 
             for(i = 0; i < len; i++)
             {
-                if(linechar[x + i] <= 0x00000020)
+                if(linechar[x + i] == CUCUL_MAGIC_FULLWIDTH)
+                    ;
+                else if(linechar[x + i] <= 0x00000020)
                     cur += sprintf(cur, "&nbsp;");
                 else if(linechar[x + i] < 0x00000080)
                     cur += sprintf(cur, "%c", (unsigned char)linechar[x + i]);
@@ -511,6 +521,9 @@ static void export_irc(cucul_canvas_t *cv, cucul_buffer_t *ex)
             uint8_t bg = palette[_cucul_argb32_to_ansi4bg(attr)];
             uint32_t ch = linechar[x];
 
+            if(ch == CUCUL_MAGIC_FULLWIDTH)
+                continue;
+
             if((attr & 0xffff) == CUCUL_COLOR_DEFAULT)
                 fg = 0x10;
 
@@ -697,7 +710,8 @@ static void export_svg(cucul_canvas_t *cv, cucul_buffer_t *ex)
     cur += sprintf(cur, svg_header, cv->width * 6, cv->height * 10,
                                     cv->width * 6, cv->height * 10);
 
-    cur += sprintf(cur, " <g id=\"mainlayer\" font-size=\"12\">\n");
+    cur += sprintf(cur, " <g id=\"mainlayer\" font-size=\"10\""
+                        " style=\"font-family: monospace\">\n");
 
     /* Background */
     for(y = 0; y < cv->height; y++)
@@ -723,10 +737,17 @@ static void export_svg(cucul_canvas_t *cv, cucul_buffer_t *ex)
         {
             uint32_t ch = *linechar++;
 
+            if(ch == ' ' || ch == CUCUL_MAGIC_FULLWIDTH)
+            {
+                lineattr++;
+                continue;
+            }
+
             cur += sprintf(cur, "<text style=\"fill:#%.03x\" "
                                 "x=\"%d\" y=\"%d\">",
                                 _cucul_argb32_to_rgb12fg(*lineattr++),
-                                x * 6, (y * 10) + 10);
+                                x * 6, (y * 10) + 8);
+
             if(ch < 0x00000020)
                 *cur++ = '?';
             else if(ch > 0x0000007f)