* Improved support for figlet fonts. We can now load them and print text.

Still no smushing, no hard blanks, no line wrapping...

src/figlet.c

@@ -20,19 +20,181 @@
 #if defined(HAVE_INTTYPES_H)
 #   include <inttypes.h>
 #endif
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 #include <cucul.h>
 
 #include "figlet.h"
 
+struct figfont
+{
+    /* From the font format */
+    unsigned char hardblank;
+    unsigned int height, baseline, max_length;
+    int old_layout;
+    unsigned int print_direction, full_layout, codetag_count;
+
+    unsigned int glyphs;
+    cucul_canvas_t *image;
+    unsigned int *lookup;
+};
+
+static struct figfont *open_font(char const *);
+static void free_font(struct figfont *);
+
 cucul_canvas_t *render_figlet(uint32_t const *string, unsigned int length,
                               char const *fontname)
 {
     cucul_canvas_t *cv;
+    struct figfont *font;
+    unsigned int x, i, c;
+
+    font = open_font(fontname);
+
+    cv = cucul_create_canvas(length * font->max_length, font->height);
+
+    for(x = 0, i = 0; i < length; i++)
+    {
+        for(c = 0; c < font->glyphs; c++)
+            if(font->lookup[c * 2] == string[i])
+                break;
+
+        if(c == font->glyphs)
+            continue;
 
+        cucul_blit(cv, x, - (int)(c * font->height), font->image, NULL);
 
+        x += font->lookup[c * 2 + 1];
+    }
+
+    free_font(font);
 
-    cv = cucul_create_canvas(3, 1);
-    cucul_putstr(cv, 0, 0, "LOL");
     return cv;
 }
 
+static struct figfont *open_font(char const *fontname)
+{
+    char *data = NULL;
+    char path[2048];
+    struct figfont *font;
+    cucul_buffer_t *b;
+    FILE *f;
+    unsigned int i, j, size, comment_lines;
+
+    /* Open font */
+    snprintf(path, 2047, "/usr/share/figlet/%s.flf", fontname);
+    path[2047] = '\0';
+    f = fopen(path, "r");
+    if(!f)
+    {
+        fprintf(stderr, "font `%s' not found\n", path);
+        return NULL;
+    }
+
+    font = malloc(sizeof(struct figfont));
+
+    /* Read header */
+    font->print_direction = 0;
+    font->full_layout = 0;
+    font->codetag_count = 0;
+    if(fscanf(f, "flf2a%c %u %u %u %i %u %u %u %u\n", &font->hardblank,
+              &font->height, &font->baseline, &font->max_length,
+              &font->old_layout, &comment_lines, &font->print_direction,
+              &font->full_layout, &font->codetag_count) < 6)
+    {
+        fprintf(stderr, "font `%s' has invalid header\n", path);
+        free(font);
+        fclose(f);
+        return NULL;
+    }
+
+    /* Skip comment lines */
+    for(i = 0; i < comment_lines; i++)
+    {
+        fscanf(f, "%*[^\n]");
+        fscanf(f, "%*c");
+    }
+
+    /* Read mandatory characters (32-127, 196, 214, 220, 228, 246, 252, 223)
+     * then read additional characters. */
+    font->glyphs = 0;
+    font->lookup = NULL;
+
+    for(i = 0, size = 0; !feof(f); font->glyphs++)
+    {
+        if((font->glyphs % 2048) == 0)
+            font->lookup = realloc(font->lookup,
+                                   (font->glyphs + 2048) * 2 * sizeof(int));
+
+        if(font->glyphs < 127 - 32)
+        {
+            font->lookup[font->glyphs * 2] = 32 + font->glyphs;
+        }
+        else if(font->glyphs < (127 - 32) + 7)
+        {
+            static int const tab[7] = { 196, 214, 220, 228, 246, 252, 223 };
+            font->lookup[font->glyphs * 2] = tab[font->glyphs = (127 - 32)];
+        }
+        else
+        {
+            fscanf(f, "%u %*[^\n]", &font->lookup[font->glyphs * 2]);
+            fscanf(f, "%*c");
+        }
+
+        font->lookup[font->glyphs * 2 + 1] = 0;
+
+        for(j = 0; j < font->height; j++)
+        {
+            if(i + 2048 >= size)
+                data = realloc(data, size += 2048);
+
+            fgets(data + i, 2048, f);
+            i = (uintptr_t)strchr(data + i, 0) - (uintptr_t)data;
+        }
+    }
+
+    fclose(f);
+
+    /* Import buffer into canvas */
+    b = cucul_load_memory(data, i);
+    font->image = cucul_import_canvas(b, "ansi");
+    cucul_free_buffer(b);
+    free(data);
+
+    /* Remove EOL characters. For now we ignore hardblanks, don’t do any
+     * smushing, nor any kind of error checking. */
+    for(j = 0; j < font->height * font->glyphs; j++)
+    {
+        unsigned long int ch, oldch = 0;
+
+        for(i = font->max_length; i--;)
+        {
+            ch = cucul_getchar(font->image, i, j);
+
+            if(ch == font->hardblank)
+                cucul_putchar(font->image, i, j, ' ');
+            else if(oldch && ch != oldch)
+            {
+                if(!font->lookup[j / font->height * 2 + 1])
+                    font->lookup[j / font->height * 2 + 1] = i + 1;
+            }
+            else if(oldch && ch == oldch)
+                cucul_putchar(font->image, i, j, ' ');
+            else if(ch != ' ')
+            {
+                oldch = ch;
+                cucul_putchar(font->image, i, j, ' ');
+            }
+        }
+    }
+
+    return font;
+}
+
+static void free_font(struct figfont *font)
+{
+    free(font->lookup);
+    free(font);
+}
+