1 files changed, 74 insertions, 0 deletions
diff --git a/src/gdisp/mcufont/mf_rlefont.h b/src/gdisp/mcufont/mf_rlefont.h
new file mode 100644
index 00000000..d8275d5c
--- /dev/null
+++ b/src/gdisp/mcufont/mf_rlefont.h
@@ -0,0 +1,74 @@
+/* A compressed font format based on run length encoding and dictionary
+ * compression.
+ */
+
+#ifndef _MF_RLEFONT_H_
+#define _MF_RLEFONT_H_
+
+#include "mf_font.h"
+
+/* Versions of the RLE font format that are supported. */
+#define MF_RLEFONT_VERSION_4_SUPPORTED 1
+
+/* Structure for a range of characters. This implements a sparse storage of
+ * character indices, so that you can e.g. pick a 100 characters in the middle
+ * of the UTF16 range and just store them. */
+struct mf_rlefont_char_range_s
+{
+    /* The number of the first character in this range. */
+    uint16_t first_char;
+    
+    /* The total count of characters in this range. */
+    uint16_t char_count;
+    
+    /* Lookup table with the start indices into glyph_data. */
+    const uint16_t *glyph_offsets;
+    
+    /* The encoded glyph data for glyphs in this range. */
+    const uint8_t *glyph_data;
+};
+
+/* Structure for a single encoded font. */
+struct mf_rlefont_s
+{
+    struct mf_font_s font;
+    
+    /* Version of the font definition used. */
+    const uint8_t version;
+    
+    /* Big array of the data for all the dictionary entries. */
+    const uint8_t *dictionary_data;
+    
+    /* Lookup table with the start indices into dictionary_data.
+     * Contains N+1 entries, so that the length of the entry can
+     * be determined by subtracting from the next offset. */
+    const uint16_t *dictionary_offsets;
+    
+    /* Number of dictionary entries using the RLE encoding.
+     * Entries starting at this index use the dictionary encoding. */
+    const uint8_t rle_entry_count;
+    
+    /* Total number of dictionary entries.
+     * Entries after this are nonexistent. */
+    const uint8_t dict_entry_count;
+    
+    /* Number of discontinuous character ranges */
+    const uint8_t char_range_count;
+    
+    /* Array of the character ranges */
+    const struct mf_rlefont_char_range_s *char_ranges;
+};
+
+#ifdef MF_RLEFONT_INTERNALS
+/* Internal functions, don't use these directly. */
+MF_EXTERN uint8_t mf_rlefont_render_character(const struct mf_font_s *font,
+                                              int16_t x0, int16_t y0,
+                                              mf_char character,
+                                              mf_pixel_callback_t callback,
+                                              void *state);
+
+MF_EXTERN uint8_t mf_rlefont_character_width(const struct mf_font_s *font,
+                                             mf_char character);
+#endif
+
+#endif