improve font handling

* macros established to build a table of fonts which get compiled into the image
* font data is mapped to irom0 to save dram space
* quirky function to retrieve font data 4-byte aligned from irom0

app/include/user_config.h

@@ -89,4 +89,13 @@
 #define LED_HIGH_COUNT_DEFAULT 10
 #define LED_LOW_COUNT_DEFAULT 0
 
+
+// Configure U8glib fonts
+// add a U8G_FONT_TABLE_ENTRY for each font you want to compile into the image
+#define U8G_FONT_TABLE_ENTRY(font)
+#define U8G_FONT_TABLE \
+    U8G_FONT_TABLE_ENTRY(font_6x10)  \
+    U8G_FONT_TABLE_ENTRY(font_chikita)
+#undef U8G_FONT_TABLE_ENTRY
+
 #endif	/* __USER_CONFIG_H__ */

app/modules/u8g.c

@@ -20,14 +20,30 @@ typedef struct lu8g_userdata
 
 
 // Font look-up array
-#define LU8G_FONT_6X10 0
+static const u8g_fntpgm_uint8_t *font_array[] =
-
-const static u8g_fntpgm_uint8_t *font_array[] =
 {
-    u8g_font_6x10
+#undef U8G_FONT_TABLE_ENTRY
+#define U8G_FONT_TABLE_ENTRY(font) u8g_ ## font ,
+    U8G_FONT_TABLE
+    NULL
 };
 
 
+// function to read 4-byte aligned from program memory AKA irom0
+u8g_pgm_uint8_t u8g_pgm_read(const u8g_pgm_uint8_t *adr)
+{
+    uint32_t iadr = (uint32_t)adr;
+    // set up pointer to 4-byte aligned memory location
+    uint32_t *ptr = (uint32_t *)(iadr & ~0x3);
+
+    // read 4-byte aligned
+    uint32_t pgm_data = *ptr;
+
+    // return the correct byte within the retrieved 32bit word
+    return pgm_data >> ((iadr % 4) * 8);
+}
+
+
 // helper function: retrieve and check userdata argument
 static lu8g_userdata_t *get_lud( lua_State *L )
 {
@@ -53,12 +69,10 @@ static int lu8g_setFont( lua_State *L )
 
     if ((lud = get_lud( L )) == NULL)
         return 0;
-    uint8_t stack = 2;
 
-    unsigned fontnr = luaL_checkinteger( L, stack );
+    lua_Integer fontnr = luaL_checkinteger( L, 2 );
-    stack++;
+    if ((fontnr >= 0) && (fontnr < (sizeof( font_array ) / sizeof( u8g_fntpgm_uint8_t ))))
-
+        u8g_SetFont( &(lud->u8g), font_array[fontnr] );
-    u8g_SetFont( &(lud->u8g), font_array[fontnr] );
 
     return 0;
 }
@@ -520,7 +534,13 @@ const LUA_REG_TYPE lu8g_map[] =
 {
     { LSTRKEY( "ssd1306_128x64_i2c" ), LFUNCVAL ( lu8g_ssd1306_128x64_i2c ) },
 #if LUA_OPTIMIZE_MEMORY > 0
-    { LSTRKEY( "font_6x10" ), LNUMVAL( LU8G_FONT_6X10 ) },
+    //{ LSTRKEY( "font_6x10" ), LNUMVAL( LU8G_FONT_6X10 ) },
+
+    // Register fonts
+#undef U8G_FONT_TABLE_ENTRY
+#define U8G_FONT_TABLE_ENTRY(font) { LSTRKEY( #font ), LNUMVAL( __COUNTER__ ) },
+    U8G_FONT_TABLE
+
     { LSTRKEY( "__metatable" ), LROVAL( lu8g_map ) },
 #endif
     { LNILKEY, LNILVAL }
@@ -540,8 +560,11 @@ LUALIB_API int ICACHE_FLASH_ATTR luaopen_u8g( lua_State *L )
     lua_setmetatable( L, -2 );
 
     // Module constants  
+
     // Register fonts
-    MOD_REG_NUMBER( L, "font_6x10", LU8G_FONT_6X10 ); 
+#undef U8G_FONT_TABLE_ENTRY
+#define U8G_FONT_TABLE_ENTRY(font) MOD_REG_NUMBER( L, #font, __COUNTER__ );
+    U8G_FONT_TABLE
 
     // create metatable
     luaL_newmetatable(L, "u8g.display");

app/u8glib/u8g.h

@@ -93,7 +93,7 @@ extern "C" {
 #endif
 
 #ifndef U8G_FONT_SECTION
-#  define U8G_FONT_SECTION(name)
+#  define U8G_FONT_SECTION(name) U8G_SECTION(".font_data." name)
 #endif
 
 
@@ -114,7 +114,8 @@ typedef uint8_t u8g_fntpgm_uint8_t;
 #define PROGMEM
 typedef uint8_t u8g_pgm_uint8_t;
 typedef uint8_t u8g_fntpgm_uint8_t;
-#define u8g_pgm_read(adr) (*(const u8g_pgm_uint8_t *)(adr)) 
+//#define u8g_pgm_read(adr) (*(const u8g_pgm_uint8_t *)(adr)) 
+u8g_pgm_uint8_t u8g_pgm_read(const u8g_pgm_uint8_t *adr);
 #define U8G_PSTR(s) ((u8g_pgm_uint8_t *)(s))
 
 #endif

app/u8glib/u8g_font_data.c

@@ -1,4 +1,3 @@
-#if 0
 /*
   Fontname: -FreeType-04b03b-Medium-R-Normal--8-80-72-72-P-39-ISO10646-1
   Copyright: 19992003 / yuji oshimoÿo / 04@dsg4.com / www.04.jp.org
@@ -1861,7 +1860,6 @@ const u8g_fntpgm_uint8_t u8g_font_5x8r[805] U8G_FONT_SECTION("u8g_font_5x8r") =
   64,240,2,71,87,48,64,32,192,32,64,48,34,22,86,128,
   128,128,128,128,128,2,71,87,192,32,64,48,64,32,192,6,
   66,82,80,160,255};
-#endif
 /*
   Fontname: -Misc-Fixed-Medium-R-Normal--10-100-75-75-C-60-ISO10646-1
   Copyright: Public domain terminal emulator font.  Share and enjoy.
@@ -1992,7 +1990,6 @@ const u8g_fntpgm_uint8_t u8g_font_6x10[1866] U8G_FONT_SECTION("u8g_font_6x10") =
   80,0,136,136,136,152,104,0,89,105,16,32,136,136,152,104,
   8,136,112,0,88,104,128,240,136,136,136,240,128,128,0,89,
   105,80,0,136,136,152,104,8,136,112};
-#if 0
 /*
   Fontname: -Misc-Fixed-Medium-R-Normal--10-100-75-75-C-60-ISO10646-1
   Copyright: Public domain terminal emulator font.  Share and enjoy.
@@ -88465,4 +88462,3 @@ const u8g_fntpgm_uint8_t u8g_font_unifontr[1485] U8G_FONT_SECTION("u8g_font_unif
   3,8,1,8,98,146,140,16,16,32,16,0,254,170,170,0,
   1,128,0,0,1,128,0,115,209,202,16,75,209,202,16,115,
   223,128,0,0,1,128,0,0,1,128,0,85,85};
-#endif

ld/eagle.app.v6.ld

@@ -72,6 +72,10 @@ SECTIONS
     *(.irom0.literal .irom.literal .irom.text.literal .irom0.text .irom.text)
     *(.literal.* .text.*)
     *(.rodata2.text)
+
+    /* put font data into irom0 */
+    *(.font_data.*)
+
     _irom0_text_end = ABSOLUTE(.);
     _flash_used_end = ABSOLUTE(.);
   } >irom0_0_seg :irom0_0_phdr