Generate new fonts¶

The Commercial edition allows to generate new fonts, to be used as header files or uploaded to an external SPI Flash.

The set of characters corresponds to the ISO 8859-1 or Latin 1 specification. The font example displays all the characters available.

Configure¶

sudo apt install php php-cli php-gd php-mbstring

The command installs PHP and other dependencies.

git clone  https://github.com/lvgl/lv_utils
cd lv_utils/
git reset --hard ec7d2676b36a27fa13b21162aca1476ad8456ec5

The commands download and install the utility from this repository and select this specific version.

Use¶

php font_conv_core.php "name=DejaVuSans28&font=DejaVuSans.ttf&height=28&bpp=1&uni_first=32&uni_last=255"

font_conv_core generates the font.

The parameters are

name sets the name of the generated C file;
font sets the name of the TTF font;
height selects the height in pixels;
bpp should be set to 1;
uni_first is set to 32 for space;
uni_last could be set to 127 or to 255 to include extended characters.

Rename the Font_DejaVuSans28.c file as Font_DejaVuSans28.cpp

$	`mv DejaVuSans28.c DejaVuSans28.cpp`

Create the corresponding header file Font_DejaVuSans28.h

// Configuration
#include "hV_Configuration.h"

// The Arduino IDE doesn't allow to select the libraries, hence this condition.
#if (FONT_MODE == USE_FONT_HEADER)

#ifndef DEJAVUSANS28FONT_RELEASE
#define DEJAVUSANS28FONT_RELEASE 507

#include "hV_Font.h"

#if (hV_FONT_HEADER_STRUCTURE_RELEASE < 507)

#error Required hV_FONT_HEADER_STRUCTURE_RELEASE 507

#endif // hV_FONT_HEADER_STRUCTURE_RELEASE

extern const font_s Font_DejaVuSans28;

#endif // DEJAVUSANS28FONT_RELEASE

#endif // FONT_MODE

Edit the Font_DejaVuSans28.cpp file and add at the beginning

// Configuration
#include "hV_Configuration.h"

// The Arduino IDE doesn't allow to select the libraries, hence this condition.
#if (FONT_MODE == USE_FONT_HEADER)

// Font_DejaVuSans28.h
#include "Font_DejaVuSans28.h"

Replace

static const uint8_t DejaVuSans28_glyph_bitmap[]

by

static const width_s Width_DejaVuSans28[] PLACE_IN_FRAM

The PLACE_IN_FRAM macro tells the compiler to locate the array in a specific region of memory, here upper-FRAM for the MSP430FR5994.

Replace

static const lv_font_glyph_dsc_t DejaVuSans28_glyph_dsc[]

by

static const uint8_t Table_DejaVuSans28[] PLACE_IN_FRAM

The PLACE_IN_FRAM macro tells the compiler to locate the array in a specific region of memory, here upper-FRAM for the MSP430FR5994.

Replace w_px and glyph_index on each entry

  {.w_px = 8, | .glyph_index = 0}, | /*Unicode: U+0020 ( )*/

by pixel and index

  {.pixel = 8, .index = 0}, | /*Unicode: U+0020 ( )*/

Finally, replace

lv_font_t DejaVuSans28 =
{
    .unicode_first = 32, /*First Unicode letter in this font*/
    .unicode_last = 255, /*Last Unicode letter in this font*/
    .h_px = 28, /*Font height in pixels*/
    .glyph_bitmap = DejaVuSans28_glyph_bitmap, /*Bitmap of glyphs*/
    .glyph_dsc = DejaVuSans28_glyph_dsc, /*Description of glyphs*/
    .glyph_cnt = 224, /*Number of glyphs in the font*/
    .unicode_list = NULL, /*Every character in the font from 'unicode_first' to 'unicode_last'*/
    .get_bitmap = lv_font_get_bitmap_continuous | /*Function pointer to get glyph's bitmap*/
    .get_width = lv_font_get_width_continuous, /*Function pointer to get glyph's width*/
    .bpp = 1, /*Bit per pixel*/
    .monospace = 0, /*Fix width (0: if not used)*/
    .next_page = NULL, /*Pointer to a font extension*/
};

by

const font_s Font_DejaVuSans28 =
{
    .kind = 0x20, // kind of font: Sans Serif
    .height = 28, // reference size, from source font
    .maxWidth = 23,
    .first = 32, // number of first character, usually 32
    .number = 224, // number of characters, usually 96 or 224
    .width = Width_DejaVuSans28, // characters widths and relative addresses
    .table = Table_DejaVuSans28 // characters definitions
};

with

kind: kind of font, to be set according to the table below;
height: height, set during font generation, set from h_px;
maxWidth: maximum width, to be calculated from the *width array;
first: first character, usually 32, set from h_px;
number: number of characters, usually 96 or 224, set from glyph_cnt or unicode_last - unicode_first + 1;
width: characters index and length in bytes, see * width array;
table: character definition, see * table array.

The kind of font is coded on 8 bits according to

Bit	Value	Content
`7`	`0x80`	High definition, 2 bits per pixel
`6`	`0x40`	Fixed Mono font
`5`	`0x20`	Proportional font, Sans Serif
`4`	`0x10`	Proportional font, Serif
`3`	`0x08`	Italic
`2`	`0x04`	Bold
`1`..`0`	`0x00`..`0x03`	Variant number

Example

0x20 refers to a proportional Sans Serif font.

Add at the end

#endif // FONT_MODE

Example¶

Header file Font_DejaVuSans28.h

// SDK
#include "hV_HAL_Peripherals.h"

// Configuration
#include "hV_Configuration.h"

#ifndef hV_FONT_HEADER_STRUCTURE_RELEASE
#define hV_FONT_HEADER_STRUCTURE_RELEASE 507

// The Arduino IDE doesn't allow to select the libraries, hence this condition.
#if (FONT_MODE == USE_FONT_HEADER)

struct width_s
{
    uint16_t pixel; ///< width in pixel
    uint16_t index; ///< relative address
};

struct font_s
{
    uint8_t kind; ///< font description
    uint8_t height; ///< general height in pixels
    uint8_t maxWidth; ///< maximum width in pixels from *width array
    uint8_t first; ///< number of first character, usually 32
    uint8_t number; ///< number of characters, usually 96 or 224
    const width_s * width; ///< characters widths and relative addresses
    const uint8_t * table; ///< characters definitions
};

#endif // USE_FONT_HEADER

#endif // hV_FONT_HEADER_STRUCTURE_RELEASE

Code file Font_DejaVuSans28.cpp

// Configuration
#include "hV_Configuration.h"

// The Arduino IDE doesn't allow to select the libraries, hence this condition.
#if (FONT_MODE == USE_FONT_HEADER)

// Font_DejaVuSans28.h
#include "Font_DejaVuSans28.h"

static const uint8_t Table_DejaVuSans28[] PLACE_IN_FRAM =
{
    /*Unicode: U+0020 ( ) , Width: 8 */
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........
    0x00,  //........

    /*Unicode: U+0021 (!) , Width: 2 */
    0x00,  //..
    0x00,  //..
    0x00,  //..
    0x00,  //..
    0xc0,  //%%
    0xc0,  //%%
    0xc0,  //%%
    0xc0,  //%%
    0xc0,  //%%
    0xc0,  //%%
    0xc0,  //%%
    0xc0,  //%%
    0xc0,  //%%
    0xc0,  //%%
    0xc0,  //%%
    0xc0,  //%%
    0x00,  //..
    0x00,  //..
    0x00,  //..
    0xc0,  //%%
    0xc0,  //%%
    0xc0,  //%%
    0x00,  //..
    0x00,  //..
    0x00,  //..
    0x00,  //..
    0x00,  //..
    0x00,  //..

    // ...

    /*Unicode: U+00ff (ÿ) , Width: 13 */
    0x00, 0x00,  //.............
    0x00, 0x00,  //.............
    0x00, 0x00,  //.............
    0x00, 0x00,  //.............
    0x0d, 0x80,  //....%%.%%....
    0x0d, 0x80,  //....%%.%%....
    0x00, 0x00,  //.............
    0x00, 0x00,  //.............
    0x00, 0x00,  //.............
    0xc0, 0x18,  //%%.........%%
    0x60, 0x30,  //.%%.......%%.
    0x60, 0x30,  //.%%.......%%.
    0x70, 0x70,  //.%%%.....%%%.
    0x30, 0x60,  //..%%.....%%..
    0x30, 0xe0,  //..%%....%%%..
    0x18, 0xc0,  //...%%...%%...
    0x18, 0xc0,  //...%%...%%...
    0x0d, 0x80,  //....%%.%%....
    0x0d, 0x80,  //....%%.%%....
    0x0f, 0x80,  //....%%%%%....
    0x07, 0x00,  //.....%%%.....
    0x07, 0x00,  //.....%%%.....
    0x06, 0x00,  //.....%%......
    0x06, 0x00,  //.....%%......
    0x0c, 0x00,  //....%%.......
    0x7c, 0x00,  //.%%%%%.......
    0x78, 0x00,  //.%%%%........
    0x00, 0x00,  //.............

};

static const width_s Width_DejaVuSans28[] PLACE_IN_FRAM =
{
    { .pixel = 8, .index = 0 }, /*Unicode: U+0020 ( )*/
    { .pixel = 2, .index = 28 }, /*Unicode: U+0021 (!)*/
    // ...
    { .pixel = 13, .index = 11592 }, /*Unicode: U+00ff (ÿ)*/
};

const font_s Font_DejaVuSans28 =
{
    .kind = 0x20, // kind of font: Sans Serif
    .height = 28, // reference size, from source font
    .maxWidth = 23,
    .first = 32, // number of first character, usually 32
    .number = 224, // number of characters, usually 96 or 224
    .width = Width_DejaVuSans28, // characters widths and relative addresses
    .table = Table_DejaVuSans28 // characters definitions
};

#endif // FONT_MODE

Next¶

Upload fonts to external SPI Flash