Generate C source text fonts for STM32Cube Fonts Utilities Driver.
For use with the BSP LCD driver for STM32xx-EVAL boards.
Refer to this project: TFT-CustomFonts
cd example
python3 ../stm32-font.py --font Menlo.ttc --size 32
Proportional fonts will have monospace-style spacing
cd example
python3 ../stm32-font.py --font 'Avenir Next.ttc' --size 20
Example shown is having chinese charsets
cd example-chinese
python3 ../stm32-font.py -f 'STHeiti Medium.ttc' -s 24 -c chinese-hello-world.txt
python3 ../stm32-font.py -f 'STHeiti Medium.ttc' -s 32 -c chinese-hello-world.txt
The main code for drawing chars on the LCD is inside stm32l073z_eval_lcd.c via the LCD_DrawChar function.
In the function, the font bytes are converted into a bitmap. However, the bitmap has a max size.
#define MAX_HEIGHT_FONT 17
#define MAX_WIDTH_FONT 24
/* Max size of bitmap will based on a font24 (17x24) */
static uint8_t bitmap[MAX_HEIGHT_FONT*MAX_WIDTH_FONT*2+OFFSET_BITMAP] = {0};
This means that that beyond 408 bytes (17x24), the fonts are not displayed at all.
For a simple fix, we can add the bitmap array locally in the function which has a dynamic size.
static void LCD_DrawChar(uint16_t Xpos, uint16_t Ypos, const uint8_t *pChar)
{
// ADDED
uint8_t *bitmap = calloc(DrawProp.pFont->Height * DrawProp.pFont->Width*2 + OFFSET_BITMAP, sizeof(uint8_t));
/* Original Code */
// ADDED
free(bitmap);
}
Another issue is that when generated font uses more than 3 bytes per row, the fonts will not display at all again.
if(((width + 7)/8) == 3)
{
line = (pchar[0]<< 16) | (pchar[1]<< 8) | pchar[2];
}
if(((width + 7)/8) == 2)
{
line = (pchar[0]<< 8) | pchar[1];
}
if(((width + 7)/8) == 1)
{
line = pchar[0];
}
This is because it is hardcoded for 1 to 3 bytes.
line is little-endian swapped order of pchar
Replace it with this which works for any number of bytes
int bytes = ((width + 7)/8);
line = 0;
for (int i = 0; i < bytes; i++) {
line <<= 8;
line |= pchar[i];
}
The changes are done accordingly in stm32l073z_eval_lcd_new.h. Copy it into the project
- if the width of the character exceeds 32 pixels or 32 bits, the font will be cut off to the left.