【E115】为STM32xx EVAL的LCD驱动程序生成文本字体

项目编号：E115

文件大小：3.8M

源码说明：带中文注释

开发环境：C编译

简要概述：

为STM32Cube字体实用程序驱动程序生成C源文本字体。

用于STM32xx评估板的BSP LCD驱动程序。

生成字体的示例

Monospace fonts

cd example

python3 ../stm32-font.py --font Menlo.ttc --size 32

Proportional font

Proportional fonts will have monospace-style spacing

cd example

python3 ../stm32-font.py --font 'Avenir Next.ttc' --size 20

Other charsets

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 

Adding fonts into project

Fixing the BSP library (Part 1)

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);

}

Fixing the BSP library (Part 2)

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

Additional Unsolved Bugs

if the width of the character exceeds 32 pixels or 32 bits, the font will be cut off to the left.

文件列表：

目录│文件列表:

 └ STM32-LCD_Font_Generator

    │ preview.jpg

    │ stm32-font.py

    │ stm32l073z_eval_lcd_new.h

    ├ example

    │  │ FontAvenirNext20.h

    │  │ FontAvenirNext20.png

    │  │ FontComicSansMS20.h

    │  │ FontComicSansMS20.png

    │  │ FontMenlo32.h

    │  └ FontMenlo32.png

    ├ example-chinese

    │  │ chinese-hello-world.txt

    │  │ FontHeitiTC24.h

    │  │ FontHeitiTC24.png

    │  │ FontHeitiTC32.h

    │  │ FontHeitiTC32.png

    │  │ FontHeitiTC40.h

    │  └ FontHeitiTC40.png

    ├ example-korean

    │  │ FontKorean32.h

    │  │ FontKorean32.png

    │  └ korean-hello-world.txt

    └ example-tamil

       │ FontTamilMN22.h

       │ FontTamilMN22.png

       └ tamil-hello-world.txt