Read truetype(.ttf) from FS(ex. SD/SPIFFS/FATFS) and write framebuffer.
- Read TrueType files ('cmap' format4).
- Write any string to the user's framebuffer.
- Supports "Simple glyphs" and part of "Compound glyphs".
- Set font size, position, color, spacing, Rotate.
- Centered and right aligned strings. By getting the length of the string.
- Read the 'kern' table (format0) and kerning.
- Beautifully arrange characters based on the 'hmtx' table.
The native library for STM32 is here.
//TrueType class declaration
truetypeClass truetype = truetypeClass();
uint8_t *framebuffer;
void setup() {
//Prepare a frame buffer
framebuffer = (uint8_t *)calloc(sizeof(uint8_t), FRAMEBUFFER_SIZE);
//Read TrueType file
//Example in SPIFFS
//I think that SD, FATFS and other codes will be almost the same
SPIFFS.begin(true);
File fontFile = SPIFFS.open("/FONTFILE.ttf", "r");
//Set framebuffer array in TrueType class
//Pay attention to the format of the framebuffer
truetype.setFramebuffer(DISPLAY_WIDTH, DISPLAY_HEIGHT, 4, 0, framebuffer);
//Initial reading of ttf files
if (!truetype.setTtfFile(fontFile)) {
Serial.println("read ttf failed");
return;
}
//TrueType class string parameter settings
truetype.setCharacterSize(100);
truetype.setCharacterSpacing(0);
truetype.setTextBoundary(10, DISPLAY_WIDTH, DISPLAY_HEIGHT);
truetype.setTextColor(0x00, 0x00);
//Write a string to the framebuffer
truetype.textDraw(10, 10, "The quick brown fox jumps over the lazy dog");
//Export framebuffer to screen
FLASH_TO_SCREEN();
//end
truetype.end();
}
-
uint8_t setTtfFile(File _file, uint8_t _checkCheckSum = 0);
- Set the ttf file read from SD, SPIFFS, FATFS, etc.
- File _file : ttf file.
- Return : 1 = read successful, 0 = read failure.
-
void setFramebuffer(uint16_t _framebufferWidth, uint16_t _framebufferHeight, uint16_t _framebuffer_bit, uint8_t _framebufferDirection, uint8_t *_framebuffer);
- Framebuffer settings.
- uint16_t _framebufferWidth : Framebuffer width.
- uint16_t _framebufferHeight : Framebuffer eight.
- uint16_t _framebuffer_bit : The number of bits per pixel. (1,4,8bit implemented)
- uint8_t _framebufferDirection : Bit orientation.
- uint8_t *_framebuffer : Framebuffer pointer.
- If you want it to correspond to your own framebuffer, edit the addPixel function. If you add code, please share it!
-
void setCharacterSpacing(int16_t _characterSpace, uint8_t _kerning = 1);
- Setting the width between characters.
- int16_t _characterSpace : Width value between characters.
- uint8_t _kerning : Read and use ttf 'kern' table. 1:'kern' + _characterSpace. 0: _characterSpace.
-
void setCharacterSize(uint16_t _characterSize);
- Font size setting.
- uint16_t _characterSize : Character height.
-
void setTextBoundary(uint16_t _start_x, uint16_t _end_x, uint16_t _end_y);
- Setting the string range.
- Coordinate axes rotate with "setTextRotation"
- uint16_t _start_x : The starting point x of the character string when a line break occurs.
- uint16_t _end_x : The final point x when breaking a line.
- uint16_t _end_y : The final point y when breaking a line.
- Setting the string range.
-
void setTextColor(uint8_t _onLine, uint8_t _inside);
- Text color setting.
- uint8_t _onLine : Character outline color.
- uint8_t _inside : Text fill color.
-
void setTextRotation(uint8_t _rotation);
- Text rotation
- Rotate along with the coordinate axes. The image is the following image.
- Text rotation
-
uint8_t _rotation : rotation angle.
- (ROTATE_0/ROTATE_90/ROTATE_180/ROTATE_270)
-
void textDraw(uint16_t _x, uint16_t _y, const wchar_t _character[]);
- Write a string to the framebuffer.
- uint16_t _x : String start point x.
- uint16_t _y : String start point y.
- const wchar_t _character[] : String pointer (double-byte character).
-
void textDraw(uint16_t _x, uint16_t _y, const char _character[]);
- Write a string to the framebuffer.
- uint16_t _x : String start point x.
- uint16_t _y : String start point y.
- const char _character[] : String pointer (single-byte character).
-
void textDraw(uint16_t _x, uint16_t _y, const String _string);
- Write a string to the framebuffer.
- uint16_t _x : String start point x.
- uint16_t _y : String start point y.
- const String _string : String pointer (String type).
-
uint16_t getStringWidth(const wchar_t _character[]);
- const wchar_t _character[] : String pointer (double-byte character).
- Return : The length of the string. Automatic line breaks are not considered.
- Can be used for text align center/right.
-
uint16_t getStringWidth(const char _character[]);
- const char _character[] : String pointer (single-byte character).
- Return : The length of the string. Automatic line breaks are not considered.
- Can be used for text align center/right.
-
uint16_t getStringWidth(const String _string);
- const String _string : String pointer (String type).
- Return : The length of the string. Automatic line breaks are not considered.
- Can be used for text align center/right.
-
void end();
- Close font file.
Bit orientation when storing information for multiple pixels per byte of the framebuffer.
The types of framebuffers are broadly divided according to this direction.
Currently supported: Horizontal - 1,4,8bit
- Fixed problem that some font files could not be read.
- Handling Bezier curves.
- It supports up to 3rd order Bezier curves, but 4th order and above are drawn as straight lines.
- Outline color and the fill color can be set individually.
- Supports writing to arrays. Fonts are drawn in some form of framebuffer(uint8_t array).
- Kerning by reading the 'kern' table.
- Read 'hmtx' table and adjust layout.
- Efficient filling process.
- Full support for "Compound glyphs"
- Diversification of supported framebuffer formats.
- Only support for 'cmap' format 4 and 'kern' format0 is supported.
- Correction that some files can not be read.
- Unable to read ttf file if file name is long(STM32F103).
- Faster glyph reading.
- Decrease usage of SRAM.
- Handling of Bezier curve(When exceeding 3 dimensions. Currently, provisional processing).
- Text from the right
- Underline
- Full color
- Mono
Feel free to post any bugs or ideas for fixes and improvements!
Confirm the copyright of the font file. I did not distribute font files.
It is based on the code by garretlab and changed.
https://github.com/garretlab/truetype
https://garretlab.web.fc2.com/arduino/lab/truetype/