Adding a getTextWidth(char* text_buffer) function

[martinberlin]

To design stuff sometimes is great to know how much is the text width (Using font size) that you will draw. Lovyan has a function like this:

uint16_t getTextWidth(char* text_buffer);

@takkaO if you give me some pointers on how to do it I can add it myself. On another question: Is possible to speed up just a little bit the drawing? Tried with ESP32 at 80Mhz and also at 160Mhz, the difference is not noticeable, but still I like a lot to see how it draws the font from the binary TTF. Amazing work!

[Bodmer]

I have issued a pull request that speeds up rendering. This should work with any Adafruit_GFX API compatible library (drawFastHLine fn).

[Bodmer]

ESP32 renders example "load from binary" now reports 54ms (8 bit parallel interface). If the cache is valid for a repeat render then this reduces to 27ms, which is circa 1ms per character.

[martinberlin]

That's awesome. I'm using this primarily in some IT8951 (parallel epaper displays) but I'm sending data from ESP32S3 as fast I can per SPI. Will try and see if I can get more speed with your fix. But I'm using @lovyan03 Lovyan GFX as a controller library and they don't use Adafruit but their own GFX.

[takkaO]

@martinberlin

getTextWidth and getTextHeight methods have been added. However, if you need both width and height, it is recommended that you use the calculateBoundingBox or calculateBoundingBoxFmt method and get the bounding box instead. You can calculate width and height from bounding box and it is less computationally intensive that way.

[martinberlin]

Awesome work will try it before closing the ticket to give you feedback. Thanks a lot!

[martinberlin]

Thanks TakkaO working as expected. Still didn't try the calculateBoundingBox but I will soon!