4. M5Paper text

M5Paper text

  • P

    When I use the code

    canvas1.createRender(100);
canvas1.setTextSize(100);

uur=random(23);
minuut=random(59);
seconde=random(59);
sprintf(charBuffer,"%02d:%02d:%02d",uur,minuut,seconde);
int nWidth = canvas1.textWidth(charBuffer);

    nWidth is zero. How can I get the width of a string?
    When I test is wihth :
    nWidth = canvas1.textWidth("test");
    the answer is sill zero.
    Any sugestion?

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  • Hello @Powersoft

    would you mind posting your complete code? I cannot compile the snippet you posted w/o errors.

    Thanks
    Felix

    0
  • M

    Are you using a freetype font?

    Looking at the source for textWidth, it does not support freetype fonts:

    int16_t TFT_eSPI::textWidth(const char *string, uint8_t font)
{
  int32_t str_width = 0;
  uint16_t uniCode  = 0;

#ifdef FREETYPE_FONT
  if((gfxFont == NULL) && _is_freetype_loaded && _use_freetype_font)
  {
    // TODO: Measure freetype width
    return 0;
  }
#endif
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  • M

    You can workaround this by using drawString instead, to an offscreen location.
    drawString returns the total width of the string drawn, and works for freetype fonts.

    int nWidth = canvas1.drawString(charBuffer,0,1000);
    0
    P
     2 Replies

  • It looks like you are trying to get information from the canvas before anything is written to the canvas which is why you are getting zero.
    As @murraypaul you need to query the data in the memory before it is drawn on the screen.

    0
  • P

    @murraypaul

    Thanks, have also take a look into the API documentation.
    Found the function drawString, but what is the meaning of "uint8_t font"

    Function: Draw string
    int16_t drawString(const char *string, int32_t poX, int32_t poY, uint8_t font)

    Thanks for any help.

    0
  • P

    @murraypaul
    Thanks for this.Was helpful

    0