Scrolling text cuts off 256 characters from end of string

Louis · November 3, 2020, 8:28am

This variable can only hold 0-255, so you’ll need to change it to a larger type, e.g. unsigned short or uint16_t:

pixelmatix/SmartMatrix/blob/master/src/Layer_Scrolling.h#L89


      
          
                  unsigned char textlen;
                  volatile int scrollcounter = 0;
                  const bitmap_font *scrollFont = &apple5x7;
          
                  int fontTopOffset = 1;
                  int fontLeftOffset = 1;
                  bool majorScrollFontChange = false;
          
                  bool ccEnabled = sizeof(RGB) <= 3 ? true : false;
                  ScrollMode scrollmode = bounceForward;
                  unsigned char framesperscroll = 4;
          
                  // these variables describe the text bitmap: size, location on the screen, and bounds of where it moves
                  unsigned int textWidth;
                  int scrollMin, scrollMax;
                  int scrollPosition;
          };
          
          #include "Layer_Scrolling_Impl.h"

I mentioned to you that SmartMatrix Library 4.0 has an optional new Layer for scrolling text, but it’s not optimized for your use case of scrolling really long strings. The Layer you’re using now allocates memory for the size of the screen. The new GFX Layer needs to allocate memory for the size of the graphics that will be displayed, and in your case a long string, with potentially a large font, could use a lot more memory. Just FYI in case you’re thinking of switching.