here it is!.
It's not a library, and i'm new in arduino and c languaje. Therefore the code will not be the best, i'm sure, but it works and display text with diferents fonts, in the desired position.
The problem with the "canton electronic" function is that it sends to the matrix a buffer matrix with two bits per pixel and reversed bit weight. I can't understand it enough to modify it for working with a bit per pixel and non reversed bytes.
Therefore, i paint the text (and another effects) in a more confortable matrix called "canvas" with the function:
textToCanvas(unsigned char *font,int fontHeight, int fontWidth, String message, int row, int column)
only one function to all the text sizes. (only tried with 6x5, 8x8 and 16x16, could be errors with other measures).
After that, i translate the canvas to reversed doble bit with translateCanvasToBuffer(). It moves and translate the canvas to the buffer before send it to the matrix.
And finally i send the buffer to the matrix with the original "canton electronics" function. I have added two params to this function, and the setup code, moved to a function for calling it from the main ino project.
There are two versions of this function , one for the arduino One, and another one for the arduino Mega. I only have an arduino mega, therefore i only tried the Mega version.
Despite this, you shouldn't have any problems with the UNO version. My code is equal in two cases, and i have done the same changes to the two "display_matrix" funtion versions.
I hope it works for you, and the code gives you ideas to paint another things to the matrix.
Dropbox link: