U8x8 rotate text by 90 degrees

[epeschier]

I am using U8x8 lib on a 64x128 display. The text comes out potrait (so 8 characters per line, 16 lines).
Is there a way to rotate by 90 degrees? So the text is displayed in landscape mode?
Oliver confirmed that there is no method currently but perhaps anyone has found a way to do this?

[olikraus]

I actually have an idea for a workaround. I will try this on the weekend.

[olikraus]

Created an issue for this topic: #2271

[olikraus]

I have created a demo on how to rotate strings by 90 in u8x8:

u8g2/sys/arduino/u8x8/Rotate90/Rotate90.ino

Lines 314 to 349 in f50cb99

	static uint8_t *rotate90(uint8_t *buf)
	{
	static uint8_t rbuf[8];
	uint8_t i, h;
	uint8_t *p;
	uint8_t j;
	for( i = 0; i < 8; i++)
	rbuf[i] = 0;
	for( i = 0; i < 8; i++ )
	{
	h = buf[i];
	p = rbuf;
	*p>>=1; *p |= (h&128); h <<= 1; p++;
	*p>>=1; *p |= (h&128); h <<= 1; p++;
	*p>>=1; *p |= (h&128); h <<= 1; p++;
	*p>>=1; *p |= (h&128); h <<= 1; p++;
	*p>>=1; *p |= (h&128); h <<= 1; p++;
	*p>>=1; *p |= (h&128); h <<= 1; p++;
	*p>>=1; *p |= (h&128); h <<= 1; p++;
	*p>>=1; *p |= (h&128); h <<= 1; p++;
	}
	return rbuf;
	}
	void u8x8_draw_glyph_90(u8x8_t *u8x8, uint8_t x, uint8_t y, uint8_t encoding)
	{
	static uint8_t buf[8];
	u8x8_get_glyph_data(u8x8, encoding, buf, 0);
	u8x8_DrawTile(u8x8, x, y, 1, rotate90(buf));
	}
	void u8x8_draw_string_90(u8x8_t *u8x8, uint8_t x, uint8_t y, const char *s)
	{
	while(*s != '\0')
	u8x8_draw_glyph_90(u8x8, x, y++, *s++);
	}

The latest u8g2 beta is required for this:

You can download the latest U8g2 beta release from here: https://github.com/olikraus/U8g2_Arduino/archive/master.zip
Arduino IDE:

1. Remove the existing U8g2_Arduino library (https://stackoverflow.com/questions/16752806/how-do-i-remove-a-library-from-the-arduino-environment)
2. Install the U8g2_Arduino Zip file via Arduino IDE, add zip library menu (https://www.arduino.cc/en/Guide/Libraries).

PlatformIO:
platformio.ini (https://docs.platformio.org/en/latest/projectconf/section_env_library.html#lib-deps) should include

lib_deps =
  u8g2=https://github.com/olikraus/U8g2_Arduino/archive/master.zip

[olikraus]

The example is also included in the latest beta.

[epeschier]

Works like a charm!
You only have to take into account that x and y are the same coordinates as when not rotating 90 degrees but you can do something like

u8x8_draw_string_90(u8x8->getU8x8(), MAX_LINES -y, x, text);

Thanks Olivier!