u8gvsu8g2

• U8g vs. U8g2
  • Improvements
  • How to port U8g code?

U8g vs. U8g2

Improvements

• Full "RAM" memory buffer without picture loop
• Arduino SPI and TWI Libraries instead of custom code
• Support for Unicode and UTF-8
• Faster compilation
• High speed text only API (U8x8)
• Hardware 180 degree rotation for some displays available
• Tested with AVR, SAM and ESP8266 boards

How to port U8g code?

Major Changes (Code rework required)

• The name of the include file has changed: Use #include "U8g2lib.h"
• The native type for pixel coordinates has changed to u8g2_uint_t. Use the following line to redefine this at the beginning of your code typedef u8g2_uint_t u8g_uint_t;
• Old Arduino IDE 00xx (before 1.00) is not supported any more. ARDUINO macro must be >= 100
• begin() must be called (this was optional in U8glib)
• Constructor contains name of communicaton interface and also contains the display orientation as first argument.
• u8g2.drawStr90 does not exist any more, use u8g2_SetFontDirection()
• "P" versions of the string functions are not yet implemented. This includes drawStrP(), getStrWidthP(), etc Use the print function with the F() macro instead. See also the PrintHelloWorld and PrintProgmem examples.
• In U8glib font transparency was defined in the begin() statement. This is now handled by setFontMode().
• U8G_PROGMEM is now called U8X8_PROGMEM.
• Screen rotation is handled by the constructor in U8g2. The functions undoRotation, setRot90, setRot180 and setRot270 are replaced by the first argument of the U8g2 constructor.
• Screen scaling is not there in u8g2. This is completly removed, there are no corresponding function in u8g2 for undoScale() and setScale2x2().
• setColorEntry(), setHiColor(), setHiColorByRGB(), setRGB: Not supported any more (u8g2 focus are monochrome displays, use Ucglib instead)
• getMode(): Is not available any more because there is only one monochrome mode.
• setDefaultForegroundColor(), setDefaultBackgroundColor() and setDefaultMidColor() are not required any more. These functions do not exist in U8g2. Use setDrawColor() instead.
• getFontLineSpacing() and setFontLineSpacingFactor() are not supported any more. Instead you can get the line spacing by calculating the difference getAscent()-getDescent().
• getStrPixelWidth() is replaced by getStrWidth()
• setHardwareBackup() not supported any more (and hopefully not required any more).
• Cursor functions are not available. This includes: setCursorFont(), setCursorStyle(), setCursorPos(), setCursorColor(), enableCursor(), disableCursor(), drawCursor()
• Virtual screen handling is not supported: setVirtualScreenDimension(), addToVirtualScreen()

Minor Changes (Code update might be required)

• U8g2 drawTriangle() expects signed arguments (u8glib expects unsigned arguments)
• U8g2 has different font names. Some of the old font names are known to u8g2 and are mapped automatically. If the font name is unknown, please choose a different font from the font list.

Change Notes (No code change required)

• sleepOn(), sleepOff(): supported, but better use setPowerSave()
• setColorIndex() and getColorIndex() are renamed to setDrawColor() and getDrawColor(). The old names are still supported.

• getFontAscent() and getFontDescent() are renamed to getAscent() and getDescent() The old names are still supported.
• Signal names are renamed in the constructor calls:

U8glib	U8g2
U8glib sck	U8g2 clock
U8glib mosi	U8g2 data
U8glib a0	U8g2 dc

• getHeight() renamed to getDisplayHeight(), old name still exists
• getWidth() renamed to getDisplayWidth(), old name still exists