Overview

• This is my attempt at understanding and documenting everything in the LCD driver as well as writing a simple graphics library
• Currently the main driver is comprehensively commented with as much as I can work out
• Code is based on the Adafruit library, detailed here

Documentation

Usage

• #include "lcd/graphics.h"
• All graphics functions are prepended with "gr"
• Some functions, for example grFillRect are just wrappers around the lcd.h functions
• The coord struct is used to wrap an x and y coordinate (accessed with (coord) c.x and (coord) c.y)
• To initialise the display, call grInit(orientation orn, colour fg, colour bg)
  • This takes an orientation and a default foreground and background colour for the display (unused)
  • This must be done before any of the other graphics functions are called

Lines

• grDrawLine(coord p1, coord p2, colour color) takes two coords and a colour
• It draws a line from the first coord to the second
• grDrawHLine(coord pos, uint16_t width, colour col) and grDrawVLine(coord pos, uint16_t height, colour col) draw horizontal and vertical lines respectively
  • Both take a coord of the starting point, and a width or height accordingly (as well as a colour)

Rectangles

• grDrawRect(coord pos, uint16_t width, uint16_t height, uint8_t lineWidth, colour fg, colour bg) takes an origin position coord, a width and a height, a line draw width and a foreground and background colour
• The rectangle drawn has its top-left corner in the origin position, and the line width is determined by the lineWidth argument
• grFillRect(coord pos, uint16_t width, uint16_t height, colour col) takes an origin position coord, a width and height and a colour, and draws a filled rectangle similar to grDrawRect
• grDrawRoundedRect(coord pos, uint16_t width, uint16_t height, uint16_t radius, colour col) is similar to grDrawRect but it takes a radius argument which determines the radius of the rectangles corners
• grFillRoundedRect(coord pos, uint16_t width, uint16_t height, uint16_t radius, colour col) is equivalent to above except the rectangle is filled

Circles

• grDrawCircle(coord pos, uint16_t radius, colour col) takes a center position coord, a radius and a colour
• grFillCircle(coord pos, uint16_t radius, colour col) is equivalent to above except the circle is filled

Triangles

• grDrawTriangle(coord p1, coord p2, coord p3, colour col) takes three points and a colour, and draws a triangle accordingly
• grFillTriangle(coord p1, coord p2, coord p3, colour color) is equivalent to above except it fills the triangle

Text

• grWriteString(coord pos, char* string, colour fg, colour bg) takes an origin position (again top-left corner of text), a char* containing the text, and a foreground and background colour for the text

Other Stuff

• grClearDisplay() clears the display
• RGB_CONVERT(r, g, b) takes three bytes for red, green and blue and converts them to a colour (uint16_t) for use with the display