Screen

Introduction

The VEX IQ (2nd gen) Brain screen provides a variety of methods to display information, draw shapes, and control the visual elements of the screen.

This page uses brain as the example Brain name. Replace it with your own configured name as needed.

Below is a list of all methods:

Cursor Print — Place and print text.

• print — Prints text at the current cursor position.

• set_cursor — Sets the cursor to a specific row and column.

• next_row — Moves the cursor to column 1 of the next row.

• clear_row — Clears a row of text.

• row — Returns the current cursor row.

• column — Returns the current cursor column.

• print_at — Prints text at a specific x and y location.

• get_string_width — Returns the width of a string.

• get_string_height — Returns the height of a string.

Mutators — Change screen settings, colors, and drawing behavior.

• clear_screen — Clears the screen of all drawings and text.

• set_font — Sets the font for printed text.

• set_pen_width — Sets the thickness for drawn shapes and lines.

• set_pen_color — Sets the color for outlines and text.

• set_fill_color — Sets the fill color for shapes and backgrounds.

• set_origin — Sets a new origin for printing and drawing.

Draw — Add graphics to the screen.

• draw_pixel — Draws a pixel at a specific x and y location.

• draw_line — Draws a line between two points.

• draw_rectangle — Draws a rectangle.

• draw_circle — Draws a circle.

• set_clip_region — Restricts where drawings and text can appear.

• render — Updates the Brain’s screen with text and drawings only when called.

Cursor Print

print

print displays text on the Brain’s screen at the current cursor position and font.

Usage:
brain.screen.print(text, precision, opaque)

Parameters	Description
text	The text, number, or variable value to display on the screen.
precision	Optional. The number of decimal places to display when displaying numbers. This must be written as a keyword argument, ie:precision=3. Default is 2.
opaque	Optional. opaque=True — The background of the text will be filled with the current fill color or black by default. opaque=False (default) — The background of the text will match the screen’s background color.

# Display a message at the starting 
# cursor position
brain.screen.print("Hello, Robot!")

# Display a percentage with 4 decimal 
# places and a blue background
brain.screen.set_fill_color(Color.BLUE)
brain.screen.print((42/100), precision = 4, opaque = True)

set_cursor

set_cursor sets the cursor at a specific row and column on the Brain’s screen. How many rows and columns can comfortably fit depends on the selected font.

Monospaced fonts have characters that are all the same width, making text placement consistent. In contrast, proportional fonts vary in character width, so some letters take up more space than others. However, regardless of which type is used, set_cursor positions the cursor based on row and column size, not font style. The font size can be adjusted using set_font.

Usage:
brain.screen.set_cursor(row, column)

Parameters	Description
row	The row of the cursor.
column	The column of the cursor.

# Repeatedly print the Brain's timer at 
# the top left of the screen
while True:
    brain.screen.print(brain.timer.time(SECONDS))
    brain.screen.next_row()
    wait(1, SECONDS)
    brain.screen.clear_screen()
    brain.screen.set_cursor(1, 1)

next_row

next_row moves the cursor to column 1 on the next row on the Brain’s screen.

Usage:
brain.screen.next_row()

Parameters	Description
	This method has no parameters.

# Display two lines of text
brain.screen.print("Line 1")
brain.screen.next_row()
brain.screen.print("Line 2")

clear_row

clear_row clears a row of drawings and text on the Brain’s screen.

Usage:
brain.screen.clear_row(row, color)

Parameters	Description
row	Optional. The row to clear. The default is the current cursor row.
color	Optional. The color to apply to the cleared row. Options include: Color.BLACK Color.BLUE Color.BLUE_GREEN Color.BLUE_VIOLET Color.GREEN Color.ORANGE Color.PURPLE Color.RED COLOR.RED_ORANGE Color.RED_VIOLET Color.VIOLET Color.WHITE Color.YELLOW Color.YELLOW_GREEN Color.YELLOW_ORANGE You can also specify a custom color.

# Display text on two rows
brain.screen.print("This text stays")
brain.screen.next_row()
brain.screen.print("This disappears")

# Wait 3 seconds before clearing 
# only the second row
wait(3, SECONDS)
brain.screen.clear_row()

# Turn the 5th row green
brain.screen.clear_row(5, Color.GREEN)

row

row returns the current row where text will be printed as an integer.

Usage:
brain.screen.row()

Parameters	Description
	This method has no parameters.

# Set cursor to (3,2) and print 
# row number
brain.screen.set_cursor(3, 2)
brain.screen.print(brain.screen.row())

column

column returns the current column where text will be printed as an integer.

Usage:
brain.screen.column()

Parameters	Description
	This method has no parameters.

# Set cursor to (3,2) and print 
# column number
brain.screen.set_cursor(3, 2)
brain.screen.print(brain.screen.column())

print_at

print_at displays text on the Brain’s screen at a specified x and y-coordinate (in pixels) with the currently set font and set origin. This method disregards the current cursor position.

Usage:
brain.screen.print_at(text, x, y, precision, opaque)

Parameters	Description
text	The text to print.
x	The x position to print at as a keyword argument, ie: x=, referenced to the screen origin.
y	The y position to print at as a keyword argument, ie: y=, referenced to the screen origin.
precision	Optional. The number of decimal places to display when displaying numbers. This must be written as a keyword argument, ie:precision=3. Default is 2.
opaque	Optional. opaque=True — The background of the text will be filled with the current fill color or black by default. opaque=False (default) — The background of the text will match the screen’s background color.

# Print the number 1 on the Brain's screen at position (100, 40)
brain.screen.print_at(1, x=100, y=40)

# Display 1/3 with 3 decimal places and a blue background
brain.screen.set_fill_color(Color.BLUE)
brain.screen.print_at((1/3), x=100, y=40, precision=3, opaque=True)

get_string_width

get_string_width returns the width of a string in pixels, as it would appear on the Brain’s screen. The width varies depending on the string’s length and the current font.

Usage:
brain.screen.get_string_width(string)

Parameters	Description
string	The string to measure.

get_string_height

get_string_height returns the height of a string in pixels, as it would appear on the Brain’s screen. The width varies depending on the string’s length and the current font.

Usage:
brain.screen.get_string_height(string)

Parameters	Description
string	The string to measure.

Mutators

clear_screen

clear_screen clears all drawings and text from the Brain’s screen.

Usage:
brain.screen.clear_screen(color)

Parameters	Description
color	Optional. Sets the screen color. Options include: Color.BLACK Color.BLUE Color.BLUE_GREEN Color.BLUE_VIOLET Color.GREEN Color.ORANGE Color.PURPLE Color.RED COLOR.RED_ORANGE Color.RED_VIOLET Color.VIOLET Color.WHITE Color.YELLOW Color.YELLOW_GREEN Color.YELLOW_ORANGE You can also specify a custom color.

# Draw a circle and clear it after 
# 2 seconds
brain.screen.draw_circle(80, 50, 20)
wait(2, SECONDS)
brain.screen.clear_screen()

# Turn the screen red
brain.screen.clear_screen(Color.RED)

set_font

set_font sets the font used for displaying text on the Brain’s screen. This font will apply to all text printed with print or print_at. The default font at the start of a project is MONO20.

Usage:
brain.screen.set_font(fontname)

Parameter	Description
fontname	Sets the font to one of the following: MONO12 MONO15 MONO20 MONO30 MONO40 MONO60 PROP20 PROP30 PROP40 PROP60 These options are shown below.

MONO12	MONO15	MONO20
MONO30	MONO40	MONO60
PROP20	PROP30	PROP40
PROP60

# Display two different fonts on 
# two separate lines
brain.screen.set_font(FontType.MONO20)
brain.screen.print("Mono Medium")
brain.screen.next_row()
brain.screen.set_font(FontType.PROP20)
brain.screen.print("Prop Medium")

set_pen_width

set_pen_width sets the pen width used for drawing lines and shapes.

Usage:
brain.screen.set_pen_width(width)

Parameter	Description
width	The pen width, given as an integer in pixels in a range from 0 to 32.

# Draw two circles with 
# different pen widths
brain.screen.draw_circle(40, 70, 20)
brain.screen.set_pen_width(5)
brain.screen.draw_circle(100, 70, 20)

set_pen_color

set_pen_color sets the pen color used for drawing lines, shapes, and text.

Usage:
brain.screen.set_pen_color(color)

Parameter	Description
color	Optional. Sets the pen color. Options include: Color.BLACK Color.BLUE Color.BLUE_GREEN Color.BLUE_VIOLET Color.GREEN Color.ORANGE Color.PURPLE Color.RED COLOR.RED_ORANGE Color.RED_VIOLET Color.VIOLET Color.WHITE Color.YELLOW Color.YELLOW_GREEN Color.YELLOW_ORANGE You can also specify a custom color.

# Draw two rectangles with 
# different colors
brain.screen.draw_rectangle(100, 50, 10, 20)
brain.screen.set_pen_color(Color.BLUE)
brain.screen.draw_rectangle(50, 50, 10, 20)

set_fill_color

set_fill_color method sets the fill color used when shapes are drawn.

Usage:
brain.screen.set_fill_color(color)

Parameter	Description
color	Optional. Sets the fill color. Options include: Color.BLACK Color.BLUE Color.BLUE_GREEN Color.BLUE_VIOLET Color.GREEN Color.ORANGE Color.PURPLE Color.RED COLOR.RED_ORANGE Color.RED_VIOLET Color.VIOLET Color.WHITE Color.YELLOW Color.YELLOW_GREEN Color.YELLOW_ORANGE You can also specify a custom color.

# Draw a yellow circle
brain.screen.set_fill_color(Color.YELLOW)
brain.screen.draw_circle(50, 50, 20)

set_origin

set_origin sets the origin (0,0) used for drawing or printing on the Brain’s screen. By default, drawing or printing methods consider the top left corner of the screen as the origin. This method can reset the origin to an alternate (x, y) screen coordinate location.

Usage:
brain.screen.set_origin(x, y)

Parameter	Description
x	The new x-coordinate to set as the origin, given as an integer from 0 to 160.
y	The new y-coordinate to set as the origin, given as an integer from 0 to 108.

# Draw a line with the origin set to (50, 50)
brain.screen.set_origin(50, 50)
brain.screen.draw_line(1, 1, 159, 107)

Draw

draw_pixel

draw_pixel draws a pixel at the specified (x, y) screen coordinate in the current pen color. It uses the current pen color set by set_pen_color.

Usage:
brain.screen.draw_pixel(x, y)

Parameter	Description
x	The x-coordinate where the pixel will be drawn, given as an integer from 0 to 160.
y	The y-coordinate where the pixel will be drawn, given as an integer from 0 to 108.

# Draw one pixel at the center 
# of the screen
brain.screen.draw_pixel(80, 50)

draw_line

draw_line draws a line from the first specified screen coordinate (x1, y1) to the second specified screen coordinate (x2, y2). It uses the current the pen width set by set_pen_width and pen color set by set_pen_color.

The x and y-coordinates use the default origin of (0, 0) unless a different origin has been set using set_origin.

Usage:
brain.screen.draw_line(x1, y1, x2, y2)

Parameter	Description
x1	The starting x-coordinate of the line, given as an integer from 0 to 160.
y1	The starting y-coordinate of the line, given as an integer from 0 to 108.
x2	The ending x-coordinate of the line, given as an integer from 0 to 160.
y2	The ending y-coordinate of the line, given as an integer from 0 to 108.

# Draw a line from the top left to 
# bottom right of the screen
brain.screen.draw_line(0, 0, 159, 107)

draw_rectangle

draw_rectangle draws a rectangle with its top-left corner at the specified (x, y) coordinate and a size determined by the given width and height, all measured in pixels. The rectangle’s outline is drawn using the current pen width set by set_pen_width and the pen color set by set_pen_color. The interior is filled with the color set by set_fill_color.

The x and y-coordinates use the default origin of (0,0) unless a different origin has been set using set_origin.

Usage:
brain.screen.draw_rectangle(x, y, width, height, color)

Parameter	Description
x	The x-coordinate of the top-left corner of the rectangle, given as an integer from 0 to 160.
y	The y-coordinate of the top-left corner of the rectangle, given as an integer from 0 to 108.
width	The width of the rectangle, given as an integer from 0 to 160.
height	The height of the rectangle, given as an integer from 0 to 108.
color	Optional. The fill color of the rectangle. Options include: Color.BLACK Color.BLUE Color.BLUE_GREEN Color.BLUE_VIOLET Color.GREEN Color.ORANGE Color.PURPLE Color.RED COLOR.RED_ORANGE Color.RED_VIOLET Color.VIOLET Color.WHITE Color.YELLOW Color.YELLOW_GREEN Color.YELLOW_ORANGE You can also specify a custom color.

# Draw a red rectangle on the screen
brain.screen.draw_rectangle(25, 25, 100, 50, Color.RED)

draw_circle

draw_circle draws a circle with its center at the specified (x, y) coordinate and a size determined by the given radius, all measured in pixels. The circle’s outline is drawn using the current pen width set by set_pen_width and the pen color set by set_pen_color. The interior is filled with the color set by set_fill_color.

The x and y-coordinates use the default origin of (0,0) unless a different origin has been set using set_origin.

Usage:
brain.screen.draw_circle(x, y, radius, color)

Parameter	Description
x	The x-coordinate of the center of the circle, given as an integer from 0 to 160.
y	The y-coordinate of the center of the circle, given as an integer from 0 to 160.
radius	The radius of the circle, given as an integer from 0 to 108 pixels.
color	Optional. The fill color of the circle. Options include: Color.BLACK Color.BLUE Color.BLUE_GREEN Color.BLUE_VIOLET Color.GREEN Color.ORANGE Color.PURPLE Color.RED COLOR.RED_ORANGE Color.RED_VIOLET Color.VIOLET Color.WHITE Color.YELLOW Color.YELLOW_GREEN Color.YELLOW_ORANGE You can also specify a custom color.

# Draw a green circle on the screen
brain.screen.draw_circle(80, 50, 20, Color.GREEN)

set_clip_region

set_clip_region defines a rectangular area on the screen where all drawings and text will be confined. Any content outside this region will not be displayed.

Usage:
brain.screen.set_clip_region(x, y, width, height)

Parameter	Description
x	The x-coordinate of the top-left corner of the clip region, given as an integer or float from 0 to 160.
y	The y-coordinate of the top-left corner of the clip region, given as an integer or float from 0 to 108.
width	The width of the clip region in pixels, given as an integer or float from 0 to 160.
height	The height of the clip region in pixels, given as an integer or float from 0 to 108.

# Restrict text and drawings to a specific region
brain.screen.set_clip_region(0, 0, 120, 120)
brain.screen.draw_rectangle(60, 60, 100, 100, Color.RED)
brain.screen.print_at("Cut off!", x=60, y=60)

render

render enables double buffering for the Brain’s screen. Once called, any drawing commands (like text, shapes, or images) will no longer appear immediately for the rest of the project. Instead, updates will only be shown when render is used again. This allows for smoother and more controlled screen updates, but means nothing will be visible until render is used.

Usage:
brain.screen.render()

Parameters	Description
	This method has no parameters.

# Render text after moving
brain.screen.render()
brain.screen.print("Render later...")
drivetrain.drive_for(FORWARD, 100, MM)
drivetrain.turn_for(RIGHT, 90, DEGREES)
brain.screen.render()