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.

For the examples below, the constructed Brain includes access to the Screen methods and will be used in all subsequent examples throughout this API documentation when referring to those methods.

Below is a list of all methods:

Cursor – Methods for text positioning and display

• print – Prints text at the current cursor position.

• setCursor – Sets the cursor to a specific row and column.

• newLine – Moves the cursor to column 1 of the next row.

• clearLine – Clears a row of text.

• row – Returns the current cursor row.

• column – Returns the current cursor column.

• printAt – Prints text at a specific x and y location.

• setClipRegion – Restricts where drawings and text can appear.

• getStringWidth – Returns the width of a string in pixels.

• getStringHeight – Returns the height of a string in pixels.

Mutators – Methods for setting screen properties

• clearScreen – Clears the screen of all drawings and text.

• setFont – Sets the font for printed text.

• setPenWidth – Sets the thickness for drawn shapes and lines.

• setPenColor – Sets the color for outlines and text.

• setFillColor – Sets the fill color for shapes and backgrounds.

• setOrigin – Sets a new origin for printing and drawing.

Draw – Methods for drawing shapes and graphics

• drawPixel – Draws a pixel at a specific x and y position.

• drawLine – Draws a line between two points.

• drawRectangle – Draws a rectangle.

• drawCircle – Draws a circle.

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

Cursor

print

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

Usage:
Brain.Screen.print(value);

Parameters	Description
value	The text to display on the screen. Use C++ string formatting to print variable.

int main() {
  // Initializing Robot Configuration. DO NOT REMOVE!
  vexcodeInit();

  // Display a message at the starting cursor
  Brain.Screen.print("Hello, Robot!");
}

setCursor

setCursor 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, setCursor positions the cursor based on row and column size, not font style. The font size can be adjusted using setFont.

Usage:
Brain.Screen.setCursor(row, col);

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

int main() {
  // Initializing Robot Configuration. DO NOT REMOVE!
  vexcodeInit();

  // Repeatedly print the Brain timer at top-left
  while (true) {
    Brain.Screen.print("%d", Brain.Timer.time(seconds));
    Brain.Screen.newLine();
    wait(1, seconds);
    Brain.Screen.clearScreen();
    Brain.Screen.setCursor(1, 1);
  }
}

newLine

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

Usage:
Brain.Screen.newLine();

Parameters	Description
	This method has no parameters.

int main() {
  // Initializing Robot Configuration. DO NOT REMOVE!
  vexcodeInit();

  // Display two lines of text
  Brain.Screen.print("Line 1");
  Brain.Screen.newLine();
  Brain.Screen.print("Line 2");
}

clearLine

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

Usage:
Brain.Screen.clearLine(row, color);

Parameters	Description
row	Optional. The row to clear. The default is the current cursor row.
color	Optional. Sets the pen color. Options include: black blue blue_green blue_violet cyan green orange purple red red_orange red_violet violet white yellow yellow_green yellow_orange You can also specify a custom color.

int main() {
  // Initializing Robot Configuration. DO NOT REMOVE!
  vexcodeInit();

  // Display text on two rows
  Brain.Screen.print("This text stays");
  Brain.Screen.newLine();
  Brain.Screen.print("This disappears");

  // Wait 3 seconds before clearing row 2
  wait(3, seconds);
  Brain.Screen.clearLine(2);
}

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.

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.

printAt

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

Usage:
Brain.Screen.printAt(x, y, value);

Parameters	Description
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.
value	The text to print on the screen. Use the C++ string formatting to print variable.

int main() {
  // Initializing Robot Configuration. DO NOT REMOVE!
  vexcodeInit();

  // Print the number 1 at pixel (100, 40)
  Brain.Screen.printAt(100, 40, "1");
}

setClipRegion

setClipRegion 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.setClipRegion(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.

int main() {
  // Initializing Robot Configuration. DO NOT REMOVE!
  vexcodeInit();

  // Restrict text and drawings to a specific region
  Brain.Screen.setClipRegion(0, 0, 120, 120);
  Brain.Screen.drawRectangle(60, 60, 100, 100, red);
  Brain.Screen.printAt(60, 60, "Cut off!");
}

getStringWidth

getStringWidth 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.getStringWidth(string);

Parameters	Description
string	The string to measure.

getStringHeight

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.getStringHeight(string);

Parameters	Description
string	The string to measure.

Mutators

clearScreen

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

Usage:
Brain.Screen.clearScreen();

Parameters	Description
color	Optional. Sets the pen color. Options include: black blue blue_green blue_violet cyan green orange purple red red_orange red_violet violet white yellow yellow_green yellow_orange You can also specify a custom color.

int main() {
  // Initializing Robot Configuration. DO NOT REMOVE!
  vexcodeInit();

  // Draw a circle and clear it after 2 seconds
  Brain.Screen.drawCircle(80, 50, 20);
  wait(2, seconds);
  Brain.Screen.clearScreen();
}

setFont

setFont sets the font used for displaying text on the Brain’s screen. This font will apply to all text printed with print or printAt. The default font at the start of a project is mono20.

Usage:
Brain.Screen.setFont(type);

Parameter	Description
type	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

int main() {
  // Initializing Robot Configuration. DO NOT REMOVE!
  vexcodeInit();

  // Display two different fonts on two lines
  Brain.Screen.setFont(mono20);
  Brain.Screen.print("Mono Medium");
  Brain.Screen.newLine();
  Brain.Screen.setFont(prop20);
  Brain.Screen.print("Prop Medium");
}

setPenWidth

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

Usage:
Brain.Screen.setPenWidth(value);

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

int main() {
  // Initializing Robot Configuration. DO NOT REMOVE!
  vexcodeInit();

  // Draw two circles with different pen widths
  Brain.Screen.drawCircle(40, 70, 20);
  Brain.Screen.setPenWidth(5);
  Brain.Screen.drawCircle(100, 70, 20);
}

setPenColor

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

Usage:
Brain.Screen.setPenColor(color);

Parameter	Description
color	Optional. Sets the pen color. Options include: black blue blue_green blue_violet cyan green orange purple red red_orange red_violet violet white yellow yellow_green yellow_orange You can also specify a custom color.

int main() {
  // Initializing Robot Configuration. DO NOT REMOVE!
  vexcodeInit();

  // Draw two rectangles with different colors
  Brain.Screen.drawRectangle(100, 50, 10, 20);
  Brain.Screen.setPenColor(blue);
  Brain.Screen.drawRectangle(50, 50, 10, 20);
}

setFillColor

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

Usage:
Brain.Screen.setFillColor(color);

Parameter	Description
color	Optional. Sets the pen color. Options include: black blue blue_green blue_violet cyan green orange purple red red_orange red_violet violet white yellow yellow_green yellow_orange You can also specify a custom color.

int main() {
  // Initializing Robot Configuration. DO NOT REMOVE!
  vexcodeInit();

  // Draw a yellow circle
  Brain.Screen.setFillColor(yellow);
  Brain.Screen.drawCircle(50, 50, 20);
}

setOrigin

setOrigin 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.setOrigin(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.

int main() {
  // Initializing Robot Configuration. DO NOT REMOVE!
  vexcodeInit();

  // Draw a line with the origin set to (50, 50)
  Brain.Screen.setOrigin(50, 50);
  Brain.Screen.drawLine(1, 1, 159, 107);
}

Draw

drawPixel

drawPixel draws a pixel at the specified (x, y) screen coordinate with the current pen color.

Usage:
Brain.Screen.drawPixel(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.

int main() {
  // Initializing Robot Configuration. DO NOT REMOVE!
  vexcodeInit();

  // Draw one pixel at the center of the screen
  Brain.Screen.drawPixel(80, 50);
}

drawLine

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

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

Usage:
Brain.Screen.drawLine(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.

int main() {
  // Initializing Robot Configuration. DO NOT REMOVE!
  vexcodeInit();

  // Draw a line from top-left to bottom-right
  Brain.Screen.drawLine(0, 0, 159, 107);
}

drawRectangle

drawRectangle 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 and pen color. The interior is filled with the current fill color.

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

Usage:
Brain.Screen.drawRectangle(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. Sets the pen color. Options include: black blue blue_green blue_violet cyan green orange purple red red_orange red_violet violet white yellow yellow_green yellow_orange You can also specify a custom color.

int main() {
  // Initializing Robot Configuration. DO NOT REMOVE!
  vexcodeInit();

  // Draw a red rectangle on the screen
  Brain.Screen.drawRectangle(25, 25, 100, 50, red);
}

drawCircle

drawCircle 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 and pen color. The interior is filled with the current fill color.

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

Usage:
Brain.Screen.drawCircle(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. Sets the pen color. Options include: black blue blue_green blue_violet cyan green orange purple red red_orange red_violet violet white yellow yellow_green yellow_orange You can also specify a custom color.

int main() {
  // Initializing Robot Configuration. DO NOT REMOVE!
  vexcodeInit();

  // Draw a green circle on the screen
  Brain.Screen.drawCircle(80, 50, 20, green);
}

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.

int main() {
  // Initializing Robot Configuration. DO NOT REMOVE!
  vexcodeInit();

  // Render text after moving
  Brain.Screen.render();
  Brain.Screen.print("Render later...");
  Drivetrain.driveFor(forward, 100, mm);
  Drivetrain.turnFor(right, 90, degrees);
  Brain.Screen.render();
}