屏幕#

介绍#

屏幕类别控制 V5 大脑的触摸屏,使机器人能够显示文本、数字和图形,并响应触摸输入。

默认情况下,打印到大脑的字体是等宽小号,它有 12 行 48 列。

对于绘画而言,大脑的分辨率为 479 x 239 像素。

The V5 Brain screen with red grid lines showing the layout of 12 rows and 48 columns in total. The pixel dimensions are 479 wide by 239 tall. The upper left corner begins at (0,0) pixels and row 1, column 1, while the lower right corner ends at (479, 239) pixels and row 12, column 48.

以下是所有方法的列表:

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 in pixels.

  • get_string_height — Returns the height of a string in pixels.

  • clear_line — Clears a line of text.

  • new_line — Moves the cursor to a new line.

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 position.

  • draw_line — Draws a line between two points.

  • draw_rectangle — Draws a rectangle.

  • draw_circle — Draws a circle.

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

  • set_clip_region — Restricts where drawings and text can appear.

Touch — Get touch input from the screen.

  • pressing — Returns whether the screen is being pressed.

  • x_position — Returns the X coordinate of the last screen event.

  • y_position — Returns the Y coordinate of the last screen event.

Callbacks — Respond to touch events on the screen.

  • pressed — Registers a function to be called when the screen is pressed.

  • released — Registers a function to be called when the screen is released.

For information on constructing a Brain to gain access to the screen methods, see Brain.

光标打印#

print#

print prints text on the screen using the current cursor position.

用法:

brain.screen.print(text, sep, precision)

参数

描述

text

要打印的文本。

sep

Optional. A string to insert between values. This must be written as a keyword argument (sep=). The default is “”.

precision

Optional. The number of decimal places to display when printing simple numbers. This must be written as a keyword argument(precision=). The default is 2.

# Print on the Brain's screen
brain.screen.print("Hello, Robot!")

A screenshot of the V5 Brain showing "Hello Screen" printed on the screen in the upper left corner in white text.

set_cursor#

set_cursor sets the cursor position. The cursor is placed at a specific row and column on the screen. How many rows and columns can comfortably fit depends on the selected font. With the default monospaced medium font, up to 8 rows and 13 columns can be displayed clearly. Text placed beyond this range may be cut off or become difficult to read.

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 the set_font.

用法:

brain.screen.set_cursor(row, column)

参数

描述

row

光标所在的行。

column

光标所在的列。

# Display text starting at Row 3 Column 12
brain.screen.set_cursor(3, 12)
brain.screen.print("Row 3, Column 12")

A screenshot of the V5 Brain showing Row 3 Column 12 printed in the upper portion near the center of screen, at that position.

next_row#

next_row moves the cursor to the next row.

用法:

brain.screen.next_row()

参数

描述

此方法没有参数。

# Print two lines of text on the Brain's screen
brain.screen.print("Line 1")
brain.screen.next_row()
brain.screen.print("Line 2")

A screenshot of the V5 Brain screen showing two lines of white text in the upper left corner. The top line reads Line 1, and the second line directly below it reads Line 2.

clear_row#

clear_row(row, color) clears a row to a single color.

用法:

brain.screen.clear_row(row, color)

参数

描述

row

可选。要清除的行。默认值为当前光标所在行。

color

可选。有效的颜色、十六进制值或网页字符串。

# Only keep the text on row 1
brain.screen.print("This text stays")
brain.screen.next_row
brain.screen.print("This text disappears")
wait(3, SECONDS)

brain.screen.clear_row()

row#

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

用法:

brain.screen.row()

参数

描述

此方法没有参数。

# Display the cursor's current row
brain.screen.set_cursor(3, 2)
brain.screen.print(brain.screen.row())

A screenshot of the V5 Brain screen showing the text 3 in white in the upper left quadrant of the screen, at the row 3 column 2 position.

column#

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

用法:

brain.screen.column()

参数

描述

此方法没有参数。

# Display the cursor's current column
brain.screen.set_cursor(3, 15)
brain.screen.print(brain.screen.column())

A screenshot of the V5 Brain screen showing the text 15 in white in the upper left quadrant of the screen, at the row 3 column 15 position.

get_string_width#

get_string_width(string) returns the width of a string in pixels as an integer as if it was on the Brain’s screen. The width of a string changes based on the length of the string and the size of the font.

Usage:
brain.screen.get_string_width(string)

参数

描述

string

待测量的绳子。

get_string_height#

get_string_height(string) returns the height of a string as an integer in pixels as if it was on the Brain’s screen. The height of a string changes based on the length of the string and the size of the font.

Usage:
brain.screen.get_string_height(string)

参数

描述

string

待测量的绳子。

clear_line#

clear_line clears the current row of text.

Usage: brain.screen.clear_line()

参数

描述

此方法没有参数。

new_line#

new_line moves the cursor to a new line.

用法:

brain.screen.new_line()

参数

描述

此方法没有参数。

变异体#

clear_screen#

clear_screen(color) clears the whole screen to a single color.

用法:

brain.screen.clear_screen(color)

参数

描述

color

Optional. A valid color option:

  • Color.RED
  • Color.GREEN
  • Color.BLUE
  • Color.YELLOW
  • Color.ORANGE
  • Color.PURPLE
  • Color.CYAN
  • Color.BLACK (Default)
  • Color.WHITE
# Print VEXcode on the screen
brain.screen.print("VEXcode")
wait(2, SECONDS)
# Clear screen to black
brain.screen.clear_screen()

# Print VEXcode on the screen
brain.screen.print("VEXcode")

# Clear screen to blue using predefined color
brain.screen.clear_screen(Color.BLUE)

A screenshot of the V5 Brain screen with the entire printable area in bright blue.

set_font#

set_font(fontname) sets the font type used for printing text on the screen.

用法:

brain.screen.set_font(font)

参数

描述

font

以下是一个有效的字体选项。

A screenshot of the V5 Brain screen with numbers and letters printed in white in the upper left corner in MONO 12 font. It shows A-Z on one line, across about a quarter of the width of screen. In the bottom left corner it reads 80 columns and 20 rows.
FontType.MONO12

The same image as the one previous, with Mono 15 font. It shows A-Z on one line, across nearly half width of the screen. In the bottom left corner it reads 68 columns and 16 rows.
FontType.MONO15

The same image as the one previous, with Mono 20 font. It shows A-Z on one line, across nearly two thirds of the width of the screen. In the bottom left corner it reads 48 columns and 12 rows.
FontType.MONO20

The same image as the one previous, with Mono 30 font. It shows A-Z on one line, across nearly the whole width of the screen. In the bottom left corner it reads 32 columns and 8 rows.
FontType.MONO30

The same image as the one previous, with Mono 40 font. It shows A-X on one line, spanning the width the screen. In the bottom left corner it reads 24 columns and 6 rows.
FontType.MONO40

The same image as the one previous, with Mono 60 font. It shows A-P on one line, spanning the width the screen. On the bottom it reads 16 columns and 4 rows.
FontType.MONO60

The same image as the one previous, with Prop 20 font. It shows A-Z on one line, across nearly two thirds of the width of the screen. In the bottom left corner it reads 48 columns and 12 rows.
FontType.PROP20

The same image as the one previous, with Prop 30 font. It shows A-Z on one line, spanning nearly the width of the screen. In the bottom left corner it reads 32 columns and 8 rows.
FontType.PROP30

The same image as the one previous, with Prop 40 font. It shows A-U on one line, spanning the width of the screen. In the bottom left corner it reads 24 columns and 6 rows.
FontType.PROP40

The same image as the one previous, with Prop 60 font. It shows A-N on one line, spanning the width of the screen. On the bottom it reads 15 columns and 4 rows.
FontType.PROP60

# Set the font type to MONO40
brain.screen.set_font(FontType.MONO40)
brain.screen.print("VEX")

A screenshot of the V5 Brain screen reads VEX in white in the upper left corner, in larger font than the default.

set_pen_width#

set_pen_width(width) sets the pen width used for drawing lines, rectangles, and circles.

用法:

brain.screen.set_pen_width(value)

参数

描述

value

笔的宽度,以像素为单位,范围从 0 到 32。

# Draw a rectangle with a pen width of 10
brain.screen.set_pen_width(10)
brain.screen.draw_rectangle(50, 50, 130, 60)

A screenshot of the V5 Brain screen showing a rectangle with thick borders printed in the upper left quadrant of the screen.

set_pen_color#

set_pen_color sets the pen color used for drawing lines, rectangles, and circles.

用法:

brain.screen.set_pen_color(color)

参数

描述

color

A valid color option:

  • Color.RED
  • Color.GREEN
  • Color.BLUE
  • Color.YELLOW
  • Color.ORANGE
  • Color.PURPLE
  • Color.CYAN
  • Color.TRANSPARENT
  • Color.WHITE
# Draw a rectangle with orange borders
brain.screen.set_pen_color(Color.ORANGE)
brain.screen.draw_rectangle(50, 50, 130, 60)

A screenshot of the V5 Brain screen showing a rectangle drawn in orange in the upper left quadrant of the screen.

set_fill_color#

set_fill_color sets the fill color used for drawing rectangles and circles.

用法:

brain.screen.set_fill_color(color)

参数

描述

color

A valid color option:

  • Color.RED
  • Color.GREEN
  • Color.BLUE
  • Color.YELLOW
  • Color.ORANGE
  • Color.PURPLE
  • Color.CYAN
  • Color.TRANSPARENT
  • Color.WHITE
# Draw a purple rectangle
brain.screen.set_fill_color(Color.PURPLE)
brain.screen.draw_rectangle(50, 130, 100, 60)

A screenshot of the V5 Brain screen showing a rectangle filled with purple in the lower left quadrant of the screen.

set_origin#

set_origin sets the origin used for drawing graphics on the Brain’s screen. Drawing functions consider the top left corner of the Brain’s screen as the origin. This function can move the origin to an alternate position such as the center of the Brain’s screen.

用法:

brain.screen.set_origin(x, y)

参数

描述

x

The origin’s x position relative to top left corner as an integer from 0 to 480.

y

The origin’s y position relative to top left corner as an integer from 0 to 240.

#

draw_pixel#

draw_pixel draws a pixel using the current pen color.

用法:

brain.screen.draw_pixel(x, y)

参数

描述

x

相对于屏幕原点的像素的 x 坐标。

y

相对于屏幕原点的 y 坐标,用于绘制像素。

# Draw the pixels marking the corners of a square
brain.screen.draw_pixel(250, 100)
brain.screen.draw_pixel(275, 100)
brain.screen.draw_pixel(250, 125)
brain.screen.draw_pixel(275, 125)

A screenshot of the V5 Brain screen showing an assortment of pixels showing the corners of a square near the center of the screen.

draw_line#

draw_line draws a line using the current pen color.

用法:

brain.screen.draw_line(start_x, start_y, end_x, end_y)

参数

描述

start_x

以屏幕原点为参考的线段起始点的 x 坐标。

start_y

线段起始点相对于屏幕原点的 y 坐标。

end_x

线段末端相对于屏幕原点的 x 坐标。

end_y

线段末端相对于屏幕原点的 y 坐标。

# Draw a line from the top left to bottom right of the screen
brain.screen.draw_line(0, 0, 479, 239)

A screenshot of the V5 Brain screen shows a thin diagonal line across the center, from the upper left corner to the lower right corner.

draw_rectangle#

draw_rectangle draws a rectangle on the screen using the current pen and fill colors.

用法:

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

参数

描述

x

矩形左上角的 x 坐标(像素),取值范围为 0 到 479。

y

矩形左上角的 y 坐标(像素),取值范围为 0 到 239。

width

矩形的宽度。

height

矩形的高度。

color

Optional. A valid color option:

  • Color.RED
  • Color.GREEN
  • Color.BLUE
  • Color.YELLOW
  • Color.ORANGE
  • Color.PURPLE
  • Color.CYAN
  • Color.TRANSPARENT
  • Color.WHITE
# Draw a rectangle on the screen
brain.screen.draw_rectangle(50, 50, 130, 60)

A screenshot of the V5 Brain's screen shows a rectangle with a thin white border printed in the upper left quadrant.

draw_circle#

draw_circle(x, y, radius, color) draws a circle using the current pen and fill colors.

用法:

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

参数

描述

x

圆心相对于屏幕原点的 x 坐标。

y

圆心相对于屏幕原点的 y 坐标。

radius

圆的半径。

color

Optional. A valid color option:

  • Color.RED
  • Color.GREEN
  • Color.BLUE
  • Color.YELLOW
  • Color.ORANGE
  • Color.PURPLE
  • Color.CYAN
  • Color.TRANSPARENT
  • Color.WHITE
# Draw a circle on the screen
brain.screen.draw_circle(120, 120, 40)

A screenshot of the V5 Brain screen shows a circle with a thin white border drawn in the center.

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.

用法:

brain.screen.render()

参数

描述

此方法没有参数。

# 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()

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.

用法:

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

参数

描述

x

矩形左上角的 x 坐标,以屏幕原点为参考。

y

矩形左上角的 y 坐标,以屏幕原点为参考。

width

矩形的宽度。

height

矩形的高度。

# 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)

A screenshot of the V5 Brain screen with white text that read Cut of with a solid red square directly beneath it, in the upper left quadrant of the screen showing what prints within the clip region.

触碰#

pressing#

pressing returns whether the screen is currently being pressed (touched).

  • True - The screen is being pressed.

  • False - The screen is not being pressed.

用法:

brain.screen.pressing()

参数

描述

此方法没有参数。

# Change the screen's color after it's pressed
while not brain.screen.pressing():
    wait(5, MSEC)
brain.screen.set_fill_color(Color.GREEN)
brain.screen.draw_rectangle(0, 0, 479, 239)

# Display different messages after the screen is pressed
while not brain.screen.pressing():
    wait(5, MSEC)
brain.screen.print("First message!")
brain.screen.next_row()
# Lift finger to press the screen again
while brain.screen.pressing():
    wait(5, MSEC)
while not brain.screen.pressing():
    wait(5, MSEC)
brain.screen.print("Second message!")
brain.screen.next_row()

x_position#

x_position returns the X coordinate of the last screen event, press or release as an integer.

用法:

brain.screen.x_position()

参数

描述

此方法没有参数。

# Display a circle where the screen is pressed
while not brain.screen.pressing():
    wait(5, MSEC)
brain.screen.set_fill_color(Color.WHITE)
brain.screen.draw_circle(brain.screen.x_position(), brain.screen.y_position(), 20)

y_position#

y_position returns the Y coordinate of the last screen event, press or release as an integer.

用法:

brain.screen.y_position()

参数

描述

此方法没有参数。

# Display a circle where the screen is pressed
while not brain.screen.pressing():
    wait(5, MSEC)
brain.screen.set_fill_color(Color.WHITE)
brain.screen.draw_circle(brain.screen.x_position(), brain.screen.y_position(), 20)

回调函数#

pressed#

pressed registers a function to be called when the Brain’s Screen is pressed.

用法:

brain.screen.pressed(callback, arg)

参数

描述

callback

A previously defined function that executes when the Brain screen is pressed.

arg

Optional. A tuple containing arguments to pass to the callback function. See Using Functions with Parameters for more information.

def my_function():
  brain.screen.print("Screen pressed")

# Call my_function whenever the Brain screen is pressed
brain.screen.pressed(my_function)

released#

released registers a function to be called when the screen is released (touch removed).

用法:

brain.screen.released(callback, arg)

参数

描述

callback

A previously defined function that executes when the Brain screen is released.

arg

Optional. A tuple containing arguments to pass to the callback function. See Using Functions with Parameters for more information.

def my_function():
  brain.screen.print("Screen released")

# Call my_function whenever the Brain screen is released
brain.screen.released(my_function)