Class StdDraw
- Object
-
- StdDraw
-
- All Implemented Interfaces:
ActionListener
,KeyListener
,MouseListener
,MouseMotionListener
,EventListener
public final class StdDraw extends Object implements ActionListener, MouseListener, MouseMotionListener, KeyListener
TheStdDraw
class provides static methods for creating drawings with your programs. It uses a simple graphics model that allows you to create drawings consisting of points, lines, squares, circles, and other geometric shapes in a window on your computer and to save the drawings to a file. Standard drawing also includes facilities for text, color, pictures, and animation, along with user interaction via the keyboard and mouse.Getting started. To use this class, you must have
StdDraw.class
in your Java classpath. If you used our autoinstaller, you should be all set. Otherwise, either download stdlib.jar and add to your Java classpath or download StdDraw.java and put a copy in your working directory.Now, cut-and-paste the following short program into your editor:
public class TestStdDraw { public static void main(String[] args) { StdDraw.setPenRadius(0.05); StdDraw.setPenColor(StdDraw.BLUE); StdDraw.point(0.5, 0.5); StdDraw.setPenColor(StdDraw.MAGENTA); StdDraw.line(0.2, 0.2, 0.8, 0.2); } }
If you compile and execute the program, you should see a window appear with a thick magenta line and a blue point. This program illustrates the two main types of methods in standard drawing—methods that draw geometric shapes and methods that control drawing parameters. The methodsStdDraw.line()
andStdDraw.point()
draw lines and points; the methodsStdDraw.setPenRadius()
andStdDraw.setPenColor()
control the line thickness and color.Points and lines. You can draw points and line segments with the following methods:
The x- and y-coordinates must be in the drawing area (between 0 and 1 and by default) or the points and lines will not be visible.
Squares, circles, rectangles, and ellipses. You can draw squares, circles, rectangles, and ellipses using the following methods:
-
circle(double x, double y, double radius)
-
ellipse(double x, double y, double semiMajorAxis, double semiMinorAxis)
-
square(double x, double y, double halfLength)
-
rectangle(double x, double y, double halfWidth, double halfHeight)
All of these methods take as arguments the location and size of the shape. The location is always specified by the x- and y-coordinates of its center. The size of a circle is specified by its radius and the size of an ellipse is specified by the lengths of its semi-major and semi-minor axes. The size of a square or rectangle is specified by its half-width or half-height. The convention for drawing squares and rectangles is parallel to those for drawing circles and ellipses, but may be unexpected to the uninitiated.
The methods above trace outlines of the given shapes. The following methods draw filled versions:
-
filledCircle(double x, double y, double radius)
-
filledEllipse(double x, double y, double semiMajorAxis, double semiMinorAxis)
-
filledSquare(double x, double y, double radius)
-
filledRectangle(double x, double y, double halfWidth, double halfHeight)
Circular arcs. You can draw circular arcs with the following method:
The arc is from the circle centered at (x, y) of the specified radius. The arc extends from angle1 to angle2. By convention, the angles are polar (counterclockwise angle from the x-axis) and represented in degrees. For example,
StdDraw.arc(0.0, 0.0, 1.0, 0, 90)
draws the arc of the unit circle from 3 o'clock (0 degrees) to 12 o'clock (90 degrees).Polygons. You can draw polygons with the following methods:
The points in the polygon are (
x[i]
,y[i]
). For example, the following code fragment draws a filled diamond with vertices (0.1, 0.2), (0.2, 0.3), (0.3, 0.2), and (0.2, 0.1):double[] x = { 0.1, 0.2, 0.3, 0.2 }; double[] y = { 0.2, 0.3, 0.2, 0.1 }; StdDraw.filledPolygon(x, y);
Pen size. The pen is circular, so that when you set the pen radius to r and draw a point, you get a circle of radius r. Also, lines are of thickness 2r and have rounded ends. The default pen radius is 0.002 and is not affected by coordinate scaling. This default pen radius is about 1/500 the width of the default canvas, so that if you draw 200 points equally spaced along a horizontal or vertical line, you will be able to see individual circles, but if you draw 250 such points, the result will look like a line.
For example,
StdDraw.setPenRadius(0.01)
makes the thickness of the lines and the size of the points to be five times the 0.002 default. To draw points with the minimum possible radius (one pixel on typical displays), set the pen radius to 0.0.Pen color. All geometric shapes (such as points, lines, and circles) are drawn using the current pen color. By default, it is black. You can change the pen color with the following methods:
The first method allows you to specify colors using the RGB color system. This color picker is a convenient way to find a desired color.
The second method allows you to specify colors using the
Color
data type, which is defined in Java'sjava.awt
package. Standard drawing defines a number of predefined colors includingBLACK
,WHITE
,RED
,GREEN
, andBLUE
. For example,StdDraw.setPenColor(StdDraw.RED)
sets the pen color to red.Window title. By default, the standard drawing window title is "Standard Draw". You can change the title with the following method:
This sets the standard drawing window title to the specified string.
Canvas size. By default, all drawing takes places in a 512-by-512 canvas. The canvas does not include the window title or window border. You can change the size of the canvas with the following method:
This sets the canvas size to be width-by-height pixels. It also clears the current drawing using the default background color (white). Ordinarily, this method is called only once, at the very beginning of a program. For example,
StdDraw.setCanvasSize(800, 800)
sets the canvas size to be 800-by-800 pixels.Canvas scale and coordinate system. By default, all drawing takes places in the unit square, with (0, 0) at lower left and (1, 1) at upper right. You can change the default coordinate system with the following methods:
-
setXscale(double xmin, double xmax)
-
setYscale(double ymin, double ymax)
-
setScale(double min, double max)
The arguments are the coordinates of the minimum and maximum x- or y-coordinates that will appear in the canvas. For example, if you wish to use the default coordinate system but leave a small margin, you can call
StdDraw.setScale(-.05, 1.05)
.These methods change the coordinate system for subsequent drawing commands; they do not affect previous drawings. These methods do not change the canvas size; so, if the x- and y-scales are different, squares will become rectangles and circles will become ellipses.
Text. You can use the following methods to annotate your drawings with text:
-
text(double x, double y, String text)
-
text(double x, double y, String text, double degrees)
-
textLeft(double x, double y, String text)
-
textRight(double x, double y, String text)
The first two methods write the specified text in the current font, centered at (x, y). The second method allows you to rotate the text. The last two methods either left- or right-align the text at (x, y).
The default font is a Sans Serif font with point size 16. You can use the following method to change the font:
To specify the font, you use the
Font
data type, which is defined in Java'sjava.awt
package. This allows you to choose the face, size, and style of the font. For example, the following code fragment sets the font to Arial Bold, 60 point. Theimport
statement allows you to refer toFont
directly, without needing the fully qualified namejava.awt.Font
.import java.awt.Font; ... Font font = new Font("Arial", Font.BOLD, 60); StdDraw.setFont(font); StdDraw.text(0.5, 0.5, "Hello, World");
Images. You can use the following methods to add images to your drawings:
-
picture(double x, double y, String filename)
-
picture(double x, double y, String filename, double degrees)
-
picture(double x, double y, String filename, double scaledWidth, double scaledHeight)
-
picture(double x, double y, String filename, double scaledWidth, double scaledHeight, double degrees)
These methods draw the specified image, centered at (x, y). The image must be in a supported file format (typically JPEG, PNG, GIF, TIFF, and BMP). The image will display at its native size, independent of the coordinate system. Optionally, you can rotate the image a specified number of degrees counterclockwise or rescale it to fit snugly inside a bounding box.
Saving to a file. You can save your image to a file using the File → Save menu option. You can also save a file programmatically using the following method:
You can save the drawing to a file in a supported file format (typically JPEG, PNG, GIF, TIFF, and BMP).
File formats. The
StdDraw
class supports reading and writing images to any of the file formats supported byjavax.imageio
(typically JPEG, PNG, GIF, TIFF, and BMP). The file extensions corresponding to JPEG, PNG, GIF, TIFF, and BMP, are.jpg
,.png
,.gif
,.tif
, and.bmp
, respectively.We recommend using PNG for drawing that consist solely of geometric shapes and JPEG for drawings that contains pictures. The JPEG file format does not support transparent backgrounds.
Clearing the canvas. To clear the entire drawing canvas, you can use the following methods:
The first method clears the canvas to the default background color (white); the second method allows you to specify the background color. For example,
StdDraw.clear(StdDraw.LIGHT_GRAY)
clears the canvas to a shade of gray. To make the background transparent, callStdDraw.clear(StdDraw.TRANSPARENT)
.Computer animations and double buffering. Double buffering is one of the most powerful features of standard drawing, enabling computer animations. The following methods control the way in which objects are drawn:
By default, double buffering is disabled, which means that as soon as you call a drawing method—such as
point()
orline()
—the results appear on the screen.When double buffering is enabled by calling
enableDoubleBuffering()
, all drawing takes place on the offscreen canvas. The offscreen canvas is not displayed. Only when you callshow()
does your drawing get copied from the offscreen canvas to the onscreen canvas, where it is displayed in the standard drawing window. You can think of double buffering as collecting all of the lines, points, shapes, and text that you tell it to draw, and then drawing them all simultaneously, upon request.The most important use of double buffering is to produce computer animations, creating the illusion of motion by rapidly displaying static drawings. To produce an animation, repeat the following four steps:
- Clear the offscreen canvas.
- Draw objects on the offscreen canvas.
- Copy the offscreen canvas to the onscreen canvas.
- Wait for a short while.
The
clear()
,show()
, andpause(int t)
methods support the first, third, and fourth of these steps, respectively.For example, this code fragment animates two balls moving in a circle.
StdDraw.setScale(-2.0, +2.0); StdDraw.enableDoubleBuffering(); for (double t = 0.0; true; t += 0.02) { double x = Math.sin(t); double y = Math.cos(t); StdDraw.clear(); StdDraw.filledCircle(x, y, 0.1); StdDraw.filledCircle(-x, -y, 0.1); StdDraw.show(); StdDraw.pause(20); }
Without double buffering, the balls would flicker as they move.Keyboard and mouse inputs. Standard drawing has very basic support for keyboard and mouse input. It is much less powerful than most user interface libraries provide, but also much simpler. You can use the following methods to intercept mouse events:
The first method tells you whether a mouse button is currently being pressed. The last two methods tells you the x- and y-coordinates of the mouse's current position, using the same coordinate system as the canvas (the unit square, by default). You should use these methods in an animation loop that waits a short while before trying to poll the mouse for its current state. You can use the following methods to intercept keyboard events:
If the user types lots of keys, they will be saved in a list until you process them. The first method tells you whether the user has typed a key (that your program has not yet processed). The second method returns the next key that the user typed (that your program has not yet processed) and removes it from the list of saved keystrokes. The third method tells you whether a key is currently being pressed.
Accessing control parameters. You can use the following methods to access the current pen color, pen radius, and font:
These methods are useful when you want to temporarily change a control parameter and, later, reset it back to its original value.
Corner cases. Here are some corner cases.
- Drawing an object outside (or partly outside) the canvas is permitted. However, only the part of the object that appears inside the canvas will be visible.
- Due to floating-point issues, an object drawn with an x- or y-coordinate that is way outside the canvas (such as the line segment from (0.5, –10^308) to (0.5, 10^308) may not be visible even in the part of the canvas where it should be.
- Any method that is passed a
null
argument will throw anIllegalArgumentException
. - Any method that is passed a
Double.NaN
,Double.POSITIVE_INFINITY
, orDouble.NEGATIVE_INFINITY
argument will throw anIllegalArgumentException
.
Performance tricks. Standard drawing is capable of drawing large amounts of data. Here are a few tricks and tips:
- Use double buffering for static drawing with a large
number of objects.
That is, call
enableDoubleBuffering()
before the sequence of drawing commands and callshow()
afterwards. Incrementally displaying a complex drawing while it is being created can be intolerably inefficient on many computer systems. - When drawing computer animations, call
show()
only once per frame, not after drawing each individual object. - If you call
picture()
multiple times with the same filename, Java will cache the image, so you do not incur the cost of reading from a file each time.
Known bugs and issues.
- The
picture()
methods may not draw the portion of the image that is inside the canvas if the center point (x, y) is outside the canvas. This bug appears only on some systems.
Reference. For additional documentation, see Section 1.5 of Computer Science: An Interdisciplinary Approach by Robert Sedgewick and Kevin Wayne.
- Author:
- Robert Sedgewick, Kevin Wayne
-
-
Field Summary
Fields Modifier and Type Field Description static Color
AQUA
The color aqua (0, 255, 255).static Color
BLACK
The color black (0, 0, 0).static Color
BLUE
The color blue (0, 0, 255).static Color
BOOK_BLUE
The shade of blue used in Introduction to Programming in Java.static Color
BOOK_LIGHT_BLUE
The shade of light blue used in Introduction to Programming in Java.static Color
BOOK_RED
The shade of red used in Algorithms, 4th edition.static Color
CYAN
The color cyan (0, 255, 255).static Color
DARK_GRAY
The color dark gray (64, 64, 64).static Color
FUSCIA
The color fuscia (255, 0, 255).static Color
GRAY
The color gray (128, 128, 128).static Color
GREEN
The color green (0, 128, 0).static Color
LIGHT_GRAY
The color light gray (192, 192, 192).static Color
LIME
The color lime (0, 255, 0).static Color
MAGENTA
The color magenta (255, 0, 255).static Color
MAROON
The color maroon (128, 0, 0).static Color
NAVY
The color navy (0, 0, 128).static Color
OLIVE
The color olive (128, 128, 0).static Color
ORANGE
The color orange (255, 200, 0).static Color
PINK
The color pink (255, 175, 175).static Color
PRINCETON_ORANGE
The shade of orange used in Princeton University's identity.static Color
PURPLE
The color purple (128, 0, 128).static Color
RED
The color red (255, 0, 0).static Color
SILVER
The color silver (192, 192, 192).static Color
TEAL
The color teal (0, 128, 128).static Color
TRANSPARENT
A 100% transparent color, for a transparent background.static Color
WHITE
The color white (255, 255, 255).static Color
YELLOW
The color yellow (255, 255, 0).
-
Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description void
actionPerformed(ActionEvent event)
This method cannot be called directly.static void
arc(double x, double y, double radius, double angle1, double angle2)
Draws a circular arc of the specified radius, centered at (x, y), from angle1 to angle2 (in degrees).static void
circle(double x, double y, double radius)
Draws a circle of the specified radius, centered at (x, y).static void
clear()
Clears the screen using the default background color (white).static void
clear(Color color)
Clears the screen using the specified background color.static void
close()
Closes the standard drawing window.static void
disableDoubleBuffering()
Disables double buffering.static void
ellipse(double x, double y, double semiMajorAxis, double semiMinorAxis)
Draws an ellipse with the specified semimajor and semiminor axes, centered at (x, y).static void
enableDoubleBuffering()
Enables double buffering.static void
filledCircle(double x, double y, double radius)
Draws a filled circle of the specified radius, centered at (x, y).static void
filledEllipse(double x, double y, double semiMajorAxis, double semiMinorAxis)
Draws a filled ellipse with the specified semimajor and semiminor axes, centered at (x, y).static void
filledPolygon(double[] x, double[] y)
Draws a filled polygon with the vertices (x0, y0), (x1, y1), ..., (xn–1, yn–1).static void
filledRectangle(double x, double y, double halfWidth, double halfHeight)
Draws a filled rectangle of the specified size, centered at (x, y).static void
filledSquare(double x, double y, double halfLength)
Draws a filled square of the specified size, centered at (x, y).static Color
getBackgroundColor()
Returns the current background color.static Font
getFont()
Returns the current font.static Color
getPenColor()
Returns the current pen color.static double
getPenRadius()
Returns the current pen radius.static boolean
hasNextKeyTyped()
Returns true if the user has typed a key (that has not yet been processed).static boolean
isKeyPressed(int keycode)
Returns true if the given key is being pressed.static boolean
isMousePressed()
Returns true if the mouse is being pressed.void
keyPressed(KeyEvent event)
This method cannot be called directly.void
keyReleased(KeyEvent event)
This method cannot be called directly.void
keyTyped(KeyEvent event)
This method cannot be called directly.static void
line(double x0, double y0, double x1, double y1)
Draws a line segment between (x0, y0) and (x1, y1).static void
main(String[] args)
Test client.void
mouseClicked(MouseEvent event)
This method cannot be called directly.void
mouseDragged(MouseEvent event)
This method cannot be called directly.void
mouseEntered(MouseEvent event)
This method cannot be called directly.void
mouseExited(MouseEvent event)
This method cannot be called directly.void
mouseMoved(MouseEvent event)
This method cannot be called directly.void
mousePressed(MouseEvent event)
This method cannot be called directly.void
mouseReleased(MouseEvent event)
This method cannot be called directly.static double
mouseX()
Returns the x-coordinate of the mouse.static double
mouseY()
Returns the y-coordinate of the mouse.static char
nextKeyTyped()
Returns the next key that was typed by the user (that your program has not already processed).static void
pause(int t)
Pauses for t milliseconds.static void
picture(double x, double y, String filename)
Draws the specified image centered at (x, y).static void
picture(double x, double y, String filename, double degrees)
Draws the specified image centered at (x, y), rotated given number of degrees.static void
picture(double x, double y, String filename, double scaledWidth, double scaledHeight)
Draws the specified image centered at (x, y), rescaled to the specified bounding box.static void
picture(double x, double y, String filename, double scaledWidth, double scaledHeight, double degrees)
Draws the specified image centered at (x, y), rotated given number of degrees, and rescaled to the specified bounding box.static void
point(double x, double y)
Draws a point centered at (x, y).static void
polygon(double[] x, double[] y)
Draws a polygon with the vertices (x0, y0), (x1, y1), ..., (xn–1, yn–1).static void
rectangle(double x, double y, double halfWidth, double halfHeight)
Draws a rectangle of the specified size, centered at (x, y).static void
save(String filename)
Saves the drawing to a file in a supported file format (typically JPEG, PNG, GIF, TIFF, and BMP).static void
setCanvasSize()
Sets the canvas (drawing area) to be 512-by-512 pixels.static void
setCanvasSize(int canvasWidth, int canvasHeight)
Sets the canvas (drawing area) to be width-by-height pixels.static void
setFont()
Sets the font to the default font (sans serif, 16 point).static void
setFont(Font font)
Sets the font to the specified value.static void
setPenColor()
Sets the pen color to the default color (black).static void
setPenColor(int red, int green, int blue)
Sets the pen color to the specified RGB color.static void
setPenColor(Color color)
Sets the pen color to the specified color.static void
setPenRadius()
Sets the pen size to the default size (0.002).static void
setPenRadius(double radius)
Sets the radius of the pen to the specified size.static void
setScale()
Sets both the x-scale and y-scale to the default range (between 0.0 and 1.0).static void
setScale(double min, double max)
Sets both the x-scale and y-scale to the (same) specified range.static void
setTitle(String title)
Sets the title of the standard drawing window to the specified string.static void
setVisible(boolean isVisible)
Makes the drawing window visible or invisible.static void
setXscale()
Sets the x-scale to the default range (between 0.0 and 1.0).static void
setXscale(double min, double max)
Sets the x-scale to the specified range.static void
setYscale()
Sets the y-scale to the default range (between 0.0 and 1.0).static void
setYscale(double min, double max)
Sets the y-scale to the specified range.static void
show()
Copies offscreen buffer to onscreen buffer.static void
square(double x, double y, double halfLength)
Draws a square of the specified size, centered at (x, y).static void
text(double x, double y, String text)
Writes the given text string in the current font, centered at (x, y).static void
text(double x, double y, String text, double degrees)
Writes the given text string in the current font, centered at (x, y) and rotated by the specified number of degrees.static void
textLeft(double x, double y, String text)
Writes the given text string in the current font, left-aligned at (x, y).static void
textRight(double x, double y, String text)
Writes the given text string in the current font, right-aligned at (x, y).
-
-
-
Field Detail
-
AQUA
public static final Color AQUA
The color aqua (0, 255, 255).
-
BLACK
public static final Color BLACK
The color black (0, 0, 0).
-
BLUE
public static final Color BLUE
The color blue (0, 0, 255).
-
CYAN
public static final Color CYAN
The color cyan (0, 255, 255).
-
FUSCIA
public static final Color FUSCIA
The color fuscia (255, 0, 255).
-
DARK_GRAY
public static final Color DARK_GRAY
The color dark gray (64, 64, 64).
-
GRAY
public static final Color GRAY
The color gray (128, 128, 128).
-
GREEN
public static final Color GREEN
The color green (0, 128, 0).
-
LIGHT_GRAY
public static final Color LIGHT_GRAY
The color light gray (192, 192, 192).
-
LIME
public static final Color LIME
The color lime (0, 255, 0).
-
MAGENTA
public static final Color MAGENTA
The color magenta (255, 0, 255).
-
MAROON
public static final Color MAROON
The color maroon (128, 0, 0).
-
NAVY
public static final Color NAVY
The color navy (0, 0, 128).
-
OLIVE
public static final Color OLIVE
The color olive (128, 128, 0).
-
ORANGE
public static final Color ORANGE
The color orange (255, 200, 0).
-
PINK
public static final Color PINK
The color pink (255, 175, 175).
-
PURPLE
public static final Color PURPLE
The color purple (128, 0, 128).
-
RED
public static final Color RED
The color red (255, 0, 0).
-
SILVER
public static final Color SILVER
The color silver (192, 192, 192).
-
TEAL
public static final Color TEAL
The color teal (0, 128, 128).
-
WHITE
public static final Color WHITE
The color white (255, 255, 255).
-
YELLOW
public static final Color YELLOW
The color yellow (255, 255, 0).
-
TRANSPARENT
public static final Color TRANSPARENT
A 100% transparent color, for a transparent background.
-
BOOK_BLUE
public static final Color BOOK_BLUE
The shade of blue used in Introduction to Programming in Java. It is Pantone 300U. The RGB values are approximately (9, 90, 166).
-
BOOK_LIGHT_BLUE
public static final Color BOOK_LIGHT_BLUE
The shade of light blue used in Introduction to Programming in Java. The RGB values are approximately (103, 198, 243).
-
BOOK_RED
public static final Color BOOK_RED
The shade of red used in Algorithms, 4th edition. It is Pantone 1805U. The RGB values are approximately (150, 35, 31).
-
PRINCETON_ORANGE
public static final Color PRINCETON_ORANGE
The shade of orange used in Princeton University's identity. It is PMS 158. The RGB values are approximately (245, 128, 37).
-
-
Method Detail
-
setVisible
public static void setVisible(boolean isVisible)
Makes the drawing window visible or invisible.- Parameters:
isVisible
- iftrue
, makes the drawing window visible, otherwise hides the drawing window.
-
setCanvasSize
public static void setCanvasSize()
Sets the canvas (drawing area) to be 512-by-512 pixels. This also clears the current drawing using the default background color (white). Ordinarily, this method is called once, at the very beginning of a program.
-
setCanvasSize
public static void setCanvasSize(int canvasWidth, int canvasHeight)
Sets the canvas (drawing area) to be width-by-height pixels. This also clears the current drawing using the default background color (white). Ordinarily, this method is called once, at the very beginning of a program.- Parameters:
canvasWidth
- the width as a number of pixelscanvasHeight
- the height as a number of pixels- Throws:
IllegalArgumentException
- unless bothcanvasWidth
andcanvasHeight
are positive
-
close
public static void close()
Closes the standard drawing window. This allows the client program to terminate instead of requiring the user to close the standard drawing window manually. Drawing after calling this method will restore the previous window state.
-
setTitle
public static void setTitle(String title)
Sets the title of the standard drawing window to the specified string.- Parameters:
title
- the title- Throws:
IllegalArgumentException
- iftitle
isnull
-
setXscale
public static void setXscale()
Sets the x-scale to the default range (between 0.0 and 1.0).
-
setYscale
public static void setYscale()
Sets the y-scale to the default range (between 0.0 and 1.0).
-
setScale
public static void setScale()
Sets both the x-scale and y-scale to the default range (between 0.0 and 1.0).
-
setXscale
public static void setXscale(double min, double max)
Sets the x-scale to the specified range.- Parameters:
min
- the minimum value of the x-scalemax
- the maximum value of the x-scale- Throws:
IllegalArgumentException
- if(max == min)
IllegalArgumentException
- if eithermin
ormax
is either NaN or infinite
-
setYscale
public static void setYscale(double min, double max)
Sets the y-scale to the specified range.- Parameters:
min
- the minimum value of the y-scalemax
- the maximum value of the y-scale- Throws:
IllegalArgumentException
- if(max == min)
IllegalArgumentException
- if eithermin
ormax
is either NaN or infinite
-
setScale
public static void setScale(double min, double max)
Sets both the x-scale and y-scale to the (same) specified range.- Parameters:
min
- the minimum value of the x- and y-scalesmax
- the maximum value of the x- and y-scales- Throws:
IllegalArgumentException
- if(max == min)
IllegalArgumentException
- if eithermin
ormax
is either NaN or infinite
-
clear
public static void clear()
Clears the screen using the default background color (white).
-
clear
public static void clear(Color color)
Clears the screen using the specified background color. To make the background transparent, useStdDraw.TRANSPARENT
.- Parameters:
color
- the color to make the background- Throws:
IllegalArgumentException
- ifcolor
isnull
-
getPenRadius
public static double getPenRadius()
Returns the current pen radius.- Returns:
- the current value of the pen radius
-
setPenRadius
public static void setPenRadius()
Sets the pen size to the default size (0.002). The pen is circular, so that lines have rounded ends, and when you set the pen radius and draw a point, you get a circle of the specified radius. The pen radius is not affected by coordinate scaling.
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setPenRadius
public static void setPenRadius(double radius)
Sets the radius of the pen to the specified size. The pen is circular, so that lines have rounded ends, and when you set the pen radius and draw a point, you get a circle of the specified radius. The pen radius is not affected by coordinate scaling.- Parameters:
radius
- the radius of the pen- Throws:
IllegalArgumentException
- ifradius
is negative, NaN, or infinite
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getPenColor
public static Color getPenColor()
Returns the current pen color.- Returns:
- the current pen color
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getBackgroundColor
public static Color getBackgroundColor()
Returns the current background color.- Returns:
- the current background color
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setPenColor
public static void setPenColor()
Sets the pen color to the default color (black).
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setPenColor
public static void setPenColor(Color color)
Sets the pen color to the specified color.There are a number predefined pen colors, such as
StdDraw.BLACK
,StdDraw.WHITE
,StdDraw.RED
,StdDraw.GREEN
, andStdDraw.BLUE
.- Parameters:
color
- the color to make the pen- Throws:
IllegalArgumentException
- ifcolor
isnull
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setPenColor
public static void setPenColor(int red, int green, int blue)
Sets the pen color to the specified RGB color.- Parameters:
red
- the amount of red (between 0 and 255)green
- the amount of green (between 0 and 255)blue
- the amount of blue (between 0 and 255)- Throws:
IllegalArgumentException
- ifred
,green
, orblue
is outside its prescribed range
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getFont
public static Font getFont()
Returns the current font.- Returns:
- the current font
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setFont
public static void setFont()
Sets the font to the default font (sans serif, 16 point).
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setFont
public static void setFont(Font font)
Sets the font to the specified value.- Parameters:
font
- the font- Throws:
IllegalArgumentException
- iffont
isnull
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line
public static void line(double x0, double y0, double x1, double y1)
Draws a line segment between (x0, y0) and (x1, y1).- Parameters:
x0
- the x-coordinate of one endpointy0
- the y-coordinate of one endpointx1
- the x-coordinate of the other endpointy1
- the y-coordinate of the other endpoint- Throws:
IllegalArgumentException
- if any coordinate is either NaN or infinite
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point
public static void point(double x, double y)
Draws a point centered at (x, y). The point is a filled circle whose radius is equal to the pen radius. To draw a single-pixel point, first set the pen radius to 0.- Parameters:
x
- the x-coordinate of the pointy
- the y-coordinate of the point- Throws:
IllegalArgumentException
- if eitherx
ory
is either NaN or infinite
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circle
public static void circle(double x, double y, double radius)
Draws a circle of the specified radius, centered at (x, y).- Parameters:
x
- the x-coordinate of the center of the circley
- the y-coordinate of the center of the circleradius
- the radius of the circle- Throws:
IllegalArgumentException
- ifradius
is negativeIllegalArgumentException
- if any argument is either NaN or infinite
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filledCircle
public static void filledCircle(double x, double y, double radius)
Draws a filled circle of the specified radius, centered at (x, y).- Parameters:
x
- the x-coordinate of the center of the circley
- the y-coordinate of the center of the circleradius
- the radius of the circle- Throws:
IllegalArgumentException
- ifradius
is negativeIllegalArgumentException
- if any argument is either NaN or infinite
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ellipse
public static void ellipse(double x, double y, double semiMajorAxis, double semiMinorAxis)
Draws an ellipse with the specified semimajor and semiminor axes, centered at (x, y).- Parameters:
x
- the x-coordinate of the center of the ellipsey
- the y-coordinate of the center of the ellipsesemiMajorAxis
- is the semimajor axis of the ellipsesemiMinorAxis
- is the semiminor axis of the ellipse- Throws:
IllegalArgumentException
- if eithersemiMajorAxis
orsemiMinorAxis
is negativeIllegalArgumentException
- if any argument is either NaN or infinite
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filledEllipse
public static void filledEllipse(double x, double y, double semiMajorAxis, double semiMinorAxis)
Draws a filled ellipse with the specified semimajor and semiminor axes, centered at (x, y).- Parameters:
x
- the x-coordinate of the center of the ellipsey
- the y-coordinate of the center of the ellipsesemiMajorAxis
- is the semimajor axis of the ellipsesemiMinorAxis
- is the semiminor axis of the ellipse- Throws:
IllegalArgumentException
- if eithersemiMajorAxis
orsemiMinorAxis
is negativeIllegalArgumentException
- if any argument is either NaN or infinite
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arc
public static void arc(double x, double y, double radius, double angle1, double angle2)
Draws a circular arc of the specified radius, centered at (x, y), from angle1 to angle2 (in degrees).- Parameters:
x
- the x-coordinate of the center of the circley
- the y-coordinate of the center of the circleradius
- the radius of the circleangle1
- the starting angle. 0 would mean an arc beginning at 3 o'clock.angle2
- the angle at the end of the arc. For example, if you want a 90 degree arc, then angle2 should be angle1 + 90.- Throws:
IllegalArgumentException
- ifradius
is negativeIllegalArgumentException
- if any argument is either NaN or infinite
-
square
public static void square(double x, double y, double halfLength)
Draws a square of the specified size, centered at (x, y).- Parameters:
x
- the x-coordinate of the center of the squarey
- the y-coordinate of the center of the squarehalfLength
- one half the length of any side of the square- Throws:
IllegalArgumentException
- ifhalfLength
is negativeIllegalArgumentException
- if any argument is either NaN or infinite
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filledSquare
public static void filledSquare(double x, double y, double halfLength)
Draws a filled square of the specified size, centered at (x, y).- Parameters:
x
- the x-coordinate of the center of the squarey
- the y-coordinate of the center of the squarehalfLength
- one half the length of any side of the square- Throws:
IllegalArgumentException
- ifhalfLength
is negativeIllegalArgumentException
- if any argument is either NaN or infinite
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rectangle
public static void rectangle(double x, double y, double halfWidth, double halfHeight)
Draws a rectangle of the specified size, centered at (x, y).- Parameters:
x
- the x-coordinate of the center of the rectangley
- the y-coordinate of the center of the rectanglehalfWidth
- one half the width of the rectanglehalfHeight
- one half the height of the rectangle- Throws:
IllegalArgumentException
- if eitherhalfWidth
orhalfHeight
is negativeIllegalArgumentException
- if any argument is either NaN or infinite
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filledRectangle
public static void filledRectangle(double x, double y, double halfWidth, double halfHeight)
Draws a filled rectangle of the specified size, centered at (x, y).- Parameters:
x
- the x-coordinate of the center of the rectangley
- the y-coordinate of the center of the rectanglehalfWidth
- one half the width of the rectanglehalfHeight
- one half the height of the rectangle- Throws:
IllegalArgumentException
- if eitherhalfWidth
orhalfHeight
is negativeIllegalArgumentException
- if any argument is either NaN or infinite
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polygon
public static void polygon(double[] x, double[] y)
Draws a polygon with the vertices (x0, y0), (x1, y1), ..., (xn–1, yn–1).- Parameters:
x
- an array of all the x-coordinates of the polygony
- an array of all the y-coordinates of the polygon- Throws:
IllegalArgumentException
- unlessx[]
andy[]
are of the same lengthIllegalArgumentException
- if any coordinate is either NaN or infiniteIllegalArgumentException
- if eitherx[]
ory[]
isnull
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filledPolygon
public static void filledPolygon(double[] x, double[] y)
Draws a filled polygon with the vertices (x0, y0), (x1, y1), ..., (xn–1, yn–1).- Parameters:
x
- an array of all the x-coordinates of the polygony
- an array of all the y-coordinates of the polygon- Throws:
IllegalArgumentException
- unlessx[]
andy[]
are of the same lengthIllegalArgumentException
- if any coordinate is either NaN or infiniteIllegalArgumentException
- if eitherx[]
ory[]
isnull
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picture
public static void picture(double x, double y, String filename)
Draws the specified image centered at (x, y). The supported image formats are typically JPEG, PNG, GIF, TIFF, and BMP. As an optimization, the picture is cached, so there is no performance penalty for redrawing the same image multiple times (e.g., in an animation). However, if you change the picture file after drawing it, subsequent calls will draw the original picture.- Parameters:
x
- the center x-coordinate of the imagey
- the center y-coordinate of the imagefilename
- the name of the image/picture, e.g., "ball.gif"- Throws:
IllegalArgumentException
- if the image filename is invalidIllegalArgumentException
- if eitherx
ory
is either NaN or infinite
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picture
public static void picture(double x, double y, String filename, double degrees)
Draws the specified image centered at (x, y), rotated given number of degrees. The supported image formats are typically JPEG, PNG, GIF, TIFF, and BMP.- Parameters:
x
- the center x-coordinate of the imagey
- the center y-coordinate of the imagefilename
- the name of the image/picture, e.g., "ball.gif"degrees
- is the number of degrees to rotate counterclockwise- Throws:
IllegalArgumentException
- if the image filename is invalidIllegalArgumentException
- ifx
,y
,degrees
is NaN or infiniteIllegalArgumentException
- iffilename
isnull
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picture
public static void picture(double x, double y, String filename, double scaledWidth, double scaledHeight)
Draws the specified image centered at (x, y), rescaled to the specified bounding box. The supported image formats are typically JPEG, PNG, GIF, TIFF, and BMP.- Parameters:
x
- the center x-coordinate of the imagey
- the center y-coordinate of the imagefilename
- the name of the image/picture, e.g., "ball.gif"scaledWidth
- the width of the scaled image (in screen coordinates)scaledHeight
- the height of the scaled image (in screen coordinates)- Throws:
IllegalArgumentException
- if eitherscaledWidth
orscaledHeight
is negativeIllegalArgumentException
- if the image filename is invalidIllegalArgumentException
- ifx
ory
is either NaN or infiniteIllegalArgumentException
- iffilename
isnull
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picture
public static void picture(double x, double y, String filename, double scaledWidth, double scaledHeight, double degrees)
Draws the specified image centered at (x, y), rotated given number of degrees, and rescaled to the specified bounding box. The supported image formats are typically JPEG, PNG, GIF, TIFF, and BMP.- Parameters:
x
- the center x-coordinate of the imagey
- the center y-coordinate of the imagefilename
- the name of the image/picture, e.g., "ball.gif"scaledWidth
- the width of the scaled image (in screen coordinates)scaledHeight
- the height of the scaled image (in screen coordinates)degrees
- is the number of degrees to rotate counterclockwise- Throws:
IllegalArgumentException
- if eitherscaledWidth
orscaledHeight
is negativeIllegalArgumentException
- if the image filename is invalid
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text
public static void text(double x, double y, String text)
Writes the given text string in the current font, centered at (x, y).- Parameters:
x
- the center x-coordinate of the texty
- the center y-coordinate of the texttext
- the text to write- Throws:
IllegalArgumentException
- iftext
isnull
IllegalArgumentException
- ifx
ory
is either NaN or infinite
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text
public static void text(double x, double y, String text, double degrees)
Writes the given text string in the current font, centered at (x, y) and rotated by the specified number of degrees.- Parameters:
x
- the center x-coordinate of the texty
- the center y-coordinate of the texttext
- the text to writedegrees
- is the number of degrees to rotate counterclockwise- Throws:
IllegalArgumentException
- iftext
isnull
IllegalArgumentException
- ifx
,y
, ordegrees
is either NaN or infinite
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textLeft
public static void textLeft(double x, double y, String text)
Writes the given text string in the current font, left-aligned at (x, y).- Parameters:
x
- the x-coordinate of the texty
- the y-coordinate of the texttext
- the text- Throws:
IllegalArgumentException
- iftext
isnull
IllegalArgumentException
- ifx
ory
is either NaN or infinite
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textRight
public static void textRight(double x, double y, String text)
Writes the given text string in the current font, right-aligned at (x, y).- Parameters:
x
- the x-coordinate of the texty
- the y-coordinate of the texttext
- the text to write- Throws:
IllegalArgumentException
- iftext
isnull
IllegalArgumentException
- ifx
ory
is either NaN or infinite
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pause
public static void pause(int t)
Pauses for t milliseconds. This method is intended to support computer animations.- Parameters:
t
- number of milliseconds- Throws:
IllegalArgumentException
- ift
is negative
-
show
public static void show()
Copies offscreen buffer to onscreen buffer. There is no reason to call this method unless double buffering is enabled.
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enableDoubleBuffering
public static void enableDoubleBuffering()
Enables double buffering. All subsequent calls to drawing methods such asline()
,circle()
, andsquare()
will be deferred until the next call to show(). Useful for animations.
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disableDoubleBuffering
public static void disableDoubleBuffering()
Disables double buffering. All subsequent calls to drawing methods such asline()
,circle()
, andsquare()
will be displayed on screen when called. This is the default.
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save
public static void save(String filename)
Saves the drawing to a file in a supported file format (typically JPEG, PNG, GIF, TIFF, and BMP). The filetype extension must be.jpg
,.png
,.gif
,.bmp
, or.tif
.- Parameters:
filename
- the name of the file- Throws:
IllegalArgumentException
- iffilename
isnull
IllegalArgumentException
- iffilename
is the empty stringIllegalArgumentException
- iffilename
has invalid filetype extensionIllegalArgumentException
- if cannot write the filefilename
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actionPerformed
public void actionPerformed(ActionEvent event)
This method cannot be called directly.- Specified by:
actionPerformed
in interfaceActionListener
-
isMousePressed
public static boolean isMousePressed()
Returns true if the mouse is being pressed.- Returns:
true
if the mouse is being pressed;false
otherwise
-
mouseX
public static double mouseX()
Returns the x-coordinate of the mouse.- Returns:
- the x-coordinate of the mouse
-
mouseY
public static double mouseY()
Returns the y-coordinate of the mouse.- Returns:
- y-coordinate of the mouse
-
mouseClicked
public void mouseClicked(MouseEvent event)
This method cannot be called directly.- Specified by:
mouseClicked
in interfaceMouseListener
-
mouseEntered
public void mouseEntered(MouseEvent event)
This method cannot be called directly.- Specified by:
mouseEntered
in interfaceMouseListener
-
mouseExited
public void mouseExited(MouseEvent event)
This method cannot be called directly.- Specified by:
mouseExited
in interfaceMouseListener
-
mousePressed
public void mousePressed(MouseEvent event)
This method cannot be called directly.- Specified by:
mousePressed
in interfaceMouseListener
-
mouseReleased
public void mouseReleased(MouseEvent event)
This method cannot be called directly.- Specified by:
mouseReleased
in interfaceMouseListener
-
mouseDragged
public void mouseDragged(MouseEvent event)
This method cannot be called directly.- Specified by:
mouseDragged
in interfaceMouseMotionListener
-
mouseMoved
public void mouseMoved(MouseEvent event)
This method cannot be called directly.- Specified by:
mouseMoved
in interfaceMouseMotionListener
-
hasNextKeyTyped
public static boolean hasNextKeyTyped()
Returns true if the user has typed a key (that has not yet been processed).- Returns:
true
if the user has typed a key (that has not yet been processed bynextKeyTyped()
;false
otherwise
-
nextKeyTyped
public static char nextKeyTyped()
Returns the next key that was typed by the user (that your program has not already processed). This method should be preceded by a call tohasNextKeyTyped()
to ensure that there is a next key to process. This method returns a Unicode character corresponding to the key typed (such as'a'
or'A'
). It cannot identify action keys (such as F1 and arrow keys) or modifier keys (such as control).- Returns:
- the next key typed by the user (that your program has not already processed).
- Throws:
NoSuchElementException
- if there is no remaining key
-
isKeyPressed
public static boolean isKeyPressed(int keycode)
Returns true if the given key is being pressed.This method takes the keycode (corresponding to a physical key) as an argument. It can handle action keys (such as F1 and arrow keys) and modifier keys (such as shift and control). See
KeyEvent
for a description of key codes.- Parameters:
keycode
- the key to check if it is being pressed- Returns:
true
ifkeycode
is currently being pressed;false
otherwise
-
keyTyped
public void keyTyped(KeyEvent event)
This method cannot be called directly.- Specified by:
keyTyped
in interfaceKeyListener
-
keyPressed
public void keyPressed(KeyEvent event)
This method cannot be called directly.- Specified by:
keyPressed
in interfaceKeyListener
-
keyReleased
public void keyReleased(KeyEvent event)
This method cannot be called directly.- Specified by:
keyReleased
in interfaceKeyListener
-
main
public static void main(String[] args)
Test client.- Parameters:
args
- the command-line arguments
-
-