1. The state of the brush
On the canvas, there is a coordinate axis whose coordinate origin is the center of the canvas by default, and there is a small turtle facing the positive direction of the x-axis on the coordinate origin. Here we use two words to describe the little turtle: coordinate origin (position), facing the positive direction of the x-axis (direction). In turtle drawing, the position and direction are used to describe the state of the little turtle (brush).
2. Properties of the brush
Brush (brush attributes, color, line width, etc.)
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turtle.pensize() : Set the width of the brush (the thickness of the brush line is the specified size);
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turtle.pencolor() : No parameters are passed in, and the current pen color is returned. The parameters passed in set the pen color, which can be strings such as "green", "red", or RGB3 tuples.
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turtle.speed(speed) : Set the pen movement speed. The pen drawing speed range is [0,10] integer. The larger the number, the faster it is.
3. Drawing commands
There are many commands for manipulating turtle drawing, and these commands can be divided into three types: one is the movement command , one is the brush control command , and the other is the global control command .
(1) Brush movement command
| Order | illustrate |
|---|---|
| turtle.forward(distance) | Move distance pixels in the direction of the current brush |
| turtle.backward(distance) | Move distance pixels in the opposite direction of the current brush |
| turtle.right(degree) | Move clockwise degree° |
| turtle.left(degree) | Move counterclockwise degree° |
| turtle.pendown() | Put down the brush and continue painting when you move to the designated location |
| turtle.goto(x,y) | Move the brush to the position where the coordinates are x, y |
| turtle.penup() | Lift the pen to move without drawing graphics. Used to draw in another place. Used in conjunction with pendown(). |
| turtle.circle() | Draw a circle with a positive (negative) radius, which means the center of the circle is to the left (right) of the brush. |
| setx() | Move the current x-axis to the specified position |
| sets( ) | Move the current y-axis to the specified position |
| setheading(angle) | Set the current orientation to angle |
| home() | Sets the current brush position as the origin, facing east. |
| dot（r） | Draws a dot of specified diameter and color |
(2) Brush control commands
| Order | illustrate |
|---|---|
| turtle.fillcolor(colorstring) | Fill color of drawing graphics |
| turtle.color(color1, color2) | Also set pencolor=color1, fillcolor=color2 |
| turtle.filling() | Returns whether the current filling state is |
| turtle.begin_fill() | Ready to start filling graphics |
| turtle.end_fill() | Filling completed |
| turtle.hideturtle() | Hide the turtle shape of the brush |
| turtle.showturtle() | Shows the turtle shape of the brush |
(3) Global control commands
| Order | illustrate |
|---|---|
| turtle.clear() | Clear the turtle window, but the turtle's position and status will not change |
| turtle.reset() | Clear the window and reset the turtle state to the starting state |
| turtle.undo() | Undo the last turtle action |
| turtle.isvisible() | Returns whether the current turtle is visible |
| stamp() | Copy current graphic |
| turtle.write(s [,font=(“font-name”,font_size,“font_type”)]) | Write text, s is the text content, font is the parameter of the font, which are the font name, size and type respectively; font is optional, and the font parameter is also optional |
(4) Other orders
| Order | illustrate |
|---|---|
| turtle.mainloop()或turtle.done() | Start the event loop - call Tkinter's mainloop function. Must be the last statement in a turtle graphics program. |
| turtle.mode(mode=None) | Set turtle mode ("standard", "logo" or "world") and perform a reset. If no mode is given, returns the current mode. (1. standard: right (east) counterclockwise 2. logo: upward (north) clockwise) |
| turtle.delay(delay=None) | Sets or returns the drawing delay in milliseconds. |
| turtle.begin_poly() | Start recording the vertices of the polygon. The current turtle position is the first vertex of the polygon. |
| turtle.end_poly() | Stops recording polygon vertices. The current turtle position is the last vertex of the polygon. Will be connected to the first vertex. |
| turtle.get_poly() | Returns the last recorded polygon. |
4. Draw a circle
turtle.circle(radius,extent=None,steps=None)
Description: Draw a circle with a given radius
Parameters:
radius (radius): The radius is positive (negative), which means the center of the circle is to the left (right) of the brush to draw a circle;
extent (radians) (optional);
steps (optional) (the radius is The regular polygon inscribed in the circle with radius, the number of sides of the polygon is steps).
Example:
circle(50) #Full circle;
circle(50,steps=3) #Triangle;
circle(120,180) #Semicircle
