8.7. Python’s turtle vs C-Turtle¶
C-Turtle varies from the Python turtle library primarily in syntax. Most of the methods
are exactly the same between implementations, however there are a few notable differences between the two.
Colors, for example, must be surrounded by curly brackets (e.g, ‘{’ and ‘}’) when referring to them by a
name such as “red”, “green”, or “blue”. You can also ask for a random color by using the string “random”.
ct::Color red = {"red"};
ct::Color green = {"green"};
ct::Color blue = {"blue"};
ct::Color random = {"random"};
//This works due to the variable above...
turtle.pencolor(red);
//And so do these.
turtle.pencolor({"green"});
turtle.pencolor({"random"});
Unlike in Python, the write method does not allow you to specify a font nor size. This is due to the complex handling
and of Fonts by operating systems that is far more cumbersome to manage in C++. Furthermore, there is no “world” screen mode like
there is in Python. Normally, this would allow you to specify the “bounds” of your canvas (e.g, specify minimum
and maximum coordinates for your canvas).
Default shapes are also different and somewhat limited in comparison. Python offers six shapes by default, being “arrow”, “circle”,
“turtle”, “square”, “triangle”, and “classic”. C-Turtle, on the other hand, offers four shapes by default: “arrow”, “triangle”,
“indented triangle”, and “square”.
There are a few utility methods available in C-Turtle that are not available in Python, such as shift and middle.
The former of the two, shift, simply adds to the X and Y coordinate position of the turtle. If your turtle is at coordinate
600x, 400y and shift is called with coordinate 50x and -50y, the turtle’s final position would be 650x, 350y. The latter
of the two, middle, returns the point exactly between two other points. See the examples below.
turtle.goTo(600, 400);
turtle.shift(50, -50);
//Turtle position is now 650x, 350y.
ct::Point a = {400, 300};
ct::Point b = {450, 300};
//Should equal the point 425x, 300y.
ct::Point middle = ct::middle(a, b);