diff --git a/turtle-lib-macroquad/examples/dragon.rs b/turtle-lib-macroquad/examples/dragon.rs new file mode 100644 index 0000000..47633f4 --- /dev/null +++ b/turtle-lib-macroquad/examples/dragon.rs @@ -0,0 +1,93 @@ +//! Draw a dragon curve, more specifically a Heighway dragon. +//! +//! (https://en.wikipedia.org/wiki/Dragon_curve) +//! +//! As can be seen in the above Wikipedia article, the Heighway dragon can be +//! constructed by repeatedly folding a strip of paper and looking at the +//! directions of the folds/turns. +//! +//! Starting with a strip going left to right (l2r): +//! +//! start|--->---l2r--->---|end +//! +//! you might fold it like this: +//! +//! end|---<---r2l---<---\ +//! start|->---l2r--->---/ +//! +//! Getting a l2r strip, followed by a left turn, followed by a r2l strip. +//! +//! Folding a right to left strip: +//! +//! end|---<---r2l---<---|start +//! +//! In the same way: +//! +//! start|-->---l2r--->---\ +//! end|----<---r2l---<---/ +//! +//! Would give you a l2r, followed by a right turn, followed by a r2l strip. +//! +//! As you can see, the only difference between the two is the direction of +//! the turn in the middle. +//! +//! This folding of paper is simulated by recursively calling the dragon(..) +//! function, passing the direction of the turn for this fold as an angle +//! (+90 for a right turn, -90 for a left turn). + +use turtle_lib_macroquad::*; + +#[turtle_main("Dragon Curve")] +fn draw_dragon(turtle: &mut TurtlePlan) { + // Fast drawing + turtle.set_speed(1200); + + // Start position + turtle.pen_up(); + turtle.backward(160.0); + turtle.right(90.0); + turtle.forward(110.0); + turtle.pen_down(); + turtle.set_pen_width(6.); + + // Draw the dragon curve with 13 folds + dragon(turtle, -90.0, 13, 0.0, 255.0); + + // Hide turtle when done + turtle.hide(); +} + +/// Draw the dragon curve by simulating folding a strip of paper +/// +/// Arguments: +/// `fold_direction`: The direction of the fold, +90 for a right, -90 for a +/// left turn. +/// `num_folds`: The number of times to fold the 'strip of paper'. +/// `color_start`/`color_end`: The color at the start/end of this subsection +/// of the curve as a number 0-255. +fn dragon( + turtle: &mut TurtlePlan, + fold_direction: f32, + num_folds: usize, + color_start: f32, + color_end: f32, +) { + let color_mid = (color_start + color_end) * 0.5; + + if num_folds == 0 { + // Mapping a color number 0-255 to an RGB gradient + let red = ((color_mid - 128.0).abs() * 2.0).floor(); + let green = color_mid; + let blue = 160.0; + + turtle.set_pen_color(Color::new(red / 255.0, green / 255.0, blue / 255.0, 1.0)); + turtle.forward(10.0); + return; + } + + // Draw a left to right strip (which has a left turn in the middle) + dragon(turtle, -90.0, num_folds - 1, color_start, color_mid); + turtle.right(fold_direction); + // Draw a right to left strip (which has a right turn in the middle) + dragon(turtle, 90.0, num_folds - 1, color_mid, color_end); +} diff --git a/turtle-lib-macroquad/examples/sierpinski_triangle.rs b/turtle-lib-macroquad/examples/sierpinski_triangle.rs new file mode 100644 index 0000000..2922a5b --- /dev/null +++ b/turtle-lib-macroquad/examples/sierpinski_triangle.rs @@ -0,0 +1,98 @@ +//! Draws a Sierpiński triangle with automatic positioning and sizing. +//! +//! The Sierpiński triangle is a fairly simple self-similar fractal geometric shape: it consists of +//! many nested equilateral triangles. More formally, such a triangle is itself three triangles of +//! one level below and a size divided by two. Level zero means a simple equilateral triangle. The +//! drawing procedure is as follows, for a given level and size: +//! +//! * If level is 0 +//! * Draw an equilateral triangle of the given size. +//! * otherwise +//! * Draw the half-sized level - 1 triangle at the bottom left. +//! * Go the start of the bottom-right slot. +//! * Draw a half-sized level - 1 triangle. +//! * Go to the start of the top slot. +//! * Draw a half-sized level - 1 triangle. +//! +//! That is relatively easy to implement, as long as you follow these steps and let recursion do +//! the rest. Another little bonus this example provides is the ability to customize the drawing +//! size: the triangle will stay correctly sized and positioned automatically. + +use macroquad::window::{screen_height, screen_width}; +use turtle_lib_macroquad::*; + +/// The number of levels to draw following the recursive procedure. +const LEVELS: u8 = 9; +/// Triangle size (adjust to fit nicely in window) +const TRIANGLE_SIZE: f32 = 300.0; + +#[turtle_main("Sierpiński Triangle")] +fn draw_sierpinski(turtle: &mut TurtlePlan) { + turtle.set_speed(1500); // Fast drawing + turtle.set_pen_width(0.2); + + // Auto-sized procedure + sierpinski_triangle_auto(turtle, LEVELS); + + // Hide turtle when done drawing in order to fully reveal the result + turtle.hide(); +} + +/// Recursive function drawing a Sierpiński triangle. +/// +/// It will do it with the given `turtle` and start at its current position and heading. `level` +/// is the depth of the drawing to be done, zero meaning a simple triangle. `size` is the length +/// of the outermost triangle's sides. +fn sierpinski_triangle(turtle: &mut TurtlePlan, level: u8, size: f32) { + // When level 0 is reached, just draw an equilateral triangle. + if level == 0 { + turtle.pen_down(); + + for _ in 0..3 { + turtle.forward(size); + turtle.left(120.0); + } + + turtle.pen_up(); + } else { + // Parameters for subsequent calls are the same. + let next_level = level - 1; + let next_size = size / 2.0; + + // Bottom-left triangle. + sierpinski_triangle(turtle, next_level, next_size); + + turtle.forward(next_size); + + // Bottom-right triangle. + sierpinski_triangle(turtle, next_level, next_size); + + turtle.left(120.0); + turtle.forward(next_size); + turtle.right(120.0); + + // Top triangle. + sierpinski_triangle(turtle, next_level, next_size); + + // Go back to the start. + turtle.right(120.0); + turtle.forward(next_size); + turtle.left(120.0); + } +} + +/// Draws a Sierpiński triangle with automatic size and start point. +/// +/// `level` is still required, it can't be computed automatically. However, given the used +/// canvas size, it will compute the appropriate size and start point so the triangle gets +/// centered and occupies as much drawing space as possible while staying in bounds. +fn sierpinski_triangle_auto(turtle: &mut TurtlePlan, level: u8) { + let size = TRIANGLE_SIZE; + + turtle.pen_up(); + turtle.go_to((-screen_width() / 2.0 + 20.0, screen_height() / 2.0 - 20.0)); + turtle.set_heading(0.0); // 0 = East (pointing right) + + // The drawing itself. + sierpinski_triangle(turtle, level, size); +} diff --git a/turtle-lib-macroquad/examples/v1_0_0.rs b/turtle-lib-macroquad/examples/v1_0_0.rs new file mode 100644 index 0000000..34cba6c --- /dev/null +++ b/turtle-lib-macroquad/examples/v1_0_0.rs @@ -0,0 +1,126 @@ +//! Celebrates the 1.0.0 release of the original sunjay/turtle library. +//! +//! This example draws "1.0.0" with decorative background lines and filled shapes. +//! Ported from the original sunjay/turtle example. + +use turtle_lib_macroquad::*; + +#[turtle_main("Version 1.0.0")] +fn draw_version(turtle: &mut TurtlePlan) { + turtle.set_pen_width(10.0); + turtle.set_speed(999); // instant + turtle.pen_up(); + turtle.go_to(vec2(350.0, 178.0)); + turtle.pen_down(); + + bg_lines(turtle); + + turtle.pen_up(); + turtle.go_to(vec2(-270.0, -200.0)); + turtle.set_heading(90.0); + turtle.pen_down(); + + turtle.set_speed(100); // normal + turtle.set_pen_color(BLUE); + // Cyan with alpha - using RGB values for Color::from("#00E5FF") + turtle.set_fill_color([0.0, 0.898, 1.0, 0.75]); + + one(turtle); + + turtle.set_speed(200); // faster + + turtle.pen_up(); + turtle.left(90.0); + turtle.backward(50.0); + turtle.pen_down(); + + small_circle(turtle); + + turtle.pen_up(); + turtle.backward(150.0); + turtle.pen_down(); + + zero(turtle); + + turtle.pen_up(); + turtle.backward(150.0); + turtle.pen_down(); + + small_circle(turtle); + + turtle.pen_up(); + turtle.backward(150.0); + turtle.pen_down(); + + zero(turtle); +} + +fn bg_lines(turtle: &mut TurtlePlan) { + // Light green color for background lines (#76FF03) + turtle.set_pen_color([0.463, 1.0, 0.012, 1.0].into()); + turtle.set_heading(165.0); + turtle.forward(280.0); + + turtle.left(147.0); + turtle.forward(347.0); + + turtle.right(158.0); + turtle.forward(547.0); + + turtle.left(138.0); + turtle.forward(539.0); + + turtle.right(168.0); + turtle.forward(477.0); + + turtle.left(154.0); + turtle.forward(377.0); + + turtle.right(158.0); + turtle.forward(329.0); +} + +fn small_circle(turtle: &mut TurtlePlan) { + turtle.begin_fill(); + for _ in 0..90 { + turtle.forward(1.0); + turtle.right(4.0); + } + turtle.end_fill(); +} + +fn one(turtle: &mut TurtlePlan) { + turtle.begin_fill(); + for _ in 0..2 { + turtle.forward(420.0); + turtle.left(90.0); + turtle.forward(50.0); + turtle.left(90.0); + } + turtle.end_fill(); +} + +fn zero(turtle: &mut TurtlePlan) { + turtle.begin_fill(); + for _ in 0..2 { + arc_right(turtle); + arc_forward(turtle); + } + turtle.end_fill(); +} + +fn arc_right(turtle: &mut TurtlePlan) { + // Draw an arc that moves right faster than it moves forward + for i in 0..90 { + turtle.forward(3.0); + turtle.right((90.0 - i as f32) / 45.0); + } +} + +fn arc_forward(turtle: &mut TurtlePlan) { + // Draw an arc that moves forward faster than it moves right + for i in 0..90 { + turtle.forward(3.0); + turtle.right(i as f32 / 45.0); + } +}