From 0d350e10738e19e4562f847b6b8f233605194ba4 Mon Sep 17 00:00:00 2001
From: shoe <shoe@tilde.town>
Date: Fri, 21 Mar 2025 21:38:47 +0000
Subject: [PATCH] Erase the trail as it goes, including deleting array items
---
random-walkers.js | 70 +++++++++++++++++++++++------------------------
1 file changed, 34 insertions(+), 36 deletions(-)
diff --git a/random-walkers.js b/random-walkers.js
index 4d8d49f..253db93 100644
--- a/random-walkers.js
+++ b/random-walkers.js
@@ -65,35 +65,46 @@ function init_walk() {
setInterval(draw, 20);
// TODO: it would be cool to have this changable, but I may just ... not
setInterval(move_walker, controls.step_time);
+}
- /*
-
- // Set default values for walker pos and empty the trail
- // TODO: ACTUAL DEFAULT VALUE AT CENTER.
- walker_position = {x: 0, y: 0};
- trail_positions = [];
- // Create array of walkers with set parameters, start walkers in center of canvas
- walker_array = []
- for (var i = 0; i < 1; i++) {
- var walker = {
- x_position: canvas.width / 2,
- y_position: canvas.height / 2,
- line_width: 1,
- color: controls.color,
- speed: 5,
- angle: Math.random() * 360,
- halt: false,
+// check if the trails array has a position.
+// return index if found, or null if not.
+function trails_find_position(row, col) {
+ for (var i = 0; i < trails.length; i++) {
+ var t = trails[i];
+ if (t.row === row && t.col === col) {
+ return i;
}
- walker.x_velocity = walker.speed * Math.cos(walker.angle)
- walker.y_velocity = walker.speed * Math.sin(walker.angle)
- walker_array.push(walker)
}
- */
+ return null;
}
function move_walker() {
- // leave a trail
- trails.push({row: walker.row, col: walker.col, color: walker.color});
+ // leave a trail behind
+ var index = trails_find_position(walker.row, walker.col);
+ if (index) {
+ trails[index].color = walker.color;
+ } else {
+ trails.push({row: walker.row, col: walker.col, color: walker.color});
+ }
+
+ // for all existing trails, make them darker
+ for (var i = 0; i < trails.length; i++) {
+ var t = trails[i];
+ t.color = tweak_color_luminance(t.color, -0.1);
+
+ // delete any trails with 0 for first digit of RGB
+ // (think of them as near-black)
+ // e.g. #050500
+ if (t.color[1] === "0" && t.color[3] == "0" && t.color[5] == "0") {
+ // draw black there just to be safe
+ draw_grid_square(t.row, t.col, "black");
+
+ // delete the item from the array
+ trails.splice(i, 1);
+ }
+ }
+ console.log(`${trails.length} items in trails array`);
// move in random dir
add_random_direction(walker);
@@ -163,9 +174,6 @@ function draw() {
console.log(`dimensions changed from ${old_width}x${old_height} to ${ctx.canvas.width}x${ctx.canvas.height}`);
}
- // grid of all one color.
- draw_grid();
-
// draw a colored square at the walker location
draw_grid_square(walker.row, walker.col, walker.color);
@@ -188,16 +196,6 @@ function draw_grid_square(row, col, color) {
ctx.fillRect(pos_h, pos_v, controls.cell_size - (2*margin), controls.cell_size - (2*margin));
}
-
-function draw_grid() {
- // Actually draw the cells lol
- for (var row = 0; row < n_rows; row++) {
- for (var col = 0; col < n_cols; col++) {
- draw_grid_square(row, col, "#282828");
- }
- }
-}
-
/****************************************************************************
* ON SCRIPT LOAD *
****************************************************************************/