From 964e6b5020152e1a0be506b7afaf5dc17a0994e8 Mon Sep 17 00:00:00 2001
From: Justin Lin <justin.sdk@gmail.com>
Date: Wed, 29 Jun 2022 16:55:28 +0800
Subject: [PATCH] add pp_poisson

---
 src/experimental/note.md      |   2 +
 src/pp/_impl/_pp_poisson.scad | 120 ++++++++++++++++++++++++++++++++++
 src/pp/pp_poisson.scad        |  28 ++++++++
 3 files changed, 150 insertions(+)
 create mode 100644 src/pp/_impl/_pp_poisson.scad
 create mode 100644 src/pp/pp_poisson.scad

diff --git a/src/experimental/note.md b/src/experimental/note.md
index b6dfada8..6fbcf5f4 100644
--- a/src/experimental/note.md
+++ b/src/experimental/note.md
@@ -26,6 +26,8 @@ new:
 
 - lsystem2, lsystem3, add seed param
 
+- pp_poisson?
+
 doc-ed
 
     deprecated:
diff --git a/src/pp/_impl/_pp_poisson.scad b/src/pp/_impl/_pp_poisson.scad
new file mode 100644
index 00000000..2b3d58d5
--- /dev/null
+++ b/src/pp/_impl/_pp_poisson.scad
@@ -0,0 +1,120 @@
+use <../../matrix/m_replace.scad>
+use <../../util/every.scad>
+use <../pp_disk.scad>
+
+function sampling(size, r, start, k) =
+    let(
+        w = r / sqrt(2),
+        rows = floor(size.y / w),
+        columns = floor(size.x / w),
+        pt = is_undef(start) ? size / 2 : start,
+        active = [pt],
+        px = floor(pt.x / w),
+        py = floor(pt.y / w),
+        grid_row = [for(i = [0:columns - 1]) undef],
+        grid = m_replace([for(j = [0:rows - 1]) grid_row], px, py, pt)
+    )
+    [r, k, w, active, grid, rows, columns, []];
+    
+function sampling_r(s) = s[0];
+function sampling_k(s) = s[1];
+function sampling_w(s) = s[2];
+function sampling_active(s) = s[3];
+function sampling_grid(s) = s[4];
+function sampling_rows(s) = s[5];
+function sampling_columns(s) = s[6];
+function sampling_history(s) = s[7];
+
+function sampling_inRow(s, y) = y > -1 && y < sampling_rows(s);
+
+function sampling_inGrid(s, x, y) = 
+    sampling_inRow(s, y) && x > -1 && x < sampling_columns(s);
+
+function sampling_noAdjacentNeighbor(s, sample, x, y) = 
+    every(
+        [
+            [x - 1, y - 1], [x, y - 1], [x + 1, y - 1],
+            [x - 1, y], [x, y], [x + 1, y],
+            [x - 1, y + 1], [x, y + 1], [x + 1, y + 1]
+        ],
+        function(nbr) !sampling_inRow(s, nbr.y) ||
+                          (let(p = sampling_grid(s)[nbr.y][nbr.x])
+                          is_undef(p) ||
+                          norm(sample - p) >= sampling_r(s))
+    );
+    
+function sampling_randomSample(s, pos) = 
+    let(
+        r = sampling_r(s),
+        a = rands(0, 360, 1)[0]
+    )
+    rands(r, 2 * r, 1)[0] * [cos(a), sin(a)] + pos;
+    
+function sampling_hasActive(s) = len(sampling_active(s)) > 0;
+
+function sampling_kSamples(s, pos) = [
+    for(n = [0:sampling_k(s) - 1])
+    let(
+        sample = sampling_randomSample(s, pos),
+        w = sampling_w(s),
+        x = floor(sample.x / w),
+        y = floor(sample.y / w)
+    )
+    if(sampling_inGrid(s, x, y) && sampling_noAdjacentNeighbor(s, sample, x, y))
+    sample
+];
+
+function sampling_minDistSample(s, pos, samples) =
+    len(samples) == 1 ? samples[0] :
+    _sampling_minDistSample(s, pos, samples, samples[0], norm(pos - samples[0]));
+
+function _sampling_minDistSample(s, pos, samples, min_s, min_dist, i = 1) = 
+    i == len(samples) ? min_s : 
+    let(
+        sample = samples[i],
+        d = norm(pos - sample),
+        params = min_dist > d ? [sample, d] : [min_s, min_dist]
+    )
+    _sampling_minDistSample(s, pos, samples, params[0], params[1], i + 1);     
+
+function sampling_trySampleFromOneActive(s) =
+    let(
+        active = sampling_active(s),
+        i = floor(rands(0, len(active) - 1, 1)[0]),
+        pos = active[i],
+        samples = sampling_kSamples(s, pos)
+    )
+    len(samples) == 0 ? 
+        [
+            sampling_r(s), 
+            sampling_k(s), 
+            sampling_w(s), 
+            [for(j = [0:len(active) - 1]) if(j != i) active[j]], 
+            sampling_grid(s), 
+            sampling_rows(s), 
+            sampling_columns(s),
+            sampling_history(s)
+        ]
+        :
+        let(
+            sample = sampling_minDistSample(s, pos, samples),
+            nx_active = [each active, sample],
+            w = sampling_w(s),
+            x = floor(sample.x / w),
+            y = floor(sample.y / w),
+            nx_grid = m_replace(sampling_grid(s), x, y, sample)
+        )
+        [
+            sampling_r(s), 
+            sampling_k(s), 
+            w, 
+            nx_active, 
+            nx_grid, 
+            sampling_rows(s), 
+            sampling_columns(s),
+            [each sampling_history(s), [pos, sample]]
+        ];
+
+function _pp_poisson(s) =
+    !sampling_hasActive(s) ? s : _pp_poisson(sampling_trySampleFromOneActive(s));
+    
\ No newline at end of file
diff --git a/src/pp/pp_poisson.scad b/src/pp/pp_poisson.scad
new file mode 100644
index 00000000..5812c8f6
--- /dev/null
+++ b/src/pp/pp_poisson.scad
@@ -0,0 +1,28 @@
+use <_impl/_pp_poisson.scad>
+
+function pp_poisson(size, r, start, k = 30, history = false) =
+    let(
+        s = _pp_poisson(sampling(size, r, start, k)),
+        samples = [
+            for(row = sampling_grid(s), sample = row)
+            if(!is_undef(sample)) sample
+        ]
+    )
+    history ? [samples, sampling_history(s)] : samples;
+
+/*
+use <pp/pp_poisson.scad>
+use <polyline_join.scad>
+
+
+pts_history = pp_poisson([100, 100], 5, history = true);
+for(p = pts_history[0]) {
+    translate(p)
+        circle(1);
+}
+
+for(h = pts_history[1]) {
+    polyline_join(h)
+        circle(.5);
+}
+*/
\ No newline at end of file