From db10e319cc2201924815b2d8c9a4c2d21c2bfbb6 Mon Sep 17 00:00:00 2001
From: iamcheeseman <[hidden email]>
Date: Sat, 17 Jan 2026 18:19:57 -0500
Subject: Verlet ropes :)

---
 src/rope.odin | 81 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 src/rope.odin

(limited to 'src/rope.odin')

diff --git a/src/rope.odin b/src/rope.odin
new file mode 100644
index 0000000..c6ade8d
--- /dev/null
+++ b/src/rope.odin
@@ -0,0 +1,81 @@
+package demonchime
+
+import "core:log"
+import "core:math"
+
+import rl "vendor:raylib"
+
+Rope :: struct {
+  handle: Entity_Handle,
+  hanging_id: Image_Id,
+  verlet: Verlet_Rope,
+}
+
+step_ropes :: proc(dt: f32) {
+  iter := iter_entity_list(state.rope_list)
+  for rope in entity_list_iter(&iter) {
+    update_verlet_rope(&rope.verlet)
+  }
+}
+
+draw_ropes :: proc() {
+  iter := iter_entity_list(state.rope_list)
+  for rope in entity_list_iter(&iter) {
+    for i in 0..<len(rope.verlet.nodes) - 1 {
+      cur := rope.verlet.nodes[i]
+      nex := rope.verlet.nodes[i + 1]
+      rl.DrawLineV(cur.pos, nex.pos, rl.WHITE)
+    }
+
+    a := rope.verlet.nodes[len(rope.verlet.nodes) - 1]
+    b := rope.verlet.nodes[len(rope.verlet.nodes) - 2]
+
+    dir := b.pos - a.pos
+    rotation := math.atan2(dir.y, dir.x) * math.DEG_PER_RAD + 90
+
+    img := get_image(rope.hanging_id)
+    draw_texture(
+      img,
+      a.pos,
+      offset = Vec2{f32(img.width) * 0.5, 0},
+      rotation = rotation,
+    )
+  }
+}
+
+clear_ropes :: proc() {
+  iter := iter_entity_list(state.rope_list)
+  for rope in entity_list_iter(&iter) {
+    delete(rope.verlet.nodes)
+    delete_entity(&state.rope_list, rope.handle)
+  }
+}
+
+on_room_open_rope :: proc(room_id: Room_Id) {
+  clear_ropes()
+}
+
+object_spawner_rope :: proc(obj: Object_Resource) {
+  image_id, is_image_id := convert_path_to_resource(obj, "image").(Image_Id)
+  if !is_image_id {
+    image_id = .Small_Lamp
+  }
+  node_length := obj.properties["node_length"].(i32)
+  length := obj.properties["length"].(i32)
+
+  nodes := make([]Verlet_Node, length)
+  for &node, i in nodes {
+    node = create_verlet_node(
+      obj.pos + Vec2{0, f32(i) * f32(node_length)},
+      i == 0,
+    )
+  }
+
+  make_entity(&state.rope_list, Rope{
+    hanging_id = image_id,
+    verlet = Verlet_Rope{
+      nodes = nodes,
+      node_length = f32(node_length),
+    },
+  })
+}
-- 
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