actual physics system

1 files changed, 65 insertions, 0 deletions

diff --git a/src/phys/body.odin b/src/phys/body.odin
new file mode 100644
index 0000000..fcae697
--- /dev/null
+++ b/src/phys/body.odin
@@ -0,0 +1,65 @@
+package phys
+
+Vec2 :: [2]f32
+
+Rect :: struct {
+  start: Vec2,
+  size: Vec2,
+}
+
+Layer :: enum(u16) {
+  DEFAULT,
+  HARD,   // hard collisions; don't let bodies intersect at all
+  SOFT,   // soft collisions; push away other bodies with a force
+  ENEMY,  // enemy hitboxes
+  PLAYER, // player hitboxes
+}
+
+Collision_Type :: enum(u16) {
+  UP,
+  DOWN,
+  RIGHT,
+  LEFT,
+  HORIZONTAL,
+  VERTICAL,
+}
+
+Body :: struct {
+  handle: Body_Handle,
+  bin_idx: i32,
+  rect: Rect,
+  active: bool,
+  pos: Vec2,
+  vel: Vec2,
+  collisions: bit_set[Collision_Type; u16],
+  layers: bit_set[Layer; u16],
+  mask: bit_set[Layer; u16],
+}
+
+make_body :: proc(
+  w: ^World,
+  rect: Rect,
+  layers := bit_set[Layer; u16]{.DEFAULT},
+  mask := bit_set[Layer; u16]{.DEFAULT},
+) -> (Body_Handle, ^Body) {
+  b := Body {
+    rect = rect,
+    layers = layers,
+    mask = mask,
+    active = true,
+  }
+  return add_body(w, b)
+}
+
+aabb_hori :: proc(a: Rect, b: Rect) -> bool {
+  return a.start.x < b.start.x + b.size.x && b.start.x < a.start.x + a.size.x
+}
+
+aabb_vert :: proc(a: Rect, b: Rect) -> bool {
+  return a.start.y < b.start.y + b.size.y && b.start.y < a.start.y + a.size.y
+}
+
+aabb :: proc(a: Rect, b: Rect) -> bool {
+  return aabb_hori(a, b) && aabb_vert(a, b)
+}
+