From 17225e5b3302e70b955110b629f2fb4d93e56230 Mon Sep 17 00:00:00 2001
From: Cameron Reikes <cameronreikes@gmail.com>
Date: Fri, 27 Jan 2023 07:56:52 -0800
Subject: [PATCH] WIP Small portion translated (does not compile)

---
 physics.jai | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/physics.jai b/physics.jai
index c0b06b3..1c61484 100644
--- a/physics.jai
+++ b/physics.jai
@@ -43,6 +43,67 @@ apply_force_at_point :: (r: *Rect, force: Vector2, point_world_space: Vector2) {
     offset_from_center_of_mass := point_world_space - r.pos;
     r.torque += offset_from_center_of_mass.x * force.y - offset_from_center_of_mass.y * force.x;
 }
+Manifold :: struct {
+    count: int;
+    depths: [2] float;
+    contact_points: [2] Vector2;
+    normal: Vector2;
+};
+MAX_POLYGON_VERTS :: 8;
+Polygon :: struct {
+    count: int;
+    verts: [MAX_POLYGON_VERTS] Vector2;
+    norms: [MAX_POLYGON_VERTS] Vector2;
+};
+// a halfspace (aka plane, aka line)
+Halfspace :: struct {
+    n: Vector2;
+    d: float; 
+}
+poly_from :: (using r: Rect) -> Polygon {
+    to_return: Polygon;
+
+    facing_to_right := rotate(xy(halfsize.x,0.0), angle);
+    facing_to_up    := rotate(xy(0.0,halfsize.y), angle);
+
+    to_return.count = 4;
+    to_return.verts[0] = -facing_to_right +  facing_up; // upper left
+    to_return.norms[0] =  #run normalize(xy(-1.0, 1.0));
+
+    to_return.verts[1] =  facing_to_right +  facing_up; // upper right
+    to_return.norms[1] =  #run normalize(xy(1.0, 1.0));
+
+    to_return.verts[2] =  facing_to_right + -facing_up; // lower right
+    to_return.norms[2] =  #run normalize(xy(1.0, -1.0));
+
+    to_return.verts[3] = -facing_to_right + -facing_up; // lower left
+    to_return.norms[3] =  #run normalize(xy(-1.0, -1.0));
+
+    return to_return;
+}
+rect_to_rect :: (a: Rect, b: Rect) -> Manifold {
+    to_return : Manifold;
+
+    check_faces :: (a: Polygon, b: Polygon) -> float {
+
+        plane_at :: (p : Polygon, i: int) -> Halfspace {
+            return .{n = p.norms[i], d = dot(p.norms[i], p.verts[i]};
+        }
+
+        support :: (verts: [] Vector2, d: Vector2 {
+
+        }
+
+        sep : float = FLT_MAX;
+        index: int = ~0;
+
+        for 0..a.count-1 {
+            h := plane_at(a, i);
+            idx :=
+        }
+    }
+
+}
 
 draw_rect :: (using r: Rect) {
     facing_to_right := rotate(xy(halfsize.x,0.0), angle);