From 587104651c89beeeb382e86777e0a1b437d7c3b4 Mon Sep 17 00:00:00 2001
From: Sergey Poznyak <Sergeeeekg@gmail.com>
Date: Sun, 12 Jan 2025 19:29:29 +0400
Subject: [PATCH] Halfedge test

---
 game/game.odin              | 32 +++++++++++++++++++++++++++++++-
 game/halfedge/debug.odin    |  5 -----
 game/halfedge/halfedge.odin |  8 ++++----
 game/physics/bvh/bvh.odin   |  2 +-
 4 files changed, 36 insertions(+), 11 deletions(-)

diff --git a/game/game.odin b/game/game.odin
index db312ef..a9fe5d6 100644
--- a/game/game.odin
+++ b/game/game.odin
@@ -472,7 +472,6 @@ draw :: proc() {
 
 	car_body := physics.get_body(&world.physics_scene, runtime_world.car_handle)
 	car_model := assets.get_model(&g_mem.assetman, "assets/toyota_corolla_ae86_trueno.glb")
-	car_halfedge := halfedge.mesh_from_vertex_index_list(car_model.meshes[0].vertices, car_model.meshes[0].indices, context.temp_allocator)
 
 	mesh_col: bvh.Collision
 	hit_mesh_idx := -1
@@ -577,6 +576,36 @@ draw :: proc() {
 					}
 				}
 			}
+
+			if mesh_col.hit {
+				mesh := car_model.meshes[hit_mesh_idx]
+				vertices := (cast([^]rl.Vector3)mesh.vertices)[:mesh.vertexCount]
+				indices := mesh.indices[:mesh.triangleCount * 3]
+				car_halfedge := halfedge.mesh_from_vertex_index_list(vertices, indices, context.temp_allocator)
+
+				face_idx := halfedge.Face_Index(mesh_col.prim)
+				face := car_halfedge.faces[face_idx]
+				first_edge_idx := face.edge
+
+				first := true
+				cur_edge_idx := first_edge_idx
+				for first || cur_edge_idx != first_edge_idx {
+					first = false
+					edge := car_halfedge.edges[cur_edge_idx]
+					cur_edge_idx = edge.next
+
+					if edge.twin >= 0 {
+						twin_edge := car_halfedge.edges[edge.twin]
+						face := twin_edge.face
+
+						i1, i2, i3 := indices[face * 3 + 0], indices[face * 3 + 1], indices[face * 3 + 2]
+						v1, v2, v3 := vertices[i1], vertices[i2], vertices[i3]
+
+						rl.DrawTriangle3D(v1, v2, v3, rl.RED)
+					}
+				}
+			}
+
 		}
 	}
 
@@ -589,6 +618,7 @@ draw :: proc() {
 		if g_mem.editor {
 			rl.DrawText("Editor", 5, 5, 8, rl.ORANGE)
 
+
 			rl.DrawText(
 				fmt.ctprintf(
 					"mesh: %v, aabb tests: %v, tri tests: %v",
diff --git a/game/halfedge/debug.odin b/game/halfedge/debug.odin
index 6bd7ece..084bcb1 100644
--- a/game/halfedge/debug.odin
+++ b/game/halfedge/debug.odin
@@ -1,7 +1,2 @@
 package halfedge
 
-import rl "vendor:raylib"
-
-debug_draw_halfedge_mesh :: proc(mesh: ^Mesh) {
-
-}
diff --git a/game/halfedge/halfedge.odin b/game/halfedge/halfedge.odin
index 26d8932..df56ef8 100644
--- a/game/halfedge/halfedge.odin
+++ b/game/halfedge/halfedge.odin
@@ -1,7 +1,5 @@
 package halfedge
 
-import "core:container/small_array"
-
 Vec3 :: [3]f32
 
 Vertex :: struct {
@@ -14,7 +12,7 @@ Face :: struct {
 }
 
 Vertex_Index :: distinct u16
-Face_Index :: distinct i16
+Face_Index :: distinct u16
 Edge_Index :: distinct i16
 
 Half_Edge :: struct {
@@ -55,7 +53,7 @@ mesh_from_vertex_index_list :: proc(
 	triangle_num := len(indices) / 3
 	for i in 0 ..< triangle_num {
 		i1, i2, i3 := indices[i * 3 + 0], indices[i * 3 + 1], indices[i * 3 + 2]
-		v1, v2, v3 := vertices[i1], vertices[i2], vertices[i3]
+		// v1, v2, v3 := vertices[i1], vertices[i2], vertices[i3]
 		e1, e2, e3 := i * 3 + 0, i * 3 + 1, i * 3 + 2
 
 		faces[i].edge = Edge_Index(e1)
@@ -98,4 +96,6 @@ mesh_from_vertex_index_list :: proc(
 			}
 		}
 	}
+
+	return mesh
 }
diff --git a/game/physics/bvh/bvh.odin b/game/physics/bvh/bvh.odin
index 323e81c..8ec1d10 100644
--- a/game/physics/bvh/bvh.odin
+++ b/game/physics/bvh/bvh.odin
@@ -334,7 +334,7 @@ internal_ray_tri_test :: proc(ray: Ray, mesh: Mesh, tri: u16, col: ^Collision) {
 	v1, v2, v3 := mesh.vertices[i1], mesh.vertices[i2], mesh.vertices[i3]
 
 	col.triangle_tests += 1
-	rl.DrawTriangle3D(v1, v2, v3, debug.int_to_color(i32(tri) + 1))
+	// rl.DrawTriangle3D(v1, v2, v3, debug.int_to_color(i32(tri) + 1))
 
 	t, _, barycentric, ok := collision.intersect_ray_triangle(
 		{ray.origin, ray.origin + ray.dir},