Merge pull request #93916 from zeux/aabb-zfight

Fix AABB computation for position compression to not depend on vertex order

servers/rendering_server.cpp

@@ -347,6 +347,22 @@ void _get_tbn_from_axis_angle(const Vector3 &p_axis, float p_angle, Vector3 &r_n
 	r_normal = tbn.rows[2];
 }
 
+AABB _compute_aabb_from_points(const Vector3 *p_data, int p_length) {
+	if (p_length == 0) {
+		return AABB();
+	}
+
+	Vector3 min = p_data[0];
+	Vector3 max = p_data[0];
+
+	for (int i = 1; i < p_length; ++i) {
+		min = min.min(p_data[i]);
+		max = max.max(p_data[i]);
+	}
+
+	return AABB(min, max - min);
+}
+
 Error RenderingServer::_surface_set_data(Array p_arrays, uint64_t p_format, uint32_t *p_offsets, uint32_t p_vertex_stride, uint32_t p_normal_stride, uint32_t p_attrib_stride, uint32_t p_skin_stride, Vector<uint8_t> &r_vertex_array, Vector<uint8_t> &r_attrib_array, Vector<uint8_t> &r_skin_array, int p_vertex_array_len, Vector<uint8_t> &r_index_array, int p_index_array_len, AABB &r_aabb, Vector<AABB> &r_bone_aabb, Vector4 &r_uv_scale) {
 	uint8_t *vw = r_vertex_array.ptrw();
 	uint8_t *aw = r_attrib_array.ptrw();
@@ -440,18 +456,10 @@ Error RenderingServer::_surface_set_data(Array p_arrays, uint64_t p_format, uint
 
 					const Vector3 *src = array.ptr();
 
-					r_aabb = AABB();
+					r_aabb = _compute_aabb_from_points(src, p_vertex_array_len);
+					r_aabb.size = r_aabb.size.max(SMALL_VEC3);
 
 					if (p_format & ARRAY_FLAG_COMPRESS_ATTRIBUTES) {
-						// First we need to generate the AABB for the entire surface.
-						for (int i = 0; i < p_vertex_array_len; i++) {
-							if (i == 0) {
-								r_aabb = AABB(src[i], SMALL_VEC3);
-							} else {
-								r_aabb.expand_to(src[i]);
-							}
-						}
-
 						if (!(p_format & RS::ARRAY_FORMAT_NORMAL)) {
 							// Early out if we are only setting vertex positions.
 							for (int i = 0; i < p_vertex_array_len; i++) {
@@ -592,12 +600,6 @@ Error RenderingServer::_surface_set_data(Array p_arrays, uint64_t p_format, uint
 							float vector[3] = { (float)src[i].x, (float)src[i].y, (float)src[i].z };
 
 							memcpy(&vw[p_offsets[ai] + i * p_vertex_stride], vector, sizeof(float) * 3);
-
-							if (i == 0) {
-								r_aabb = AABB(src[i], SMALL_VEC3);
-							} else {
-								r_aabb.expand_to(src[i]);
-							}
 						}
 					}
 				}