mat4
calc_matrix(transform_t* transform)
{
	mat4 translation = mat4_identity();
	translation.e03 = transform->position.x;
	translation.e13 = transform->position.y;
	translation.e23 = transform->position.z;

	mat4 rotation;
	{
		mat4 rotation_x = mat4_identity();
		{
			float cos_angle = cosf(transform->rotation.x);
			float sin_angle = sinf(transform->rotation.x);

			rotation_x.e11 = cos_angle;
			rotation_x.e12 = -sin_angle;
			rotation_x.e21 = sin_angle;
			rotation_x.e22 = cos_angle;
		}

		mat4 rotation_y = mat4_identity();
		{
			float cos_angle = cosf(transform->rotation.y);
			float sin_angle = sinf(transform->rotation.y);

			rotation_y.e00 = cos_angle;
			rotation_y.e02 = sin_angle;
			rotation_y.e20 = -sin_angle;
			rotation_y.e22 = cos_angle;
		}

		mat4 rotation_z = mat4_identity();
		{
			float cos_angle = cosf(transform->rotation.z);
			float sin_angle = sinf(transform->rotation.z);

			rotation_z.e00 = cos_angle;
			rotation_z.e01 = -sin_angle;
			rotation_z.e10 = sin_angle;
			rotation_z.e11 = cos_angle;
		}

		rotation = mat4_multm(rotation_z, mat4_multm(rotation_y, rotation_x));
	}

	mat4 scale = mat4_identity();
	scale.e00 = transform->scale.x;
	scale.e11 = transform->scale.y;
	scale.e22 = transform->scale.z;

	mat4 result = mat4_multm(translation, mat4_multm(rotation, scale));

	return result;
}

void
update_transform(transform_t* transform)
{
	transform_t* parent = get_transform(transform->parent);
	transform->matrix = mat4_multm(parent->matrix, calc_matrix(transform));

	for (size_t i = 0; i < transform->child_count; i++)
	{
		transform_t* child = get_transform(transform->children[i]);
		update_transform(child);
	}
}