From 534d47904eddf90b062b1f1dfa4211653c36a5aa Mon Sep 17 00:00:00 2001
From: bjorn <mail@bjornbyt.es>
Date: Mon, 17 Jul 2023 13:23:57 -0700
Subject: [PATCH] World:queryBox/World:querySphere callback is optional;

They also return a bool indicating if any intersections occurred.
---
 src/api/l_physics_world.c     | 14 ++++++++------
 src/modules/physics/physics.c | 19 +++++++++++--------
 src/modules/physics/physics.h |  4 ++--
 3 files changed, 21 insertions(+), 16 deletions(-)

diff --git a/src/api/l_physics_world.c b/src/api/l_physics_world.c
index 71869069..a97271d8 100644
--- a/src/api/l_physics_world.c
+++ b/src/api/l_physics_world.c
@@ -254,10 +254,11 @@ static int l_lovrWorldQueryBox(lua_State* L) {
   int index = 2;
   index = luax_readvec3(L, index, position, NULL);
   index = luax_readvec3(L, index, size, NULL);
-  luaL_checktype(L, index, LUA_TFUNCTION);
+  bool function = lua_type(L, index) == LUA_TFUNCTION;
   lua_settop(L, index);
-  lovrWorldQueryBox(world, position, size, queryCallback, L);
-  return 0;
+  bool any = lovrWorldQueryBox(world, position, size, function ? queryCallback : NULL, L);
+  lua_pushboolean(L, any);
+  return 1;
 }
 
 static int l_lovrWorldQuerySphere(lua_State* L) {
@@ -265,10 +266,11 @@ static int l_lovrWorldQuerySphere(lua_State* L) {
   float position[3];
   int index = luax_readvec3(L, 2, position, NULL);
   float radius = luax_checkfloat(L, index++);
-  luaL_checktype(L, index, LUA_TFUNCTION);
+  bool function = lua_type(L, index) == LUA_TFUNCTION;
   lua_settop(L, index);
-  lovrWorldQuerySphere(world, position, radius, queryCallback, L);
-  return 0;
+  bool any = lovrWorldQuerySphere(world, position, radius, function ? queryCallback : NULL, L);
+  lua_pushboolean(L, any);
+  return 1;
 }
 
 static int l_lovrWorldGetGravity(lua_State* L) {
diff --git a/src/modules/physics/physics.c b/src/modules/physics/physics.c
index 5e87ce6f..c4f695a6 100644
--- a/src/modules/physics/physics.c
+++ b/src/modules/physics/physics.c
@@ -82,20 +82,21 @@ static void raycastCallback(void* data, dGeomID a, dGeomID b) {
 typedef struct {
   QueryCallback callback;
   void* userdata;
+  bool called;
 } QueryData;
 
-static void queryCallback(void* data, dGeomID a, dGeomID b) {
-  QueryCallback callback = ((QueryData*) data)->callback;
-  void* userdata = ((QueryData*) data)->userdata;
+static void queryCallback(void* d, dGeomID a, dGeomID b) {
   Shape* shape = dGeomGetData(b);
 
   if (!shape) {
     return;
   }
 
+  QueryData* data = d;
   dContactGeom contact;
   if (dCollide(a, b, 1 | CONTACTS_UNIMPORTANT, &contact, sizeof(contact))) {
-    callback(shape, userdata);
+    if (data->callback) data->callback(shape, data->userdata);
+    data->called = true;
   }
 }
 
@@ -308,20 +309,22 @@ void lovrWorldRaycast(World* world, float x1, float y1, float z1, float x2, floa
   dGeomDestroy(ray);
 }
 
-void lovrWorldQueryBox(World* world, float position[3], float size[3], QueryCallback callback, void* userdata) {
-  QueryData data = { .callback = callback, .userdata = userdata };
+bool lovrWorldQueryBox(World* world, float position[3], float size[3], QueryCallback callback, void* userdata) {
+  QueryData data = { .callback = callback, .userdata = userdata, .called = false };
   dGeomID box = dCreateBox(world->space, fabsf(size[0]), fabsf(size[1]), fabsf(size[2]));
   dGeomSetPosition(box, position[0], position[1], position[2]);
   dSpaceCollide2(box, (dGeomID) world->space, &data, queryCallback);
   dGeomDestroy(box);
+  return data.called;
 }
 
-void lovrWorldQuerySphere(World* world, float position[3], float radius, QueryCallback callback, void* userdata) {
-  QueryData data = { .callback = callback, .userdata = userdata };
+bool lovrWorldQuerySphere(World* world, float position[3], float radius, QueryCallback callback, void* userdata) {
+  QueryData data = { .callback = callback, .userdata = userdata, .called = false };
   dGeomID sphere = dCreateSphere(world->space, fabsf(radius));
   dGeomSetPosition(sphere, position[0], position[1], position[2]);
   dSpaceCollide2(sphere, (dGeomID) world->space, &data, queryCallback);
   dGeomDestroy(sphere);
+  return data.called;
 }
 
 Collider* lovrWorldGetFirstCollider(World* world) {
diff --git a/src/modules/physics/physics.h b/src/modules/physics/physics.h
index 39ea296b..54a204ed 100644
--- a/src/modules/physics/physics.h
+++ b/src/modules/physics/physics.h
@@ -51,8 +51,8 @@ int lovrWorldGetNextOverlap(World* world, Shape** a, Shape** b);
 int lovrWorldCollide(World* world, Shape* a, Shape* b, float friction, float restitution);
 void lovrWorldGetContacts(World* world, Shape* a, Shape* b, Contact contacts[MAX_CONTACTS], uint32_t* count);
 void lovrWorldRaycast(World* world, float x1, float y1, float z1, float x2, float y2, float z2, RaycastCallback callback, void* userdata);
-void lovrWorldQueryBox(World* world, float position[3], float size[3], QueryCallback callback, void* userdata);
-void lovrWorldQuerySphere(World* world, float position[3], float radius, QueryCallback callback, void* userdata);
+bool lovrWorldQueryBox(World* world, float position[3], float size[3], QueryCallback callback, void* userdata);
+bool lovrWorldQuerySphere(World* world, float position[3], float radius, QueryCallback callback, void* userdata);
 Collider* lovrWorldGetFirstCollider(World* world);
 void lovrWorldGetGravity(World* world, float* x, float* y, float* z);
 void lovrWorldSetGravity(World* world, float x, float y, float z);