New mass API;

- All of the mass properties have regular getters/setters
  - :get/setMass
  - :get/setInertia
  - :get/setCenterOfMass
- You can use nil for any of the setters to set the mass property to an
  "automatic" value, computed from the shape and/or other overridden
  mass properties.
- If you override the mass properties, we assume you know what you're
  doing and don't try to be sneaky and auto-update downstream values.
  So changing the mass or center of mass doesn't auto-scale the inertia.
- If you change the shape (or enabled axes), mass data gets reset.
- You can use :resetMass to reset all 3 mass properties at once.  It's
  also useful if something about the underlying shape changed.

src/api/l_physics_collider.c

@@ -173,53 +173,67 @@ static int l_lovrColliderGetMass(lua_State* L) {
 
 static int l_lovrColliderSetMass(lua_State* L) {
   Collider* collider = luax_checktype(L, 1, Collider);
-  float mass = luax_checkfloat(L, 2);
-  lovrColliderSetMass(collider, mass);
+  if (lua_isnoneornil(L, 2)) {
+    lovrColliderSetMass(collider, NULL);
+  } else {
+    float mass = luax_checkfloat(L, 2);
+    lovrColliderSetMass(collider, &mass);
+  }
   return 0;
 }
 
-static int l_lovrColliderGetMassData(lua_State* L) {
+static int l_lovrColliderGetInertia(lua_State* L) {
   Collider* collider = luax_checktype(L, 1, Collider);
-  float centerOfMass[3], mass, inertia[6];
-  lovrColliderGetMassData(collider, centerOfMass, &mass, inertia);
-  lua_pushnumber(L, centerOfMass[0]);
-  lua_pushnumber(L, centerOfMass[1]);
-  lua_pushnumber(L, centerOfMass[2]);
-  lua_pushnumber(L, mass);
-  lua_newtable(L);
-  for (int i = 0; i < 6; i++) {
-    lua_pushnumber(L, inertia[i]);
-    lua_rawseti(L, -2, i + 1);
+  float diagonal[3], rotation[4];
+  lovrColliderGetInertia(collider, diagonal, rotation);
+  lua_pushnumber(L, diagonal[0]);
+  lua_pushnumber(L, diagonal[1]);
+  lua_pushnumber(L, diagonal[2]);
+  lua_pushnumber(L, rotation[0]);
+  lua_pushnumber(L, rotation[1]);
+  lua_pushnumber(L, rotation[2]);
+  lua_pushnumber(L, rotation[3]);
+  return 7;
+}
+
+static int l_lovrColliderSetInertia(lua_State* L) {
+  Collider* collider = luax_checktype(L, 1, Collider);
+  if (lua_isnoneornil(L, 2)) {
+    lovrColliderSetInertia(collider, NULL, NULL);
+  } else {
+    float diagonal[3], rotation[4];
+    int index = luax_readvec3(L, 2, diagonal, NULL);
+    luax_readquat(L, index, rotation, NULL);
+    lovrColliderSetInertia(collider, diagonal, rotation);
   }
-  return 5;
+  return 0;
 }
 
-static int l_lovrColliderSetMassData(lua_State* L) {
+static int l_lovrColliderGetCenterOfMass(lua_State* L) {
   Collider* collider = luax_checktype(L, 1, Collider);
-  float centerOfMass[3];
-  int index = luax_readvec3(L, 2, centerOfMass, NULL);
-  float mass = luax_checkfloat(L, index++);
-  float inertia[6];
-  if (lua_istable(L, index) && luax_len(L, index) >= 6) {
-    for (int i = 0; i < 6; i++) {
-      lua_rawgeti(L, index, i + 1);
-      if (!lua_isnumber(L, -1)) {
-        return luaL_argerror(L, 6, "Expected 6 numbers or a table with 6 numbers");
-      }
+  float center[3];
+  lovrColliderGetCenterOfMass(collider, center);
+  lua_pushnumber(L, center[0]);
+  lua_pushnumber(L, center[1]);
+  lua_pushnumber(L, center[2]);
+  return 3;
+}
 
-      inertia[i] = lua_tonumber(L, -1);
-      lua_pop(L, 1);
-    }
+static int l_lovrColliderSetCenterOfMass(lua_State* L) {
+  Collider* collider = luax_checktype(L, 1, Collider);
+  if (lua_isnoneornil(L, 2)) {
+    lovrColliderSetCenterOfMass(collider, NULL);
   } else {
-    for (int i = index; i < index + 6; i++) {
-      if (lua_isnumber(L, i)) {
-        inertia[i - index] = lua_tonumber(L, i);
-      } else {
-        return luaL_argerror(L, i, "Expected 6 numbers or a table with 6 numbers");
-      }
-    }
+    float center[3];
+    luax_readvec3(L, 2, center, NULL);
+    lovrColliderSetCenterOfMass(collider, center);
   }
-  lovrColliderSetMassData(collider, centerOfMass, mass, inertia);
+  return 0;
+}
+
+static int l_lovrColliderResetMassData(lua_State* L) {
+  Collider* collider = luax_checktype(L, 1, Collider);
+  lovrColliderResetMassData(collider);
   return 0;
 }
 
@@ -478,26 +492,6 @@ static int l_lovrColliderApplyAngularImpulse(lua_State* L) {
   return 0;
 }
 
-static int l_lovrColliderGetLocalCenter(lua_State* L) {
-  Collider* collider = luax_checktype(L, 1, Collider);
-  float center[3];
-  lovrColliderGetLocalCenter(collider, center);
-  lua_pushnumber(L, center[0]);
-  lua_pushnumber(L, center[1]);
-  lua_pushnumber(L, center[2]);
-  return 3;
-}
-
-static int l_lovrColliderGetWorldCenter(lua_State* L) {
-  Collider* collider = luax_checktype(L, 1, Collider);
-  float center[3];
-  lovrColliderGetWorldCenter(collider, center);
-  lua_pushnumber(L, center[0]);
-  lua_pushnumber(L, center[1]);
-  lua_pushnumber(L, center[2]);
-  return 3;
-}
-
 static int l_lovrColliderGetLocalPoint(lua_State* L) {
   Collider* collider = luax_checktype(L, 1, Collider);
   float world[3], local[3];
@@ -662,8 +656,11 @@ const luaL_Reg lovrCollider[] = {
   { "setAwake", l_lovrColliderSetAwake },
   { "getMass", l_lovrColliderGetMass },
   { "setMass", l_lovrColliderSetMass },
-  { "getMassData", l_lovrColliderGetMassData },
-  { "setMassData", l_lovrColliderSetMassData },
+  { "getInertia", l_lovrColliderGetInertia },
+  { "setInertia", l_lovrColliderSetInertia },
+  { "getCenterOfMass", l_lovrColliderGetCenterOfMass },
+  { "setCenterOfMass", l_lovrColliderSetCenterOfMass },
+  { "resetMassData", l_lovrColliderResetMassData },
   { "getEnabledAxes", l_lovrColliderGetEnabledAxes },
   { "setEnabledAxes", l_lovrColliderSetEnabledAxes },
   { "getPosition", l_lovrColliderGetPosition },
@@ -686,8 +683,6 @@ const luaL_Reg lovrCollider[] = {
   { "applyTorque", l_lovrColliderApplyTorque },
   { "applyLinearImpulse", l_lovrColliderApplyLinearImpulse },
   { "applyAngularImpulse", l_lovrColliderApplyAngularImpulse },
-  { "getLocalCenter", l_lovrColliderGetLocalCenter },
-  { "getWorldCenter", l_lovrColliderGetWorldCenter },
   { "getLocalPoint", l_lovrColliderGetLocalPoint },
   { "getWorldPoint", l_lovrColliderGetWorldPoint },
   { "getLocalVector", l_lovrColliderGetLocalVector },

src/api/l_physics_shapes.c

@@ -272,44 +272,31 @@ static int l_lovrShapeSetDensity(lua_State* L) {
   return 0;
 }
 
-static int l_lovrShapeGetMassData(lua_State* L) {
-  Shape* shape = luax_checkshape(L, 1);
-  float mass, inertia[9], center[3];
-  lovrShapeGetMassData(shape, &mass, inertia, center);
-  lua_pushnumber(L, mass);
-  lua_createtable(L, 9, 0);
-  for (int i = 0; i < 9; i++) {
-    lua_pushnumber(L, inertia[i]);
-    lua_rawseti(L, -2, i + 1);
-  }
-  lua_pushnumber(L, center[0]);
-  lua_pushnumber(L, center[1]);
-  lua_pushnumber(L, center[2]);
-  return 5;
-}
-
 static int l_lovrShapeGetMass(lua_State* L) {
   Shape* shape = luax_checkshape(L, 1);
-  float mass;
-  lovrShapeGetMassData(shape, &mass, NULL, NULL);
+  float mass = lovrShapeGetMass(shape);
   lua_pushnumber(L, mass);
   return 1;
 }
 
 static int l_lovrShapeGetInertia(lua_State* L) {
   Shape* shape = luax_checkshape(L, 1);
-  float inertia[9];
-  lovrShapeGetMassData(shape, NULL, inertia, NULL);
-  for (int i = 0; i < 9; i++) {
-    lua_pushnumber(L, inertia[i]);
-  }
-  return 9;
+  float diagonal[3], rotation[4];
+  lovrShapeGetInertia(shape, diagonal, rotation);
+  lua_pushnumber(L, diagonal[0]);
+  lua_pushnumber(L, diagonal[1]);
+  lua_pushnumber(L, diagonal[2]);
+  lua_pushnumber(L, rotation[0]);
+  lua_pushnumber(L, rotation[1]);
+  lua_pushnumber(L, rotation[2]);
+  lua_pushnumber(L, rotation[3]);
+  return 7;
 }
 
-static int l_lovrShapeGetCenter(lua_State* L) {
+static int l_lovrShapeGetCenterOfMass(lua_State* L) {
   Shape* shape = luax_checkshape(L, 1);
   float center[3];
-  lovrShapeGetMassData(shape, NULL, NULL, center);
+  lovrShapeGetCenterOfMass(shape, center);
   lua_pushnumber(L, center[0]);
   lua_pushnumber(L, center[1]);
   lua_pushnumber(L, center[2]);
@@ -340,10 +327,9 @@ static int l_lovrShapeGetAABB(lua_State* L) {
   { "getVolume", l_lovrShapeGetVolume }, \
   { "getDensity", l_lovrShapeGetDensity }, \
   { "setDensity", l_lovrShapeSetDensity }, \
-  { "getMassData", l_lovrShapeGetMassData }, \
   { "getMass", l_lovrShapeGetMass }, \
   { "getInertia", l_lovrShapeGetInertia }, \
-  { "getCenter", l_lovrShapeGetCenter }, \
+  { "getCenterOfMass", l_lovrShapeGetCenterOfMass }, \
   { "getAABB", l_lovrShapeGetAABB }
 
 static int l_lovrBoxShapeGetDimensions(lua_State* L) {

src/modules/physics/physics.h

@@ -131,9 +131,12 @@ void lovrColliderSetSleepingAllowed(Collider* collider, bool allowed);
 bool lovrColliderIsAwake(Collider* collider);
 void lovrColliderSetAwake(Collider* collider, bool awake);
 float lovrColliderGetMass(Collider* collider);
-void lovrColliderSetMass(Collider* collider, float mass);
-void lovrColliderGetMassData(Collider* collider, float centerOfMass[3], float* mass, float inertia[6]);
-void lovrColliderSetMassData(Collider* collider, float centerOfMass[3], float mass, float inertia[6]);
+void lovrColliderSetMass(Collider* collider, float* mass);
+void lovrColliderGetInertia(Collider* collider, float diagonal[3], float rotation[4]);
+void lovrColliderSetInertia(Collider* collider, float diagonal[3], float rotation[4]);
+void lovrColliderGetCenterOfMass(Collider* collider, float center[3]);
+void lovrColliderSetCenterOfMass(Collider* collider, float center[3]);
+void lovrColliderResetMassData(Collider* collider);
 void lovrColliderGetEnabledAxes(Collider* collider, bool translation[3], bool rotation[3]);
 void lovrColliderSetEnabledAxes(Collider* collider, bool translation[3], bool rotation[3]);
 void lovrColliderGetPosition(Collider* collider, float position[3]);
@@ -156,8 +159,6 @@ void lovrColliderApplyTorque(Collider* collider, float torque[3]);
 void lovrColliderApplyLinearImpulse(Collider* collider, float impulse[3]);
 void lovrColliderApplyLinearImpulseAtPosition(Collider* collider, float impulse[3], float position[3]);
 void lovrColliderApplyAngularImpulse(Collider* collider, float impulse[3]);
-void lovrColliderGetLocalCenter(Collider* collider, float center[3]);
-void lovrColliderGetWorldCenter(Collider* collider, float center[3]);
 void lovrColliderGetLocalPoint(Collider* collider, float world[3], float local[3]);
 void lovrColliderGetWorldPoint(Collider* collider, float local[3], float world[3]);
 void lovrColliderGetLocalVector(Collider* collider, float world[3], float local[3]);
@@ -184,7 +185,9 @@ ShapeType lovrShapeGetType(Shape* shape);
 float lovrShapeGetVolume(Shape* shape);
 float lovrShapeGetDensity(Shape* shape);
 void lovrShapeSetDensity(Shape* shape, float density);
-void lovrShapeGetMassData(Shape* shape, float* mass, float inertia[9], float center[3]);
+float lovrShapeGetMass(Shape* shape);
+void lovrShapeGetInertia(Shape* shape, float diagonal[3], float rotation[4]);
+void lovrShapeGetCenterOfMass(Shape* shape, float center[3]);
 void lovrShapeGetAABB(Shape* shape, float position[3], float orientation[4], float aabb[6]);
 
 BoxShape* lovrBoxShapeCreate(float dimensions[3]);