store constraints array in world frame

src/pp/pp.c

@@ -1294,9 +1294,15 @@ P_Frame *P_PushFrame(P_World *world, P_Frame *src_frame, i64 tick)
     SllStackPop(world->first_free_frame);
     i64 old_ent_bins_count = frame->ent_bins_count;
     P_EntBin *old_ent_bins = frame->ent_bins;
-    ZeroStruct(frame);
+    i64 old_max_constraints = frame->max_constraints;
+    P_Constraint *old_constraints = frame->constraints;
+    {
+      ZeroStruct(frame);
+    }
     frame->ent_bins_count = old_ent_bins_count;
     frame->ent_bins = old_ent_bins;
+    frame->max_constraints = old_max_constraints;
+    frame->constraints = old_constraints;
     ZeroStructs(frame->ent_bins, frame->ent_bins_count);
   }
   else
@@ -1311,12 +1317,19 @@ P_Frame *P_PushFrame(P_World *world, P_Frame *src_frame, i64 tick)
 
     frame->first_ent = &P_NilEnt;
     frame->last_ent = &P_NilEnt;
-    if (frame->ent_bins_count == 0)
+    if (!frame->ent_bins)
     {
       frame->ent_bins_count = Kibi(16);
       frame->ent_bins = PushStructs(world->frames_arena, P_EntBin, frame->ent_bins_count);
     }
 
+    if (!frame->constraints)
+    {
+      frame->max_constraints = Kibi(4);
+      frame->constraints_count = 0;
+      frame->constraints = PushStructsNoZero(world->frames_arena, P_Constraint, frame->max_constraints);
+    }
+
     u64 hash = MixU64(tick);
     P_FrameBin *bin = &world->frame_bins[hash % world->frame_bins_count];
 
@@ -1324,6 +1337,7 @@ P_Frame *P_PushFrame(P_World *world, P_Frame *src_frame, i64 tick)
     DllQueuePushNPZ(0, bin->first, bin->last, frame, next_in_bin, prev_in_bin);
   }
 
+  // Copy ents
   for (P_Ent *src = P_FirstEnt(src_frame); !P_IsEntNil(src); src = P_NextEnt(src))
   {
     P_Ent *dst = world->first_free_ent;
@@ -1474,17 +1488,10 @@ void P_StepFrame(P_Frame *frame, P_CmdList cmds)
 
   // TODO: Not like this
 
-  // i64 max_constraints = 4096;
+  frame->constraints_count = MinI64(prev_frame->constraints_count, frame->max_constraints);
-  // i64 constraints_count = 0;
+  CopyStructs(frame->constraints, prev_frame->constraints, frame->constraints_count);
-  // P_Constraint *constraints = PushStructs(scratch.arena, P_Constraint, max_constraints);
+
 
-  PERSIST i64 max_constraints = 4096;
-  PERSIST i64 constraints_count = 0;
-  PERSIST P_Constraint *constraints = 0;
-  if (!constraints)
-  {
-    constraints = PushStructs(scratch.arena, P_Constraint, max_constraints);
-  }
 
   for (P_Ent *ent0 = P_FirstEnt(frame); !P_IsEntNil(ent0); ent0 = P_NextEnt(ent0))
   {
@@ -1503,9 +1510,9 @@ void P_StepFrame(P_Frame *frame, P_CmdList cmds)
           P_Constraint *constraint = 0;
           {
             b32 match = 0;
-            for (i64 constraint_idx = 0; constraint_idx < constraints_count; ++constraint_idx)
+            for (i64 constraint_idx = 0; constraint_idx < frame->constraints_count; ++constraint_idx)
             {
-              constraint = &constraints[constraint_idx];
+              constraint = &frame->constraints[constraint_idx];
               if (P_MatchKey(constraint->ent0, ent0->key) && P_MatchKey(constraint->ent1, ent1->key))
               {
                 match = 1;
@@ -1514,10 +1521,10 @@ void P_StepFrame(P_Frame *frame, P_CmdList cmds)
             }
             if (!match)
             {
-              if (constraints_count < max_constraints)
+              if (frame->constraints_count < frame->max_constraints)
               {
-                constraint = &constraints[constraints_count];
+                constraint = &frame->constraints[frame->constraints_count];
-                constraints_count += 1;
+                frame->constraints_count += 1;
                 ZeroStruct(constraint);
               }
             }
@@ -1626,9 +1633,9 @@ void P_StepFrame(P_Frame *frame, P_CmdList cmds)
 
   {
     i64 constraint_idx = 0;
-    while (constraint_idx < constraints_count)
+    while (constraint_idx < frame->constraints_count)
     {
-      P_Constraint *constraint = &constraints[constraint_idx];
+      P_Constraint *constraint = &frame->constraints[constraint_idx];
       b32 prune = 1;
       if (constraint->last_touched_tick == frame->tick)
       {
@@ -1643,9 +1650,9 @@ void P_StepFrame(P_Frame *frame, P_CmdList cmds)
       {
         // Prune by replacing with last constraint
         // TODO: Investigate whether the reordering here can degrade stability
-        P_Constraint *last_constraint = &constraints[constraints_count - 1];
+        P_Constraint *last_constraint = &frame->constraints[frame->constraints_count - 1];
         *constraint = *last_constraint;
-        constraints_count -= 1;
+        frame->constraints_count -= 1;
       }
       else
       {
@@ -1666,9 +1673,9 @@ void P_StepFrame(P_Frame *frame, P_CmdList cmds)
     //////////////////////////////
     //- Prepare constraints
 
-    for (i64 constraint_idx = 0; constraint_idx < constraints_count; ++constraint_idx)
+    for (i64 constraint_idx = 0; constraint_idx < frame->constraints_count; ++constraint_idx)
     {
-      P_Constraint *constraint = &constraints[constraint_idx];
+      P_Constraint *constraint = &frame->constraints[constraint_idx];
       Vec2 normal = constraint->normal;
       Vec2 tangent = PerpVec2(normal);
       f32 inv_m0 = constraint->inv_m0;
@@ -1703,9 +1710,9 @@ void P_StepFrame(P_Frame *frame, P_CmdList cmds)
     //////////////////////////////
     //- Warm start constraints
 
-    for (i64 constraint_idx = 0; constraint_idx < constraints_count; ++constraint_idx)
+    for (i64 constraint_idx = 0; constraint_idx < frame->constraints_count; ++constraint_idx)
     {
-      P_Constraint *constraint = &constraints[constraint_idx];
+      P_Constraint *constraint = &frame->constraints[constraint_idx];
 
       P_Ent *ent0 = P_EntFromKey(frame, constraint->ent0);
       P_Ent *ent1 = P_EntFromKey(frame, constraint->ent1);
@@ -1747,9 +1754,9 @@ void P_StepFrame(P_Frame *frame, P_CmdList cmds)
     //////////////////////////////
     //- Solve constraints
 
-    for (i64 constraint_idx = 0; constraint_idx < constraints_count; ++constraint_idx)
+    for (i64 constraint_idx = 0; constraint_idx < frame->constraints_count; ++constraint_idx)
     {
-      P_Constraint *constraint = &constraints[constraint_idx];
+      P_Constraint *constraint = &frame->constraints[constraint_idx];
 
       P_Ent *ent0 = P_EntFromKey(frame, constraint->ent0);
       P_Ent *ent1 = P_EntFromKey(frame, constraint->ent1);

src/pp/pp.h

@@ -141,6 +141,43 @@ Struct(P_EntBin)
   P_Ent *last;
 };
 
+////////////////////////////////////////////////////////////
+//~ Constraint types
+
+Struct(P_ContactPoint)
+{
+  Vec2 vcp0;
+  Vec2 vcp1;
+  f32 starting_separation;
+  f32 inv_normal_mass;
+  f32 inv_tangent_mass;
+  u32 id;
+
+  f32 solved_normal_impulse;
+  f32 solved_tangent_impulse;
+};
+
+Struct(P_Constraint)
+{
+  i64 last_touched_tick;
+  P_Key ent0;
+  P_Key ent1;
+
+  Vec2 static_center0;
+  Vec2 static_center1;
+
+  f32 inv_m0;
+  f32 inv_m1;
+  f32 inv_i0;
+  f32 inv_i1;
+
+  Vec2 normal;
+  f32 friction;
+
+  i32 points_count;
+  P_ContactPoint points[2];
+};
+
 ////////////////////////////////////////////////////////////
 //~ World types
 
@@ -169,6 +206,10 @@ Struct(P_Frame)
 
   i64 ent_bins_count;
   P_EntBin *ent_bins;
+
+  i64 max_constraints;
+  i64 constraints_count;
+  P_Constraint *constraints;
 };
 
 Struct(P_FrameBin)
@@ -321,43 +362,6 @@ Struct(P_RaycastResult)
   Vec2 normal;
 };
 
-////////////////////////////////////////////////////////////
-//~ Constraint types
-
-Struct(P_ContactPoint)
-{
-  Vec2 vcp0;
-  Vec2 vcp1;
-  f32 starting_separation;
-  f32 inv_normal_mass;
-  f32 inv_tangent_mass;
-  u32 id;
-
-  f32 solved_normal_impulse;
-  f32 solved_tangent_impulse;
-};
-
-Struct(P_Constraint)
-{
-  i64 last_touched_tick;
-  P_Key ent0;
-  P_Key ent1;
-
-  Vec2 static_center0;
-  Vec2 static_center1;
-
-  f32 inv_m0;
-  f32 inv_m1;
-  f32 inv_i0;
-  f32 inv_i1;
-
-  Vec2 normal;
-  f32 friction;
-
-  i32 points_count;
-  P_ContactPoint points[2];
-};
-
 ////////////////////////////////////////////////////////////
 //~ Command types
 

src/pp/pp_vis/pp_vis_gpu.g

@@ -148,7 +148,7 @@ ComputeShader2D(V_BackdropCS, 8, 8)
         if (tile == P_TileKind_Wall)
         {
           Vec4 outer = LinearFromSrgb(Vec4(0.05, 0.05, 0.05, 1));
-          Vec4 inner = LinearFromSrgb(Vec4(0.10, 0.10, 0.10, 1));
+          Vec4 inner = LinearFromSrgb(Vec4(0.15, 0.15, 0.15, 1));
           result = lerp(outer, inner, smoothstep(0, 1, tile_edge_dist / 0.375));
           // result = lerp(outer, inner, smoothstep(0, 1, tile_edge_dist / 0.5));
         }