fix edge collisions, update readme

1 files changed, 48 insertions, 10 deletions

diff --git a/src/game/physics/movement.cpp b/src/game/physics/movement.cpp
index c9b7688..ecee539 100644
--- a/src/game/physics/movement.cpp
+++ b/src/game/physics/movement.cpp
@@ -125,8 +125,6 @@ void gmove_accelerate( VEC3& wishdir, F32 wishspeed, F32 accel ) {
   gmove->velocity += wishdir * accelspeed;
 }
 
-// todo: player hull extends at center instead of at feet
-// should extend at feet
 void gmove_stay_on_ground() {
   BSP_TRACE tr{};
   VEC3 start = gmove->pos;
@@ -155,9 +153,10 @@ void gmove_categorize_pos() {
   
 }
 
-VEC3 gmove_clip_planes( VEC3 vel, LIST<VEC3>* planes, F32 overbounce ) {
-  if( planes->size > 2 )
-    vel = {};
+VEC3 gmove_clip_planes( VEC3 vel, VEC3* pos, LIST<VEC3>* planes, F32 overbounce ) {
+  if( planes->size > 2 ) {
+    return {};
+  }
 
   planes->each( fn( VEC3* p ) {
     vel = gmove_clip_velocity( vel, *p, overbounce );
@@ -168,6 +167,7 @@ VEC3 gmove_clip_planes( VEC3 vel, LIST<VEC3>* planes, F32 overbounce ) {
       if( vec_dot( vel, planes->data[i] ) < 0.f ) {
         VEC3 dir = vec_cross( planes->data[0], planes->data[1] );
         F32 len = vec_len( dir );
+
         if( len > 0.00001f ) {
           dir *= 1.0f / len;
           vel = dir * vec_dot( vel, dir );
@@ -183,6 +183,43 @@ VEC3 gmove_clip_planes( VEC3 vel, LIST<VEC3>* planes, F32 overbounce ) {
   return vel;
 }
 
+void gmove_check_stuck( VEC3* pos ) {
+  BSP_TRACE t;
+  bsp_trace( &t, gmove->bsp, gmove->aabb, *pos, *pos );
+  if( !t.hit )
+    return;
+
+  VEC3 p1 = *pos;
+
+  // try nudge away from wall
+  *pos = p1 + t.normal * BSP_TRACE_EPSILON * 2.f;
+  bsp_trace( &t, gmove->bsp, gmove->aabb, *pos, *pos );
+  if( !t.hit )
+    return;
+
+  // nudge +90deg away horizontal
+  *pos = p1 + VEC3{ -t.normal.y, t.normal.x, t.normal.z } * BSP_TRACE_EPSILON * 2.f;
+  bsp_trace( &t, gmove->bsp, gmove->aabb, *pos, *pos );
+  if( !t.hit )
+    return;
+
+  // nudge -90deg away horizontal
+  *pos = p1 + VEC3{ t.normal.y, -t.normal.x, t.normal.z } * BSP_TRACE_EPSILON * 2.f;
+  bsp_trace( &t, gmove->bsp, gmove->aabb, *pos, *pos );
+  if( !t.hit )
+    return;
+
+  // nudge -180deg away horizontal
+  *pos = p1 + VEC3{ t.normal.y, t.normal.x, -t.normal.z } * BSP_TRACE_EPSILON * 2.f;
+  bsp_trace( &t, gmove->bsp, gmove->aabb, *pos, *pos );
+  if( !t.hit )
+    return;
+
+  // todo : loop over every dir from current pos and incrementally increase distance.
+  // kinda like source
+  *pos = p1; // restore original pos - failed to unstuck
+}
+
 F32 gmove_try_move( BSP_TRACE* t, VEC3* pos, VEC3* vel ) {
   F32        dt = TICK_INTERVAL;
   AABB       aabb = gmove->aabb;
@@ -198,7 +235,8 @@ F32 gmove_try_move( BSP_TRACE* t, VEC3* pos, VEC3* vel ) {
 
     *pos += wishmove * t->frac;
     // nudge player away from wall
-    *pos += t->normal * (BSP_TRACE_EPSILON * 2.f);
+    if( vec_dot( *vel, t->normal ) < 0.f )
+      *pos += t->normal * (BSP_TRACE_EPSILON * 2.f);
 
     planes.push( t->normal );
 
@@ -206,7 +244,7 @@ F32 gmove_try_move( BSP_TRACE* t, VEC3* pos, VEC3* vel ) {
     if( dt <= 0.0001f )
       break;
 
-    *vel = gmove_clip_planes( *vel, &planes, 1.f /* todo : surface friction */ );
+    *vel = gmove_clip_planes( *vel, pos, &planes, 1.f /* todo : surface friction */ );
   }
 
   return dt < 0 ? 0 : dt;
@@ -279,23 +317,23 @@ void gmove_walk_move() {
   gmove_accelerate( wishdir, speed, var_getf( mv_accelerate ) );
   speed = vec_len( vel );
 
+  defer( gmove_check_stuck( &gmove->pos ) );
   if( speed < 1.f ) {
     gmove->velocity = {};
     return;
   }
 
-  VEC3 dest = gmove->pos + vel * TICK_INTERVAL;
+  VEC3 dest = gmove->pos + gmove->velocity * TICK_INTERVAL;
   BSP_TRACE tr{};
   bsp_trace( &tr, gmove->bsp, gmove->aabb, gmove->pos, dest );
 
+  defer( gmove_stay_on_ground() );
   if( !tr.hit ) {
     gmove->pos = dest;
-    gmove_stay_on_ground();
     return;
   }
 
   gmove_step_move( dest, &tr );
-  gmove_stay_on_ground();
 }
 
 void gmove_full_walk_move() {