1 files changed, 157 insertions, 0 deletions
diff --git a/src/game/physics/movement.cpp b/src/game/physics/movement.cpp
new file mode 100644
index 0000000..e9e0132
--- /dev/null
+++ b/src/game/physics/movement.cpp
@@ -0,0 +1,157 @@
+#include "movement.h"
+#include "../world/trace.h"
+#include "../../util/math.h"
+#include "../../util/string.h"
+#include "../../game.h"
+
+GAME_MOVEMENT* gmove;
+
+void gmove_init( GAME_DATA* game ) {
+  gmove = new GAME_MOVEMENT;
+  gmove->game = game;
+}
+
+U8 gmove_check_valid( STR<256> from ) {
+  if( !gmove->game ) {
+    dlog( "%s : game not init\n", from.data );
+    return 0;
+  }
+
+  if( !gmove->pl ) {
+    dlog( "%s : player null\n", from.data );
+    return 0;
+  }
+
+  if( !gmove->input ) {
+    dlog( "%s : input null\n", from.data );
+    return 0;
+  }
+
+  if( !gmove->game->state.map ) {
+    dlog( "%s : no map loaded\n", from.data );
+    return 0;
+  }
+
+  if( !gmove->game->state.map->bsp ) {
+    dlog( "%s : no bsp loaded\n", from.data );
+    return 0;
+  }
+
+  return 1;
+}
+
+void gmove_set_player( PLAYER* player ) {
+  gmove->pl = player;
+  gmove->input = &player->input;
+}
+
+VEC3 gmove_clip_velocity( VEC3 in, VEC3 norm, F32 overbounce ) {
+  F32 blocked = vec_dot( in, norm );
+  F32 backoff = blocked * overbounce;
+  VEC3 out = in - norm * backoff;
+
+  F32 adjust = vec_dot( out, norm );
+  if( adjust < 0.f )
+    out -= (norm * adjust);
+
+  // uncomment to enable quake/hl1-like wallboosting
+  // F32 len = vec_len( out );
+  // if( len > 0.f )
+  //   out *= ( -1.f * blocked + len ) / len;
+
+  return out;
+}
+
+VEC3 gmove_clip_planes( VEC3 vel, LIST<VEC3>* planes, F32 overbounce ) {
+  if( planes->size > 2 )
+    vel = {};
+
+  planes->each( fn( VEC3* p ) {
+    vel = gmove_clip_velocity( vel, *p, overbounce );
+  } );
+
+  if( planes->size > 1 ) {
+    for( U32 i = 0; i < planes->size; ++i ) {
+      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 );
+        } else {
+          vel = {};
+        }
+
+        break;
+      }
+    }
+  }
+
+  return vel;
+}
+
+F32 gmove_try_move( BSP_TRACE* t, AABB aabb, VEC3* pos, VEC3 vel ) {
+  F32 dt = TICK_INTERVAL;
+  LIST<VEC3> planes;
+
+  for( U32 bump = 0; bump < 4; ++bump ) {
+    VEC3 wishmove = vel * dt;
+    bsp_trace( t, gmove->game->state.map->bsp, aabb, *pos, *pos + wishmove );
+    if( !t->hit ) {
+      *pos = t->point;
+      break;
+    }
+
+    *pos += wishmove * t->frac;
+    // nudge player away from wall
+    *pos += t->normal * (BSP_TRACE_EPSILON * 2.f);
+
+    planes.push( t->normal );
+
+    dt *= (1.f - t->frac);
+    if( dt <= 0.0001f )
+      break;
+
+    vel = gmove_clip_planes( vel, &planes, 1.f /* surface friction */ );
+  }
+
+  return dt < 0 ? 0 : dt;
+}
+
+void gmove_walk_move() {
+  PLAYER* p = gmove->pl;
+  VEC2    move = gmove->input->move;
+  F32     yawrad = m_deg2rad( p->rot.y );
+  VEC3    wishdir = {
+    move.x * cosf( yawrad ) - move.y * sinf( yawrad ),
+    move.y * cosf( yawrad ) + move.x * sinf( yawrad ),
+    0
+  };
+
+  VEC3 vel = wishdir * p->maxspeed;
+  VEC3 wishmove = vel * TICK_INTERVAL;
+  p->velocity = vel;
+
+  if( vec_len( wishmove ) < BSP_TRACE_EPSILON )
+    return;
+
+  BSP_TRACE tr{};
+  AABB aabb{};
+  aabb.min = p->mins;
+  aabb.max = p->maxs;
+  VEC3 npos = p->pos;
+
+  F32 frac = gmove_try_move( &tr, aabb, &npos, vel );
+  p->velocity *= frac / TICK_INTERVAL;
+  p->pos = npos;
+}
+
+void gmove_process_move() {
+  gmove_walk_move();
+}
+
+void gmove_tick() {
+  if( !gmove_check_valid( "gmove_tick()" ) )
+    return;
+  gmove_process_move();
+}