Add re-release fog effect support.

Keep fog parameters in player_state_t for proper delta compression.
Height fog seems broken but that's how it is in re-release.

doc/client.asciidoc

@@ -687,6 +687,12 @@ gl_waterwarp::
     Enable screen warping effect when underwater. Only effective when using
     GLSL backend. Default value is 0 (disabled).
 
+gl_fog::
+    Enable re-release fog effect. Default value is 2.
+      - 0 — disable fog
+      - 1 — enable global fog
+      - 2 — enable global fog and height fog
+
 gl_flarespeed::
     Specifies flare fading effect speed. Default value is 8. Set this to 0
     to disable fading.

inc/common/msg.h

@@ -48,6 +48,14 @@ typedef struct {
     uint8_t     loop_attenuation;
 } entity_packed_t;
 
+typedef struct {
+    uint8_t             color[3][3];
+    uint32_t            density;
+    uint16_t            height_density;
+    uint16_t            height_falloff;
+    int32_t             height_dist[2];
+} player_packed_fog_t;
+
 typedef struct {
     pmove_state_new_t   pmove;
     int16_t             viewangles[3];
@@ -59,6 +67,7 @@ typedef struct {
     uint8_t             gunframe;
     uint8_t             blend[4];
     uint8_t             damage_blend[4];
+    player_packed_fog_t fog;
     uint8_t             fov;
     uint8_t             rdflags;
     int16_t             stats[MAX_STATS_NEW];
@@ -73,8 +82,9 @@ typedef enum {
     MSG_PS_IGNORE_PREDICTION    = BIT(5),   // mutually exclusive with IGNORE_VIEWANGLES
     MSG_PS_EXTENSIONS           = BIT(6),   // enable protocol extensions
     MSG_PS_EXTENSIONS_2         = BIT(7),   // enable more protocol extensions
-    MSG_PS_FORCE                = BIT(8),   // send even if unchanged (MVD stream only)
-    MSG_PS_REMOVE               = BIT(9),   // player is removed (MVD stream only)
+    MSG_PS_MOREBITS             = BIT(8),   // read more playerstate bits
+    MSG_PS_FORCE                = BIT(9),   // send even if unchanged (MVD stream only)
+    MSG_PS_REMOVE               = BIT(10),  // player is removed (MVD stream only)
 } msgPsFlags_t;
 
 typedef enum {

inc/common/protocol.h

@@ -29,8 +29,11 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #define PROTOCOL_VERSION_R1Q2           35
 #define PROTOCOL_VERSION_Q2PRO          36
 #define PROTOCOL_VERSION_MVD            37      // not used for UDP connections
-#define PROTOCOL_VERSION_EXTENDED_OLD   3434
-#define PROTOCOL_VERSION_EXTENDED       3435
+
+#define PROTOCOL_VERSION_EXTENDED_MINIMUM       3434    // r2894
+#define PROTOCOL_VERSION_EXTENDED_LIMITS_2      3435    // r3300
+#define PROTOCOL_VERSION_EXTENDED_PLAYERFOG     3436    // r3579
+#define PROTOCOL_VERSION_EXTENDED_CURRENT       3436    // r3579
 
 #define PROTOCOL_VERSION_R1Q2_MINIMUM           1903    // b6377
 #define PROTOCOL_VERSION_R1Q2_UCMD              1904    // b7387
@@ -48,13 +51,15 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #define PROTOCOL_VERSION_Q2PRO_CINEMATICS           1023    // r2263
 #define PROTOCOL_VERSION_Q2PRO_EXTENDED_LIMITS      1024    // r2894
 #define PROTOCOL_VERSION_Q2PRO_EXTENDED_LIMITS_2    1025    // r3300
-#define PROTOCOL_VERSION_Q2PRO_CURRENT              1025    // r3300
+#define PROTOCOL_VERSION_Q2PRO_PLAYERFOG            1026    // r3579
+#define PROTOCOL_VERSION_Q2PRO_CURRENT              1026    // r3579
 
 #define PROTOCOL_VERSION_MVD_MINIMUM            2009    // r168
 #define PROTOCOL_VERSION_MVD_DEFAULT            2010    // r177
 #define PROTOCOL_VERSION_MVD_EXTENDED_LIMITS    2011    // r2894
 #define PROTOCOL_VERSION_MVD_EXTENDED_LIMITS_2  2012    // r3300
-#define PROTOCOL_VERSION_MVD_CURRENT            2012    // r3300
+#define PROTOCOL_VERSION_MVD_PLAYERFOG          2013    // r3579
+#define PROTOCOL_VERSION_MVD_CURRENT            2013    // r3579
 
 #define R1Q2_SUPPORTED(x) \
     ((x) >= PROTOCOL_VERSION_R1Q2_MINIMUM && \
@@ -68,6 +73,10 @@ with this program; if not, write to the Free Software Foundation, Inc.,
     ((x) >= PROTOCOL_VERSION_MVD_MINIMUM && \
      (x) <= PROTOCOL_VERSION_MVD_CURRENT)
 
+#define EXTENDED_SUPPORTED(x) \
+    ((x) >= PROTOCOL_VERSION_EXTENDED_MINIMUM && \
+     (x) <= PROTOCOL_VERSION_EXTENDED_CURRENT)
+
 #define VALIDATE_CLIENTNUM(csr, x) \
     ((x) >= -1 && (x) < (csr)->max_edicts - 1)
 
@@ -213,6 +222,17 @@ typedef enum {
 
 //==============================================
 
+typedef enum {
+    FOG_BIT_COLOR               = BIT(0),
+    FOG_BIT_DENSITY             = BIT(1),
+    FOG_BIT_HEIGHT_DENSITY      = BIT(2),
+    FOG_BIT_HEIGHT_FALLOFF      = BIT(3),
+    FOG_BIT_HEIGHT_START_COLOR  = BIT(4),
+    FOG_BIT_HEIGHT_END_COLOR    = BIT(5),
+    FOG_BIT_HEIGHT_START_DIST   = BIT(6),
+    FOG_BIT_HEIGHT_END_DIST     = BIT(7),
+} fog_bits_t;
+
 // player_state_t communication
 
 #define PS_M_TYPE           BIT(0)
@@ -231,7 +251,9 @@ typedef enum {
 #define PS_WEAPONINDEX      BIT(12)
 #define PS_WEAPONFRAME      BIT(13)
 #define PS_RDFLAGS          BIT(14)
-#define PS_RESERVED         BIT(15)
+#define PS_MOREBITS         BIT(15)     // read one additional byte
+
+#define PS_FOG              BIT(16)
 
 // R1Q2 protocol specific extra flags
 #define EPS_GUNOFFSET       BIT(0)
@@ -264,7 +286,11 @@ typedef enum {
 #define PPS_GUNANGLES       BIT(12)
 #define PPS_RDFLAGS         BIT(13)
 #define PPS_STATS           BIT(14)
-#define PPS_REMOVE          BIT(15)
+#define PPS_MOREBITS        BIT(15)     // read one additional byte
+                                        // same as PPS_REMOVE for old demos!!!
+
+#define PPS_REMOVE          BIT(16)
+#define PPS_FOG             BIT(17)
 
 // this is just a small hack to store inuse flag
 // in a field left otherwise unused by MVD code

inc/refresh/refresh.h

@@ -91,6 +91,8 @@ typedef struct {
     vec3_t      viewangles;
     vec4_t      screen_blend;       // rgba 0-1 full screen blend
     vec4_t      damage_blend;       // rgba 0-1 damage blend
+    player_fog_t        fog;
+    player_heightfog_t  heightfog;
     float       time;               // time is uesed to auto animate
     int         rdflags;            // RDF_UNDERWATER, etc
     bool        extended;

inc/shared/game.h

@@ -25,7 +25,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 //
 
 #define GAME_API_VERSION_OLD    3       // game uses gclient_old_t
-#define GAME_API_VERSION_NEW    3300    // game uses gclient_new_t
+#define GAME_API_VERSION_NEW    3301    // game uses gclient_new_t
 
 #if USE_NEW_GAME_API
 #define GAME_API_VERSION    GAME_API_VERSION_NEW

inc/shared/shared.h

@@ -1537,6 +1537,21 @@ typedef struct {
 } player_state_old_t;
 
 #if USE_NEW_GAME_API
+typedef struct {
+    vec3_t color;
+    float density;
+    float sky_factor;
+} player_fog_t;
+
+typedef struct {
+    struct {
+        vec3_t color;
+        float dist;
+    } start, end;
+    float density;
+    float falloff;
+} player_heightfog_t;
+
 typedef struct {
     pmove_state_new_t   pmove;  // for prediction
 
@@ -1551,15 +1566,21 @@ typedef struct {
     vec3_t      gunoffset;
     int         gunindex;
     int         gunframe;
+    int         reserved_1;
+    int         reserved_2;
 
     vec4_t      blend;          // rgba full screen effect
     vec4_t      damage_blend;
 
+    player_fog_t        fog;
+    player_heightfog_t  heightfog;
+
     float       fov;            // horizontal field of view
 
     int         rdflags;        // refdef flags
 
-    int         reserved[4];
+    int         reserved_3;
+    int         reserved_4;
 
     int16_t     stats[MAX_STATS_NEW];   // fast status bar updates
 } player_state_new_t;

src/client/client.h

@@ -495,6 +495,7 @@ typedef struct {
         player_packed_t     ps;
         entity_packed_t     entities[MAX_EDICTS];
         msgEsFlags_t        esFlags;    // for writing
+        msgPsFlags_t        psFlags;
 
         sizebuf_t       message;
     } gtv;
@@ -693,7 +694,7 @@ void CL_SendCmd(void);
     (MSG_ES_LONGSOLID | MSG_ES_UMASK | MSG_ES_BEAMORIGIN | MSG_ES_SHORTANGLES | MSG_ES_EXTENSIONS)
 
 #define CL_ES_EXTENDED_MASK_2 (CL_ES_EXTENDED_MASK | MSG_ES_EXTENSIONS_2)
-#define CL_PS_EXTENDED_MASK_2 (MSG_PS_EXTENSIONS | MSG_PS_EXTENSIONS_2)
+#define CL_PS_EXTENDED_MASK_2 (MSG_PS_EXTENSIONS | MSG_PS_EXTENSIONS_2 | MSG_PS_MOREBITS)
 
 typedef struct {
     int type;

src/client/demo.c

@@ -420,7 +420,7 @@ static void CL_Record_f(void)
     // send the serverdata
     MSG_WriteByte(svc_serverdata);
     if (cl.csr.extended)
-        MSG_WriteLong(PROTOCOL_VERSION_EXTENDED);
+        MSG_WriteLong(PROTOCOL_VERSION_EXTENDED_CURRENT);
     else
         MSG_WriteLong(min(cls.serverProtocol, PROTOCOL_VERSION_DEFAULT));
     MSG_WriteLong(cl.servercount);
@@ -1185,7 +1185,7 @@ bool CL_GetDemoInfo(const char *path, demoInfo_t *info)
             goto fail;
         }
         c = MSG_ReadLong();
-        if (c == PROTOCOL_VERSION_EXTENDED || c == PROTOCOL_VERSION_EXTENDED_OLD) {
+        if (EXTENDED_SUPPORTED(c)) {
             csr = &cs_remap_new;
         } else if (c < PROTOCOL_VERSION_OLD || c > PROTOCOL_VERSION_DEFAULT) {
             goto fail;

src/client/entities.c

@@ -1315,6 +1315,14 @@ static inline float lerp_client_fov(float ofov, float nfov, float lerp)
     return ofov + lerp * (nfov - ofov);
 }
 
+static inline void lerp_values(const void *from, const void *to, float lerp, void *out, int count)
+{
+    float backlerp = 1.0f - lerp;
+
+    for (int i = 0; i < count; i++)
+        ((float *)out)[i] = ((const float *)from)[i] * backlerp + ((const float *)to)[i] * lerp;
+}
+
 /*
 ===============
 CL_CalcViewValues
@@ -1389,6 +1397,19 @@ void CL_CalcViewValues(void)
     Vector4Copy(ps->blend, cl.refdef.screen_blend);
     Vector4Copy(ps->damage_blend, cl.refdef.damage_blend);
 
+    // interpolate fog
+    if (cl.psFlags & MSG_PS_MOREBITS) {
+        lerp_values(&ops->fog, &ps->fog, lerp,
+                    &cl.refdef.fog, sizeof(cl.refdef.fog) / sizeof(float));
+        // no lerping if moved too far
+        if (fabsf(ps->heightfog.start.dist - ops->heightfog.start.dist) > 512 ||
+            fabsf(ps->heightfog.end  .dist - ops->heightfog.end  .dist) > 512)
+            cl.refdef.heightfog = ps->heightfog;
+        else
+            lerp_values(&ops->heightfog, &ps->heightfog, lerp,
+                        &cl.refdef.heightfog, sizeof(cl.refdef.heightfog) / sizeof(float));
+    }
+
 #if USE_FPS
     ps = &cl.keyframe.ps;
     ops = &cl.oldkeyframe.ps;

src/client/gtv.c

@@ -54,6 +54,10 @@ static void build_gamestate(void)
 
     // set protocol flags
     cls.gtv.esFlags = MSG_ES_UMASK | MSG_ES_BEAMORIGIN | (cl.esFlags & CL_ES_EXTENDED_MASK_2);
+    cls.gtv.psFlags = MSG_PS_FORCE | (cl.psFlags & CL_PS_EXTENDED_MASK_2);
+
+    if (cls.gtv.psFlags & MSG_PS_EXTENSIONS_2)
+        cls.gtv.psFlags |= MSG_PS_MOREBITS;
 }
 
 static void emit_gamestate(void)
@@ -99,8 +103,7 @@ static void emit_gamestate(void)
     MSG_WriteByte(0);
 
     // send player state
-    MSG_WriteDeltaPlayerstate_Packet(NULL, &cls.gtv.ps,
-                                     cl.clientNum, cl.psFlags | MSG_PS_FORCE);
+    MSG_WriteDeltaPlayerstate_Packet(NULL, &cls.gtv.ps, cl.clientNum, cls.gtv.psFlags);
     MSG_WriteByte(CLIENTNUM_NONE);
 
     // send entity states
@@ -138,8 +141,7 @@ void CL_GTV_EmitFrame(void)
     // send player state
     MSG_PackPlayerNew(&newps, &cl.frame.ps);
 
-    MSG_WriteDeltaPlayerstate_Packet(&cls.gtv.ps, &newps,
-                                     cl.clientNum, cl.psFlags | MSG_PS_FORCE);
+    MSG_WriteDeltaPlayerstate_Packet(&cls.gtv.ps, &newps, cl.clientNum, cls.gtv.psFlags);
 
     // shuffle current state to previous
     cls.gtv.ps = newps;

src/client/parse.c

@@ -320,6 +320,9 @@ static void CL_ParseFrame(int extrabits)
 
     // parse playerstate
     bits = MSG_ReadWord();
+    if (cl.psFlags & MSG_PS_MOREBITS && bits & PS_MOREBITS)
+        bits |= (uint32_t)MSG_ReadByte() << 16;
+
     if (cls.serverProtocol > PROTOCOL_VERSION_DEFAULT) {
         MSG_ParseDeltaPlayerstate_Enhanced(from, &frame.ps, bits, extraflags, cl.psFlags);
 #if USE_DEBUG
@@ -532,7 +535,7 @@ static void CL_ParseServerData(void)
                       cls.serverProtocol, protocol);
         }
         // BIG HACK to let demos from release work with the 3.0x patch!!!
-        if (protocol == PROTOCOL_VERSION_EXTENDED || protocol == PROTOCOL_VERSION_EXTENDED_OLD) {
+        if (EXTENDED_SUPPORTED(protocol)) {
             cl.csr = cs_remap_new;
             cls.serverProtocol = PROTOCOL_VERSION_DEFAULT;
         } else if (protocol < PROTOCOL_VERSION_OLD || protocol > PROTOCOL_VERSION_DEFAULT) {
@@ -649,6 +652,8 @@ static void CL_ParseServerData(void)
                 Com_DPrintf("Q2PRO protocol extensions v2 enabled\n");
                 cl.esFlags |= MSG_ES_EXTENSIONS_2;
                 cl.psFlags |= MSG_PS_EXTENSIONS_2;
+                if (cls.protocolVersion >= PROTOCOL_VERSION_Q2PRO_PLAYERFOG)
+                    cl.psFlags |= MSG_PS_MOREBITS;
                 PmoveEnableExt(&cl.pmp);
             }
         } else {
@@ -684,9 +689,13 @@ static void CL_ParseServerData(void)
         cl.psFlags |= MSG_PS_EXTENSIONS;
 
         // hack for demo playback
-        if (protocol == PROTOCOL_VERSION_EXTENDED) {
-            cl.esFlags |= MSG_ES_EXTENSIONS_2;
-            cl.psFlags |= MSG_PS_EXTENSIONS_2;
+        if (EXTENDED_SUPPORTED(protocol)) {
+            if (protocol >= PROTOCOL_VERSION_EXTENDED_LIMITS_2) {
+                cl.esFlags |= MSG_ES_EXTENSIONS_2;
+                cl.psFlags |= MSG_PS_EXTENSIONS_2;
+            }
+            if (protocol >= PROTOCOL_VERSION_EXTENDED_PLAYERFOG)
+                cl.psFlags |= MSG_PS_MOREBITS;
         }
     }