Renderer: Automatically adjust FOV for view aspect ratio

The FOV angle is now interpreted to be the horizontal FOV angle for
a view with 4:3 aspect ratio (matching the original DOOM). For wider
or narrower views, the FOV is increased accordingly, making it
independent of view width.

This fixes the problem of inappropriately low FOV angles with 16:9
or 16:10 displays.

doomsday/client/include/render/rend_main.h

@@ -42,7 +42,7 @@ class Map;
 #define SHADOW_SURFACE_LUMINOSITY_ATTRIBUTION_MIN (.05f)
 
 DENG_EXTERN_C coord_t vOrigin[3];
-DENG_EXTERN_C float vang, vpitch, fieldOfView, yfov;
+DENG_EXTERN_C float vang, vpitch, yfov;
 DENG_EXTERN_C float viewsidex, viewsidey;
 DENG_EXTERN_C float fogColor[4];
 
@@ -91,6 +91,8 @@ void Rend_Shutdown();
 void Rend_Reset();
 void Rend_RenderMap(de::Map &map);
 
+float Rend_FieldOfView();
+
 /**
  * @param useAngles  @c true= Apply viewer angle rotation.
  */

doomsday/client/src/gl/gl_main.cpp

@@ -588,7 +588,7 @@ void GL_ProjectionMatrix()
 
     glMatrixMode(GL_PROJECTION);
     glLoadIdentity();
-    gluPerspective(yfov = fieldOfView / aspect, aspect, glNearClip, glFarClip);
+    gluPerspective(yfov = Rend_FieldOfView() / aspect, aspect, glNearClip, glFarClip);
 
     // We'd like to have a left-handed coordinate system.
     glScalef(1, 1, -1);

doomsday/client/src/network/net_demo.cpp

@@ -349,7 +349,7 @@ boolean Demo_BeginPlayback(const char* fileName)
     lookdirDelta = 0;
     demoFrameZ = 1;
     demoZ = 0;
-    startFOV = fieldOfView;
+    startFOV = 95; //Rend_FieldOfView();
     demoStartTic = DEMOTIC;
     memset(posDelta, 0, sizeof(posDelta));
     // Start counting frames from here.
@@ -375,7 +375,7 @@ void Demo_StopPlayback(void)
     playback = false;
     lzClose(playdemo);
     playdemo = 0;
-    fieldOfView = startFOV;
+    //fieldOfView = startFOV;
     Net_StopGame();
 
     /*
@@ -455,7 +455,7 @@ void Demo_WriteLocalCamera(int plrNum)
     mobj_t* mo = ddpl->mo;
     fixed_t x, y, z;
     byte flags;
-    boolean incfov = (writeInfo[plrNum].fov != fieldOfView);
+    boolean incfov = false; //(writeInfo[plrNum].fov != fieldOfView);
     const viewdata_t* viewData = R_ViewData(plrNum);
 
     if(!mo)
@@ -487,11 +487,11 @@ void Demo_WriteLocalCamera(int plrNum)
     Writer_WriteInt16(msgWriter, mo->angle /*ddpl->clAngle*/ >> 16); /* $unifiedangles */
     Writer_WriteInt16(msgWriter, ddpl->lookDir / 110 * DDMAXSHORT /* $unifiedangles */);
     // Field of view is optional.
-    if(incfov)
+    /*if(incfov)
     {
         Writer_WriteInt16(msgWriter, fieldOfView / 180 * DDMAXSHORT);
         writeInfo[plrNum].fov = fieldOfView;
-    }
+    }*/
     Msg_End();
     Net_SendBuffer(plrNum, SPF_DONT_SEND);
 }
@@ -544,8 +544,10 @@ void Demo_ReadLocalCamera(void)
     dlook = Reader_ReadInt16(msgReader) * 110.0f / DDMAXSHORT;
 
     // FOV included?
+    /*
     if(flags & LCAMF_FOV)
         fieldOfView = Reader_ReadInt16(msgReader) * 180.0f / DDMAXSHORT;
+    */
 
     if(intertics == 1 || demoFrameZ == 1)
     {

doomsday/client/src/render/r_main.cpp

@@ -1024,8 +1024,8 @@ void R_SetupPlayerSprites()
             spr->data.model.pitchAngleOffset =
                 (32 - psp->pos[VY]) * weaponOffsetScale * weaponOffsetScaleY / 1000.0f;
             // Is the FOV shift in effect?
-            if(weaponFOVShift > 0 && fieldOfView > 90)
-                spr->data.model.pitchAngleOffset -= weaponFOVShift * (fieldOfView - 90) / 90;
+            if(weaponFOVShift > 0 && Rend_FieldOfView() > 90)
+                spr->data.model.pitchAngleOffset -= weaponFOVShift * (Rend_FieldOfView() - 90) / 90;
             // Real rotation angles.
             spr->data.model.yaw =
                 viewData->current.angle / (float) ANGLE_MAX *-360 + spr->data.model.yawAngleOffset + 90;
@@ -1130,7 +1130,7 @@ DENG_EXTERN_C void R_RenderPlayerView(int num)
         GL_DrawFilter();
     }
 
-    Vignette_Render(&vd->window, fieldOfView);
+    Vignette_Render(&vd->window, Rend_FieldOfView());
 
     // Now we can show the viewPlayer's mobj again.
     if(!(player->shared.flags & DDPF_CHASECAM))

doomsday/client/src/render/rend_main.cpp

@@ -323,6 +323,12 @@ void Rend_Reset()
     }
 }
 
+float Rend_FieldOfView()
+{
+    float const widescreenCorrection = float(viewpw)/float(viewph) / (4.f / 3.f);
+    return widescreenCorrection * fieldOfView;
+}
+
 void Rend_ModelViewMatrix(bool useAngles)
 {
     viewdata_t const *viewData = R_ViewData(viewPlayer - ddPlayers);
@@ -2559,7 +2565,7 @@ void Rend_RenderMap(Map &map)
         if(vpitch <= 90 - yfov / 2 && vpitch >= -90 + yfov / 2)
         {
             float a = de::abs(vpitch) / (90 - yfov / 2);
-            binangle_t startAngle = binangle_t(BANG_45 * fieldOfView / 90) * (1 + a);
+            binangle_t startAngle = binangle_t(BANG_45 * Rend_FieldOfView() / 90) * (1 + a);
             binangle_t angLen = BANG_180 - startAngle;
 
             binangle_t viewside = (viewData->current.angle >> (32 - BAMS_BITS)) + startAngle;

doomsday/client/src/render/rend_model.cpp

@@ -1009,7 +1009,7 @@ static void Mod_RenderSubModel(uint number, rendmodelparams_t const *parm)
     // Determine the suitable LOD.
     if(mdl->info.numLODs > 1 && rend_model_lod != 0)
     {
-        float lodFactor = rend_model_lod * DENG_WINDOW->width() / 640.0f / (fieldOfView / 90.0f);
+        float lodFactor = rend_model_lod * DENG_WINDOW->width() / 640.0f / (Rend_FieldOfView() / 90.0f);
         if(!FEQUAL(lodFactor, 0))
             lodFactor = 1 / lodFactor;