From 4143c31176a39643e25883e075afe76fe32b49c2 Mon Sep 17 00:00:00 2001
From: fickleheart <fickle@tinted.red>
Date: Sat, 23 Feb 2019 10:31:37 -0600
Subject: [PATCH] Add field-of-view support in software mode

---
 src/p_user.c | 15 +--------------
 src/r_main.c | 17 +++++++++++------
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/p_user.c b/src/p_user.c
index 76f57a9b..e26acdfd 100644
--- a/src/p_user.c
+++ b/src/p_user.c
@@ -8295,9 +8295,6 @@ boolean P_MoveChaseCamera(player_t *player, camera_t *thiscam, boolean resetcall
 	if (mo->eflags & MFE_VERTICALFLIP)
 		camheight += thiscam->height;
 
-	if (splitscreen == 1)
-		camspeed = (3*camspeed)/4;
-
 	if (camspeed > FRACUNIT)
 		camspeed = FRACUNIT;
 
@@ -8351,13 +8348,6 @@ boolean P_MoveChaseCamera(player_t *player, camera_t *thiscam, boolean resetcall
 		height -= FixedMul(height, player->kartstuff[k_boostcam]);
 	}
 
-	// in splitscreen modes, mess with the camera distances to make it feel proportional to how it feels normally
-	if (splitscreen == 1) // widescreen splits should get x1.5 distance
-	{
-		dist = FixedMul(dist, 3*FRACUNIT/2);
-		height = FixedMul(height, 3*FRACUNIT/2);
-	}
-
 	x = mo->x - FixedMul(FINECOSINE((angle>>ANGLETOFINESHIFT) & FINEMASK), dist);
 	y = mo->y - FixedMul(FINESINE((angle>>ANGLETOFINESHIFT) & FINEMASK), dist);
 
@@ -8623,10 +8613,7 @@ boolean P_MoveChaseCamera(player_t *player, camera_t *thiscam, boolean resetcall
 	{
 		thiscam->momx = x - thiscam->x;
 		thiscam->momy = y - thiscam->y;
-		if (splitscreen == 1) // Wide-screen needs to follow faster, due to a smaller vertical:horizontal ratio of screen space
-			thiscam->momz = FixedMul(z - thiscam->z, (3*camspeed)/4);
-		else
-			thiscam->momz = FixedMul(z - thiscam->z, camspeed/2);
+		thiscam->momz = FixedMul(z - thiscam->z, camspeed/2);
 	}
 
 	thiscam->pan = pan;
diff --git a/src/r_main.c b/src/r_main.c
index ee613076..29f8c77e 100644
--- a/src/r_main.c
+++ b/src/r_main.c
@@ -56,6 +56,7 @@ INT32 centerx, centery;
 fixed_t centerxfrac, centeryfrac;
 fixed_t projection;
 fixed_t projectiony; // aspect ratio
+fixed_t fovtan; // field of view
 
 // just for profiling purposes
 size_t framecount;
@@ -529,7 +530,7 @@ static void R_InitTextureMapping(void)
 	//
 	// Calc focallength
 	//  so FIELDOFVIEW angles covers SCREENWIDTH.
-	focallength = FixedDiv(centerxfrac,
+	focallength = FixedDiv(projection,
 		FINETANGENT(FINEANGLES/4+/*cv_fov.value*/ FIELDOFVIEW/2));
 
 #ifdef ESLOPE
@@ -644,6 +645,7 @@ void R_ExecuteSetViewSize(void)
 	INT32 j;
 	INT32 level;
 	INT32 startmapl;
+	angle_t fov;
 
 	setsizeneeded = false;
 
@@ -672,9 +674,12 @@ void R_ExecuteSetViewSize(void)
 	centerxfrac = centerx<<FRACBITS;
 	centeryfrac = centery<<FRACBITS;
 
-	projection = centerxfrac;
-	//projectiony = (((vid.height*centerx*BASEVIDWIDTH)/BASEVIDHEIGHT)/vid.width)<<FRACBITS;
-	projectiony = centerxfrac;
+	fov = FixedAngle(cv_fov.value/2) + ANGLE_90;
+	fovtan = FINETANGENT(fov >> ANGLETOFINESHIFT);
+	if (splitscreen == 1) // Splitscreen FOV should be adjusted to maintain expected vertical view
+		fovtan *= 2;
+
+	projection = projectiony = FixedDiv(centerxfrac, fovtan);
 
 	R_InitViewBuffer(scaledviewwidth, viewheight);
 
@@ -700,7 +705,7 @@ void R_ExecuteSetViewSize(void)
 		for (i = 0; i < j; i++)
 		{
 			dy = ((i - viewheight*8)<<FRACBITS) + FRACUNIT/2;
-			dy = abs(dy);
+			dy = FixedMul(abs(dy), fovtan);
 			yslopetab[i] = FixedDiv(centerx*FRACUNIT, dy);
 		}
 	}
@@ -815,7 +820,7 @@ subsector_t *R_IsPointInSubsector(fixed_t x, fixed_t y)
 static mobj_t *viewmobj;
 
 // WARNING: a should be unsigned but to add with 2048, it isn't!
-#define AIMINGTODY(a) ((FINETANGENT((2048+(((INT32)a)>>ANGLETOFINESHIFT)) & FINEMASK)*160)>>FRACBITS)
+#define AIMINGTODY(a) FixedDiv((FINETANGENT((2048+(((INT32)a)>>ANGLETOFINESHIFT)) & FINEMASK)*160)>>FRACBITS, fovtan)
 
 // recalc necessary stuff for mouseaiming
 // slopes are already calculated for the full possible view (which is 4*viewheight).