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Fix zokumbsp seg angle manipulation (horizon line effect) in software renderring #773

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Merged
merged 1 commit into from
Sep 26, 2025
Merged

Fix zokumbsp seg angle manipulation (horizon line effect) in software renderring #773

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19 changes: 19 additions & 0 deletions prboom2/src/p_setup.c
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Original file line number Diff line number Diff line change
Expand Up @@ -36,6 +36,7 @@
#include <zlib.h>

#include "doomstat.h"
#include "doomtype.h"
#include "m_bbox.h"
#include "g_game.h"
#include "w_wad.h"
Expand Down Expand Up @@ -3288,6 +3289,18 @@ static void P_RemoveSlimeTrails(void) // killough 10/98
Z_Free(hit);
}

// [crispy] fix long wall wobble
static angle_t anglediff(angle_t a, angle_t b)
{
if (b > a)
return anglediff(b, a);

if (a - b < ANG180)
return a - b;
else // [crispy] wrap around
return b - a;
}

static void R_CalcSegsLength(void)
{
int i;
Expand All @@ -3301,6 +3314,12 @@ static void R_CalcSegsLength(void)
li->halflength = (uint32_t)(length / 2.0);
// [crispy] re-calculate angle used for rendering
li->pangle = R_PointToAngleEx2(li->v1->px, li->v1->py, li->v2->px, li->v2->py);
// [crispy] more than just a little adjustment?
// back to the original angle then
if (anglediff(li->pangle, li->angle) > ANG60/2)
{
li->pangle = li->angle;
}
}
}

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4 changes: 2 additions & 2 deletions prboom2/src/r_segs.c
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Original file line number Diff line number Diff line change
Expand Up @@ -206,8 +206,8 @@ void R_FixWiggle(sector_t *sec)

static fixed_t R_ScaleFromGlobalAngle(angle_t visangle)
{
int anglea = ANG90 + (visangle - viewangle);
int angleb = ANG90 + (visangle - rw_normalangle);
angle_t anglea = ANG90 + (visangle - viewangle);
angle_t angleb = ANG90 + (visangle - rw_normalangle);
int den = FixedMul(rw_distance, finesine[anglea >> ANGLETOFINESHIFT]);
// proff 11/06/98: Changed for high-res
fixed_t num = FixedMul(projectiony, finesine[angleb >> ANGLETOFINESHIFT]);
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