From d2d1f83b62de98a9f08f5197e9bed84306f12741 Mon Sep 17 00:00:00 2001
From: LJ Sonic <lamr@free.fr>
Date: Sat, 13 Feb 2021 17:45:54 +0100
Subject: [PATCH] Revert "Use R_PointToDist2 instead"
This reverts commit e19196a86e5347edf7f25b335214cede978b91b8.
---
src/m_fixed.c | 40 ++++++++++++----------------------------
src/r_main.c | 24 +++++++++++++++++++++++-
2 files changed, 35 insertions(+), 29 deletions(-)
diff --git a/src/m_fixed.c b/src/m_fixed.c
index 09d6936f2e..eb10fd5f80 100644
--- a/src/m_fixed.c
+++ b/src/m_fixed.c
@@ -18,10 +18,8 @@
#define HAVE_SQRTF
#endif
#endif
-
#include "doomdef.h"
#include "m_fixed.h"
-#include "tables.h" // ANGLETOFINESHIFT
#ifdef __USE_C_FIXEDMUL__
@@ -107,34 +105,20 @@ fixed_t FixedSqrt(fixed_t x)
fixed_t FixedHypot(fixed_t x, fixed_t y)
{
- // Moved the code from R_PointToDist2 to here,
- // since R_PointToDist2 did the same thing,
- // except less prone to overflowing.
-
- angle_t angle;
- fixed_t dist;
-
- x = abs(x);
- y = abs(y);
-
- if (y > x)
+ fixed_t ax, yx, yx2, yx1;
+ if (abs(y) > abs(x)) // |y|>|x|
{
- fixed_t temp;
-
- temp = x;
- x = y;
- y = temp;
+ ax = abs(y); // |y| => ax
+ yx = FixedDiv(x, y); // (x/y)
}
-
- if (!y)
- return x;
-
- angle = (tantoangle[FixedDiv(y, x)>>DBITS] + ANGLE_90) >> ANGLETOFINESHIFT;
-
- // use as cosine
- dist = FixedDiv(x, FINESINE(angle));
-
- return dist;
+ else // |x|>|y|
+ {
+ ax = abs(x); // |x| => ax
+ yx = FixedDiv(y, x); // (x/y)
+ }
+ yx2 = FixedMul(yx, yx); // (x/y)^2
+ yx1 = FixedSqrt(1 * FRACUNIT + yx2); // (1 + (x/y)^2)^1/2
+ return FixedMul(ax, yx1); // |x|*((1 + (x/y)^2)^1/2)
}
vector2_t *FV2_Load(vector2_t *vec, fixed_t x, fixed_t y)
diff --git a/src/r_main.c b/src/r_main.c
index f6c05e312a..f82fb589e0 100644
--- a/src/r_main.c
+++ b/src/r_main.c
@@ -357,7 +357,29 @@ angle_t R_PointToAngle2(fixed_t pviewx, fixed_t pviewy, fixed_t x, fixed_t y)
fixed_t R_PointToDist2(fixed_t px2, fixed_t py2, fixed_t px1, fixed_t py1)
{
- return FixedHypot(px1 - px2, py1 - py2);
+ angle_t angle;
+ fixed_t dx, dy, dist;
+
+ dx = abs(px1 - px2);
+ dy = abs(py1 - py2);
+
+ if (dy > dx)
+ {
+ fixed_t temp;
+
+ temp = dx;
+ dx = dy;
+ dy = temp;
+ }
+ if (!dy)
+ return dx;
+
+ angle = (tantoangle[FixedDiv(dy, dx)>>DBITS] + ANGLE_90) >> ANGLETOFINESHIFT;
+
+ // use as cosine
+ dist = FixedDiv(dx, FINESINE(angle));
+
+ return dist;
}
// Little extra utility. Works in the same way as R_PointToAngle2
--
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