From 12576d2eb55cb4591d9a2b6ecad5e83515f6ebb8 Mon Sep 17 00:00:00 2001
From: Randy Heit <rheit@zdoom.fake>
Date: Tue, 8 Sep 2009 23:48:34 +0000
Subject: [PATCH] - Because entryway timed it, here is a new version of
R_PointToAngle2 that is closer to the original. The old code was shorter
but a little slower. The new code is a bit faster than the original with
VC++ and about the same with GCC. Interestingly, GCC produces code for
Killough's version that performs about the same as the original, but when
compiled with VC++, Killough's is notably worse.
SVN r1813 (trunk)
---
docs/rh-log.txt | 8 +++++++
src/r_main.cpp | 58 +++++++++++++++++++++++++++++--------------------
src/tables.h | 15 -------------
3 files changed, 43 insertions(+), 38 deletions(-)
diff --git a/docs/rh-log.txt b/docs/rh-log.txt
index 6bf28cda4..1ccb3031b 100644
--- a/docs/rh-log.txt
+++ b/docs/rh-log.txt
@@ -1,3 +1,11 @@
+September 8, 2009
+- Because entryway timed it, here is a new version of R_PointToAngle2 that is
+ closer to the original. The old code was shorter but a little slower. The
+ new code is a bit faster than the original with VC++ and about the same
+ with GCC. Interestingly, GCC produces code for Killough's version that
+ performs about the same as the original, but when compiled with VC++,
+ Killough's is notably worse.
+
September 8, 2009 (Changes by Graf Zahl)
- moved ENDOOM lump name definition into gameinfo.
- moved default item drop style into gameinfo.
diff --git a/src/r_main.cpp b/src/r_main.cpp
index adac3dc19..d20ec9670 100644
--- a/src/r_main.cpp
+++ b/src/r_main.cpp
@@ -221,6 +221,27 @@ static bool NoInterpolateView;
// CODE --------------------------------------------------------------------
+//==========================================================================
+//
+// SlopeDiv
+//
+// Utility function, called by R_PointToAngle.
+//
+//==========================================================================
+
+angle_t SlopeDiv (unsigned int num, unsigned den)
+{
+ unsigned int ans;
+
+ if (den < 512)
+ return (ANG45 - 1); //tantoangle[SLOPERANGE]
+
+ ans = (num << 3) / (den >> 8);
+
+ return ans <= SLOPERANGE ? tantoangle[ans] : (ANG45 - 1);
+}
+
+
//==========================================================================
//
// R_PointToAngle
@@ -242,65 +263,56 @@ angle_t R_PointToAngle2 (fixed_t x1, fixed_t y1, fixed_t x, fixed_t y)
return 0;
}
- fixed_t ax = abs (x);
- fixed_t ay = abs (y);
- int div;
- angle_t angle;
-
- if (ax > ay)
- {
- swap (ax, ay);
- }
- div = SlopeDiv (ax, ay);
- angle = tantoangle[div];
-
if (x >= 0)
{
if (y >= 0)
{
if (x > y)
{ // octant 0
- return angle;
+ return SlopeDiv(y, x);
}
else
{ // octant 1
- return ANG90 - 1 - angle;
+ return ANG90 - 1 - SlopeDiv(x, y);
}
}
else // y < 0
{
- if (x > -y)
+ y = -y;
+ if (x > y)
{ // octant 8
- return (angle_t)-(SDWORD)angle;
+ return 0 - SlopeDiv(y, x);
}
else
{ // octant 7
- return ANG270 + angle;
+ return ANG270 + SlopeDiv(x, y);
}
}
}
else // x < 0
{
+ x = -x;
if (y >= 0)
{
- if (-x > y)
+ if (x > y)
{ // octant 3
- return ANG180 - 1 - angle;
+ return ANG180 - 1 - SlopeDiv(y, x);
}
else
{ // octant 2
- return ANG90 + angle;
+ return ANG90 + SlopeDiv(x, y);
}
}
else // y < 0
{
- if (x < y)
+ y = -y;
+ if (x > y)
{ // octant 4
- return ANG180 + angle;
+ return ANG180 + SlopeDiv(y, x);
}
else
{ // octant 5
- return ANG270 - 1 - angle;
+ return ANG270 - 1 - SlopeDiv(x, y);
}
}
}
diff --git a/src/tables.h b/src/tables.h
index 826333a1a..72a79383d 100644
--- a/src/tables.h
+++ b/src/tables.h
@@ -105,21 +105,6 @@ inline angle_t abs (angle_t ang)
// without additional checking.
extern angle_t tantoangle[SLOPERANGE+1];
-
-// Utility function,
-// called by R_PointToAngle.
-inline int SlopeDiv (unsigned int num, unsigned den)
-{
- unsigned int ans;
-
- if (den < 512)
- return SLOPERANGE;
-
- ans = (num << 3) / (den >> 8);
-
- return ans <= SLOPERANGE ? ans : SLOPERANGE;
-}
-
inline double bam2rad(angle_t ang)
{
return double(ang >> 1) * (PI / ANGLE_90);