josh/treacherous-terrain
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

simpler HexTile::point_within()

Browse Source
This commit is contained in:
Josh Holtrop 2012-09-10 21:04:02 -04:00
parent 433d702096
commit f77df195e0
1 changed files with 10 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
src/common/HexTile.cc
View File

@ -1,8 +1,11 @@
#include <math.h>
#include "HexTile.h" #include "HexTile.h"
#define COS_60 0.5 #define COS_60 0.5f
#define SIN_60 0.8660254037844386 #define SIN_60 0.8660254037844386f
#define COS_120 (-0.5f)
#define SIN_120 SIN_60
/* points of a horizontal hexagon 2.0 units high */ /* points of a horizontal hexagon 2.0 units high */
static const float hex_points[][2] = { static const float hex_points[][2] = {
@ -37,15 +40,13 @@ bool HexTile::point_within(float x, float y)
* x' = x * 0.5 - y * 0.8660254 * x' = x * 0.5 - y * 0.8660254
* y' = y * 0.5 + x * 0.8660254 * y' = y * 0.5 + x * 0.8660254
*/ */
if ((y > 1.0) || (y < -1.0)) if (fabsf(y) > 1.0)
return false; return false;
float rx = x * COS_60 - y * SIN_60; float y_60 = y * COS_60 + x * SIN_60;
float ry = y * COS_60 + x * SIN_60; if (fabsf(y_60) > 1.0)
if ((ry > 1.0) || (ry < -1.0))
return false; return false;
x = rx * COS_60 - ry * SIN_60; float y_120 = y * COS_120 + x * SIN_120;
y = ry * COS_60 + rx * SIN_60; if (fabsf(y_120) > 1.0)
if ((y > 1.0) || (y < -1.0))
return false; return false;
return true; return true;
} }