Use single-precision math functions when available

Since C99 we have floating point functions available for single precision,
so as it is what we need we detect them (configure) and use them when
appropriate. The goal is to avoid unnecessary float->double + double->float
conversion.

Signed-off-by: Christophe CURIS <christophe.curis@free.fr>

m4/wm_libmath.m4

@@ -50,5 +50,35 @@ AS_IF([test "x$wm_cv_libm_pi" = "xno"],
         [Defines how to access the value of Pi])
      AS_IF([test "x$wm_cv_libm_pi" != "xyes"],
         [CFLAGS="$CFLAGS $wm_cv_libm_pi"]) ])
+AC_CACHE_CHECK([if sinf+cosf are defined in math.h], [wm_cv_libm_sinf],
+    [wm_cv_libm_sinf="no"
+     wm_save_CFLAGS="$CFLAGS"
+     wm_save_LIBS="$LIBS"
+     LIBS="$LIBS $LIBM"
+     for wm_arg in dnl
+       "% yes" dnl natively available (C99 compliant)
+       "-D_XOPEN_SOURCE=600" ; dnl Explicit request
+     do
+       CFLAGS="$wm_save_CFLAGS `echo "$wm_arg" | sed -e 's, *%.*$,,' `"
+       AC_LINK_IFELSE([AC_LANG_PROGRAM([dnl
+@%:@include <math.h>
+], [dnl
+  float a, b;
+
+  a = WM_PI;
+  b = sqrtf(a);
+  a = atan2f(a, b);
+  b = cosf(a);
+  a = sinf(b);
+  return (int)a;])],
+           [wm_cv_libm_sinf="`echo "$wm_arg" | sed -e 's,^.*% *,,' `" ; break])
+     done
+     LIBS="$wm_save_LIBS"
+     CFLAGS="$wm_save_CFLAGS"])
+AS_IF([test "x$wm_cv_libm_sinf" != "xno"],
+    [AC_DEFINE([HAVE_FLOAT_MATHFUNC], [1],
+        [Defined if the 'float'-typed math function are available (sinf, cosf)])
+     AS_IF([test "x$wm_cv_libm_sinf" != "xyes"],
+        [CFLAGS="$CFLAGS $wm_cd_libm_sinf"]) ])
 AC_SUBST(LIBM) dnl
 ])

src/actions.c

@@ -52,6 +52,13 @@
 #include "event.h"
 
 
+#ifndef HAVE_FLOAT_MATHFUNC
+#define sinf(x) ((float)sin((double)(x)))
+#define cosf(x) ((float)cos((double)(x)))
+#define sqrtf(x) ((float)sqrt((double)(x)))
+#define atan2f(y, x) ((float)atan((double)(y) / (double)(x)))
+#endif
+
 static void find_Maximus_geometry(WWindow *wwin, WArea usableArea, int *new_x, int *new_y,
 				  unsigned int *new_width, unsigned int *new_height);
 static void save_old_geometry(WWindow *wwin, int directions);
@@ -792,8 +799,8 @@ static void animateResizeFlip(WScreen *scr, int x, int y, int w, int h, int fx,
 		if (angle > final_angle)
 			angle = final_angle;
 
-		dx = (cw / 10) - ((cw / 5) * sin(angle));
+		dx = (cw / 10) - ((cw / 5) * sinf(angle));
-		dch = (ch / 2) * cos(angle);
+		dch = (ch / 2) * cosf(angle);
 		midy = cy + (ch / 2);
 
 		points[0].x = cx + dx;
@@ -857,19 +864,19 @@ animateResizeTwist(WScreen *scr, int x, int y, int w, int h, int fx, int fy, int
 		if (angle > final_angle)
 			angle = final_angle;
 
-		a = atan(ch / cw);
+		a = atan2f(ch, cw);
-		d = sqrt((cw / 2) * (cw / 2) + (ch / 2) * (ch / 2));
+		d = sqrtf((cw / 2) * (cw / 2) + (ch / 2) * (ch / 2));
 
-		points[0].x = cx + cos(angle - a) * d;
+		points[0].x = cx + cosf(angle - a) * d;
-		points[0].y = cy + sin(angle - a) * d;
+		points[0].y = cy + sinf(angle - a) * d;
-		points[1].x = cx + cos(angle + a) * d;
+		points[1].x = cx + cosf(angle + a) * d;
-		points[1].y = cy + sin(angle + a) * d;
+		points[1].y = cy + sinf(angle + a) * d;
-		points[2].x = cx + cos(angle - a + WM_PI) * d;
+		points[2].x = cx + cosf(angle - a + (float)WM_PI) * d;
-		points[2].y = cy + sin(angle - a + WM_PI) * d;
+		points[2].y = cy + sinf(angle - a + (float)WM_PI) * d;
-		points[3].x = cx + cos(angle + a + WM_PI) * d;
+		points[3].x = cx + cosf(angle + a + (float)WM_PI) * d;
-		points[3].y = cy + sin(angle + a + WM_PI) * d;
+		points[3].y = cy + sinf(angle + a + (float)WM_PI) * d;
-		points[4].x = cx + cos(angle - a) * d;
+		points[4].x = cx + cosf(angle - a) * d;
-		points[4].y = cy + sin(angle - a) * d;
+		points[4].y = cy + sinf(angle - a) * d;
 		XGrabServer(dpy);
 		XDrawLines(dpy, scr->root_win, scr->frame_gc, points, 5, CoordModeOrigin);
 		XFlush(dpy);