documentation for fixed point API

AUTHORS

@@ -2,3 +2,4 @@ Matthew Allum <mallum@o-hand.com> - primary authour
 Emmanuele Bassi <ebassi@o-hand.com> - python bindings, gobject/glib mastery
 Iain Holmes <iain@o-hand.com> - GTK Clutter widget
 Jorn Baayen <jorn@o-hand.com> - Gstreamer bits
+Tomas Frydrych <tf@o-hand.com> - Fixed point magic

ChangeLog

@@ -1,3 +1,15 @@
+2007-01-17  Tomas Frydrych  <tf@openedhand.com>
+	* configure.ac: 
+	* clutter/clutter-behavior-path.c:
+	Added --without-fpu option.
+
+	* doc/refrence/tmpl/clutter-fixed.sgml:
+	* clutter/clutter-fixed.c:
+	* clutter/clutter-fixed.h:
+	Documentation for fixed point API.
+
+	* AUTHORS: added self.
+	
 2007-01-17  Emmanuele Bassi  <ebassi@openedhand.com>
 
 	* clutter/clutter-feature.h:

clutter/clutter-behaviour-path.c

@@ -196,8 +196,13 @@ node_distance (const ClutterKnot *begin,
   if (clutter_knot_equal (begin, end))
         return 0;
 
+#ifdef CFX_NO_FPU
   return clutter_sqrti ((end->x - begin->x) * (end->x - begin->x) +
 			(end->y - begin->y) * (end->y - begin->y));
+#else
+  return (gint) sqrt ((end->x - begin->x) * (end->x - begin->x) +
+		      (end->y - begin->y) * (end->y - begin->y));
+#endif
 }
 
 static gint

clutter/clutter-fixed.c

@@ -115,7 +115,7 @@ static ClutterFixed sin_tbl [] =
  *
  * Fixed point implementation of sine function
  * 
- * Return value: sine value (as fixed point).
+ * Return value: #ClutterFixed sine value.
  *
  * Since: 0.2
  */
@@ -204,7 +204,7 @@ clutter_sinx (ClutterFixed angle)
  * ClutterAngle is an integer such that 1024 represents
  * full circle.
  * 
- * Return value: sine value (as fixed point).
+ * Return value: #ClutterFixed sine value.
  *
  * Since: 0.2
  */
@@ -331,7 +331,7 @@ ClutterFixed sqrt_tbl [] =
  *
  * A fixed point implementation of squre root
  *
- * Return value: square root (as fixed point).
+ * Return value: #ClutterFixed square root.
  *
  * Since: 0.2
  */
@@ -450,7 +450,7 @@ clutter_sqrtx (ClutterFixed x)
  *
  * A fixed point implementation of square root for integers
  *
- * Return value: square root (as truncated integer).
+ * Return value: integer square root (truncated).
  *
  *
  * Since: 0.2

clutter/clutter-fixed.h

@@ -30,7 +30,19 @@
 
 G_BEGIN_DECLS
 
+/**
+ * ClutterFixed:
+ * 
+ * Fixed point number (16.16)
+ */
 typedef gint32 ClutterFixed;
+
+/**
+ * ClutterAngle:
+ * 
+ * Integer representation of an agnle such that 1024 corresponds to
+ * fool circle (i.e., 2*Pi).
+ */
 typedef gint32 ClutterAngle;    /* angle such that 1024 == 2*PI */
 
 #define CFX_Q      16		/* Decimal part size in bits */
@@ -41,47 +53,156 @@ typedef gint32 ClutterAngle;    /* angle such that 1024 == 2*PI */
 /*
  * some commonly used constants
  */
+
+/**
+ * CFX_PI:
+ * 
+ * Fixed point representation of Pi
+ */
 #define CFX_PI     0x0003243f
+/**
+ * CFX_2PI:
+ * 
+ * Fixed point representation of Pi*2
+ */
 #define CFX_2PI    0x0006487f
+/**
+ * CFX_PI2:
+ * 
+ * Fixed point representation of Pi/2
+ */
 #define CFX_PI_2   0x00019220   /* pi/2 */
+/**
+ * CFX_PI4:
+ * 
+ * Fixed point representation of Pi/4
+ */
 #define CFX_PI_4   0x0000c910   /* pi/4 */
-#define CFX_PI8192 0x6487ed51   /* pi * 0x2000, to improve precision */    
+/**
-
+ * CFX_360:
+ * 
+ * Fixed point representation of the number 360
+ */
 #define CFX_360 CLUTTER_INT_TO_FIXED (360)
+/**
+ * CFX_240:
+ * 
+ * Fixed point representation of the number 240
+ */
 #define CFX_240 CLUTTER_INT_TO_FIXED (240)
+/**
+ * CFX_180:
+ * 
+ * Fixed point representation of the number 180
+ */
 #define CFX_180 CLUTTER_INT_TO_FIXED (180)
+/**
+ * CFX_120:
+ * 
+ * Fixed point representation of the number 120
+ */
 #define CFX_120 CLUTTER_INT_TO_FIXED (120)
+/**
+ * CFX_60:
+ * 
+ * Fixed point representation of the number 60
+ */
 #define CFX_60  CLUTTER_INT_TO_FIXED (60)
+/**
+ * CFX_255:
+ * 
+ * Fixed point representation of the number 255
+ */
 #define CFX_255 CLUTTER_INT_TO_FIXED (255)
-
+/**
+ * CLUTTER_FIXED_TO_FLOAT:
+ * 
+ * Macro to convert from fixed to floating point.
+ */
 #define CLUTTER_FIXED_TO_FLOAT(x) ((float)((int)(x)/65536.0))
-
+/**
+ * CLUTTER_FIXED_TO_DOUBLE:
+ * 
+ * Macro to convert from fixed to doulbe precission floating point.
+ */
 #define CLUTTER_FIXED_TO_DOUBLE(x) ((double)((int)(x)/65536.0))
-
+/**
+ * CLUTTER_FLOAT_TO_FIXED:
+ * 
+ * Macro to convert from floating to fixed point.
+ */
 #define CLUTTER_FLOAT_TO_FIXED(x)   \
   ( (ABS(x) > 32767.0) ?            \
             (((x)/(x))*0x7fffffff)  \
           : ((long)((x) * 65536.0  + ((x) < 0 ? -0.5 : 0.5))) )
 
 
+/**
+ * CLUTTER_INT_TO_FIXED:
+ * 
+ * Macro to convert from int to fixed point representation.
+ */
 #define CLUTTER_INT_TO_FIXED(x) ((x) << CFX_Q)
-
+/**
+ * CLUTTER_FIXED_INT:
+ * 
+ * Macro to convert from fixed point to integer.
+ */
 #define CLUTTER_FIXED_INT(x) ((x) >> CFX_Q)
-
+/**
+ * CLUTTER_FIXED_FRACTION:
+ * 
+ * Macro to retrive the fraction of a fixed point number.
+ */
 #define CLUTTER_FIXED_FRACTION(x) ((x) & ((1 << CFX_Q) - 1))
 
+/**
+ * CLUTTER_FIXED_FLOOR:
+ * 
+ * Macro to obtain greatest integer lesser than given fixed point value.
+ */
 #define CLUTTER_FIXED_FLOOR(x) \
    (((x) >= 0) ? ((x) >> CFX_Q) : ~((~(x)) >> CFX_Q))
-
+/**
+ * CLUTTER_FIXED_CEIL:
+ * 
+ * Macro to obtain smallest integer greater than given fixed point value.
+ */
 #define CLUTTER_FIXED_CEIL(x) CLUTTER_FIXED_FLOOR(x + 0xffff) 
-
+/**
+ * CLUTTER_FIXED_MUL:
+ * 
+ * Macro to multiply two fixed point numbers.
+ */
 #define CLUTTER_FIXED_MUL(x,y) ((x) >> 8) * ((y) >> 8)
 
+/**
+ * CLUTTER_FIXED_DIV:
+ * 
+ * Macro to divide two fixed point numbers.
+ */
 #define CLUTTER_FIXED_DIV(x,y) ((((x) << 8)/(y)) << 8)
 
 /* some handy short aliases to avoid exessively long lines */
+
+/**
+ * CFX_INT:
+ * 
+ * Alias for CLUTTER_FIXED_INT:
+ */
 #define CFX_INT CLUTTER_FIXED_INT
+/**
+ * CFX_MUL:
+ * 
+ * Alias for CLUTTER_FIXED_MUL:
+ */
 #define CFX_MUL CLUTTER_FIXED_MUL
+
+/**
+ * CFX_DIV:
+ * 
+ * Alias for CLUTTER_FIXED_DIV:
+ */
 #define CFX_DIV CLUTTER_FIXED_DIV
 
 /* Fixed point math routines */
@@ -89,7 +210,36 @@ ClutterFixed clutter_sinx (ClutterFixed angle);
 ClutterFixed clutter_sini (ClutterAngle angle);
 
 /* convenience macros for the cos functions */
+
+/**
+ * clutter_cosx:
+ * @angle: a #ClutterFixed angle in radians
+ *
+ * Fixed point cosine function
+ * 
+ * Return value: #ClutterFixed cosine value.
+ *
+ * Note: Implemneted as a macro.
+ *
+ * Since: 0.2
+ */
 #define clutter_cosx(x) clutter_fixed_sin((x) - CFX_PI_2)
+
+/**
+ * clutter_cosi:
+ * @angle: a #ClutterAngle angle
+ *
+ * Very fast fixed point implementation of cosine function.
+ *
+ * ClutterAngle is an integer such that 1024 represents
+ * full circle.
+ * 
+ * Return value: #ClutterFixed cosine value.
+ *
+ * Note: Implemneted as a macro.
+ *
+ * Since: 0.2
+ */
 #define clutter_cosi(x) clutter_sini((x) - 256)
 
 ClutterFixed clutter_sqrtx (ClutterFixed x);

configure.ac

@@ -132,6 +132,14 @@ fi
 
 AC_SUBST(CLUTTER_DEBUG_CFLAGS)
 
+AC_ARG_WITH(fpu, AS_HELP_STRING([--without-fpu], 
+                                [Assume no fpu is present]),
+              [with_fpu=$withval], [with_fpu=yes])
+
+if test "x$with_fpu" != "xyes" ; then
+   CLUTTER_FIXED_CFLAGS="-DCFX_NO_FPU"
+fi
+
 dnl = GTK Doc check ========================================================
 
 GTK_DOC_CHECK([1.4])
@@ -140,7 +148,7 @@ dnl ========================================================================
 
 AC_SUBST(GCC_FLAGS)
 
-CLUTTER_CFLAGS="$GLX_CLAGS $CLUTTER_DEPS_CFLAGS"
+CLUTTER_CFLAGS="$GLX_CLAGS $CLUTTER_DEPS_CFLAGS $CLUTTER_FIXED_CFLAGS"
 CLUTTER_LIBS="$GLX_LIBS $CLUTTER_DEPS_LIBS"
 
 AC_SUBST(CLUTTER_CFLAGS)
@@ -170,4 +178,5 @@ echo "                   prefix:   ${prefix}"
 echo ""
 echo "              Debug level:   ${enable_debug}"
 echo "            Documentation:   ${enable_gtk_doc}"
+echo "                      FPU:   ${with_fpu}"
 echo ""

doc/reference/tmpl/clutter-fixed.sgml

@@ -29,28 +29,28 @@ floating-to-fixed conversion.
 
 <!-- ##### MACRO CFX_Q ##### -->
 <para>
-
+Number of bits used to store fractional part of #ClutterFixed.
 </para>
 
 
 
 <!-- ##### MACRO CFX_ONE ##### -->
 <para>
-
+#ClutterFixed representation of 1.
 </para>
 
 
 
 <!-- ##### MACRO CFX_MAX ##### -->
 <para>
-
+Maximum number representable by #ClutterFixed.
 </para>
 
 
 
 <!-- ##### MACRO CFX_MIN ##### -->
 <para>
-
+Minumum number representable by #ClutterFixed.
 </para>
 
 
@@ -63,198 +63,191 @@ floating-to-fixed conversion.
 
 <!-- ##### MACRO CFX_PI ##### -->
 <para>
-
+#ClutterFixed  representation of Pi.
 </para>
 
 
 
 <!-- ##### MACRO CFX_2PI ##### -->
 <para>
-
+#ClutterFixed representation of 2 * Pi.
 </para>
 
 
 
 <!-- ##### MACRO CFX_PI_2 ##### -->
 <para>
-
+#ClutterFixed representation of Pi/2.
 </para>
 
 
 
 <!-- ##### MACRO CFX_PI_4 ##### -->
 <para>
-
+#ClutterFixed representation of Pi/4.
-</para>
-
-
-
-<!-- ##### MACRO CFX_PI8192 ##### -->
-<para>
-
 </para>
 
 
 
 <!-- ##### MACRO CFX_120 ##### -->
 <para>
-
+#ClutterFixed representation of 120.
 </para>
 
 
 
 <!-- ##### MACRO CFX_180 ##### -->
 <para>
-
+#ClutterFixed representation of 180.
 </para>
 
 
 
 <!-- ##### MACRO CFX_240 ##### -->
 <para>
-
+#ClutterFixed representation of 240.
 </para>
 
 
 
 <!-- ##### MACRO CFX_360 ##### -->
 <para>
-
+#ClutterFixed representation of 360.
 </para>
 
 
 
 <!-- ##### MACRO CFX_60 ##### -->
 <para>
-
+#ClutterFixed representation of 60.
 </para>
 
 
 
 <!-- ##### MACRO CFX_255 ##### -->
 <para>
-
+#ClutterFixed representation of 255.
 </para>
 
 
 
 <!-- ##### MACRO CFX_DIV ##### -->
 <para>
-
+Alias for #CLUTTER_FIXED_DIV.
 </para>
 
 
 
 <!-- ##### MACRO CFX_INT ##### -->
 <para>
-
+Alias for #CLUTTER_FIXED_INT.
 </para>
 
 
 
 <!-- ##### MACRO CFX_MUL ##### -->
 <para>
-
+Alias for #CLUTTER_FIXED_MUL.
 </para>
 
 
 
 <!-- ##### MACRO CLUTTER_FIXED_TO_FLOAT ##### -->
 <para>
-
+Macro for converting #ClutterFixed to single precission floating point.
 </para>
 
-@x: 
+@x: #ClutterFixed
 
 
 <!-- ##### MACRO CLUTTER_FIXED_TO_DOUBLE ##### -->
 <para>
-
+Macro for converting #ClutterFixed to double precission floating point.
 </para>
 
-@x: 
+@x: #ClutterFixed
 
 
 <!-- ##### MACRO CLUTTER_FLOAT_TO_FIXED ##### -->
 <para>
-
+Macro for converting floating point numbers to #ClutterFixed.
 </para>
 
-@x: 
+@x: double or float
 
 
 <!-- ##### MACRO CLUTTER_INT_TO_FIXED ##### -->
 <para>
-
+Macro for converting integers to #ClutterFixed.
 </para>
 
-@x: 
+@x: int
 
 
 <!-- ##### MACRO CLUTTER_FIXED_INT ##### -->
 <para>
-
+Macro to obtain integer part of #ClutterFixed.
 </para>
 
-@x: 
+@x: #ClutterFixed
 
 
 <!-- ##### MACRO CLUTTER_FIXED_FRACTION ##### -->
 <para>
-
+Macro to obtain the fraction of #ClutterFixed.
 </para>
 
-@x: 
+@x: #ClutterFixed
 
 
 <!-- ##### MACRO CLUTTER_FIXED_FLOOR ##### -->
 <para>
-
+Macro to obtain greatest integer smaller than given #ClutterFixed.
 </para>
 
-@x: 
+@x: #ClutterFixed
 
 
 <!-- ##### MACRO CLUTTER_FIXED_CEIL ##### -->
 <para>
-
+Macro to obtain smallest integer greater than given #ClutterFixed.
 </para>
 
-@x: 
+@x: #ClutterFixed
 
 
 <!-- ##### MACRO CLUTTER_FIXED_MUL ##### -->
 <para>
-
+Macro for multiplication of two #ClutterFixed numbers.
 </para>
 
-@x: 
+@x: #ClutterFixed
-@y: 
+@y: #ClutterFixed
 
 
 <!-- ##### MACRO CLUTTER_FIXED_DIV ##### -->
 <para>
-
+Macro for difvision of two #ClutterFixed numbers.
 </para>
 
-@x: 
+@x: #ClutterFixed
-@y: 
+@y: #ClutterFixed
 
 
 <!-- ##### MACRO clutter_cosi ##### -->
 <para>
-
+Very fast fixed point cosine function.
 </para>
 
-@x: 
+@x: #ClutterAngle
 
 
 <!-- ##### MACRO clutter_cosx ##### -->
 <para>
-
+Fast fixed point cosine function.
 </para>
 
-@x: 
+@x: #ClutterFixed
 
 
 <!-- ##### FUNCTION clutter_sini ##### -->