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added clutter_exp_inc_func() and clutter_exp_dec_func()

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This commit is contained in:
Tomas Frydrych 2007-05-17 07:09:24 +00:00
parent a4eeaceda4
commit 733a767657
4 changed files with 104 additions and 0 deletions
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7
ChangeLog
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@ -1,3 +1,10 @@
2007-05-17 Tomas Frydrych <tf@openedhand.com>
* clutter/clutter-alpha.h:
* clutter/clutter-alpha.c:
* doc/reference/clutter-sections.txt:
Added clutter_exp_inc_func() and clutter_exp_dec_func().
2007-05-16 Emmanuele Bassi <ebassi@openedhand.com>
* clutter/clutter-main.[ch]: Add clutter_base_init(), semi-private

87
clutter/clutter-alpha.c
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@ -851,3 +851,90 @@ clutter_smoothstep_func (ClutterAlpha * alpha,
return CFX_INT (r * CLUTTER_ALPHA_MAX_ALPHA);
}
/**
* clutter_exp_inc_func:
* @alpha: a #ClutterAlpha
* @dummy: unused argument
*
* Convenience alpha function for a 2^x curve. You can use this function as the
* alpha function for clutter_alpha_set_func().
*
* Return value: an alpha value.
*
* Since: 0.4
*/
guint32
clutter_exp_inc_func (ClutterAlpha *alpha,
gpointer dummy)
{
ClutterTimeline * timeline;
gint frame;
gint n_frames;
ClutterFixed x;
ClutterFixed x_alpha_max = 0x100000;
guint32 result;
/*
* Choose x_alpha_max such that
*
* (2^x_alpha_max) - 1 == CLUTTER_ALPHA_MAX_ALPHA
*/
#if CLUTTER_ALPHA_MAX_ALPHA != 0xffff
#error Adjust x_alpha_max to match CLUTTER_ALPHA_MAX_ALPHA
#endif
timeline = clutter_alpha_get_timeline (alpha);
frame = clutter_timeline_get_current_frame (timeline);
n_frames = clutter_timeline_get_n_frames (timeline);
x = x_alpha_max * frame / n_frames;
result = clutter_pow2x (x) - 1;
return result;
}
/**
* clutter_exp_dec_func:
* @alpha: a #ClutterAlpha
* @dummy: unused argument
*
* Convenience alpha function for a decreasing 2^x curve. You can use this
* function as the alpha function for clutter_alpha_set_func().
*
* Return value: an alpha value.
*
* Since: 0.4
*/
guint32
clutter_exp_dec_func (ClutterAlpha *alpha,
gpointer dummy)
{
ClutterTimeline * timeline;
gint frame;
gint n_frames;
ClutterFixed x;
ClutterFixed x_alpha_max = 0x100000;
guint32 result;
/*
* Choose x_alpha_max such that
*
* (2^x_alpha_max) - 1 == CLUTTER_ALPHA_MAX_ALPHA
*/
#if CLUTTER_ALPHA_MAX_ALPHA != 0xffff
#error Adjust x_alpha_max to match CLUTTER_ALPHA_MAX_ALPHA
#endif
timeline = clutter_alpha_get_timeline (alpha);
frame = clutter_timeline_get_current_frame (timeline);
n_frames = clutter_timeline_get_n_frames (timeline);
x = (x_alpha_max * (n_frames - frame)) / n_frames;
result = clutter_pow2x (x) - 1;
return result;
}

6
clutter/clutter-alpha.h
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@ -111,6 +111,8 @@ ClutterTimeline *clutter_alpha_get_timeline (ClutterAlpha *alpha);
#define CLUTTER_ALPHA_SINE_HALF clutter_sine_half_func
#define CLUTTER_ALPHA_SQUARE clutter_square_func
#define CLUTTER_ALPHA_SMOOTHSTEP clutter_smoothstep_func
#define CLUTTER_ALPHA_EXP_INC clutter_exp_inc_func
#define CLUTTER_ALPHA_EXP_DEC clutter_exp_dec_func
#define CLUTTER_TYPE_SMOOTHSTEP (clutter_smoothstep_get_type ())
@ -144,6 +146,10 @@ guint32 clutter_square_func (ClutterAlpha *alpha,
gpointer dummy);
guint32 clutter_smoothstep_func (ClutterAlpha *alpha,
gpointer *data);
guint32 clutter_exp_inc_func (ClutterAlpha *alpha,
gpointer dummy);
guint32 clutter_exp_dec_func (ClutterAlpha *alpha,
gpointer dummy);
G_END_DECLS

4
doc/reference/clutter-sections.txt
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@ -122,6 +122,10 @@ CLUTTER_ALPHA_SQUARE
clutter_square_func
CLUTTER_ALPHA_SMOOTHSTEP
clutter_smoothstep_func
CLUTTER_ALPHA_EXP_INC
clutter_exp_inc_func
CLUTTER_ALPHA_EXP_DEC
clutter_exp_dec_func
<SUBSECTION Standard>
CLUTTER_ALPHA
CLUTTER_IS_ALPHA