[screensavers] / screenhack / colors.h

/* xscreensaver, Copyright (c) 1992-2013 Jamie Zawinski <jwz@jwz.org>
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation.  No representations are made about the suitability of this
 * software for any purpose.  It is provided "as is" without express or 
 * implied warranty.
 */

#ifndef __COLORS_H__
#define __COLORS_H__

/* Like XFreeColors, but works on `XColor *' instead of `unsigned long *'
 */
extern void free_colors (Screen *, Colormap, XColor *, int ncolors);


/* Allocates writable, non-contiguous color cells.  The number requested is
   passed in *ncolorsP, and the number actually allocated is returned there.
   (Unlike XAllocColorCells(), this will allocate as many as it can, instead
   of failing if they can't all be allocated.)
 */
extern void allocate_writable_colors (Screen *, Colormap,
				      unsigned long *pixels, int *ncolorsP);


/* Generates a sequence of colors evenly spaced between the given pair
   of HSV coordinates.

   If closed_p is true, the colors will go from the first point to the
   second then back to the first.

   If allocate_p is true, the colors will be allocated from the map;
   if enough colors can't be allocated, we will try for less, and the
   result will be returned to ncolorsP.

   If writable_p is true, writable color cells will be allocated;
   otherwise, read-only cells will be allocated.

   If allocate_p is false, screen and cmap are unused (OpenGL usage).
 */
extern void make_color_ramp (Screen *, Visual *, Colormap,
			     int h1, double s1, double v1,
			     int h2, double s2, double v2,
			     XColor *colors, int *ncolorsP,
			     Bool closed_p,
			     Bool allocate_p,
			     Bool *writable_pP);

/* Generates a sequence of colors evenly spaced around the triangle
   indicated by the thee HSV coordinates.

   If allocate_p is true, the colors will be allocated from the map;
   if enough colors can't be allocated, we will try for less, and the
   result will be returned to ncolorsP.

   If writable_p is true, writable color cells will be allocated;
   otherwise, read-only cells will be allocated.

   If allocate_p is false, screen, visual and cmap are unused (OpenGL usage).
 */
extern void make_color_loop (Screen *, Visual *, Colormap,
			     int h1, double s1, double v1,
			     int h2, double s2, double v2,
			     int h3, double s3, double v3,
			     XColor *colors, int *ncolorsP,
			     Bool allocate_p,
			     Bool *writable_pP);


/* Allocates a hopefully-interesting colormap, which will be a closed loop
   without any sudden transitions.

   If allocate_p is true, the colors will be allocated from the map;
   if enough colors can't be allocated, we will try for less, and the
   result will be returned to ncolorsP.  An error message will be
   printed on stderr (if verbose_p).

   If *writable_pP is true, writable color cells will be allocated;
   otherwise, read-only cells will be allocated.  If no writable cells
   cannot be allocated, we will try to allocate unwritable cells
   instead, and print a message on stderr to that effect (if verbose_p).

   If allocate_p is false, screen, visual and cmap are unused (OpenGL usage).
 */
extern void make_smooth_colormap (Screen *, Visual *, Colormap,
				  XColor *colors, int *ncolorsP,
				  Bool allocate_p,
				  Bool *writable_pP,
				  Bool verbose_p);

/* Allocates a uniform colormap which touches each hue of the spectrum,
   evenly spaced.  The saturation and intensity are chosen randomly, but
   will be high enough to be visible.

   If allocate_p is true, the colors will be allocated from the map;
   if enough colors can't be allocated, we will try for less, and the
   result will be returned to ncolorsP.  An error message will be
   printed on stderr (if verbose_p).

   If *writable_pP is true, writable color cells will be allocated;
   otherwise, read-only cells will be allocated.  If no writable cells
   cannot be allocated, we will try to allocate unwritable cells
   instead, and print a message on stderr to that effect (if verbose_p).

   If allocate_p is false, screen, visual and cmap are unused (OpenGL usage).
 */
extern void make_uniform_colormap (Screen *, Visual *, Colormap,
				   XColor *colors, int *ncolorsP,
				   Bool allocate_p,
				   Bool *writable_pP,
				   Bool verbose_p);

/* Allocates a random colormap (the colors are unrelated to one another.)
   If `bright_p' is false, the colors will be completely random; if it is
   true, all of the colors will be bright enough to see on a black background.

   If allocate_p is true, the colors will be allocated from the map;
   if enough colors can't be allocated, we will try for less, and the
   result will be returned to ncolorsP.  An error message will be
   printed on stderr (if verbose_p).

   If *writable_pP is true, writable color cells will be allocated;
   otherwise, read-only cells will be allocated.  If no writable cells
   cannot be allocated, we will try to allocate unwritable cells
   instead, and print a message on stderr to that effect (if verbose_p).

   If allocate_p is false, screen, visual and cmap are unused (OpenGL usage).
 */
extern void make_random_colormap (Screen *, Visual *, Colormap,
				  XColor *colors, int *ncolorsP,
				  Bool bright_p,
				  Bool allocate_p,
				  Bool *writable_pP,
				  Bool verbose_p);


/* Assuming that the array of colors indicates the current state of a set
   of writable color cells, this rotates the contents of the array by
   `distance' steps, moving the colors of cell N to cell (N - distance).
 */
extern void rotate_colors (Screen *, Colormap,
			   XColor *, int ncolors, int distance);

#endif /* __COLORS_H__ */
Commit	Line	Data
3144ee8a AT	1	/* xscreensaver, Copyright (c) 1992-2013 Jamie Zawinski <jwz@jwz.org>
	2	*
	3	* Permission to use, copy, modify, distribute, and sell this software and its
	4	* documentation for any purpose is hereby granted without fee, provided that
	5	* the above copyright notice appear in all copies and that both that
	6	* copyright notice and this permission notice appear in supporting
	7	* documentation. No representations are made about the suitability of this
	8	* software for any purpose. It is provided "as is" without express or
	9	* implied warranty.
	10	*/
	11
	12	#ifndef __COLORS_H__
	13	#define __COLORS_H__
	14
	15	/* Like XFreeColors, but works on `XColor ' instead of `unsigned long '
	16	*/
	17	extern void free_colors (Screen , Colormap, XColor , int ncolors);
	18
	19
	20	/* Allocates writable, non-contiguous color cells. The number requested is
	21	passed in *ncolorsP, and the number actually allocated is returned there.
	22	(Unlike XAllocColorCells(), this will allocate as many as it can, instead
	23	of failing if they can't all be allocated.)
	24	*/
	25	extern void allocate_writable_colors (Screen *, Colormap,
	26	unsigned long pixels, int ncolorsP);
	27
	28
	29	/* Generates a sequence of colors evenly spaced between the given pair
	30	of HSV coordinates.
	31
	32	If closed_p is true, the colors will go from the first point to the
	33	second then back to the first.
	34
	35	If allocate_p is true, the colors will be allocated from the map;
	36	if enough colors can't be allocated, we will try for less, and the
	37	result will be returned to ncolorsP.
	38
	39	If writable_p is true, writable color cells will be allocated;
	40	otherwise, read-only cells will be allocated.
	41
	42	If allocate_p is false, screen and cmap are unused (OpenGL usage).
	43	*/
	44	extern void make_color_ramp (Screen , Visual , Colormap,
	45	int h1, double s1, double v1,
	46	int h2, double s2, double v2,
	47	XColor colors, int ncolorsP,
	48	Bool closed_p,
	49	Bool allocate_p,
	50	Bool *writable_pP);
	51
	52	/* Generates a sequence of colors evenly spaced around the triangle
	53	indicated by the thee HSV coordinates.
	54
	55	If allocate_p is true, the colors will be allocated from the map;
	56	if enough colors can't be allocated, we will try for less, and the
	57	result will be returned to ncolorsP.
	58
	59	If writable_p is true, writable color cells will be allocated;
	60	otherwise, read-only cells will be allocated.
	61
	62	If allocate_p is false, screen, visual and cmap are unused (OpenGL usage).
	63	*/
	64	extern void make_color_loop (Screen , Visual , Colormap,
65	int h1, double s1, double v1,
66	int h2, double s2, double v2,
67	int h3, double s3, double v3,
68	XColor colors, int ncolorsP,
69	Bool allocate_p,
70	Bool *writable_pP);
71
72
73	/* Allocates a hopefully-interesting colormap, which will be a closed loop
74	without any sudden transitions.
75
76	If allocate_p is true, the colors will be allocated from the map;
77	if enough colors can't be allocated, we will try for less, and the
78	result will be returned to ncolorsP. An error message will be
79	printed on stderr (if verbose_p).
80
81	If *writable_pP is true, writable color cells will be allocated;
82	otherwise, read-only cells will be allocated. If no writable cells
83	cannot be allocated, we will try to allocate unwritable cells
84	instead, and print a message on stderr to that effect (if verbose_p).
85
86	If allocate_p is false, screen, visual and cmap are unused (OpenGL usage).
87	*/
88	extern void make_smooth_colormap (Screen , Visual , Colormap,
89	XColor colors, int ncolorsP,
90	Bool allocate_p,
91	Bool *writable_pP,
92	Bool verbose_p);
93
94	/* Allocates a uniform colormap which touches each hue of the spectrum,
95	evenly spaced. The saturation and intensity are chosen randomly, but
96	will be high enough to be visible.
97
98	If allocate_p is true, the colors will be allocated from the map;
99	if enough colors can't be allocated, we will try for less, and the
100	result will be returned to ncolorsP. An error message will be
101	printed on stderr (if verbose_p).
102
103	If *writable_pP is true, writable color cells will be allocated;
104	otherwise, read-only cells will be allocated. If no writable cells
105	cannot be allocated, we will try to allocate unwritable cells
106	instead, and print a message on stderr to that effect (if verbose_p).
107
108	If allocate_p is false, screen, visual and cmap are unused (OpenGL usage).
109	*/
110	extern void make_uniform_colormap (Screen , Visual , Colormap,
111	XColor colors, int ncolorsP,
112	Bool allocate_p,
113	Bool *writable_pP,
114	Bool verbose_p);
115
116	/* Allocates a random colormap (the colors are unrelated to one another.)
117	If `bright_p' is false, the colors will be completely random; if it is
118	true, all of the colors will be bright enough to see on a black background.
119
120	If allocate_p is true, the colors will be allocated from the map;
121	if enough colors can't be allocated, we will try for less, and the
122	result will be returned to ncolorsP. An error message will be
123	printed on stderr (if verbose_p).
124
125	If *writable_pP is true, writable color cells will be allocated;
126	otherwise, read-only cells will be allocated. If no writable cells
127	cannot be allocated, we will try to allocate unwritable cells
128	instead, and print a message on stderr to that effect (if verbose_p).
129
130	If allocate_p is false, screen, visual and cmap are unused (OpenGL usage).
131	*/
132	extern void make_random_colormap (Screen , Visual , Colormap,
133	XColor colors, int ncolorsP,
134	Bool bright_p,
135	Bool allocate_p,
136	Bool *writable_pP,
137	Bool verbose_p);
138
139
140	/* Assuming that the array of colors indicates the current state of a set
141	of writable color cells, this rotates the contents of the array by
142	`distance' steps, moving the colors of cell N to cell (N - distance).
143	*/
144	extern void rotate_colors (Screen *, Colormap,
145	XColor *, int ncolors, int distance);
146
147	#endif /* __COLORS_H__ */