/*
 * Color.h -- Header for color routines.
 *
 * Authors              : Patrick Lecoanet.
 * Creation date        : Thu Dec 16 15:41:04 1999
 *
 * $Id: Color.h,v 1.15 2005/04/27 07:32:03 lecoanet Exp $
 */

/*
 *  Copyright (c) 1993 - 2005 CENA, Patrick Lecoanet --
 *
 * See the file "Copyright" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 */


#ifndef _Color_h
#define _Color_h


#include "Types.h"
#include "Geo.h"


/*
 * Types of gradients.
 */
#define ZN_AXIAL_GRADIENT       0
#define ZN_RADIAL_GRADIENT      1
#define ZN_PATH_GRADIENT        2
#define ZN_CONICAL_GRADIENT     3

typedef struct _ZnGradientColor {
  unsigned char position;       /* Color starting position along the gradient axis.
                                 * This is in percent of the gradient total size. */
  unsigned char control;        /* Middle-shade position in percent of this color
                                 * size along the gradient axis. */
  unsigned char alpha;          /* The color alpha channel in percent */
  unsigned char mid_alpha;
  XColor        *rgb;           /* The actual color description */
  XColor        *mid_rgb;
} ZnGradientColor;

typedef struct _ZnGradient {
  int           ref_count;
  Tcl_HashEntry *hash;
  char          type;           /* Either ZN_AXIAL_GRADIENT, ZN_RADIAL_GRADIENT or
                                 * ZN_PATH_GRADIENT. */
  int           angle;          /* Angle for an axial gradient (Degrees). */
  ZnPoint       p;              /* Start for an axial/radial/path gradiant. In
                                 * percent of the bbox. */
  ZnPoint       e;              /* End of the axial/radial gradiant in percent
                                 * of bbox. */
  unsigned int  num_actual_colors;/* Number of adjusted colors */
  ZnGradientColor *actual_colors;/* Actual adjusted gradient color spec. May
                                  * be the same array as color_spec. */
  unsigned int  num_colors_in;  /* Number of colors in gradient spec. */
  ZnGradientColor colors_in[1]; /* Gradient color spec */
} ZnGradient;


#define ZnGetGradientPixel(gradient, position) \
  ZnPixel(ZnGetGradientColor(gradient, position, NULL))

ZnGradient *ZnGetGradient(Tcl_Interp *interp, Tk_Window tkwin,
                          Tk_Uid name);
ZnGradient *ZnGetGradientByValue(ZnGradient *gradient);
ZnGradient *ZnGetReliefGradient(Tcl_Interp *interp, Tk_Window tkwin,
                                Tk_Uid name, unsigned short alpha);
ZnBool ZnGradientFlat(ZnGradient *grad);
XColor *ZnGetGradientColor(ZnGradient *gradient, ZnReal position,
                           unsigned short *alpha);
void ZnInterpGradientColor(ZnGradient *gradient, ZnReal position,
                           XColor *color, unsigned short *alpha);
char *ZnNameOfGradient(ZnGradient *gradient);
void ZnFreeGradient(ZnGradient *gradient);
void ZnDeleteGradientName(char *name);
ZnBool ZnGradientNameExists(char *name);
ZnBool ZnNameGradient(Tcl_Interp *interp, Tk_Window tkwin,
                      char *grad_descr, char *name);
int ZnComposeAlpha(unsigned short alpha1, unsigned short alpha2);

#endif /* _Color_h */