cairoint.h

按照官方的说法：Cairo is a vector graphics library with cross-device output support. 翻译过来

    unsigned int next_clip_serial;
    /*
     * The serial number of the current clip.  This is set when
     * the surface clipping is set.  The gstate can then cheaply
     * check whether the surface clipping is already correct before
     * performing a rendering operation.
     *
     * The special value '0' is reserved for the unclipped case.
     */
    unsigned int current_clip_serial;

    /* A "snapshot" surface is immutable. See _cairo_surface_snapshot. */
    cairo_bool_t is_snapshot;
};

struct _cairo_image_surface {
    cairo_surface_t base;

    /* libic-specific fields */
    cairo_format_t format;
    unsigned char *data;
    cairo_bool_t owns_data;
    cairo_bool_t has_clip;

    int width;
    int height;
    int stride;
    int depth;

    pixman_image_t *pixman_image;
};

extern const cairo_private cairo_surface_backend_t cairo_image_surface_backend;

/* XXX: Right now, the cairo_color structure puts unpremultiplied
   color in the doubles and premultiplied color in the shorts. Yes,
   this is crazy insane, (but at least we don't export this
   madness). I'm still working on a cleaner API, but in the meantime,
   at least this does prevent precision loss in color when changing
   alpha. */
struct _cairo_color {
    double red;
    double green;
    double blue;
    double alpha;

    unsigned short red_short;
    unsigned short green_short;
    unsigned short blue_short;
    unsigned short alpha_short;
};

typedef enum {
    CAIRO_STOCK_WHITE,
    CAIRO_STOCK_BLACK,
    CAIRO_STOCK_TRANSPARENT
} cairo_stock_t;

#define CAIRO_EXTEND_SURFACE_DEFAULT CAIRO_EXTEND_NONE
#define CAIRO_EXTEND_GRADIENT_DEFAULT CAIRO_EXTEND_PAD
#define CAIRO_FILTER_DEFAULT CAIRO_FILTER_BEST

struct _cairo_pattern {
    cairo_pattern_type_t type;
    unsigned int	 ref_count;
    cairo_status_t       status;
    cairo_matrix_t	 matrix;
    cairo_filter_t	 filter;
    cairo_extend_t	 extend;
};

typedef struct _cairo_solid_pattern {
    cairo_pattern_t base;
    cairo_color_t color;
} cairo_solid_pattern_t;

extern const cairo_private cairo_solid_pattern_t cairo_pattern_nil;

typedef struct _cairo_surface_pattern {
    cairo_pattern_t base;

    cairo_surface_t *surface;
} cairo_surface_pattern_t;

typedef struct _cairo_gradient_pattern {
    cairo_pattern_t base;

    pixman_gradient_stop_t *stops;
    int			   n_stops;
} cairo_gradient_pattern_t;

typedef struct _cairo_linear_pattern {
    cairo_gradient_pattern_t base;

    pixman_linear_gradient_t gradient;
} cairo_linear_pattern_t;

typedef struct _cairo_radial_pattern {
    cairo_gradient_pattern_t base;

    pixman_radial_gradient_t gradient;
} cairo_radial_pattern_t;

typedef union {
    cairo_gradient_pattern_t base;

    cairo_linear_pattern_t linear;
    cairo_radial_pattern_t radial;
} cairo_gradient_pattern_union_t;

typedef union {
    cairo_pattern_t base;

    cairo_solid_pattern_t	   solid;
    cairo_surface_pattern_t	   surface;
    cairo_gradient_pattern_union_t gradient;
} cairo_pattern_union_t;

typedef struct _cairo_surface_attributes {
    cairo_matrix_t matrix;
    cairo_extend_t extend;
    cairo_filter_t filter;
    int		   x_offset;
    int		   y_offset;
    cairo_bool_t   acquired;
    void	   *extra;
} cairo_surface_attributes_t;

typedef struct _cairo_traps {
    cairo_trapezoid_t *traps;
    int num_traps;
    int traps_size;
    cairo_box_t extents;
} cairo_traps_t;

#define CAIRO_FONT_SLANT_DEFAULT   CAIRO_FONT_SLANT_NORMAL
#define CAIRO_FONT_WEIGHT_DEFAULT  CAIRO_FONT_WEIGHT_NORMAL

#define CAIRO_WIN32_FONT_FAMILY_DEFAULT "Arial"
#define CAIRO_ATSUI_FONT_FAMILY_DEFAULT  "Monaco"
#define CAIRO_FT_FONT_FAMILY_DEFAULT     ""

#if   CAIRO_HAS_WIN32_FONT

#define CAIRO_FONT_FAMILY_DEFAULT CAIRO_WIN32_FONT_FAMILY_DEFAULT
#define CAIRO_SCALED_FONT_BACKEND_DEFAULT &cairo_win32_scaled_font_backend

#elif CAIRO_HAS_ATSUI_FONT

#define CAIRO_FONT_FAMILY_DEFAULT CAIRO_ATSUI_FONT_FAMILY_DEFAULT
#define CAIRO_SCALED_FONT_BACKEND_DEFAULT &cairo_atsui_scaled_font_backend

#elif CAIRO_HAS_FT_FONT

#define CAIRO_FONT_FAMILY_DEFAULT CAIRO_FT_FONT_FAMILY_DEFAULT
#define CAIRO_SCALED_FONT_BACKEND_DEFAULT &cairo_ft_scaled_font_backend

#endif

#define CAIRO_GSTATE_OPERATOR_DEFAULT	CAIRO_OPERATOR_OVER
#define CAIRO_GSTATE_TOLERANCE_DEFAULT	0.1
#define CAIRO_GSTATE_FILL_RULE_DEFAULT	CAIRO_FILL_RULE_WINDING
#define CAIRO_GSTATE_LINE_WIDTH_DEFAULT	2.0
#define CAIRO_GSTATE_LINE_CAP_DEFAULT	CAIRO_LINE_CAP_BUTT
#define CAIRO_GSTATE_LINE_JOIN_DEFAULT	CAIRO_LINE_JOIN_MITER
#define CAIRO_GSTATE_MITER_LIMIT_DEFAULT	10.0
#define CAIRO_GSTATE_DEFAULT_FONT_SIZE  10.0

#define CAIRO_SURFACE_FALLBACK_RESOLUTION_DEFAULT 300.0

typedef struct _cairo_gstate cairo_gstate_t;

typedef struct _cairo_stroke_face {
    cairo_point_t ccw;
    cairo_point_t point;
    cairo_point_t cw;
    cairo_slope_t dev_vector;
    cairo_point_double_t usr_vector;
} cairo_stroke_face_t;

/* cairo.c */
cairo_private void
_cairo_restrict_value (double *value, double min, double max);

/* cairo_fixed.c */
cairo_private cairo_fixed_t
_cairo_fixed_from_int (int i);

#define CAIRO_FIXED_ONE _cairo_fixed_from_int (1)

cairo_private cairo_fixed_t
_cairo_fixed_from_double (double d);

cairo_private cairo_fixed_t
_cairo_fixed_from_26_6 (uint32_t i);

cairo_private double
_cairo_fixed_to_double (cairo_fixed_t f);

cairo_private int
_cairo_fixed_is_integer (cairo_fixed_t f);

cairo_private int
_cairo_fixed_integer_part (cairo_fixed_t f);

cairo_private int
_cairo_fixed_integer_floor (cairo_fixed_t f);

cairo_private int
_cairo_fixed_integer_ceil (cairo_fixed_t f);

/* cairo_gstate.c */
cairo_private cairo_gstate_t *
_cairo_gstate_create (cairo_surface_t *target);

cairo_private void
_cairo_gstate_destroy (cairo_gstate_t *gstate);

cairo_private cairo_gstate_t *
_cairo_gstate_clone (cairo_gstate_t *gstate);

cairo_private cairo_bool_t
_cairo_gstate_is_redirected (cairo_gstate_t *gstate);

cairo_private void
_cairo_gstate_redirect_target (cairo_gstate_t *gstate, cairo_surface_t *child);

cairo_private cairo_surface_t *
_cairo_gstate_get_target (cairo_gstate_t *gstate);

cairo_private cairo_surface_t *
_cairo_gstate_get_parent_target (cairo_gstate_t *gstate);

cairo_private cairo_surface_t *
_cairo_gstate_get_original_target (cairo_gstate_t *gstate);

cairo_private cairo_clip_t *
_cairo_gstate_get_clip (cairo_gstate_t *gstate);

cairo_private cairo_status_t
_cairo_gstate_set_source (cairo_gstate_t *gstate, cairo_pattern_t *source);

cairo_private cairo_pattern_t *
_cairo_gstate_get_source (cairo_gstate_t *gstate);

cairo_private cairo_status_t
_cairo_gstate_set_operator (cairo_gstate_t *gstate, cairo_operator_t op);

cairo_private cairo_operator_t
_cairo_gstate_get_operator (cairo_gstate_t *gstate);

cairo_private cairo_status_t
_cairo_gstate_set_tolerance (cairo_gstate_t *gstate, double tolerance);

cairo_private double
_cairo_gstate_get_tolerance (cairo_gstate_t *gstate);

cairo_private cairo_status_t
_cairo_gstate_set_fill_rule (cairo_gstate_t *gstate, cairo_fill_rule_t fill_rule);

cairo_private cairo_fill_rule_t
_cairo_gstate_get_fill_rule (cairo_gstate_t *gstate);

cairo_private cairo_status_t
_cairo_gstate_set_line_width (cairo_gstate_t *gstate, double width);

cairo_private double
_cairo_gstate_get_line_width (cairo_gstate_t *gstate);

cairo_private cairo_status_t
_cairo_gstate_set_line_cap (cairo_gstate_t *gstate, cairo_line_cap_t line_cap);

cairo_private cairo_line_cap_t
_cairo_gstate_get_line_cap (cairo_gstate_t *gstate);

cairo_private cairo_status_t
_cairo_gstate_set_line_join (cairo_gstate_t *gstate, cairo_line_join_t line_join);

cairo_private cairo_line_join_t
_cairo_gstate_get_line_join (cairo_gstate_t *gstate);

cairo_private cairo_status_t
_cairo_gstate_set_dash (cairo_gstate_t *gstate, double *dash, int num_dashes, double offset);

cairo_private cairo_status_t
_cairo_gstate_set_miter_limit (cairo_gstate_t *gstate, double limit);

cairo_private double
_cairo_gstate_get_miter_limit (cairo_gstate_t *gstate);

cairo_private void
_cairo_gstate_get_matrix (cairo_gstate_t *gstate, cairo_matrix_t *matrix);

cairo_private cairo_status_t
_cairo_gstate_translate (cairo_gstate_t *gstate, double tx, double ty);

cairo_private cairo_status_t
_cairo_gstate_scale (cairo_gstate_t *gstate, double sx, double sy);

cairo_private cairo_status_t
_cairo_gstate_rotate (cairo_gstate_t *gstate, double angle);

cairo_private cairo_status_t
_cairo_gstate_transform (cairo_gstate_t	      *gstate,
			 const cairo_matrix_t *matrix);

cairo_private cairo_status_t
_cairo_gstate_set_matrix (cairo_gstate_t       *gstate,
			  const cairo_matrix_t *matrix);

cairo_private cairo_status_t
_cairo_gstate_identity_matrix (cairo_gstate_t *gstate);

cairo_private cairo_status_t
_cairo_gstate_user_to_device (cairo_gstate_t *gstate, double *x, double *y);

cairo_private cairo_status_t
_cairo_gstate_user_to_device_distance (cairo_gstate_t *gstate, double *dx, double *dy);

cairo_private cairo_status_t
_cairo_gstate_device_to_user (cairo_gstate_t *gstate, double *x, double *y);

cairo_private cairo_status_t
_cairo_gstate_device_to_user_distance (cairo_gstate_t *gstate, double *dx, double *dy);

cairo_private void
_cairo_gstate_user_to_backend (cairo_gstate_t *gstate, double *x, double *y);

cairo_private void
_cairo_gstate_backend_to_user (cairo_gstate_t *gstate, double *x, double *y);

cairo_private cairo_status_t
_cairo_gstate_paint (cairo_gstate_t *gstate);

cairo_private cairo_status_t
_cairo_gstate_mask (cairo_gstate_t  *gstate,
		    cairo_pattern_t *mask);

cairo_private cairo_status_t
_cairo_gstate_stroke (cairo_gstate_t *gstate, cairo_path_fixed_t *path);

cairo_private cairo_status_t
_cairo_gstate_fill (cairo_gstate_t *gstate, cairo_path_fixed_t *path);

cairo_private cairo_status_t
_cairo_gstate_copy_page (cairo_gstate_t *gstate);

cairo_private cairo_status_t
_cairo_gstate_show_page (cairo_gstate_t *gstate);

cairo_private cairo_status_t
_cairo_gstate_stroke_extents (cairo_gstate_t	 *gstate,
			      cairo_path_fixed_t *path,
                              double *x1, double *y1,
			      double *x2, double *y2);

cairo_private cairo_status_t
_cairo_gstate_fill_extents (cairo_gstate_t     *gstate,
			    cairo_path_fixed_t *path,
                            double *x1, double *y1,
			    double *x2, double *y2);

cairo_private cairo_status_t
_cairo_gstate_in_stroke (cairo_gstate_t	    *gstate,
			 cairo_path_fixed_t *path,
			 double		     x,
			 double		     y,
			 cairo_bool_t	    *inside_ret);

cairo_private cairo_status_t
_cairo_gstate_in_fill (cairo_gstate_t	  *gstate,
		       cairo_path_fixed_t *path,
		       double		   x,
		       double		   y,
		       cairo_bool_t	  *inside_ret);

cairo_private cairo_status_t
_cairo_gstate_clip (cairo_gstate_t *gstate, cairo_path_fixed_t *path);

cairo_private cairo_status_t
_cairo_gstate_reset_clip (cairo_gstate_t *gstate);

cairo_private cairo_status_t
_cairo_gstate_show_surface (cairo_gstate_t	*gstate,
			    cairo_surface_t	*surface,
			    double		 x,
			    double		 y,
			    double		width,
			    double		height);

cairo_private cairo_status_t
_cairo_gstate_select_font_face (cairo_gstate_t *gstate,
				const char *family,
				cairo_font_slant_t slant,
				cairo_font_weight_t weight);

cairo_private cairo_status_t
_cairo_gstate_set_font_size (cairo_gstate_t *gstate,
			     double          size);

cairo_private void
_cairo_gstate_get_font_matrix (cairo_gstate_t *gstate,
			       cairo_matrix_t *matrix);

cairo_private cairo_status_t
_cairo_gstate_set_font_matrix (cairo_gstate_t	    *gstate,
			       const cairo_matrix_t *matrix);

cairo_private void
_cairo_gstate_get_font_options (cairo_gstate_t       *gstate,
				cairo_font_options_t *options);

cairo_private cairo_status_t
_cairo_gstate_set_font_options (cairo_gstate_t	           *gstate,
				const cairo_font_options_t *options);

cairo_private cairo_status_t
_cairo_gstate_get_font_face (cairo_gstate_t     *gstate,
			     cairo_font_face_t **font_face);

cairo_private cairo_status_t
_cairo_gstate_get_font_extents (cairo_gstate_t *gstate,
				cairo_font_extents_t *extents);

cairo_private cairo_status_t
_cairo_gstate_set_font_face (cairo_gstate_t    *gstate,
			     cairo_font_face_t *font_face);

cairo_private cairo_status_t
_cairo_gstate_text_to_glyphs (cairo_gstate_t *font,
			      const char     *utf8,
			      double	      x,
			      double	      y,
			      cairo_glyph_t **glyphs,
			      int	     *num_glyphs);

cairo_private cairo_status_t
_cairo_gstate_glyph_extents (cairo_gstate_t *gstate,
			     cairo_glyph_t *glyphs,
			     int num_glyphs,
			     cairo_text_extents_t *extents);