xref: /plan9/sys/src/cmd/gs/src/gdevvec.h (revision 3ff48bf5ed603850fcd251ddf13025d23d693782)

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/*$Id: gdevvec.h,v 1.7 2001/07/12 03:28:02 lpd Exp $ */
/* Common definitions for "vector" devices */

#ifndef gdevvec_INCLUDED
#  define gdevvec_INCLUDED

#include "gp.h"			/* for gp_file_name_sizeof */
#include "gsropt.h"
#include "gxdevice.h"
#include "gdevbbox.h"
#include "gxiparam.h"
#include "gxistate.h"
#include "stream.h"

/*
 * "Vector" devices produce a stream of higher-level drawing commands rather
 * than a raster image.  (We don't like the term "vector", since the command
 * vocabulary typically includes text and raster images as well as actual
 * vectors, but it's widely used in the industry, and we weren't able to
 * find one that read better.)  Some examples of "vector" formats are PDF,
 * PostScript, PCL XL, HP-GL/2 + RTL, CGM, Windows Metafile, and Macintosh
 * PICT.
 *
 * This file extends the basic driver structure with elements likely to be
 * useful to vector devices.  These include:
 *
 *      - Tracking whether any marks have been made on the page;
 *
 *      - Keeping track of the page bounding box;
 *
 *      - A copy of the most recently written current graphics state
 *      parameters;
 *
 *      - An output stream (for drivers that compress or otherwise filter
 *      their output);
 *
 *      - A vector of procedures for writing changes to the graphics state.
 *
 *      - The ability to work with scaled output coordinate systems.
 *
 * We expect to add more elements and procedures as we gain more experience
 * with this kind of driver.
 */

/* ================ Types and structures ================ */

/* Define the abstract type for a vector device. */
typedef struct gx_device_vector_s gx_device_vector;

/* Define the maximum size of the output file name. */
#define fname_size (gp_file_name_sizeof - 1)

/* Define the longest dash pattern we can remember. */
#define max_dash 11

/*
 * Define procedures for writing common output elements.  Not all devices
 * will support all of these elements.  Note that these procedures normally
 * only write out commands, and don't update the driver state itself.  All
 * of them are optional, called only as indicated under the utility
 * procedures below.
 */
typedef enum {
    gx_path_type_none = 0,
    /*
     * All combinations of flags are legal.  Multiple commands are
     * executed in the order fill, stroke, clip.
     */
    gx_path_type_fill = 1,
    gx_path_type_stroke = 2,
    gx_path_type_clip = 4,
    gx_path_type_winding_number = 0,
    gx_path_type_even_odd = 8,
    gx_path_type_optimize = 16,	/* OK to optimize paths by merging seg.s */
    gx_path_type_always_close = 32, /* include final closepath even if not stroke */
    gx_path_type_rule = gx_path_type_winding_number | gx_path_type_even_odd
} gx_path_type_t;
typedef enum {
    gx_rect_x_first,
    gx_rect_y_first
} gx_rect_direction_t;
typedef struct gx_device_vector_procs_s {
    /* Page management */
    int (*beginpage) (P1(gx_device_vector * vdev));
    /* Imager state */
    int (*setlinewidth) (P2(gx_device_vector * vdev, floatp width));
    int (*setlinecap) (P2(gx_device_vector * vdev, gs_line_cap cap));
    int (*setlinejoin) (P2(gx_device_vector * vdev, gs_line_join join));
    int (*setmiterlimit) (P2(gx_device_vector * vdev, floatp limit));
    int (*setdash) (P4(gx_device_vector * vdev, const float *pattern,
		       uint count, floatp offset));
    int (*setflat) (P2(gx_device_vector * vdev, floatp flatness));
    int (*setlogop) (P3(gx_device_vector * vdev, gs_logical_operation_t lop,
			gs_logical_operation_t diff));
    /* Other state */
    int (*setfillcolor) (P2(gx_device_vector * vdev, const gx_drawing_color * pdc));
    int (*setstrokecolor) (P2(gx_device_vector * vdev, const gx_drawing_color * pdc));
    /* Paths */
    /* dopath and dorect are normally defaulted */
    int (*dopath) (P4(gx_device_vector * vdev, const gx_path * ppath,
		      gx_path_type_t type, const gs_matrix *pmat));
    int (*dorect) (P6(gx_device_vector * vdev, fixed x0, fixed y0, fixed x1,
		      fixed y1, gx_path_type_t type));
    int (*beginpath) (P2(gx_device_vector * vdev, gx_path_type_t type));
    int (*moveto) (P6(gx_device_vector * vdev, floatp x0, floatp y0,
		      floatp x, floatp y, gx_path_type_t type));
    int (*lineto) (P6(gx_device_vector * vdev, floatp x0, floatp y0,
		      floatp x, floatp y, gx_path_type_t type));
    int (*curveto) (P10(gx_device_vector * vdev, floatp x0, floatp y0,
			floatp x1, floatp y1, floatp x2, floatp y2,
			floatp x3, floatp y3, gx_path_type_t type));
    int (*closepath) (P6(gx_device_vector * vdev, floatp x0, floatp y0,
		      floatp x_start, floatp y_start, gx_path_type_t type));
    int (*endpath) (P2(gx_device_vector * vdev, gx_path_type_t type));
} gx_device_vector_procs;

/* Default implementations of procedures */
/* setflat does nothing */
int gdev_vector_setflat(P2(gx_device_vector * vdev, floatp flatness));

/* dopath may call dorect, beginpath, moveto/lineto/curveto/closepath, */
/* endpath */
int gdev_vector_dopath(P4(gx_device_vector * vdev, const gx_path * ppath,
			  gx_path_type_t type, const gs_matrix *pmat));

/* dorect may call beginpath, moveto, lineto, closepath */
int gdev_vector_dorect(P6(gx_device_vector * vdev, fixed x0, fixed y0,
			  fixed x1, fixed y1, gx_path_type_t type));

/* Finally, define the extended device structure. */
#define gx_device_vector_common\
	gx_device_common;\
	gs_memory_t *v_memory;\
		/* Output element writing procedures */\
	const gx_device_vector_procs *vec_procs;\
		/* Output file */\
	char fname[fname_size + 1];\
	FILE *file;\
	stream *strm;\
	byte *strmbuf;\
	uint strmbuf_size;\
	int open_options;	/* see below */\
		/* Graphics state */\
	gs_imager_state state;\
	float dash_pattern[max_dash];\
	gx_drawing_color fill_color, stroke_color;\
	gs_id no_clip_path_id;	/* indicates no clipping */\
	gs_id clip_path_id;\
		/* Other state */\
	gx_path_type_t fill_options, stroke_options;  /* optimize */\
	gs_point scale;		/* device coords / scale => output coords */\
	bool in_page;		/* true if any marks on this page */\
	gx_device_bbox *bbox_device;	/* for tracking bounding box */\
		/* Cached values */\
	gx_color_index black, white
#define vdev_proc(vdev, p) ((vdev)->vec_procs->p)

#define vector_initial_values\
	0,		/* v_memory */\
	0,		/* vec_procs */\
	 { 0 },		/* fname */\
	0,		/* file */\
	0,		/* strm */\
	0,		/* strmbuf */\
	0,		/* strmbuf_size */\
	0,		/* open_options */\
	 { 0 },		/* state */\
	 { 0 },		/* dash_pattern */\
	 { 0 },		/* fill_color ****** WRONG ****** */\
	 { 0 },		/* stroke_color ****** WRONG ****** */\
	gs_no_id,	/* clip_path_id */\
	gs_no_id,	/* no_clip_path_id */\
	0, 0,		/* fill/stroke_options */\
	 { X_DPI/72.0, Y_DPI/72.0 },	/* scale */\
	0/*false*/,	/* in_page */\
	0,		/* bbox_device */\
	gx_no_color_index,	/* black */\
	gx_no_color_index	/* white */

struct gx_device_vector_s {
    gx_device_vector_common;
};

/* st_device_vector is never instantiated per se, but we still need to */
/* extern its descriptor for the sake of subclasses. */
extern_st(st_device_vector);
#define public_st_device_vector()	/* in gdevvec.c */\
  gs_public_st_suffix_add3_final(st_device_vector, gx_device_vector,\
    "gx_device_vector", device_vector_enum_ptrs,\
    device_vector_reloc_ptrs, gx_device_finalize, st_device, strm, strmbuf,\
    bbox_device)
#define st_device_vector_max_ptrs (st_device_max_ptrs + 3)

/* ================ Utility procedures ================ */

/* Initialize the state. */
void gdev_vector_init(P1(gx_device_vector * vdev));

/* Reset the remembered graphics state. */
void gdev_vector_reset(P1(gx_device_vector * vdev));

/*
 * Open the output file and stream, with optional bbox tracking.
 * The options must be defined so that 0 is always the default.
 */
#define VECTOR_OPEN_FILE_ASCII 1	/* open file as text, not binary */
#define VECTOR_OPEN_FILE_SEQUENTIAL 2	/* open as non-seekable */
#define VECTOR_OPEN_FILE_SEQUENTIAL_OK 4  /* open as non-seekable if */
					/* open as seekable fails */
#define VECTOR_OPEN_FILE_BBOX 8		/* also open bbox device */
int gdev_vector_open_file_options(P3(gx_device_vector * vdev,
				     uint strmbuf_size, int open_options));
#define gdev_vector_open_file_bbox(vdev, bufsize, bbox)\
  gdev_vector_open_file_options(vdev, bufsize,\
				(bbox ? VECTOR_OPEN_FILE_BBOX : 0))
#define gdev_vector_open_file(vdev, strmbuf_size)\
  gdev_vector_open_file_bbox(vdev, strmbuf_size, false)

/* Get the current stream, calling beginpage if in_page is false. */
stream *gdev_vector_stream(P1(gx_device_vector * vdev));

/* Bring the logical operation up to date. */
/* May call setlogop. */
int gdev_vector_update_log_op(P2(gx_device_vector * vdev,
				 gs_logical_operation_t lop));

/* Bring the fill color up to date. */
/* May call setfillcolor. */
int gdev_vector_update_fill_color(P2(gx_device_vector * vdev,
				     const gx_drawing_color * pdcolor));

/* Bring state up to date for filling. */
/* May call setflat, setfillcolor, setlogop. */
int gdev_vector_prepare_fill(P4(gx_device_vector * vdev,
				const gs_imager_state * pis,
				const gx_fill_params * params,
				const gx_drawing_color * pdcolor));

/* Bring state up to date for stroking.  Note that we pass the scale */
/* for the line width and dash offset explicitly. */
/* May call setlinewidth, setlinecap, setlinejoin, setmiterlimit, */
/* setdash, setflat, setstrokecolor, setlogop. */
/* Any of pis, params, and pdcolor may be NULL. */
int gdev_vector_prepare_stroke(P5(gx_device_vector * vdev,
				  const gs_imager_state * pis,
				  const gx_stroke_params * params,
				  const gx_drawing_color * pdcolor,
				  floatp scale));

/*
 * Compute the scale for transforming the line width and dash pattern for a
 * stroke operation, and, if necessary to handle anisotropic scaling, a full
 * transformation matrix to be inverse-applied to the path elements as well.
 * Return 0 if only scaling, 1 if a full matrix is needed.
 */
int gdev_vector_stroke_scaling(P4(const gx_device_vector *vdev,
				  const gs_imager_state *pis,
				  double *pscale, gs_matrix *pmat));

/* Prepare to write a path using the default implementation. */
typedef struct gdev_vector_dopath_state_s {
    /* Initialized by _init */
    gx_device_vector *vdev;
    gx_path_type_t type;
    bool first;
    gs_matrix scale_mat;
    /* Change dynamically */
    gs_point start;
    gs_point prev;
} gdev_vector_dopath_state_t;
void gdev_vector_dopath_init(P4(gdev_vector_dopath_state_t *state,
				gx_device_vector *vdev,
				gx_path_type_t type, const gs_matrix *pmat));

/* Write a segment of a path using the default implementation. */
int gdev_vector_dopath_segment(P3(gdev_vector_dopath_state_t *state, int pe_op,
				  gs_fixed_point vs[3]));

/* Write a polygon as part of a path (type = gx_path_type_none) */
/* or as a path. */
/* May call moveto, lineto, closepath (if close); */
/* may call beginpath & endpath if type != none. */
int gdev_vector_write_polygon(P5(gx_device_vector * vdev,
				 const gs_fixed_point * points, uint count,
				 bool close, gx_path_type_t type));

/* Write a rectangle.  This is just a special case of write_polygon. */
int gdev_vector_write_rectangle(P7(gx_device_vector * vdev,
				   fixed x0, fixed y0, fixed x1, fixed y1,
				   bool close, gx_rect_direction_t dir));

/* Write a clipping path by calling the path procedures. */
/* May call the same procedures as writepath. */
int gdev_vector_write_clip_path(P2(gx_device_vector * vdev,
				   const gx_clip_path * pcpath));

/* Bring the clipping state up to date. */
/* May call write_rectangle (q.v.), write_clip_path (q.v.). */
int gdev_vector_update_clip_path(P2(gx_device_vector * vdev,
				    const gx_clip_path * pcpath));

/* Close the output file and stream. */
int gdev_vector_close_file(P1(gx_device_vector * vdev));

/* ---------------- Image enumeration ---------------- */

/* Define a common set of state parameters for enumerating images. */
#define gdev_vector_image_enum_common\
	gx_image_enum_common;\
		/* Set by begin_image */\
	gs_memory_t *memory;	/* from begin_image */\
	gx_image_enum_common_t *default_info;	/* non-0 iff using default implementation */\
	gx_image_enum_common_t *bbox_info;	/* non-0 iff passing image data to bbox dev */\
	int width, height;\
	int bits_per_pixel;	/* (per plane) */\
	uint bits_per_row;	/* (per plane) */\
		/* Updated dynamically by image_data */\
	int y			/* 0 <= y < height */
typedef struct gdev_vector_image_enum_s {
    gdev_vector_image_enum_common;
} gdev_vector_image_enum_t;

extern_st(st_vector_image_enum);
#define public_st_vector_image_enum()	/* in gdevvec.c */\
  gs_public_st_ptrs2(st_vector_image_enum, gdev_vector_image_enum_t,\
    "gdev_vector_image_enum_t", vector_image_enum_enum_ptrs,\
    vector_image_enum_reloc_ptrs, default_info, bbox_info)

/*
 * Initialize for enumerating an image.  Note that the last argument is an
 * already-allocated enumerator, not a pointer to the place to store the
 * enumerator.
 */
int gdev_vector_begin_image(P10(gx_device_vector * vdev,
			const gs_imager_state * pis, const gs_image_t * pim,
			gs_image_format_t format, const gs_int_rect * prect,
	      const gx_drawing_color * pdcolor, const gx_clip_path * pcpath,
		    gs_memory_t * mem, const gx_image_enum_procs_t * pprocs,
				gdev_vector_image_enum_t * pie));

/* End an image, optionally supplying any necessary blank padding rows. */
/* Return 0 if we used the default implementation, 1 if not. */
int gdev_vector_end_image(P4(gx_device_vector * vdev,
       gdev_vector_image_enum_t * pie, bool draw_last, gx_color_index pad));

/* ================ Device procedures ================ */

/* Redefine get/put_params to handle OutputFile. */
dev_proc_put_params(gdev_vector_put_params);
dev_proc_get_params(gdev_vector_get_params);

/* ---------------- Defaults ---------------- */

/* fill_rectangle may call setfillcolor, dorect. */
dev_proc_fill_rectangle(gdev_vector_fill_rectangle);
/* fill_path may call prepare_fill, writepath, write_clip_path. */
dev_proc_fill_path(gdev_vector_fill_path);
/* stroke_path may call prepare_stroke, write_path, write_clip_path. */
dev_proc_stroke_path(gdev_vector_stroke_path);
/* fill_trapezoid, fill_parallelogram, and fill_triangle may call */
/* setfillcolor, setlogop, beginpath, moveto, lineto, endpath. */
dev_proc_fill_trapezoid(gdev_vector_fill_trapezoid);
dev_proc_fill_parallelogram(gdev_vector_fill_parallelogram);
dev_proc_fill_triangle(gdev_vector_fill_triangle);

#endif /* gdevvec_INCLUDED */