ngspice/xgraph/README.HARDCOPY

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/*
* Hardcopy Interface for Xgraph
*
* Major differences from first version:
* A flags argument has been added to xg_init(). This new argument
* is used to specify a new binary option: D_DOCU. See below
* for details.
*
* Four new parameters are passed to the device initialization routine:
* title_family, title_size, axis_family, and axis_size. See the
* description of xg_init() for details.
*
* Clipping is done automatically by xgraph. The xg_clip() routine
* is obsolete.
*
* The xg_line() routine has become the xg_seg() routine. It now
* draws segments rather than a series of lines.
*
* A new field (max_segs) in the device structure now specifies
* the maximum number of segments the device can handle in a group.
*/
/*
* Adding an output device to xgraph
*
* Step 1
* Write versions of the following routines for your device:
* xg_init(), xg_text(), xg_seg(), xg_dot(), and xg_end().
* The interface and function of these routines are described
* in detail below. These routines should be named according
* to your device. For example, the initialization routine
* for the Postscript output device is psInit(). Also, name
* your source file after your device (e.g. the postscript
* routines are in the file ps.c). Instructions continue
* after the description of the interface routines.
*
* The definitions below are quoted here as a convenience. In
* your output module, you can include "xgout.h" to obtain these
* definitions.
*/
#define D_COLOR 0x01
#define ERRBUFSIZE 2048
#define D_DOCU 0x01
typedef struct xg_out {
int dev_flags; /* Device characteristic flags */
int area_w, area_h; /* Width and height in pixels */
int bdr_pad; /* Padding from border */
int axis_pad; /* Extra space around axis labels */
int tick_len; /* Length of a tick mark */
int legend_pad; /* Top of legend text to legend line */
int axis_width; /* Width of big character of axis font */
int axis_height; /* Height of big character of axis font */
int title_width; /* Width of big character of title font */
int title_height; /* Height of big character of title font */
int max_segs; /* Maximum number of segments in group */
void (*xg_text)(); /* Draws text at a location */
void (*xg_seg)(); /* Draws a series of segments */
void (*xg_dot)(); /* Draws a dot or marker at a location */
void (*xg_end)(); /* Stops the drawing sequence */
char *user_state; /* User supplied state information */
} xgOut;
int xg_init(strm, width, height, title_family, title_size,
axis_family, axis_size, out_info, errmsg)
FILE *strm; /* Output stream */
int width, height; /* Size of space (microns) */
char *title_family; /* Name of title font family */
double title_size; /* Title font height (points) */
char *axis_family; /* Name of axis font family */
double axis_size; /* Axis font height (points) */
int flags; /* Flags (see below) */
xgOut *out_info; /* Device info (RETURN) */
char errmsg[ERRBUFSIZE]; /* Error message area */
/*
* This routine is called by xgraph just before drawing is to
* begin. The desired size of the plot is given by `width'
* and `height'. The parameters `title_family', `title_size',
* `axis_family', and `axis_size' specify the names of the
* title and axis fonts and their vertical sizes (in points).
* These parameters can be ignored if your device does not
* support multiple fonts. The `flags' argument specifies
* certain binary flags to the output routines. These
* flags are:
* D_DOCU:
* If this flag is set, it indicates the user has specified that
* the output will be included in some larger document. Devices
* may choose to use this information to produce output that
* can be integrated into documents with less effort. For example,
* the Postscript output routines produce bounding box information
* when this flag is set.
* The routine should fill in all of the fields of `out_info' with
* appropriate values. The values are described below:
* area_w, area_h:
* Size of the drawing space in device coordinates.
* This should take in account the requested area
* given by `width', and `height'.
* bdr_pad:
* Xgraph will leave this number of device coordinates around
* all of the outer edges of the graph.
* axis_pad:
* Additional space around axis labels (in devcoords)
* so that the labels do not appear crowded.
* legend_pad:
* Space (in devcoords) from the top of legend text to
* the representative line drawn above the legend text.
* tick_len:
* Size of a tick mark placed on axis (in devcoords)
* axis_width:
* An estimate of the width of a large character in
* the axis font (in devcoords). This can be an overestimate. An
* underestimate may produce bad results.
* axis_height:
* An estimate of the height of a large character in
* the axis labeling font (in devcoords).
* title_width, title_height:
* Same as above except for the title font.
* max_segs:
* Due to buffering constraints, some devices may not be able to
* handle massive segment lists. This parameter tells xgraph not
* to send more than `max_segs' segments in one request.
* Output to the device should be written to the stream `strm'.
* The functions are described individually below. After filling
* in the parameters and setting the function pointers, the routine
* should initialize its drawing state and store any extra needed
* information in `user_state'. This value will be passed to all
* other routines during the drawing sequence. If the device
* cannot initialize, it should return a zero status and fill
* `errmsg' with an informative error message.
*/
/* Text justifications */
#define T_CENTER 0
#define T_LEFT 1
#define T_UPPERLEFT 2
#define T_TOP 3
#define T_UPPERRIGHT 4
#define T_RIGHT 5
#define T_LOWERRIGHT 6
#define T_BOTTOM 7
#define T_LOWERLEFT 8
/* Text styles */
#define T_AXIS 0
#define T_TITLE 1
void xg_text(user_state, x, y, text, just, style)
char *user_state; /* Value set in xg_init */
int x, y; /* Text position (pixels) */
char *text; /* Null terminated text */
int just; /* Justification (above) */
int style; /* Text style (above) */
/*
* This routine should draw text at the indicated position using
* the indicated justification and style. The justification refers
* to the location of the point in reference to the text. For example,
* if just is T_LOWERLEFT, (x,y) should be located at the lower left
* edge of the text string.
*/
/* Line Styles */
#define L_AXIS 0
#define L_ZERO 1
#define L_VAR 2
void xg_seg(user_state, ns, seglist, width, style, lappr, color)
char *user_state; /* Value set in xg_init */
int ns; /* Number of segments */
XSegment *seglist; /* X array of segments */
int width; /* Width of lines */
int style; /* See above */
int lappr; /* Line appearence */
int color; /* Line color (if any) */
/*
* This routine draws a number of line segments at the points
* given in `seglist'. Note that contiguous segments need not share
* endpoints but often do. All segments should be `width' devcoords wide
* and drawn in style `style'. The `width' may be zero meaning that
* the line should be drawn as thin as the device allows. If `style' is
* L_VAR, the parameters `color' and `lappr' should be used to draw the
* line. Both parameters vary from 0 to 7. If the device is capable of
* color, `color' varies faster than `style'. If the device
* has no color, `style' will vary faster than `color' and
* `color' can be safely ignored. However, if the
* the device has more than 8 line appearences, the two can
* be combined to specify 64 line style variations.
* Xgraph promises not to send more than the `max_segs' in the
* xgOut structure passed back from xg_init().
*/
/* Marker styles */
#define P_PIXEL 0
#define P_DOT 1
#define P_MARK 2
void xg_dot(user_state, x, y, style, type, color)
char *user_state; /* Value set in xg_init */
int x, y; /* Location in pixel units */
int style; /* Dot style */
int type; /* Type of marker */
int color; /* Marker color (if any) */
/*
* This routine should draw a marker at location `x,y'. If the
* style is P_PIXEL, the dot should be a single pixel. If
* the style is P_DOT, the dot should be a reasonably large
* dot. If the style is P_MARK, it should be a distinguished
* mark which is specified by `type' (0-7). If the output
* device is capable of color, the marker should be drawn in
* `color' (0-7) which corresponds with the color for xg_line.
*/
void xg_end(user_state)
char *user_state;
/*
* This routine is called after a drawing sequence is complete.
* It can be used to clean up the user state and set the device
* state appropriately. This routine is optional in the structure.
*/
/*
* Adding an output device to xgraph
*
* Step 2
* Edit the file hard_devices.c. Declare your initialization
* function and add your device to the list of devices,
* hard_devices[]. The structure hard_dev is described below
* and is defined in hard_devices.h:
*/
#define MFNAME 25
typedef enum hard_dev_docu_defn { NONE, NO, YES } hard_dev_docu;
typedef struct hard_dev {
char *dev_name; /* Device name */
int (*dev_init)(); /* Initialization function */
char *dev_spec; /* Default pipe program */
char dev_file[MFNAME]; /* Default file name */
char dev_printer[MFNAME]; /* Default printer name */
double dev_max_dim; /* Default maximum dimension (cm) */
char dev_title_font[MFNAME];/* Default name of title font */
double dev_title_size; /* Default size of title font (pnts) */
char dev_axis_font[MFNAME]; /* Default name of axis font */
double dev_axis_size; /* Default size of axis font (pnts) */
hard_dev_docu dev_docu; /* Document predicate */
};
/*
* dev_spec:
* The dev_spec field should be a command that directly outputs to
* your device. The command should contain one %s directive that
* will be filled in with the name of the device from the hardcopy
* dialog.
* dev_file:
* The default file to write output to if the user selects `To File'.
* dev_printer:
* The default printer to write output to if the user selects
* `To Device'.
* dev_max_dim:
* The default maximum dimension for the device in centimeters.
* dev_title_font, dev_title_size:
* The default title font and size. Sizes are specified in
* points (1/72 inch).
* dev_axis_font, dev_axis_size:
* The default axis font and size.
* dev_docu
* Some devices may require extra preparation when including xgraph
* output in a document. This parameter indicates the default
* value of the Document predicate in the hardcopy dialog. If
* the value is NONE, the device doesn't need any special preparation
* for producing output for inclusion in documents.
*/
/*
* Adding an output device to xgraph
*
* Step 3
* Edit the file Makefile. Add your source file to the SRC variable
* and the corresponding object file to the OBJ variable. Finally,
* remake xgraph. Your device should now be available in the
* hardcopy dialog.
*/