libwmf-0.2.0 Tutorial 2: The IPA
Contents
#intro
Introduction
#types
Types
#ipafnref
IPA
Function Reference
#ipafns
IPA Functions
#bitmap
Bitmap Functions
#fns
Other Functions
#guide
Guidelines
#compile
Compiling - The Distribution
Introduction
This is a combination of tutorial and reference guide for writing new device
layers for
libwmf
.
Since no two graphics interfaces are identical, the task of the
IPA
(the interface between the interpreter and the device layer) is to simplify the
task of translating the metafile drawing commands. (It cannot be denied that
there is still considerable room for improvement.)
When writing a new device layer you will need to include the following headers:
#include <libwmf/ipa.h>
#include <libwmf/defs.h>
The former includes the
API
declarations as well as the
IPA
declarations, while the latter defines metafile constants.
Types
#RGB
wmfRGB
|
#BMP
wmfBMP
|
#Brush
wmfBrush
|
#Pen
wmfPen
|
#Font
wmfFont
|
#DC
wmfDC
|
#Flood
wmfFlood_t
|
#DrawPixel
wmfDrawPixel_t
|
#DrawArc
wmfDrawArc_t
|
#DrawLine
wmfDrawLine_t
|
#PolyLine
wmfPolyLine_t
|
#DrawRect
wmfDrawRectangle_t
|
#PolyRect
wmfPolyRectangle_t
|
#BMPRead
wmfBMP_Read_t
|
#BMPDraw
wmfBMP_Draw_t
|
#ROPDraw
wmfROP_Draw_t
|
#DrawText
wmfDrawText_t
|
#UserData
wmfUserData_t
|
#CharDrawer
wmfCharDrawer
wmfRGB
typedef struct _wmfRGB wmfRGB;
struct _wmfRGB
{	unsigned char r;
unsigned char g;
unsigned char b;
};
wmfRGB
describes a color, with
r = g = b = 255
corresponding
to
white
and
r = g = b = 0
corresponding to
black
.
wmfBMP
typedef struct _wmfBMP wmfBMP;
struct _wmfBMP
{	U16 width;
U16 height;
void* data;
};
Container for a bitmap, of dimensions
width
and
height
.
If non-zero,
data
is a pointer to an internal representation of the
bitmap. The interpreter does not reference
data
and will not attempt
to draw a bitmap if
data
is zero; however, a bitmap brush pattern
may be set even though
data
is zero. (
data=0
indicates
either that the device layer has no support for bitmaps or that the bitmap
is corrupt or unreadable.)
wmfBrush
typedef struct _wmfBrush wmfBrush;
struct _wmfBrush
{	U16 lbStyle;
U16 lbHatch;
wmfRGB lbColor;
wmfBMP bmp;
};
wmfBrush
is one element of the current drawing context.
lbStyle
is one of the following:
/* Brush Styles */
#define BS_SOLID            0
#define BS_NULL             1
#define BS_HOLLOW     BS_NULL
#define BS_HATCHED          2
#define BS_PATTERN          3
#define BS_INDEXED          4
#define BS_DIBPATTERN       5
#define BS_DIBPATTERNPT     6
#define BS_PATTERN8X8       7
#define BS_DIBPATTERN8X8    8
where
BS_NULL
indicates that no brush is set. If
lbStyle=BS_HATCHED
then the brush has the pattern, specified by
lbHatch
which is one of:
/* Hatch Styles */
#define HS_HORIZONTAL       0       /* ----- */
#define HS_VERTICAL         1       /* ||||| */
#define HS_FDIAGONAL        2       /* \\\\\ */
#define HS_BDIAGONAL        3       /* ///// */
#define HS_CROSS            4       /* +++++ */
#define HS_DIAGCROSS        5       /* xxxxx */
If
lbStyle=BS_HATCHED
or
lbStyle=BS_SOLID
then the foreground
color of the brush is
lbColor
. Otherwise, if the brush is a bitmap,
ensure that
bmp.data
is non-zero.
The following macros should be used to retrieve the above info.:
#include
/* WMF_BRUSH_STYLE(wmfBrush* B) -> (U16) brush style
* WMF_BRUSH_HATCH(wmfBrush* B) -> (U16) brush hatch style
*
* WMF_BRUSH_COLOR(wmfBrush* B) -> (wmfRGB*) brush color
*
* WMF_BRUSH_BITMAP(wmfBrush* B) -> (wmfBMP*) brush bitmap
*/
#define WMF_BRUSH_STYLE(B)  ((B)->lbStyle)
#define WMF_BRUSH_HATCH(B)  ((B)->lbHatch)
#define WMF_BRUSH_COLOR(B)  (&((B)->lbColor))
#define WMF_BRUSH_BITMAP(B) (&((B)->bmp))
wmfPen
typedef struct _wmfPen wmfPen;
struct _wmfPen
{	U16 lopnStyle;
double width;
double height;
wmfRGB lopnColor;
};
wmfPen
is one element of the current drawing context. The nib has
dimensions
width
and
height
and color
lopnColor
.
lopnStyle
contains style information on the line itself, on the ends,
on the joins, and on the type:
#define PS_STYLE_MASK       0x0000000F
#define PS_ENDCAP_MASK      0x00000F00
#define PS_JOIN_MASK        0x0000F000
#define PS_TYPE_MASK        0x000F0000
lopnStyle & PS_STYLE_MASK
is one of:
#define PS_SOLID            0
#define PS_DASH             1       /* -------  */
#define PS_DOT              2       /* .......  */
#define PS_DASHDOT          3       /* _._._._  */
#define PS_DASHDOTDOT       4       /* _.._.._  */
#define PS_NULL             5
#define PS_INSIDEFRAME      6
#define PS_USERSTYLE        7
#define PS_ALTERNATE        8
where PS_NULL indicates that no pen has been set.
lopnStyle & PS_ENDCAP_MASK
is one of:
#define PS_ENDCAP_ROUND     0x00000000
#define PS_ENDCAP_SQUARE    0x00000100
#define PS_ENDCAP_FLAT      0x00000200
and
lopnStyle & PS_JOIN_MASK
is one of:
#define PS_JOIN_ROUND       0x00000000
#define PS_JOIN_BEVEL       0x00001000
#define PS_JOIN_MITER       0x00002000
Finally,
lopnStyle & PS_TYPE_MASK
is one of:
#define PS_COSMETIC         0x00000000
#define PS_GEOMETRIC        0x00010000
The following macros should be used to retrieve the above info.:
#include
/* WMF_PEN_STYLE(wmfPen* P)  -> (U16) pen style
* WMF_PEN_ENDCAP(wmfPen* P) -> (U16) endcap style
* WMF_PEN_JOIN(wmfPen* P)   -> (U16) join style
* WMF_PEN_TYPE(wmfPen* P)   -> (U16) `type' of pen (??)
*
* WMF_PEN_WIDTH(wmfPen* P)  -> (double) pen `width'  (thickness w.r.t. x-axis)
* WMF_PEN_HEIGHT(wmfPen* P) -> (double) pen `height' (thickness w.r.t. y-axis)
*
* WMF_PEN_COLOR(wmfPen* P) -> (wmfRGB*) pen color
*/
#define WMF_PEN_STYLE(P)  ((P)->lopnStyle & PS_STYLE_MASK)
#define WMF_PEN_ENDCAP(P) ((P)->lopnStyle & PS_ENDCAP_MASK)
#define WMF_PEN_JOIN(P)   ((P)->lopnStyle & PS_JOIN_MASK)
#define WMF_PEN_TYPE(P)   ((P)->lopnStyle & PS_TYPE_MASK)
#define WMF_PEN_WIDTH(P)  ((P)->width)
#define WMF_PEN_HEIGHT(P) ((P)->height)
#define WMF_PEN_COLOR(P)  (&((P)->lopnColor))
wmfFont
typedef struct _wmfFont wmfFont;
struct _wmfFont
{	U16 lfHeight;
U16 lfWidth;
S16 lfEscapement;
S16 lfOrientation;
U16 lfWeight;
U8 lfItalic;
U8 lfUnderline;
U8 lfStrikeOut;
U8 lfCharSet;
U8 lfOutPrecision;
U8 lfClipPrecision;
U8 lfQuality;
U8 lfPitchAndFamily;
char* lfFaceName;
char* ps_name;
FT_Face ft_face;
};
wmfFont
is one element of the current drawing context. Of all of this,
the most important elements are
ps_name
(the postscript font name) and
ft_face
, the freetype (2) font face for which
bold
and
italics
have already been determined.
The following macros should be used to retrieve the above info.:
#include
/* WMF_TEXT_ANGLE(wmfFont* F) -> (double) text angle in radians
*
* WMF_TEXT_UNDERLINE(wmfFont* F) -> (U8) ?? whether to underline (?? how thick)
* WMF_TEXT_STRIKEOUT(wmfFont* F) -> (U8) ?? whether to strikeout (?? how thick)
*
* WMF_FONT_NAME(wmfFont* F)   -> (char*) font name supplied by metafile
* WMF_FONT_PSNAME(wmfFont* F) -> (char*) font name to use in postscript output
* WMF_FONT_FTFACE(wmfFont* F) -> (FT_Face) freetype(2) font face
*/
#define WMF_TEXT_ANGLE(F)     ((((double) (F)->lfEscapement) / 10) * M_PI / 180)
#define WMF_TEXT_UNDERLINE(F) ((F)->lfUnderline)
#define WMF_TEXT_STRIKEOUT(F) ((F)->lfStrikeOut)
#define WMF_FONT_NAME(F)   ((F)->lfFaceName)
#define WMF_FONT_PSNAME(F) ((F)->ps_name)
#define WMF_FONT_FTFACE(F) ((F)->ft_face)
wmfDC
typedef struct _wmfDC wmfDC;
struct _wmfDC
{	void* userdata;
wmfBrush* brush;
wmfPen* pen;
wmfFont* font;
int key;     /* Is this used ?? */
wmfDC* next; /* Is this used ?? */
wmfRGB textcolor;
wmfRGB bgcolor;
U16 textalign;
U16 bgmode;
U16 polyfillmode;
U16 charextra;
U16 breakextra;
U16 ROPmode;
struct
{	S32 Ox;
S32 Oy;
S32 width;
S32 height;
} Window;
double pixel_width; /* Display pixel dimensions (inches) */
double pixel_height;
U16 map_mode;
void* clip;
};
Still very much a work in progress, especially with regard to the drawing
context
wmfDC
; there is much in this structure that is (or should
be) irrelevant to the
IPA
.
See
wmfBrush
,
wmfPen
and
wmfFont
.
textcolor
is
the color to draw text,
bgcolor
is the background color (generally, as
well as with text) unless
bgmode=TRANSPARENT
, in which case there is
no background.
bgmode
is one of:
#define TRANSPARENT         1
#define OPAQUE              2
#define BKMODE_LAST         2
The following macros should be used to retrieve the above info.:
#include
/* WMF_DC_BRUSH(wmfDC* C) -> (wmfBrush*) current brush
* WMF_DC_PEN(wmfDC* C)   -> (wmfPen*)   current pen
* WMF_DC_FONT(wmfDC* C)  -> (wmfFont*)  current font
*
* WMF_DC_TEXTCOLOR(wmfDC* C)  -> (wmfRGB*) text color
* WMF_DC_BACKGROUND(wmfDC* C) -> (wmfRGB*) background color
*
* WMF_DC_OPAQUE(wmfDC* C) -> (U16) whether to fill opaque (non-zero if true)
*
* WMF_DC_POLYFILL(wmfDC* C) -> (U16) how to fill polygons
*
* WMF_DC_ROP(wmfDC* C) -> (U16) ROP mode
*/
#define WMF_DC_BRUSH(C)      ((C)->brush)
#define WMF_DC_PEN(C)        ((C)->pen)
#define WMF_DC_FONT(C)       ((C)->font)
#define WMF_DC_TEXTCOLOR(C)  (&((C)->textcolor))
#define WMF_DC_BACKGROUND(C) (&((C)->bgcolor))
#define WMF_DC_OPAQUE(C)     ((C)->bgmode - 1)
#define WMF_DC_POLYFILL(C)   ((C)->polyfillmode)
#define WMF_DC_ROP(C)        ((C)->ROPmode)
wmfFlood_t
typedef struct _wmfFlood_t wmfFlood_t;
struct _wmfFlood_t
{	wmfDC* dc;
wmfD_Coord pt;
wmfRGB color;
U16 type;
double pixel_width;
double pixel_height;
};
Flood-fill region with color
color
, starting at point
pt
.
Since this is almost certainly not a vector operation, the pixel width and
height are given (and are probably best ignored...).
type
is one
of:
#define  FLOODFILLBORDER    0
#define  FLOODFILLSURFACE   1
wmfDrawPixel_t
typedef struct _wmfDrawPixel_t wmfDrawPixel_t;
struct _wmfDrawPixel_t
{	wmfDC* dc;
wmfD_Coord pt;
wmfRGB color;
double pixel_width;
double pixel_height;
};
Set pixel at point
pt
to color
color
. The pixel width and
height are given.
wmfDrawArc_t
typedef struct _wmfDrawArc_t wmfDrawArc_t;
struct _wmfDrawArc_t
{	wmfDC* dc;
wmfD_Coord TL;
wmfD_Coord BR;
wmfD_Coord start; /* draw_ellipse: (ignored) */
wmfD_Coord end;
};
Draw a complete or partial ellipse.
TL
and
BR
are the
coordinates of the top left and bottom right of the ellipse's bounding box
respectively. If incomplete, then
start
and
end
give the
start and end coordinates of the arc.
wmfDrawLine_t
typedef struct _wmfDrawLine_t wmfDrawLine_t;
struct _wmfDrawLine_t
{	wmfDC* dc;
wmfD_Coord from;
wmfD_Coord to;
};
Draw line from point
from
to point
to
.
wmfPolyLine_t
typedef struct _wmfPolyLine_t wmfPolyLine_t;
struct _wmfPolyLine_t
{	wmfDC* dc;
wmfD_Coord* pt;
U16 count;
};
An array (of length
count
) of points
pt[]
. This may be used
to describe polygons as well as line sequences.
wmfDrawRectangle_t
typedef struct _wmfDrawRectangle_t wmfDrawRectangle_t;
struct _wmfDrawRectangle_t
{	wmfDC* dc;
wmfD_Coord TL;
wmfD_Coord BR;
float width; /* draw_rectangle: axes of corner ellipses; zero if un-rounded */
float height;
};
A rectangle, possibly with rounded corners - in which case
width
and
height
give the elliptic axes of the rectangle's corners.
wmfPolyRectangle_t
typedef struct _wmfPolyRectangle_t wmfPolyRectangle_t;
struct _wmfPolyRectangle_t
{	wmfDC* dc;
wmfD_Coord* TL; /* region_frame & region_paint: TL[count],BR[count] give the */
wmfD_Coord* BR; /* final `extents'... */
unsigned int count;
float width;  /* region_frame: border thickness; zero otherwise */
float height;
};
Used by region and clip calls,
wmfPolyRectangle_t
is used to describe
multiple rectangles, whose top left and bottom right corners are given by the
TL
and
BR
arrays respectively. These arrays are of length
count
in the case of clip calls, and of length
count
+ 1 in
the case of the region calls, the extra element containing the overall bounding
box (the region extents). In the case of
region_frame
,
width
and
height
give the thickness of the frame.
wmfBMP_Read_t
typedef struct _wmfBMP_Read_t wmfBMP_Read_t;
struct _wmfBMP_Read_t          /* Two means available for accessing BMP image:        */
{	long offset;           /* (1) position in source file of start of BMP;        *
* use API->bbuf.seek to set pos(ition), etc.          */
long length;           /* (2) buffer of length length containing image of BMP */
unsigned char* buffer;
U16 width;  /* WMF player may preset these values; zero otherwise. */
U16 height; /* Use caution - may be buggy... ?? [TODO]             */
wmfBMP bmp;
};
There are two ways to read a bitmap presented by
libwmf
: the first is
to read it directly from the input stream using the internal stream functions:
/* Macro-wrappers for stream functions:
* (int)  WMF_READ ((wmfAPI*) API)                 - returns unsigned char cast to int, or EOF
* (int)  WMF_SEEK ((wmfAPI*) API,(long) position) - returns (-1) on error, else 0
* (long) WMF_TELL ((wmfAPI*) API)                 - returns (-1) on error, else current position
*/
where the bitmap starts at offset
offset
; the second (which is
preferred) is to use the buffer
buffer
of length
length
.
To complicate matters, the bitmap's data may be truncated so that the bitmap's
header is incorrect -
width
and
height
give the
real
dimensions of the bitmap.
The bitmap's width and height should be entered into
bmp
(see
#BMP
wmfBMP
above) as well as a pointer to the bitmap data (which
can be in any format you choose; the library does not need to know).
wmfBMP_Draw_t
typedef struct _wmfBMP_Draw_t wmfBMP_Draw_t;
struct _wmfBMP_Draw_t
{	wmfDC* dc;
wmfD_Coord pt;
wmfBMP bmp;
U32 type;
struct
{	U16 x;
U16 y;
U16 w;
U16 h;
} crop;
double pixel_width;
double pixel_height;
};
In contrast to earlier versions,
libwmf
no longer makes any attempt to
crop or scale the bitmap. Instead the crop data are presented to the device
layer to use as it sees fit, and the pixel width and height as well. The bitmap
referenced by
bmp
(see
#BMP
wmfBMP
above) is to be drawn
at point
pt
.
TODO:
info on
type
wmfROP_Draw_t
typedef struct _wmfROP_Draw_t wmfROP_Draw_t;
struct _wmfROP_Draw_t
{	wmfDC* dc;
wmfD_Coord TL;
wmfD_Coord BR;
U32 ROP;
double pixel_width;
double pixel_height;
};
TODO:
wmfDrawText_t
typedef struct _wmfDrawText_t wmfDrawText_t;
struct _wmfDrawText_t
{	wmfDC* dc;
wmfD_Coord pt;
wmfD_Coord TL; /* Clip zone */
wmfD_Coord BR;
struct /* An estimated surround zone */
{	wmfD_Coord TL;
wmfD_Coord TR;
wmfD_Coord BL;
wmfD_Coord BR;
} bbox;
char* str;
U16 flags;
double font_height;
double font_ratio;  /* width to height ratio */
};
Fonts and text are
triiicky
! Fortunately
libwmf
tries to do
most of the work. As such text justification is taken care of by the
interpreter, and fonts (
bold
,
italic
, etc.) are selected
elsewhere. The emphasis with
wmfDrawText_t
is therefore the rendering
of text.
The text can be assumed to be left-justified, starting at point
pt
.
TL
and
BR
are the corners of a clip rectangle.
bbox
gives four corners of rectangle - an
estimate
of the background zone.
str
is the text to draw;
font_height
is the height of the
font and
font_ratio
is how much to stretch the font width-wise. The
values for
flags
are:
#define ETO_OPAQUE          0x0002
#define ETO_CLIPPED         0x0004
#define ETO_GLYPH_INDEX     0x0010
#define ETO_RTLREADING      0x0080
wmfUserData_t
typedef struct _wmfUserData_t wmfUserData_t;
struct _wmfUserData_t	/* TODO: Need to be careful with usage here; not all these are set by the player! */
{	wmfDC* dc;          /* dc is guaranteed */
void* data;         /* data also, except for init */
};
Redundant; may be removed at some point...
wmfCharDrawer
typedef void (*wmfCharDrawer) (wmfAPI*,wmfDrawText_t*);
IPA Function Reference
Let us assume that you are writing a device layer called
mydev
, then the
first requirement is an initialization function:
#include <libwmf/ipa.h>
#include <libwmf/defs.h>
#include <libwmf/
mydev
.h>
void wmf_
mydev
_function (wmfAPI* API)
{	wmfFunctionReference* FR = (wmfFunctionReference*) API->function_reference;
/* */
The function reference has the following definition:
typedef struct _wmfFunctionReference wmfFunctionReference;
struct _wmfFunctionReference
{	void (*device_open) (wmfAPI*);
void (*device_close) (wmfAPI*);
void (*device_begin) (wmfAPI*);
void (*device_end) (wmfAPI*);
void (*flood_interior) (wmfAPI*,wmfFlood_t*);
void (*flood_exterior) (wmfAPI*,wmfFlood_t*);
void (*draw_pixel) (wmfAPI*,wmfDrawPixel_t*);
void (*draw_pie) (wmfAPI*,wmfDrawArc_t*);
void (*draw_chord) (wmfAPI*,wmfDrawArc_t*);
void (*draw_arc) (wmfAPI*,wmfDrawArc_t*);
void (*draw_ellipse) (wmfAPI*,wmfDrawArc_t*);
void (*draw_line) (wmfAPI*,wmfDrawLine_t*);
void (*poly_line) (wmfAPI*,wmfPolyLine_t*);
void (*draw_polygon) (wmfAPI*,wmfPolyLine_t*);
void (*draw_rectangle) (wmfAPI*,wmfDrawRectangle_t*);
void (*rop_draw) (wmfAPI*,wmfROP_Draw_t*);
void (*bmp_draw) (wmfAPI*,wmfBMP_Draw_t*);
void (*bmp_read) (wmfAPI*,wmfBMP_Read_t*);
void (*bmp_free) (wmfAPI*,wmfBMP*);
void (*draw_text) (wmfAPI*,wmfDrawText_t*);
void (*udata_init) (wmfAPI*,wmfUserData_t*);
void (*udata_copy) (wmfAPI*,wmfUserData_t*);
void (*udata_set) (wmfAPI*,wmfUserData_t*);
void (*udata_free) (wmfAPI*,wmfUserData_t*);
void (*region_frame) (wmfAPI*,wmfPolyRectangle_t*);
void (*region_paint) (wmfAPI*,wmfPolyRectangle_t*);
void (*region_clip) (wmfAPI*,wmfPolyRectangle_t*);
};
The initialization function has two purposes, the first being to establish the
links that create the
IPA
by pointing the function reference variables
to your own drawing functions:
#include <libwmf/ipa.h>
#include <libwmf/defs.h>
#include <libwmf/
mydev
.h>
void wmf_
mydev
_function (wmfAPI* API)
{	wmfFunctionReference* FR = (wmfFunctionReference*) API->function_reference;
FR->device_open  = wmf_
mydev
_device_open;
FR->device_close = wmf_
mydev
_device_close;
FR->device_begin = wmf_
mydev
_device_begin;
FR->device_end   = wmf_
mydev
_device_end;
/* etc. */
/* */
}
void wmf_
mydev
_device_open (wmfAPI* API)
{	/* */
}
/* etc. */
The second purpose of the initialization function is to allocate the device's
data structure, set the device parameters to default values if necessary, and
then to attach the data to the
API->device_data
hook.
/* */
typedef struct _wmf_
mydev
_t wmf_
mydev
_t;
struct _wmf_
mydev
_t
{	/* */
unsigned long flags;
}
void wmf_
mydev
_function (wmfAPI* API)
{	wmfFunctionReference* FR = (wmfFunctionReference*) API->function_reference;
wmf_
mydev
_t* ddata = 0;
FR->device_open  = wmf_
mydev
_device_open;
/* etc. */
API->device_data = wmf_malloc (API,sizeof (wmf_
mydev
_t));
if (API->err != wmf_E_None) return; /* insufficient memory? */
ddata = (wmf_
mydev
_t*) API->device_data;
/* */
ddata->flags = 0;
}
/* */
IPA Functions
The
IPA
functions are called by
wmf_play ()
, the only exception
being
device_close
which is called by
wmf_api_destroy ()
-
and then only if
device_open
has been called by
wmf_play ()
.
device_open
is called the first time (and
only
the first time)
wmf_play ()
is called, and is the very first
IPA
function to be
called, just as
device_close
will be the very last.
At the beginning of each
play
cycle (i.e., each call to
wmf_play ()
)
device_begin
is called (after
device_open
if it is the first cycle), and at the end of each cycle
device_end
is called. The metafile graphics use other
IPA
functions.
device_open
,
device_begin
,
device_end
and
device_close
should
be written so that
wmf_play ()
can
be called repeatedly.
The names of the functions are not important. The generic names are used below:
#devopen
device_open
|
#devclose
device_close
|
#devbegin
device_begin
|
#devend
device_end
|
#floodint
flood_interior
|
#floodext
flood_exterior
|
#dpixel
draw_pixel
|
#dpie
draw_pie
|
#dchord
draw_chord
|
#darc
draw_arc
|
#dellipse
draw_ellipse
|
#dline
draw_line
|
#pline
poly_line
|
#dpoly
draw_polygon
|
#drect
draw_rectangle
|
#ropdraw
rop_draw
|
#bmpdraw
bmp_draw
|
#bmpread
bmp_read
|
#bmpfree
bmp_free
|
#dtext
draw_text
|
#uinit
udata_init
|
#ucopy
udata_copy
|
#uset
udata_set
|
#ufree
udata_free
|
#rframe
region_frame
|
#rpaint
region_paint
|
#rclip
region_clip
device_open
void device_open (wmfAPI*);
device_open
is the very first
IPA
function to be called. It is
called only once, the first time
wmf_play ()
is called.
device_close
void device_close (wmfAPI*);
device_close
is the very last
IPA
function to be called. It is
called by
wmf_api_destroy ()
, and only if
device_open
has
been called earlier.
device_begin
void device_begin (wmfAPI*);
device_begin
is the first
IPA
function called from
wmf_play ()
(with the exception of
device_open
the first time
wmf_play ()
is called).
device_end
void device_end (wmfAPI*);
device_end
is the last
IPA
function called from
wmf_play ()
.
flood_interior
void flood_interior (wmfAPI*,
#Flood
wmfFlood_t
*);
flood_exterior
void flood_exterior (wmfAPI*,
#Flood
wmfFlood_t
*);
draw_pixel
void draw_pixel (wmfAPI*,
#DrawPixel
wmfDrawPixel_t
*);
draw_pie
void draw_pie (wmfAPI*,
#DrawArc
wmfDrawArc_t
*);
draw_chord
void draw_chord (wmfAPI*,
#DrawArc
wmfDrawArc_t
*);
draw_arc
void draw_arc (wmfAPI*,
#DrawArc
wmfDrawArc_t
*);
draw_ellipse
void draw_ellipse (wmfAPI*,
#DrawArc
wmfDrawArc_t
*);
draw_line
void draw_line (wmfAPI*,
#DrawLine
wmfDrawLine_t
*);
poly_line
void poly_line (wmfAPI*,
#PolyLine
wmfPolyLine_t
*);
draw_polygon
void draw_polygon (wmfAPI*,
#PolyLine
wmfPolyLine_t
*);
draw_rectangle
void draw_rectangle (wmfAPI*,
#DrawRect
wmfDrawRectangle_t
*);
rop_draw
void rop_draw (wmfAPI*,
#ROPDraw
wmfROP_Draw_t
*);
TODO:
bmp_draw
void bmp_draw (wmfAPI*,
#BMPDraw
wmfBMP_Draw_t
*);
Note:
Unless you're feeling masochistic and want to write, or re-write,
your own suite of functions for the reading, writing and general manipulation
of bitmaps, you should defer this to
libwmf
's built-in support which
is adapted from
ImageMagick
's excellent BMP coder.
See section on bitmaps below.
bmp_read
void bmp_read (wmfAPI*,
#BMPRead
wmfBMP_Read_t
*);
Note:
Unless you're feeling masochistic and want to write, or re-write,
your own suite of functions for the reading, writing and general manipulation
of bitmaps, you should defer this to
libwmf
's built-in support which
is adapted from
ImageMagick
's excellent BMP coder.
void bmp_read (wmfAPI* API,
#BMPRead
wmfBMP_Read_t
* bmp_read)
{	wmf_ipa_bmp_read (API,bmp_read);
}
bmp_free
void bmp_free (wmfAPI*,
#BMP
wmfBMP
*);
Note:
Unless you're feeling masochistic and want to write, or re-write,
your own suite of functions for the reading, writing and general manipulation
of bitmaps, you should defer this to
libwmf
's built-in support which
is adapted from
ImageMagick
's excellent BMP coder.
void bmp_free (wmfAPI* API,
#BMP
wmfBMP
* bmp)
{	wmf_ipa_bmp_free (API,bmp);
}
draw_text
void draw_text (wmfAPI*,
#DrawText
wmfDrawText_t
*);
If desired, strings can be decomposed into individual chars using
wmf_ipa_draw_text ()
. Best to see source for the various device layers
in
libwmf
.
udata_init
void udata_init (wmfAPI*,
#UserData
wmfUserData_t
*);
Redundant; may be removed at some point...
udata_copy
void udata_copy (wmfAPI*,
#UserData
wmfUserData_t
*);
Redundant; may be removed at some point...
udata_set
void udata_set (wmfAPI*,
#UserData
wmfUserData_t
*);
Redundant; may be removed at some point...
udata_free
void udata_free (wmfAPI*,
#UserData
wmfUserData_t
*);
Redundant; may be removed at some point...
region_frame
void region_frame (wmfAPI*,
#PolyRect
wmfPolyRectangle_t
*);
region_paint
void region_paint (wmfAPI*,
#PolyRect
wmfPolyRectangle_t
*);
region_clip
void region_clip (wmfAPI*,
#PolyRect
wmfPolyRectangle_t
*);
If the number of clip rectangles is zero, the current clip region should be
unset.
Bitmap Functions
Other Functions
Guidelines
Compiling - The Distribution
The section applies only if you are working on the
libwmf
sources.
The build system uses
automake
and
autoconf
. If any changes are
made to any of the various
Makefile.am
files, or to
configure.in
or
libwmf.m4
, then the build system will need to
be updated. Change to the top source directory (containing
configure.in
and
libwmf.m4
) and:
# aclocal
# automake
# autoheader
# autoconf
# date > stamp-h.in
When adding a new device layer,
include/libwmf/Makefile.am
and
src/ipa/Makefile.am
will need to be modifiled. Source files
(
src/ipa/new.c
) and installing header files
(
include/libwmf/new.h
) do not need to be added to the distribution,
but other headers (
src/ipa/new.h
&
src/ipa/new/*.h
) will.
Copyright 2001 wvWare/libwmf
http://www.wvware.com/
http://www.wvware.com/
