VGL(3) BSD Library Functions Manual VGL(3)NAME
VGLBitmapAllocateBits, VGLBitmapCopy, VGLBitmapCreate, VGLBitmapDestroy,
VGLBitmapPutChar, VGLBitmapString, VGLBlankDisplay, VGLBox,
VGLCheckSwitch, VGLClear, VGLEllipse, VGLEnd, VGLFilledBox,
VGLFilledEllipse, VGLGetXY, VGLInit, VGLLine, VGLKeyboardInit,
VGLKeyboardEnd, VGLKeyboardGetCh, VGLMouseInit, VGLMouseMode,
VGLMouseSetImage, VGLMouseSetStdImage, VGLMouseStatus, VGLPanScreen,
VGLSetBorder, VGLSetPalette, VGLSetPaletteIndex, VGLSetVScreenSize,
VGLSetXY, VGLTextSetFontFile — Video Graphics Library functions
LIBRARY
library “libvgl”
SYNOPSIS
#include <sys/fbio.h>
#include <sys/consio.h>
#include <sys/kbio.h>
#include <vgl.h>
int
VGLInit(int mode);
void
VGLEnd(void);
void
VGLCheckSwitch(void);
int
VGLTextSetFontFile(char *filename);
int
VGLKeyboardInit(int code);
void
VGLKeyboardEnd(void);
int
VGLKeyboardGetCh(void);
int
VGLMouseInit(int mode);
void
VGLMouseMode(int mode);
int
VGLMouseStatus(int *x, int *y, char *buttons);
void
VGLMouseSetImage(VGLBitmap *AndMask, VGLBitmap *OrMask);
void
VGLMouseSetStdImage(void);
u_long
VGLGetXY(VGLBitmap *object, int x, int y);
void
VGLSetXY(VGLBitmap *object, int x, int y, u_long color);
void
VGLLine(VGLBitmap *object, int x1, int y1, int x2, int y2, u_long color);
void
VGLBox(VGLBitmap *object, int x1, int y1, int x2, int y2, u_long color);
void
VGLFilledBox(VGLBitmap *object, int x1, int y1, int x2, int y2,
u_long color);
void
VGLEllipse(VGLBitmap *object, int xc, int yc, int a, int b,
u_long color);
void
VGLFilledEllipse(VGLBitmap *object, int xc, int yc, int a, int b,
u_long color);
VGLBitmap *
VGLBitmapCreate(int type, int xsize, int ysize, byte *bits);
void
VGLBitmapDestroy(VGLBitmap *object);
int
VGLBitmapAllocateBits(VGLBitmap *object);
int
VGLBitmapCopy(VGLBitmap *src, int srcx, int srcy, VGLBitmap *dst,
int dstx, int dsty, int width, int hight);
void
VGLBitmapPutChar(VGLBitmap *Object, int x, int y, byte ch, byte fgcol,
byte bgcol, int fill, int dir);
void
VGLBitmapString(VGLBitmap *Object, int x, int y, char *str, byte fgcol,
byte bgcol, int fill, int dir);
void
VGLClear(VGLBitmap *object, u_long color);
void
VGLSetPalette(byte *red, byte *green, byte *blue);
void
VGLSetPaletteIndex(byte color, byte red, byte green, byte blue);
void
VGLSetBorder(byte color);
int
VGLSetVScreenSize(VGLBitmap *object, int vxsize, int vysize);
int
VGLPanScreen(VGLBitmap *object, int x, int y);
void
VGLBlankDisplay(int blank);
DESCRIPTION
Libvgl is a library that enables the programmer access to the graphics
modes supported by the console driver (syscons). The library takes care
of programming the actual video hardware, and provides a number of simple
functions to do various graphic operations. There is also support for a
mouse via the standard mouse system in FreeBSD, see mouse(4), including
the ability to transparently have a mouse pointer superimposed on the
graphic image currently being worked on. The library takes care of
screen switching by storing the current image in memory before switching
to another virtual console, and restoring when the user switches back.
This allows several graphic applications at once, but on different vir‐
tual consoles.
Below is a short description of the various functions:
VGLInit() initialize the library and set up the graphic mode mode.
VGLEnd() terminate graphic mode, and restore the screenmode that was
active before VGLInit() was called.
VGLCheckSwitch() if the program goes into longer periods of processing
without doing any graphics output, calling this function occasionally
will allow the system to switch screens.
VGLTextSetFontFile() instruct the char/string functions to use the font
in file filename instead of the builtin font.
VGLKeyboardInit() set up the keyboard in the “raw” I/O mode and specify
the key code to be used. code must be VGL_XLATEKEYS, VGL_CODEKEYS, or
VGL_RAWKEYS. When VGL_XLATEKEYS is specified, the keyboard translates
the raw keyboard scan code into a character code. If VGL_RAWKEYS is
used, the raw keyboard scan code is read as is. VGL_CODEKEYS is the
intermediate key code; each key is assigned a unique code whereas more
than one raw scan code may be generated when a key is pressed.
VGLKeyboardEnd() when you have finished using the keyboard, call this
function.
VGLKeyboardGetCh() read one byte from the keyboard. As the keyboard I/O
is in the “raw” input mode, the function will not block even if there is
no input data, and returns 0.
VGLMouseInit() initialize the mouse. The optional on-screen mouse
pointer is shown if the argument is VGL_MOUSESHOW.
VGLMouseMode() either shows the mouse pointer if the argument is
VGL_MOUSESHOW, or hides the mouse pointer if the argument is
VGL_MOUSEHIDE.
VGLMouseStatus() returns the current mouse pointer coordinates and button
state in x, y, buttons. The return value reflects if the mouse pointer
is currently shown on screen or not.
VGLMouseSetImage() with this function it is possible to change the image
of the mouse pointer on screen.
VGLMouseSetStdImage() this function restores the mouse pointer to the
standard arrow.
VGLGetXY() retrieves the color of the pixel located at x, y, coordinates
of the object argument, and returns it as a byte value.
VGLSetXY() sets the color of the pixel located at x, y, coordinates of
the object argument to color byte value.
VGLLine() draw a line from x1, y1 to x2, y2 in color color.
VGLBox() draw a box with upper left hand corner at x1, y1 and lower right
hand corner at x2, y2 in color color.
VGLFilledBox() draw a filled (solid) box with upper left hand corner at
x1, y1 and lower right hand corner at x2, y2 in color color.
VGLEllipse() draw an ellipse centered at xc, yc make it a pixels wide,
and b pixels high in color color.
VGLFilledEllipse() draw a filled (solid) ellipse centered at xc, yc make
it a pixels wide, and b pixels high in color color.
VGLBitmapCreate() create a bitmap object and initialize it with the spec‐
ified values and bit data. type must be MEMBUF for the in-memory bitmap.
bits may be NULL so that bitmap data may be associated later.
There also is a macro, VGLBITMAP_INITIALIZER(type, xsize, ysize, bits) to
initialize a statically declared bitmap object.
VGLBitmapDestroy() free the bitmap data and the bitmap object.
VGLBitmapAllocateBits() allocate a bit data buffer for the specified
object.
VGLBitmapCopy() copy a rectangle of pixels from bitmap src upper left
hand corner at srcx, srcy to bitmap dst at dstx, dsty of the size width,
height.
VGLBitmapPutChar() write the character ch at position x, y in foreground
color fgcol. If fill is != 0, use the color bgcol as background other‐
wise the background is transparent. The character is drawn in the direc‐
tion specified by the argument dir.
VGLBitmapString() write the string str at position x, y in foreground
color fgcol. If fill is != 0, use the color bgcol as background other‐
wise the background is transparent. The string is drawn in the direction
specified by the argument dir.
VGLClear() clears the entire bitmap to color color.
VGLSetPalette() this function sets the palette used, the arguments red,
green, blue should point to byte arrays of 256 positions each.
VGLSetPaletteIndex() set the palette index color to the specified RGB
value.
VGLSetBorder() set the border color to color color.
VGLSetVScreenSize() change the virtual screen size of the display. Note
that this function must be called when our vty is in the foreground. And
object must be VGLDisplay. Passing an in-memory bitmap to this function
results in error.
The desired virtual screen width may not be achievable because of the
video card hardware. In such case the video driver (and underlaying
video BIOS) may choose the next largest values. Always examine
object->VXsize and VYsize after calling this function, in order to see
how the virtual screen is actually set up.
In order to set up the largest possible virtual screen, you may call this
function with arbitrary large values.
VGLSetVScreenSize(10000, 10000);
VGLPanScreen() change the origin of the displayed screen in the virtual
screen. Note that this function must be called when our vty is in the
foreground. object must be VGLDisplay. Passing an in-memory bitmap to
this function results in error.
VGLBlankDisplay() blank the display if the argument blank ≠ 0. This can
be done to shut off the screen during display updates that the user
should first see when it is done.
Program termination and signal processing
It is important to call VGLEnd() before terminating the program. Care
must be taken if you install signal handlers and try to call VGLEnd() and
exit(3) to end the program. If a signal is caught while the program is
inside libvgl functions, VGLEnd() may not be able to properly restore the
graphics hardware.
The recommended way to handle signals and program termination is to have
a flag to indicate signal's delivery. Your signal handlers set this flag
but do not terminate the program immediately. The main part of the pro‐
gram checks the flag to see if it is supposed to terminate, and calls
VGLEnd() and exit(3) if the flag is set.
Note that VGLInit() installs its internal signal handlers for SIGINT,
SIGTERM, SIGSEGV, and SIGBUS, and terminates the program at appropriate
time, after one of these signals is caught. If you want to have your own
signal handlers for these signals, install handlers after VGLInit().
SIGUSR1 and SIGUSR2 are internally used by libvgl to control screen
switching and the mouse pointer, and are not available to libvgl client
programs.
HISTORY
The vgl library appeared in FreeBSD 3.0.
AUTHORS
Søren Schmidt ⟨sos@FreeBSD.org⟩
BSD November 7, 1999 BSD
