NAME
Tk_Get3DBorder, Tk_Draw3DRectangle, Tk_Fill3DRectangle, Tk_Draw3DPolygon, Tk_Fill3DPolygon, Tk_SetBackgroundFromBorder, Tk_NameOf3DBorder, Tk_Free3DBorder - draw borders with three-dimensional appearance

SYNOPSIS
#include <tk.h>

Tk_3DBorder
Tk_Get3DBorder(interp, tkwin, colorMap, colorName)

void
Tk_Draw3DRectangle(display, drawable, border, x, y, width, height, borderWidth, relief)

void
Tk_Fill3DRectangle(display, drawable, border, x, y, width, height, borderWidth, relief)

void
Tk_Draw3DPolygon(display, drawable, border, pointPtr, numPoints, polyBorderWidth, leftRelief)

void
Tk_Fill3DPolygon(display, drawable, border, pointPtr, numPoints, polyBorderWidth, leftRelief)

void
Tk_SetBackgroundFromBorder(tkwin, border)

char *
Tk_NameOf3DBorder(border)

XColor *
Tk_3DBorderColor(border)

Tk_Free3DBorder(border)

ARGUMENTS
Interpreter to use for error reporting. Token for window in which border will be drawn. Colormap from which to allocate colors. If None, then the default colormap for tkwin's screen is used. Textual description of color corresponding to background (flat areas). Illuminated edges will be brighter than this, and shadowed edges will be darker than this. Xlib pointer indicating display with which drawable is associated. X token for window or pixmap; indicates where border is to be drawn. Token for border previously allocated in call to Tk_Get3DBorder. X-coordinate of upper-left corner of rectangle describing border. Y-coordinate of upper-left corner of rectangle describing border. Width of rectangle describing border, in pixels. Height of rectangle describing border, in pixels. Width of border in pixels. Positive means border is inside rectangle given by x, y, width, height, negative means border is outside rectangle. Indicates 3-D position of interior of rectangle relative to exterior; should be TK_RELIEF_RAISED, TK_RELIEF_SUNKEN, TK_RELIEF_GROOVE, or TK_RELIEF_RIDGE (may also be TK_RELIEF_FLAT for Tk_Fill3DRectangle). Pointer to array of points describing the set of vertices in a polygon. The polygon need not be closed (it will be closed automatically if it isn't). Number of points at *pointPtr. Width of border in pixels. If positive, border is drawn to left of trajectory given by pointPtr; if negative, border is drawn to right of trajectory. If leftRelief is TK_RELIEF_GROOVE or TK_RELIEF_RIDGE then the border is centered on the trajectory. Height of left side of polygon's path relative to right. TK_RELIEF_RAISED means left side should appear higher and TK_RELIEF_SUNKEN means right side should appear higher; TK_RELIEF_GROOVE and TK_RELIEF_RIDGE mean the obvious things. For Tk_Fill3DPolygon, TK_RELIEF_FLAT may also be specified to indicate no difference in height.

DESCRIPTION

These procedures provide facilities for drawing window borders in a way that produces a three-dimensional appearance. Tk_Get3DBorder allocates colors and Pixmaps needed to draw a border in the window given by the tkwin argument. The colormap argument specifies a Colormap to use for allocating colors, and the colorName argument indicates what colors should be used in the border. ColorName may be any value acceptable to Tk_GetColor. The color indicated by colorName will not actually be used in the border; it indicates the background color for the window (i.e. a color for flat surfaces). The illuminated portions of the border will appear brighter than indicated by colorName, and the shadowed portions of the border will appear darker than colorName.

Tk_Get3DBorder returns a token that may be used in later calls to Tk_Draw3DRectangle. If an error occurs in allocating information for the border (e.g. colorName isn't a legal color specifier), then NULL is returned and an error message is left in interp->result.

Once a border structure has been created, Tk_Draw3DRectangle may be invoked to draw the border. The display and drawable arguments specify a window or pixmap in which the border is to be drawn. Drawable need not refer to the same window as the tkwin used to create the border, but it must refer to a compatible pixmap or window: one associated with the same display and with the same depth as the tkwin used to create the border. The x, y, width, and height arguments define the bounding box of the border region within drawable (usually x and y are zero and width and height are the dimensions of the window), and borderWidth specifies the number of pixels actually occupied by the border. The relief argument indicates which of several three-dimensional effects is desired: TK_RELIEF_RAISED means that the interior of the rectangle should appear raised relative to the exterior of the rectangle, and TK_RELIEF_SUNKEN means that the interior should appear depressed. TK_RELIEF_GROOVE and TK_RELIEF_RIDGE mean that there should appear to be a groove or ridge around the exterior of the rectangle.

Tk_Fill3DRectangle is somewhat like Tk_Draw3DRectangle except that it first fills the rectangular area with the background color (one corresponding to the colorName used to create border). Then it calls Tk_Draw3DRectangle to draw a border just inside the outer edge of the rectangular area. The argument relief indicates the desired effect (TK_RELIEF_FLAT means no border should be drawn; all that happens is to fill the rectangle with the background color).

The procedure Tk_Draw3DPolygon may be used to draw more complex shapes with a three-dimensional appearance. The pointPtr and numPoints arguments define a trajectory, polyBorderWidth indicates how wide the border should be (and on which side of the trajectory to draw it), and leftRelief indicates which side of the trajectory should appear raised. Tk_Draw3DPolygon draws a border around the given trajectory using the colors from border to produce a three-dimensional appearance. If the trajectory is non-self-intersecting, the appearance will be a raised or sunken polygon shape. The trajectory may be self-intersecting, although it's not clear how useful this is.

Tk_Fill3DPolygon is to Tk_Draw3DPolygon what Tk_Fill3DRectangle is to Tk_Draw3DRectangle: it fills the polygonal area with the background color from border, then calls Tk_Draw3DPolygon to draw a border around the area (unless leftRelief is TK_RELIEF_FLAT; in this case no border is drawn).

The procedure Tk_SetBackgroundFromBorder will modify the background pixel and/or pixmap of tkwin to produce a result compatible with border. For color displays, the resulting background will just be the color given by the colorName argument passed to Tk_Get3DBorder when border was created; for monochrome displays, the resulting background will be a light stipple pattern, in order to distinguish the background from the illuminated portion of the border.

Given a token for a border, the procedure Tk_NameOf3DBorder will return the colorName string that was passed to Tk_Get3DBorder to create the border.

The procedure Tk_3DBorderColor returns the XColor structure that will be used for flat surfaces drawn for its border argument by procedures like Tk_Fill3DRectangle. The return value corresponds to the colorName passed to Tk_Get3DBorder. The XColor, and its associated pixel value, will remain allocated as long as border exists.

When a border is no longer needed, Tk_Free3DBorder should be called to release the resources associated with the border. There should be exactly one call to Tk_Free3DBorder for each call to Tk_Get3DBorder.

KEYWORDS
3D, background, border, color, depressed, illumination, polygon, raised, shadow, three-dimensional effect