Initial revision

1 files changed, 949 insertions, 0 deletions

diff --git a/generic/tk3d.c b/generic/tk3d.c
new file mode 100644
index 0000000..53eec8b
--- /dev/null
+++ b/generic/tk3d.c
@@ -0,0 +1,949 @@
+/* 
+ * tk3d.c --
+ *
+ *	This module provides procedures to draw borders in
+ *	the three-dimensional Motif style.
+ *
+ * Copyright (c) 1990-1994 The Regents of the University of California.
+ * Copyright (c) 1994-1997 Sun Microsystems, Inc.
+ *
+ * See the file "license.terms" for information on usage and redistribution
+ * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
+ *
+ * SCCS: @(#) tk3d.c 1.60 97/01/13 17:23:10
+ */
+
+#include <tk3d.h>
+
+/*
+ * Hash table to map from a border's values (color, etc.) to a
+ * Border structure for those values.
+ */
+
+static Tcl_HashTable borderTable;
+typedef struct {
+    Tk_Uid colorName;		/* Color for border. */
+    Colormap colormap;		/* Colormap used for allocating border
+				 * colors. */
+    Screen *screen;		/* Screen on which border will be drawn. */
+} BorderKey;
+
+static int initialized = 0;	/* 0 means static structures haven't
+				 * been initialized yet. */
+
+/*
+ * Forward declarations for procedures defined in this file:
+ */
+
+static void		BorderInit _ANSI_ARGS_((void));
+static int		Intersect _ANSI_ARGS_((XPoint *a1Ptr, XPoint *a2Ptr,
+			    XPoint *b1Ptr, XPoint *b2Ptr, XPoint *iPtr));
+static void		ShiftLine _ANSI_ARGS_((XPoint *p1Ptr, XPoint *p2Ptr,
+			    int distance, XPoint *p3Ptr));
+
+/*
+ *--------------------------------------------------------------
+ *
+ * Tk_Get3DBorder --
+ *
+ *	Create a data structure for displaying a 3-D border.
+ *
+ * Results:
+ *	The return value is a token for a data structure
+ *	describing a 3-D border.  This token may be passed
+ *	to Tk_Draw3DRectangle and Tk_Free3DBorder.  If an
+ *	error prevented the border from being created then
+ *	NULL is returned and an error message will be left
+ *	in interp->result.
+ *
+ * Side effects:
+ *	Data structures, graphics contexts, etc. are allocated.
+ *	It is the caller's responsibility to eventually call
+ *	Tk_Free3DBorder to release the resources.
+ *
+ *--------------------------------------------------------------
+ */
+
+Tk_3DBorder
+Tk_Get3DBorder(interp, tkwin, colorName)
+    Tcl_Interp *interp;		/* Place to store an error message. */
+    Tk_Window tkwin;		/* Token for window in which border will
+				 * be drawn. */
+    Tk_Uid colorName;		/* String giving name of color
+				 * for window background. */
+{
+    BorderKey key;
+    Tcl_HashEntry *hashPtr;
+    register TkBorder *borderPtr;
+    int new;
+    XGCValues gcValues;
+
+    if (!initialized) {
+	BorderInit();
+    }
+
+    /*
+     * First, check to see if there's already a border that will work
+     * for this request.
+     */
+
+    key.colorName = colorName;
+    key.colormap = Tk_Colormap(tkwin);
+    key.screen = Tk_Screen(tkwin);
+
+    hashPtr = Tcl_CreateHashEntry(&borderTable, (char *) &key, &new);
+    if (!new) {
+	borderPtr = (TkBorder *) Tcl_GetHashValue(hashPtr);
+	borderPtr->refCount++;
+    } else {
+	XColor *bgColorPtr;
+
+	/*
+	 * No satisfactory border exists yet.  Initialize a new one.
+	 */
+    
+	bgColorPtr = Tk_GetColor(interp, tkwin, colorName);
+	if (bgColorPtr == NULL) {
+	    Tcl_DeleteHashEntry(hashPtr);
+	    return NULL;
+	}
+
+	borderPtr = TkpGetBorder();
+	borderPtr->screen = Tk_Screen(tkwin);
+	borderPtr->visual = Tk_Visual(tkwin);
+	borderPtr->depth = Tk_Depth(tkwin);
+	borderPtr->colormap = key.colormap;
+	borderPtr->refCount = 1;
+	borderPtr->bgColorPtr = bgColorPtr;
+	borderPtr->darkColorPtr = NULL;
+	borderPtr->lightColorPtr = NULL;
+	borderPtr->shadow = None;
+	borderPtr->bgGC = None;
+	borderPtr->darkGC = None;
+	borderPtr->lightGC = None;
+	borderPtr->hashPtr = hashPtr;
+	Tcl_SetHashValue(hashPtr, borderPtr);
+    
+	/*
+	 * Create the information for displaying the background color,
+	 * but delay the allocation of shadows until they are actually
+	 * needed for drawing.
+	 */
+    
+	gcValues.foreground = borderPtr->bgColorPtr->pixel;
+	borderPtr->bgGC = Tk_GetGC(tkwin, GCForeground, &gcValues);
+    }
+    return (Tk_3DBorder) borderPtr;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * Tk_Draw3DRectangle --
+ *
+ *	Draw a 3-D border at a given place in a given window.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	A 3-D border will be drawn in the indicated drawable.
+ *	The outside edges of the border will be determined by x,
+ *	y, width, and height.  The inside edges of the border
+ *	will be determined by the borderWidth argument.
+ *
+ *--------------------------------------------------------------
+ */
+
+void
+Tk_Draw3DRectangle(tkwin, drawable, border, x, y, width, height,
+	borderWidth, relief)
+    Tk_Window tkwin;		/* Window for which border was allocated. */
+    Drawable drawable;		/* X window or pixmap in which to draw. */
+    Tk_3DBorder border;		/* Token for border to draw. */
+    int x, y, width, height;	/* Outside area of region in
+				 * which border will be drawn. */
+    int borderWidth;		/* Desired width for border, in
+				 * pixels. */
+    int relief;			/* Type of relief: TK_RELIEF_RAISED,
+				 * TK_RELIEF_SUNKEN, TK_RELIEF_GROOVE, etc. */
+{
+    if (width < 2*borderWidth) {
+	borderWidth = width/2;
+    }
+    if (height < 2*borderWidth) {
+	borderWidth = height/2;
+    }
+    Tk_3DVerticalBevel(tkwin, drawable, border, x, y, borderWidth, height,
+	    1, relief);
+    Tk_3DVerticalBevel(tkwin, drawable, border, x+width-borderWidth, y,
+	    borderWidth, height, 0, relief);
+    Tk_3DHorizontalBevel(tkwin, drawable, border, x, y, width, borderWidth,
+	    1, 1, 1, relief);
+    Tk_3DHorizontalBevel(tkwin, drawable, border, x, y+height-borderWidth,
+	    width, borderWidth, 0, 0, 0, relief);
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * Tk_NameOf3DBorder --
+ *
+ *	Given a border, return a textual string identifying the
+ *	border's color.
+ *
+ * Results:
+ *	The return value is the string that was used to create
+ *	the border.
+ *
+ * Side effects:
+ *	None.
+ *
+ *--------------------------------------------------------------
+ */
+
+char *
+Tk_NameOf3DBorder(border)
+    Tk_3DBorder border;		/* Token for border. */
+{
+    TkBorder *borderPtr = (TkBorder *) border;
+
+    return ((BorderKey *) borderPtr->hashPtr->key.words)->colorName;
+}
+
+/*
+ *--------------------------------------------------------------------
+ *
+ * Tk_3DBorderColor --
+ *
+ *	Given a 3D border, return the X color used for the "flat"
+ *	surfaces.
+ *
+ * Results:
+ *	Returns the color used drawing flat surfaces with the border.
+ *
+ * Side effects:
+ *	None.
+ *
+ *--------------------------------------------------------------------
+ */
+XColor *
+Tk_3DBorderColor(border)
+    Tk_3DBorder border;		/* Border whose color is wanted. */
+{
+    return(((TkBorder *) border)->bgColorPtr);
+}
+
+/*
+ *--------------------------------------------------------------------
+ *
+ * Tk_3DBorderGC --
+ *
+ *	Given a 3D border, returns one of the graphics contexts used to
+ *	draw the border.
+ *
+ * Results:
+ *	Returns the graphics context given by the "which" argument.
+ *
+ * Side effects:
+ *	None.
+ *
+ *--------------------------------------------------------------------
+ */
+GC
+Tk_3DBorderGC(tkwin, border, which)
+    Tk_Window tkwin;		/* Window for which border was allocated. */
+    Tk_3DBorder border;		/* Border whose GC is wanted. */
+    int which;			/* Selects one of the border's 3 GC's:
+				 * TK_3D_FLAT_GC, TK_3D_LIGHT_GC, or
+				 * TK_3D_DARK_GC. */
+{
+    TkBorder * borderPtr = (TkBorder *) border;
+
+    if ((borderPtr->lightGC == None) && (which != TK_3D_FLAT_GC)) {
+	TkpGetShadows(borderPtr, tkwin);
+    }
+    if (which == TK_3D_FLAT_GC) {
+	return borderPtr->bgGC;
+    } else if (which == TK_3D_LIGHT_GC) {
+	return borderPtr->lightGC;
+    } else if (which == TK_3D_DARK_GC){
+	return borderPtr->darkGC;
+    }
+    panic("bogus \"which\" value in Tk_3DBorderGC");
+
+    /*
+     * The code below will never be executed, but it's needed to
+     * keep compilers happy.
+     */
+
+    return (GC) None;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * Tk_Free3DBorder --
+ *
+ *	This procedure is called when a 3D border is no longer
+ *	needed.  It frees the resources associated with the
+ *	border.  After this call, the caller should never again
+ *	use the "border" token.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Resources are freed.
+ *
+ *--------------------------------------------------------------
+ */
+
+void
+Tk_Free3DBorder(border)
+    Tk_3DBorder border;		/* Token for border to be released. */
+{
+    register TkBorder *borderPtr = (TkBorder *) border;
+    Display *display = DisplayOfScreen(borderPtr->screen);
+
+    borderPtr->refCount--;
+    if (borderPtr->refCount == 0) {
+	TkpFreeBorder(borderPtr);
+	if (borderPtr->bgColorPtr != NULL) {
+	    Tk_FreeColor(borderPtr->bgColorPtr);
+	}
+	if (borderPtr->darkColorPtr != NULL) {
+	    Tk_FreeColor(borderPtr->darkColorPtr);
+	}
+	if (borderPtr->lightColorPtr != NULL) {
+	    Tk_FreeColor(borderPtr->lightColorPtr);
+	}
+	if (borderPtr->shadow != None) {
+	    Tk_FreeBitmap(display, borderPtr->shadow);
+	}
+	if (borderPtr->bgGC != None) {
+	    Tk_FreeGC(display, borderPtr->bgGC);
+	}
+	if (borderPtr->darkGC != None) {
+	    Tk_FreeGC(display, borderPtr->darkGC);
+	}
+	if (borderPtr->lightGC != None) {
+	    Tk_FreeGC(display, borderPtr->lightGC);
+	}
+	Tcl_DeleteHashEntry(borderPtr->hashPtr);
+	ckfree((char *) borderPtr);
+    }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tk_SetBackgroundFromBorder --
+ *
+ *	Change the background of a window to one appropriate for a given
+ *	3-D border.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Tkwin's background gets modified.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+Tk_SetBackgroundFromBorder(tkwin, border)
+    Tk_Window tkwin;		/* Window whose background is to be set. */
+    Tk_3DBorder border;		/* Token for border. */
+{
+    register TkBorder *borderPtr = (TkBorder *) border;
+
+    Tk_SetWindowBackground(tkwin, borderPtr->bgColorPtr->pixel);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tk_GetRelief --
+ *
+ *	Parse a relief description and return the corresponding
+ *	relief value, or an error.
+ *
+ * Results:
+ *	A standard Tcl return value.  If all goes well then
+ *	*reliefPtr is filled in with one of the values
+ *	TK_RELIEF_RAISED, TK_RELIEF_FLAT, or TK_RELIEF_SUNKEN.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+Tk_GetRelief(interp, name, reliefPtr)
+    Tcl_Interp *interp;		/* For error messages. */
+    char *name;			/* Name of a relief type. */
+    int *reliefPtr;		/* Where to store converted relief. */
+{
+    char c;
+    size_t length;
+
+    c = name[0];
+    length = strlen(name);
+    if ((c == 'f') && (strncmp(name, "flat", length) == 0)) {
+	*reliefPtr = TK_RELIEF_FLAT;
+    } else if ((c == 'g') && (strncmp(name, "groove", length) == 0)
+	    && (length >= 2)) {
+        *reliefPtr = TK_RELIEF_GROOVE;
+    } else if ((c == 'r') && (strncmp(name, "raised", length) == 0)
+	    && (length >= 2)) {
+	*reliefPtr = TK_RELIEF_RAISED;
+    } else if ((c == 'r') && (strncmp(name, "ridge", length) == 0)) {
+        *reliefPtr = TK_RELIEF_RIDGE;
+    } else if ((c == 's') && (strncmp(name, "solid", length) == 0)) {
+	*reliefPtr = TK_RELIEF_SOLID;
+    } else if ((c == 's') && (strncmp(name, "sunken", length) == 0)) {
+	*reliefPtr = TK_RELIEF_SUNKEN;
+    } else {
+	sprintf(interp->result, "bad relief type \"%.50s\": must be %s",
+		name, "flat, groove, raised, ridge, solid, or sunken");
+	return TCL_ERROR;
+    }
+    return TCL_OK;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * Tk_NameOfRelief --
+ *
+ *	Given a relief value, produce a string describing that
+ *	relief value.
+ *
+ * Results:
+ *	The return value is a static string that is equivalent
+ *	to relief.
+ *
+ * Side effects:
+ *	None.
+ *
+ *--------------------------------------------------------------
+ */
+
+char *
+Tk_NameOfRelief(relief)
+    int relief;		/* One of TK_RELIEF_FLAT, TK_RELIEF_RAISED,
+			 * or TK_RELIEF_SUNKEN. */
+{
+    if (relief == TK_RELIEF_FLAT) {
+	return "flat";
+    } else if (relief == TK_RELIEF_SUNKEN) {
+	return "sunken";
+    } else if (relief == TK_RELIEF_RAISED) {
+	return "raised";
+    } else if (relief == TK_RELIEF_GROOVE) {
+	return "groove";
+    } else if (relief == TK_RELIEF_RIDGE) {
+	return "ridge";
+    } else if (relief == TK_RELIEF_SOLID) {
+	return "solid";
+    } else {
+	return "unknown relief";
+    }
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * Tk_Draw3DPolygon --
+ *
+ *	Draw a border with 3-D appearance around the edge of a
+ *	given polygon.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Information is drawn in "drawable" in the form of a
+ *	3-D border borderWidth units width wide on the left
+ *	of the trajectory given by pointPtr and numPoints (or
+ *	-borderWidth units wide on the right side, if borderWidth
+ *	is negative).
+ *
+ *--------------------------------------------------------------
+ */
+
+void
+Tk_Draw3DPolygon(tkwin, drawable, border, pointPtr, numPoints,
+	borderWidth, leftRelief)
+    Tk_Window tkwin;		/* Window for which border was allocated. */
+    Drawable drawable;		/* X window or pixmap in which to draw. */
+    Tk_3DBorder border;		/* Token for border to draw. */
+    XPoint *pointPtr;		/* Array of points describing
+				 * polygon.  All points must be
+				 * absolute (CoordModeOrigin). */
+    int numPoints;		/* Number of points at *pointPtr. */
+    int borderWidth;		/* Width of border, measured in
+				 * pixels to the left of the polygon's
+				 * trajectory.   May be negative. */
+    int leftRelief;		/* TK_RELIEF_RAISED or
+				 * TK_RELIEF_SUNKEN: indicates how
+				 * stuff to left of trajectory looks
+				 * relative to stuff on right. */
+{
+    XPoint poly[4], b1, b2, newB1, newB2;
+    XPoint perp, c, shift1, shift2;	/* Used for handling parallel lines. */
+    register XPoint *p1Ptr, *p2Ptr;
+    TkBorder *borderPtr = (TkBorder *) border;
+    GC gc;
+    int i, lightOnLeft, dx, dy, parallel, pointsSeen;
+    Display *display = Tk_Display(tkwin);
+
+    if (borderPtr->lightGC == None) {
+	TkpGetShadows(borderPtr, tkwin);
+    }
+
+    /*
+     * Handle grooves and ridges with recursive calls.
+     */
+
+    if ((leftRelief == TK_RELIEF_GROOVE) || (leftRelief == TK_RELIEF_RIDGE)) {
+	int halfWidth;
+
+	halfWidth = borderWidth/2;
+	Tk_Draw3DPolygon(tkwin, drawable, border, pointPtr, numPoints,
+		halfWidth, (leftRelief == TK_RELIEF_GROOVE) ? TK_RELIEF_RAISED
+		: TK_RELIEF_SUNKEN);
+	Tk_Draw3DPolygon(tkwin, drawable, border, pointPtr, numPoints,
+		-halfWidth, (leftRelief == TK_RELIEF_GROOVE) ? TK_RELIEF_SUNKEN
+		: TK_RELIEF_RAISED);
+	return;
+    }
+
+    /*
+     * If the polygon is already closed, drop the last point from it
+     * (we'll close it automatically).
+     */
+
+    p1Ptr = &pointPtr[numPoints-1];
+    p2Ptr = &pointPtr[0];
+    if ((p1Ptr->x == p2Ptr->x) && (p1Ptr->y == p2Ptr->y)) {
+	numPoints--;
+    }
+
+    /*
+     * The loop below is executed once for each vertex in the polgon.
+     * At the beginning of each iteration things look like this:
+     *
+     *          poly[1]       /
+     *             *        /
+     *             |      /
+     *             b1   * poly[0] (pointPtr[i-1])
+     *             |    |
+     *             |    |
+     *             |    |
+     *             |    |
+     *             |    |
+     *             |    | *p1Ptr            *p2Ptr
+     *             b2   *--------------------*
+     *             |
+     *             |
+     *             x-------------------------
+     *
+     * The job of this iteration is to do the following:
+     * (a) Compute x (the border corner corresponding to
+     *     pointPtr[i]) and put it in poly[2].  As part of
+     *	   this, compute a new b1 and b2 value for the next
+     *	   side of the polygon.
+     * (b) Put pointPtr[i] into poly[3].
+     * (c) Draw the polygon given by poly[0..3].
+     * (d) Advance poly[0], poly[1], b1, and b2 for the
+     *     next side of the polygon.
+     */
+
+    /*
+     * The above situation doesn't first come into existence until
+     * two points have been processed;  the first two points are
+     * used to "prime the pump", so some parts of the processing
+     * are ommitted for these points.  The variable "pointsSeen"
+     * keeps track of the priming process;  it has to be separate
+     * from i in order to be able to ignore duplicate points in the
+     * polygon.
+     */
+
+    pointsSeen = 0;
+    for (i = -2, p1Ptr = &pointPtr[numPoints-2], p2Ptr = p1Ptr+1;
+	    i < numPoints; i++, p1Ptr = p2Ptr, p2Ptr++) {
+	if ((i == -1) || (i == numPoints-1)) {
+	    p2Ptr = pointPtr;
+	}
+	if ((p2Ptr->x == p1Ptr->x) && (p2Ptr->y == p1Ptr->y)) {
+	    /*
+	     * Ignore duplicate points (they'd cause core dumps in
+	     * ShiftLine calls below).
+	     */
+	    continue;
+	}
+	ShiftLine(p1Ptr, p2Ptr, borderWidth, &newB1);
+	newB2.x = newB1.x + (p2Ptr->x - p1Ptr->x);
+	newB2.y = newB1.y + (p2Ptr->y - p1Ptr->y);
+	poly[3] = *p1Ptr;
+	parallel = 0;
+	if (pointsSeen >= 1) {
+	    parallel = Intersect(&newB1, &newB2, &b1, &b2, &poly[2]);
+
+	    /*
+	     * If two consecutive segments of the polygon are parallel,
+	     * then things get more complex.  Consider the following
+	     * diagram:
+	     *
+	     * poly[1]
+	     *    *----b1-----------b2------a
+	     *                                \
+	     *                                  \
+	     *         *---------*----------*    b
+	     *        poly[0]  *p2Ptr   *p1Ptr  /
+	     *                                /
+	     *              --*--------*----c
+	     *              newB1    newB2
+	     *
+	     * Instead of using x and *p1Ptr for poly[2] and poly[3], as
+	     * in the original diagram, use a and b as above.  Then instead
+	     * of using x and *p1Ptr for the new poly[0] and poly[1], use
+	     * b and c as above.
+	     *
+	     * Do the computation in three stages:
+	     * 1. Compute a point "perp" such that the line p1Ptr-perp
+	     *    is perpendicular to p1Ptr-p2Ptr.
+	     * 2. Compute the points a and c by intersecting the lines
+	     *    b1-b2 and newB1-newB2 with p1Ptr-perp.
+	     * 3. Compute b by shifting p1Ptr-perp to the right and
+	     *    intersecting it with p1Ptr-p2Ptr.
+	     */
+
+	    if (parallel) {
+		perp.x = p1Ptr->x + (p2Ptr->y - p1Ptr->y);
+		perp.y = p1Ptr->y - (p2Ptr->x - p1Ptr->x);
+		(void) Intersect(p1Ptr, &perp, &b1, &b2, &poly[2]);
+		(void) Intersect(p1Ptr, &perp, &newB1, &newB2, &c);
+		ShiftLine(p1Ptr, &perp, borderWidth, &shift1);
+		shift2.x = shift1.x + (perp.x - p1Ptr->x);
+		shift2.y = shift1.y + (perp.y - p1Ptr->y);
+		(void) Intersect(p1Ptr, p2Ptr, &shift1, &shift2, &poly[3]);
+	    }
+	}
+	if (pointsSeen >= 2) {
+	    dx = poly[3].x - poly[0].x;
+	    dy = poly[3].y - poly[0].y;
+	    if (dx > 0) {
+		lightOnLeft = (dy <= dx);
+	    } else {
+		lightOnLeft = (dy < dx);
+	    }
+	    if (lightOnLeft ^ (leftRelief == TK_RELIEF_RAISED)) {
+		gc = borderPtr->lightGC;
+	    } else {
+		gc = borderPtr->darkGC;
+	    }
+	    XFillPolygon(display, drawable, gc, poly, 4, Convex,
+		    CoordModeOrigin);
+	}
+	b1.x = newB1.x;
+	b1.y = newB1.y;
+	b2.x = newB2.x;
+	b2.y = newB2.y;
+	poly[0].x = poly[3].x;
+	poly[0].y = poly[3].y;
+	if (parallel) {
+	    poly[1].x = c.x;
+	    poly[1].y = c.y;
+	} else if (pointsSeen >= 1) {
+	    poly[1].x = poly[2].x;
+	    poly[1].y = poly[2].y;
+	}
+	pointsSeen++;
+    }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tk_Fill3DRectangle --
+ *
+ *	Fill a rectangular area, supplying a 3D border if desired.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Information gets drawn on the screen.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+Tk_Fill3DRectangle(tkwin, drawable, border, x, y, width,
+	height, borderWidth, relief)
+    Tk_Window tkwin;		/* Window for which border was allocated. */
+    Drawable drawable;		/* X window or pixmap in which to draw. */
+    Tk_3DBorder border;		/* Token for border to draw. */
+    int x, y, width, height;	/* Outside area of rectangular region. */
+    int borderWidth;		/* Desired width for border, in
+				 * pixels. Border will be *inside* region. */
+    int relief;			/* Indicates 3D effect: TK_RELIEF_FLAT,
+				 * TK_RELIEF_RAISED, or TK_RELIEF_SUNKEN. */
+{
+    register TkBorder *borderPtr = (TkBorder *) border;
+    int doubleBorder;
+
+    /*
+     * This code is slightly tricky because it only draws the background
+     * in areas not covered by the 3D border. This avoids flashing
+     * effects on the screen for the border region.
+     */
+  
+    if (relief == TK_RELIEF_FLAT) {
+	borderWidth = 0;
+    }
+    doubleBorder = 2*borderWidth;
+
+    if ((width > doubleBorder) && (height > doubleBorder)) {
+	XFillRectangle(Tk_Display(tkwin), drawable, borderPtr->bgGC,
+		x + borderWidth, y + borderWidth,
+		(unsigned int) (width - doubleBorder),
+		(unsigned int) (height - doubleBorder));
+    }
+    if (borderWidth) {
+	Tk_Draw3DRectangle(tkwin, drawable, border, x, y, width,
+		height, borderWidth, relief);
+    }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tk_Fill3DPolygon --
+ *
+ *	Fill a polygonal area, supplying a 3D border if desired.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Information gets drawn on the screen.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+Tk_Fill3DPolygon(tkwin, drawable, border, pointPtr, numPoints,
+	borderWidth, leftRelief)
+    Tk_Window tkwin;		/* Window for which border was allocated. */
+    Drawable drawable;		/* X window or pixmap in which to draw. */
+    Tk_3DBorder border;		/* Token for border to draw. */
+    XPoint *pointPtr;		/* Array of points describing
+				 * polygon.  All points must be
+				 * absolute (CoordModeOrigin). */
+    int numPoints;		/* Number of points at *pointPtr. */
+    int borderWidth;		/* Width of border, measured in
+				 * pixels to the left of the polygon's
+				 * trajectory.   May be negative. */
+    int leftRelief;			/* Indicates 3D effect of left side of
+				 * trajectory relative to right:
+				 * TK_RELIEF_FLAT, TK_RELIEF_RAISED,
+				 * or TK_RELIEF_SUNKEN. */
+{
+    register TkBorder *borderPtr = (TkBorder *) border;
+
+    XFillPolygon(Tk_Display(tkwin), drawable, borderPtr->bgGC,
+	    pointPtr, numPoints, Complex, CoordModeOrigin);
+    if (leftRelief != TK_RELIEF_FLAT) {
+	Tk_Draw3DPolygon(tkwin, drawable, border, pointPtr, numPoints,
+		borderWidth, leftRelief);
+    }
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * BorderInit --
+ *
+ *	Initialize the structures used for border management.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Read the code.
+ *
+ *-------------------------------------------------------------
+ */
+
+static void
+BorderInit()
+{
+    initialized = 1;
+    Tcl_InitHashTable(&borderTable, sizeof(BorderKey)/sizeof(int));
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * ShiftLine --
+ *
+ *	Given two points on a line, compute a point on a
+ *	new line that is parallel to the given line and
+ *	a given distance away from it.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	None.
+ *
+ *--------------------------------------------------------------
+ */
+
+static void
+ShiftLine(p1Ptr, p2Ptr, distance, p3Ptr)
+    XPoint *p1Ptr;		/* First point on line. */
+    XPoint *p2Ptr;		/* Second point on line. */
+    int distance;		/* New line is to be this many
+				 * units to the left of original
+				 * line, when looking from p1 to
+				 * p2.  May be negative. */
+    XPoint *p3Ptr;		/* Store coords of point on new
+				 * line here. */
+{
+    int dx, dy, dxNeg, dyNeg;
+
+    /*
+     * The table below is used for a quick approximation in
+     * computing the new point.  An index into the table
+     * is 128 times the slope of the original line (the slope
+     * must always be between 0 and 1).  The value of the table
+     * entry is 128 times the amount to displace the new line
+     * in y for each unit of perpendicular distance.  In other
+     * words, the table maps from the tangent of an angle to
+     * the inverse of its cosine.  If the slope of the original
+     * line is greater than 1, then the displacement is done in
+     * x rather than in y.
+     */
+
+    static int shiftTable[129];
+
+    /*
+     * Initialize the table if this is the first time it is
+     * used.
+     */
+
+    if (shiftTable[0] == 0) {
+	int i;
+	double tangent, cosine;
+
+	for (i = 0; i <= 128; i++) {
+	    tangent = i/128.0;
+	    cosine = 128/cos(atan(tangent)) + .5;
+	    shiftTable[i] = (int) cosine;
+	}
+    }
+
+    *p3Ptr = *p1Ptr;
+    dx = p2Ptr->x - p1Ptr->x;
+    dy = p2Ptr->y - p1Ptr->y;
+    if (dy < 0) {
+	dyNeg = 1;
+	dy = -dy;
+    } else {
+	dyNeg = 0;
+    }
+    if (dx < 0) {
+	dxNeg = 1;
+	dx = -dx;
+    } else {
+	dxNeg = 0;
+    }
+    if (dy <= dx) {
+	dy = ((distance * shiftTable[(dy<<7)/dx]) + 64) >> 7;
+	if (!dxNeg) {
+	    dy = -dy;
+	}
+	p3Ptr->y += dy;
+    } else {
+	dx = ((distance * shiftTable[(dx<<7)/dy]) + 64) >> 7;
+	if (dyNeg) {
+	    dx = -dx;
+	}
+	p3Ptr->x += dx;
+    }
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * Intersect --
+ *
+ *	Find the intersection point between two lines.
+ *
+ * Results:
+ *	Under normal conditions 0 is returned and the point
+ *	at *iPtr is filled in with the intersection between
+ *	the two lines.  If the two lines are parallel, then
+ *	-1 is returned and *iPtr isn't modified.
+ *
+ * Side effects:
+ *	None.
+ *
+ *--------------------------------------------------------------
+ */
+
+static int
+Intersect(a1Ptr, a2Ptr, b1Ptr, b2Ptr, iPtr)
+    XPoint *a1Ptr;		/* First point of first line. */
+    XPoint *a2Ptr;		/* Second point of first line. */
+    XPoint *b1Ptr;		/* First point of second line. */
+    XPoint *b2Ptr;		/* Second point of second line. */
+    XPoint *iPtr;		/* Filled in with intersection point. */
+{
+    int dxadyb, dxbdya, dxadxb, dyadyb, p, q;
+
+    /*
+     * The code below is just a straightforward manipulation of two
+     * equations of the form y = (x-x1)*(y2-y1)/(x2-x1) + y1 to solve
+     * for the x-coordinate of intersection, then the y-coordinate.
+     */
+
+    dxadyb = (a2Ptr->x - a1Ptr->x)*(b2Ptr->y - b1Ptr->y);
+    dxbdya = (b2Ptr->x - b1Ptr->x)*(a2Ptr->y - a1Ptr->y);
+    dxadxb = (a2Ptr->x - a1Ptr->x)*(b2Ptr->x - b1Ptr->x);
+    dyadyb = (a2Ptr->y - a1Ptr->y)*(b2Ptr->y - b1Ptr->y);
+
+    if (dxadyb == dxbdya) {
+	return -1;
+    }
+    p = (a1Ptr->x*dxbdya - b1Ptr->x*dxadyb + (b1Ptr->y - a1Ptr->y)*dxadxb);
+    q = dxbdya - dxadyb;
+    if (q < 0) {
+	p = -p;
+	q = -q;
+    }
+    if (p < 0) {
+	iPtr->x = - ((-p + q/2)/q);
+    } else {
+	iPtr->x = (p + q/2)/q;
+    }
+    p = (a1Ptr->y*dxadyb - b1Ptr->y*dxbdya + (b1Ptr->x - a1Ptr->x)*dyadyb);
+    q = dxadyb - dxbdya;
+    if (q < 0) {
+	p = -p;
+	q = -q;
+    }
+    if (p < 0) {
+	iPtr->y = - ((-p + q/2)/q);
+    } else {
+	iPtr->y = (p + q/2)/q;
+    }
+    return 0;
+}