/* * tkCanvLine.c -- * * This file implements line items for canvas widgets. * * Copyright (c) 1991-1994 The Regents of the University of California. * Copyright (c) 1994-1995 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: @(#) tkCanvLine.c 1.46 97/04/25 16:51:02 */ #include #include "tkInt.h" #include "tkPort.h" /* * The structure below defines the record for each line item. */ typedef struct LineItem { Tk_Item header; /* Generic stuff that's the same for all * types. MUST BE FIRST IN STRUCTURE. */ Tk_Canvas canvas; /* Canvas containing item. Needed for * parsing arrow shapes. */ int numPoints; /* Number of points in line (always >= 2). */ double *coordPtr; /* Pointer to malloc-ed array containing * x- and y-coords of all points in line. * X-coords are even-valued indices, y-coords * are corresponding odd-valued indices. If * the line has arrowheads then the first * and last points have been adjusted to refer * to the necks of the arrowheads rather than * their tips. The actual endpoints are * stored in the *firstArrowPtr and * *lastArrowPtr, if they exist. */ int width; /* Width of line. */ XColor *fg; /* Foreground color for line. */ Pixmap fillStipple; /* Stipple bitmap for filling line. */ int capStyle; /* Cap style for line. */ int joinStyle; /* Join style for line. */ GC gc; /* Graphics context for filling line. */ GC arrowGC; /* Graphics context for drawing arrowheads. */ Tk_Uid arrow; /* Indicates whether or not to draw arrowheads: * "none", "first", "last", or "both". */ float arrowShapeA; /* Distance from tip of arrowhead to center. */ float arrowShapeB; /* Distance from tip of arrowhead to trailing * point, measured along shaft. */ float arrowShapeC; /* Distance of trailing points from outside * edge of shaft. */ double *firstArrowPtr; /* Points to array of PTS_IN_ARROW points * describing polygon for arrowhead at first * point in line. First point of arrowhead * is tip. Malloc'ed. NULL means no arrowhead * at first point. */ double *lastArrowPtr; /* Points to polygon for arrowhead at last * point in line (PTS_IN_ARROW points, first * of which is tip). Malloc'ed. NULL means * no arrowhead at last point. */ int smooth; /* Non-zero means draw line smoothed (i.e. * with Bezier splines). */ int splineSteps; /* Number of steps in each spline segment. */ } LineItem; /* * Number of points in an arrowHead: */ #define PTS_IN_ARROW 6 /* * Prototypes for procedures defined in this file: */ static int ArrowheadPostscript _ANSI_ARGS_((Tcl_Interp *interp, Tk_Canvas canvas, LineItem *linePtr, double *arrowPtr)); static void ComputeLineBbox _ANSI_ARGS_((Tk_Canvas canvas, LineItem *linePtr)); static int ConfigureLine _ANSI_ARGS_((Tcl_Interp *interp, Tk_Canvas canvas, Tk_Item *itemPtr, int argc, char **argv, int flags)); static int ConfigureArrows _ANSI_ARGS_((Tk_Canvas canvas, LineItem *linePtr)); static int CreateLine _ANSI_ARGS_((Tcl_Interp *interp, Tk_Canvas canvas, struct Tk_Item *itemPtr, int argc, char **argv)); static void DeleteLine _ANSI_ARGS_((Tk_Canvas canvas, Tk_Item *itemPtr, Display *display)); static void DisplayLine _ANSI_ARGS_((Tk_Canvas canvas, Tk_Item *itemPtr, Display *display, Drawable dst, int x, int y, int width, int height)); static int LineCoords _ANSI_ARGS_((Tcl_Interp *interp, Tk_Canvas canvas, Tk_Item *itemPtr, int argc, char **argv)); static int LineToArea _ANSI_ARGS_((Tk_Canvas canvas, Tk_Item *itemPtr, double *rectPtr)); static double LineToPoint _ANSI_ARGS_((Tk_Canvas canvas, Tk_Item *itemPtr, double *coordPtr)); static int LineToPostscript _ANSI_ARGS_((Tcl_Interp *interp, Tk_Canvas canvas, Tk_Item *itemPtr, int prepass)); static int ParseArrowShape _ANSI_ARGS_((ClientData clientData, Tcl_Interp *interp, Tk_Window tkwin, char *value, char *recordPtr, int offset)); static char * PrintArrowShape _ANSI_ARGS_((ClientData clientData, Tk_Window tkwin, char *recordPtr, int offset, Tcl_FreeProc **freeProcPtr)); static void ScaleLine _ANSI_ARGS_((Tk_Canvas canvas, Tk_Item *itemPtr, double originX, double originY, double scaleX, double scaleY)); static void TranslateLine _ANSI_ARGS_((Tk_Canvas canvas, Tk_Item *itemPtr, double deltaX, double deltaY)); /* * Information used for parsing configuration specs. If you change any * of the default strings, be sure to change the corresponding default * values in CreateLine. */ static Tk_CustomOption arrowShapeOption = {ParseArrowShape, PrintArrowShape, (ClientData) NULL}; static Tk_CustomOption tagsOption = {Tk_CanvasTagsParseProc, Tk_CanvasTagsPrintProc, (ClientData) NULL }; static Tk_ConfigSpec configSpecs[] = { {TK_CONFIG_UID, "-arrow", (char *) NULL, (char *) NULL, "none", Tk_Offset(LineItem, arrow), TK_CONFIG_DONT_SET_DEFAULT}, {TK_CONFIG_CUSTOM, "-arrowshape", (char *) NULL, (char *) NULL, #ifdef STk_CODE "(8 10 3)", Tk_Offset(LineItem, arrowShapeA), #else "8 10 3", Tk_Offset(LineItem, arrowShapeA), #endif TK_CONFIG_DONT_SET_DEFAULT, &arrowShapeOption}, {TK_CONFIG_CAP_STYLE, "-capstyle", (char *) NULL, (char *) NULL, "butt", Tk_Offset(LineItem, capStyle), TK_CONFIG_DONT_SET_DEFAULT}, {TK_CONFIG_COLOR, "-fill", (char *) NULL, (char *) NULL, "black", Tk_Offset(LineItem, fg), TK_CONFIG_NULL_OK}, {TK_CONFIG_JOIN_STYLE, "-joinstyle", (char *) NULL, (char *) NULL, "round", Tk_Offset(LineItem, joinStyle), TK_CONFIG_DONT_SET_DEFAULT}, {TK_CONFIG_BOOLEAN, "-smooth", (char *) NULL, (char *) NULL, #ifdef STk_CODE "#f", Tk_Offset(LineItem, smooth), TK_CONFIG_DONT_SET_DEFAULT}, #else "0", Tk_Offset(LineItem, smooth), TK_CONFIG_DONT_SET_DEFAULT}, #endif {TK_CONFIG_INT, "-splinesteps", (char *) NULL, (char *) NULL, "12", Tk_Offset(LineItem, splineSteps), TK_CONFIG_DONT_SET_DEFAULT}, {TK_CONFIG_BITMAP, "-stipple", (char *) NULL, (char *) NULL, (char *) NULL, Tk_Offset(LineItem, fillStipple), TK_CONFIG_NULL_OK}, {TK_CONFIG_CUSTOM, "-tags", (char *) NULL, (char *) NULL, (char *) NULL, 0, TK_CONFIG_NULL_OK, &tagsOption}, {TK_CONFIG_PIXELS, "-width", (char *) NULL, (char *) NULL, "1", Tk_Offset(LineItem, width), TK_CONFIG_DONT_SET_DEFAULT}, {TK_CONFIG_END, (char *) NULL, (char *) NULL, (char *) NULL, (char *) NULL, 0, 0} }; /* * The structures below defines the line item type by means * of procedures that can be invoked by generic item code. */ Tk_ItemType tkLineType = { "line", /* name */ sizeof(LineItem), /* itemSize */ CreateLine, /* createProc */ configSpecs, /* configSpecs */ ConfigureLine, /* configureProc */ LineCoords, /* coordProc */ DeleteLine, /* deleteProc */ DisplayLine, /* displayProc */ 0, /* alwaysRedraw */ LineToPoint, /* pointProc */ LineToArea, /* areaProc */ LineToPostscript, /* postscriptProc */ ScaleLine, /* scaleProc */ TranslateLine, /* translateProc */ (Tk_ItemIndexProc *) NULL, /* indexProc */ (Tk_ItemCursorProc *) NULL, /* icursorProc */ (Tk_ItemSelectionProc *) NULL, /* selectionProc */ (Tk_ItemInsertProc *) NULL, /* insertProc */ (Tk_ItemDCharsProc *) NULL, /* dTextProc */ (Tk_ItemType *) NULL /* nextPtr */ }; /* * The Tk_Uid's below refer to uids for the various arrow types: */ static Tk_Uid noneUid = NULL; static Tk_Uid firstUid = NULL; static Tk_Uid lastUid = NULL; static Tk_Uid bothUid = NULL; /* * The definition below determines how large are static arrays * used to hold spline points (splines larger than this have to * have their arrays malloc-ed). */ #define MAX_STATIC_POINTS 200 /* *-------------------------------------------------------------- * * CreateLine -- * * This procedure is invoked to create a new line item in * a canvas. * * Results: * A standard Tcl return value. If an error occurred in * creating the item, then an error message is left in * interp->result; in this case itemPtr is left uninitialized, * so it can be safely freed by the caller. * * Side effects: * A new line item is created. * *-------------------------------------------------------------- */ static int CreateLine(interp, canvas, itemPtr, argc, argv) Tcl_Interp *interp; /* Interpreter for error reporting. */ Tk_Canvas canvas; /* Canvas to hold new item. */ Tk_Item *itemPtr; /* Record to hold new item; header * has been initialized by caller. */ int argc; /* Number of arguments in argv. */ char **argv; /* Arguments describing line. */ { LineItem *linePtr = (LineItem *) itemPtr; int i; if (argc < 4) { Tcl_AppendResult(interp, "wrong # args: should be \"", Tk_PathName(Tk_CanvasTkwin(canvas)), " create ", itemPtr->typePtr->name, " x1 y1 x2 y2 ?x3 y3 ...? ?options?\"", (char *) NULL); return TCL_ERROR; } /* * Carry out initialization that is needed to set defaults and to * allow proper cleanup after errors during the the remainder of * this procedure. */ linePtr->canvas = canvas; linePtr->numPoints = 0; linePtr->coordPtr = NULL; linePtr->width = 1; linePtr->fg = None; linePtr->fillStipple = None; linePtr->capStyle = CapButt; linePtr->joinStyle = JoinRound; linePtr->gc = None; linePtr->arrowGC = None; if (noneUid == NULL) { noneUid = Tk_GetUid("none"); firstUid = Tk_GetUid("first"); lastUid = Tk_GetUid("last"); bothUid = Tk_GetUid("both"); } linePtr->arrow = noneUid; linePtr->arrowShapeA = (float)8.0; linePtr->arrowShapeB = (float)10.0; linePtr->arrowShapeC = (float)3.0; linePtr->firstArrowPtr = NULL; linePtr->lastArrowPtr = NULL; linePtr->smooth = 0; linePtr->splineSteps = 12; /* * Count the number of points and then parse them into a point * array. Leading arguments are assumed to be points if they * start with a digit or a minus sign followed by a digit. */ for (i = 4; i < (argc-1); i+=2) { if ((!isdigit(UCHAR(argv[i][0]))) && ((argv[i][0] != '-') || ((argv[i][1] != '.') && !isdigit(UCHAR(argv[i][1]))))) { break; } } if (LineCoords(interp, canvas, itemPtr, i, argv) != TCL_OK) { goto error; } if (ConfigureLine(interp, canvas, itemPtr, argc-i, argv+i, 0) == TCL_OK) { return TCL_OK; } error: DeleteLine(canvas, itemPtr, Tk_Display(Tk_CanvasTkwin(canvas))); return TCL_ERROR; } /* *-------------------------------------------------------------- * * LineCoords -- * * This procedure is invoked to process the "coords" widget * command on lines. See the user documentation for details * on what it does. * * Results: * Returns TCL_OK or TCL_ERROR, and sets interp->result. * * Side effects: * The coordinates for the given item may be changed. * *-------------------------------------------------------------- */ static int LineCoords(interp, canvas, itemPtr, argc, argv) Tcl_Interp *interp; /* Used for error reporting. */ Tk_Canvas canvas; /* Canvas containing item. */ Tk_Item *itemPtr; /* Item whose coordinates are to be * read or modified. */ int argc; /* Number of coordinates supplied in * argv. */ char **argv; /* Array of coordinates: x1, y1, * x2, y2, ... */ { LineItem *linePtr = (LineItem *) itemPtr; char buffer[TCL_DOUBLE_SPACE]; int i, numPoints; if (argc == 0) { double *coordPtr; int numCoords; numCoords = 2*linePtr->numPoints; if (linePtr->firstArrowPtr != NULL) { coordPtr = linePtr->firstArrowPtr; } else { coordPtr = linePtr->coordPtr; } for (i = 0; i < numCoords; i++, coordPtr++) { if (i == 2) { coordPtr = linePtr->coordPtr+2; } if ((linePtr->lastArrowPtr != NULL) && (i == (numCoords-2))) { coordPtr = linePtr->lastArrowPtr; } Tcl_PrintDouble(interp, *coordPtr, buffer); Tcl_AppendElement(interp, buffer); } } else if (argc < 4) { Tcl_AppendResult(interp, "too few coordinates for line: must have at least 4", (char *) NULL); return TCL_ERROR; } else if (argc & 1) { Tcl_AppendResult(interp, "odd number of coordinates specified for line", (char *) NULL); return TCL_ERROR; } else { numPoints = argc/2; if (linePtr->numPoints != numPoints) { if (linePtr->coordPtr != NULL) { ckfree((char *) linePtr->coordPtr); } linePtr->coordPtr = (double *) ckalloc((unsigned) (sizeof(double) * argc)); linePtr->numPoints = numPoints; } for (i = argc-1; i >= 0; i--) { if (Tk_CanvasGetCoord(interp, canvas, argv[i], &linePtr->coordPtr[i]) != TCL_OK) { return TCL_ERROR; } } /* * Update arrowheads by throwing away any existing arrow-head * information and calling ConfigureArrows to recompute it. */ if (linePtr->firstArrowPtr != NULL) { ckfree((char *) linePtr->firstArrowPtr); linePtr->firstArrowPtr = NULL; } if (linePtr->lastArrowPtr != NULL) { ckfree((char *) linePtr->lastArrowPtr); linePtr->lastArrowPtr = NULL; } if (linePtr->arrow != noneUid) { ConfigureArrows(canvas, linePtr); } ComputeLineBbox(canvas, linePtr); } return TCL_OK; } /* *-------------------------------------------------------------- * * ConfigureLine -- * * This procedure is invoked to configure various aspects * of a line item such as its background color. * * Results: * A standard Tcl result code. If an error occurs, then * an error message is left in interp->result. * * Side effects: * Configuration information, such as colors and stipple * patterns, may be set for itemPtr. * *-------------------------------------------------------------- */ static int ConfigureLine(interp, canvas, itemPtr, argc, argv, flags) Tcl_Interp *interp; /* Used for error reporting. */ Tk_Canvas canvas; /* Canvas containing itemPtr. */ Tk_Item *itemPtr; /* Line item to reconfigure. */ int argc; /* Number of elements in argv. */ char **argv; /* Arguments describing things to configure. */ int flags; /* Flags to pass to Tk_ConfigureWidget. */ { LineItem *linePtr = (LineItem *) itemPtr; XGCValues gcValues; GC newGC, arrowGC; unsigned long mask; Tk_Window tkwin; tkwin = Tk_CanvasTkwin(canvas); if (Tk_ConfigureWidget(interp, tkwin, configSpecs, argc, argv, (char *) linePtr, flags) != TCL_OK) { return TCL_ERROR; } /* * A few of the options require additional processing, such as * graphics contexts. */ if (linePtr->fg == NULL) { newGC = arrowGC = None; } else { gcValues.foreground = linePtr->fg->pixel; gcValues.join_style = linePtr->joinStyle; if (linePtr->width < 0) { linePtr->width = 1; } gcValues.line_width = linePtr->width; mask = GCForeground|GCJoinStyle|GCLineWidth; if (linePtr->fillStipple != None) { gcValues.stipple = linePtr->fillStipple; gcValues.fill_style = FillStippled; mask |= GCStipple|GCFillStyle; } if (linePtr->arrow == noneUid) { gcValues.cap_style = linePtr->capStyle; mask |= GCCapStyle; } newGC = Tk_GetGC(tkwin, mask, &gcValues); gcValues.line_width = 0; arrowGC = Tk_GetGC(tkwin, mask, &gcValues); } if (linePtr->gc != None) { Tk_FreeGC(Tk_Display(tkwin), linePtr->gc); } if (linePtr->arrowGC != None) { Tk_FreeGC(Tk_Display(tkwin), linePtr->arrowGC); } linePtr->gc = newGC; linePtr->arrowGC = arrowGC; /* * Keep spline parameters within reasonable limits. */ if (linePtr->splineSteps < 1) { linePtr->splineSteps = 1; } else if (linePtr->splineSteps > 100) { linePtr->splineSteps = 100; } /* * Setup arrowheads, if needed. If arrowheads are turned off, * restore the line's endpoints (they were shortened when the * arrowheads were added). */ if ((linePtr->firstArrowPtr != NULL) && (linePtr->arrow != firstUid) && (linePtr->arrow != bothUid)) { linePtr->coordPtr[0] = linePtr->firstArrowPtr[0]; linePtr->coordPtr[1] = linePtr->firstArrowPtr[1]; ckfree((char *) linePtr->firstArrowPtr); linePtr->firstArrowPtr = NULL; } if ((linePtr->lastArrowPtr != NULL) && (linePtr->arrow != lastUid) && (linePtr->arrow != bothUid)) { int i; i = 2*(linePtr->numPoints-1); linePtr->coordPtr[i] = linePtr->lastArrowPtr[0]; linePtr->coordPtr[i+1] = linePtr->lastArrowPtr[1]; ckfree((char *) linePtr->lastArrowPtr); linePtr->lastArrowPtr = NULL; } if (linePtr->arrow != noneUid) { if ((linePtr->arrow != firstUid) && (linePtr->arrow != lastUid) && (linePtr->arrow != bothUid)) { Tcl_AppendResult(interp, "bad arrow spec \"", linePtr->arrow, "\": must be none, first, last, or both", (char *) NULL); linePtr->arrow = noneUid; return TCL_ERROR; } ConfigureArrows(canvas, linePtr); } /* * Recompute bounding box for line. */ ComputeLineBbox(canvas, linePtr); return TCL_OK; } /* *-------------------------------------------------------------- * * DeleteLine -- * * This procedure is called to clean up the data structure * associated with a line item. * * Results: * None. * * Side effects: * Resources associated with itemPtr are released. * *-------------------------------------------------------------- */ static void DeleteLine(canvas, itemPtr, display) Tk_Canvas canvas; /* Info about overall canvas widget. */ Tk_Item *itemPtr; /* Item that is being deleted. */ Display *display; /* Display containing window for * canvas. */ { LineItem *linePtr = (LineItem *) itemPtr; if (linePtr->coordPtr != NULL) { ckfree((char *) linePtr->coordPtr); } if (linePtr->fg != NULL) { Tk_FreeColor(linePtr->fg); } if (linePtr->fillStipple != None) { Tk_FreeBitmap(display, linePtr->fillStipple); } if (linePtr->gc != None) { Tk_FreeGC(display, linePtr->gc); } if (linePtr->arrowGC != None) { Tk_FreeGC(display, linePtr->arrowGC); } if (linePtr->firstArrowPtr != NULL) { ckfree((char *) linePtr->firstArrowPtr); } if (linePtr->lastArrowPtr != NULL) { ckfree((char *) linePtr->lastArrowPtr); } } /* *-------------------------------------------------------------- * * ComputeLineBbox -- * * This procedure is invoked to compute the bounding box of * all the pixels that may be drawn as part of a line. * * Results: * None. * * Side effects: * The fields x1, y1, x2, and y2 are updated in the header * for itemPtr. * *-------------------------------------------------------------- */ static void ComputeLineBbox(canvas, linePtr) Tk_Canvas canvas; /* Canvas that contains item. */ LineItem *linePtr; /* Item whose bbos is to be * recomputed. */ { double *coordPtr; int i, width; coordPtr = linePtr->coordPtr; linePtr->header.x1 = linePtr->header.x2 = (int) *coordPtr; linePtr->header.y1 = linePtr->header.y2 = (int) coordPtr[1]; /* * Compute the bounding box of all the points in the line, * then expand in all directions by the line's width to take * care of butting or rounded corners and projecting or * rounded caps. This expansion is an overestimate (worst-case * is square root of two over two) but it's simple. Don't do * anything special for curves. This causes an additional * overestimate in the bounding box, but is faster. */ for (i = 1, coordPtr = linePtr->coordPtr+2; i < linePtr->numPoints; i++, coordPtr += 2) { TkIncludePoint((Tk_Item *) linePtr, coordPtr); } width = linePtr->width; if (width < 1) { width = 1; } linePtr->header.x1 -= width; linePtr->header.x2 += width; linePtr->header.y1 -= width; linePtr->header.y2 += width; /* * For mitered lines, make a second pass through all the points. * Compute the locations of the two miter vertex points and add * those into the bounding box. */ if (linePtr->joinStyle == JoinMiter) { for (i = linePtr->numPoints, coordPtr = linePtr->coordPtr; i >= 3; i--, coordPtr += 2) { double miter[4]; int j; if (TkGetMiterPoints(coordPtr, coordPtr+2, coordPtr+4, (double) width, miter, miter+2)) { for (j = 0; j < 4; j += 2) { TkIncludePoint((Tk_Item *) linePtr, miter+j); } } } } /* * Add in the sizes of arrowheads, if any. */ if (linePtr->arrow != noneUid) { if (linePtr->arrow != lastUid) { for (i = 0, coordPtr = linePtr->firstArrowPtr; i < PTS_IN_ARROW; i++, coordPtr += 2) { TkIncludePoint((Tk_Item *) linePtr, coordPtr); } } if (linePtr->arrow != firstUid) { for (i = 0, coordPtr = linePtr->lastArrowPtr; i < PTS_IN_ARROW; i++, coordPtr += 2) { TkIncludePoint((Tk_Item *) linePtr, coordPtr); } } } /* * Add one more pixel of fudge factor just to be safe (e.g. * X may round differently than we do). */ linePtr->header.x1 -= 1; linePtr->header.x2 += 1; linePtr->header.y1 -= 1; linePtr->header.y2 += 1; } /* *-------------------------------------------------------------- * * DisplayLine -- * * This procedure is invoked to draw a line item in a given * drawable. * * Results: * None. * * Side effects: * ItemPtr is drawn in drawable using the transformation * information in canvas. * *-------------------------------------------------------------- */ static void DisplayLine(canvas, itemPtr, display, drawable, x, y, width, height) Tk_Canvas canvas; /* Canvas that contains item. */ Tk_Item *itemPtr; /* Item to be displayed. */ Display *display; /* Display on which to draw item. */ Drawable drawable; /* Pixmap or window in which to draw * item. */ int x, y, width, height; /* Describes region of canvas that * must be redisplayed (not used). */ { LineItem *linePtr = (LineItem *) itemPtr; XPoint staticPoints[MAX_STATIC_POINTS]; XPoint *pointPtr; XPoint *pPtr; double *coordPtr; int i, numPoints; if (linePtr->gc == None) { return; } /* * Build up an array of points in screen coordinates. Use a * static array unless the line has an enormous number of points; * in this case, dynamically allocate an array. For smoothed lines, * generate the curve points on each redisplay. */ if ((linePtr->smooth) && (linePtr->numPoints > 2)) { numPoints = 1 + linePtr->numPoints*linePtr->splineSteps; } else { numPoints = linePtr->numPoints; } if (numPoints <= MAX_STATIC_POINTS) { pointPtr = staticPoints; } else { pointPtr = (XPoint *) ckalloc((unsigned) (numPoints * sizeof(XPoint))); } if ((linePtr->smooth) && (linePtr->numPoints > 2)) { numPoints = TkMakeBezierCurve(canvas, linePtr->coordPtr, linePtr->numPoints, linePtr->splineSteps, pointPtr, (double *) NULL); } else { for (i = 0, coordPtr = linePtr->coordPtr, pPtr = pointPtr; i < linePtr->numPoints; i += 1, coordPtr += 2, pPtr++) { Tk_CanvasDrawableCoords(canvas, coordPtr[0], coordPtr[1], &pPtr->x, &pPtr->y); } } /* * Display line, the free up line storage if it was dynamically * allocated. If we're stippling, then modify the stipple offset * in the GC. Be sure to reset the offset when done, since the * GC is supposed to be read-only. */ if (linePtr->fillStipple != None) { Tk_CanvasSetStippleOrigin(canvas, linePtr->gc); Tk_CanvasSetStippleOrigin(canvas, linePtr->arrowGC); } XDrawLines(display, drawable, linePtr->gc, pointPtr, numPoints, CoordModeOrigin); if (pointPtr != staticPoints) { ckfree((char *) pointPtr); } /* * Display arrowheads, if they are wanted. */ if (linePtr->firstArrowPtr != NULL) { TkFillPolygon(canvas, linePtr->firstArrowPtr, PTS_IN_ARROW, display, drawable, linePtr->gc, NULL); } if (linePtr->lastArrowPtr != NULL) { TkFillPolygon(canvas, linePtr->lastArrowPtr, PTS_IN_ARROW, display, drawable, linePtr->gc, NULL); } if (linePtr->fillStipple != None) { XSetTSOrigin(display, linePtr->gc, 0, 0); XSetTSOrigin(display, linePtr->arrowGC, 0, 0); } } /* *-------------------------------------------------------------- * * LineToPoint -- * * Computes the distance from a given point to a given * line, in canvas units. * * Results: * The return value is 0 if the point whose x and y coordinates * are pointPtr[0] and pointPtr[1] is inside the line. If the * point isn't inside the line then the return value is the * distance from the point to the line. * * Side effects: * None. * *-------------------------------------------------------------- */ /* ARGSUSED */ static double LineToPoint(canvas, itemPtr, pointPtr) Tk_Canvas canvas; /* Canvas containing item. */ Tk_Item *itemPtr; /* Item to check against point. */ double *pointPtr; /* Pointer to x and y coordinates. */ { LineItem *linePtr = (LineItem *) itemPtr; double *coordPtr, *linePoints; double staticSpace[2*MAX_STATIC_POINTS]; double poly[10]; double bestDist, dist; int numPoints, count; int changedMiterToBevel; /* Non-zero means that a mitered corner * had to be treated as beveled after all * because the angle was < 11 degrees. */ bestDist = 1.0e36; /* * Handle smoothed lines by generating an expanded set of points * against which to do the check. */ if ((linePtr->smooth) && (linePtr->numPoints > 2)) { numPoints = 1 + linePtr->numPoints*linePtr->splineSteps; if (numPoints <= MAX_STATIC_POINTS) { linePoints = staticSpace; } else { linePoints = (double *) ckalloc((unsigned) (2*numPoints*sizeof(double))); } numPoints = TkMakeBezierCurve(canvas, linePtr->coordPtr, linePtr->numPoints, linePtr->splineSteps, (XPoint *) NULL, linePoints); } else { numPoints = linePtr->numPoints; linePoints = linePtr->coordPtr; } /* * The overall idea is to iterate through all of the edges of * the line, computing a polygon for each edge and testing the * point against that polygon. In addition, there are additional * tests to deal with rounded joints and caps. */ changedMiterToBevel = 0; for (count = numPoints, coordPtr = linePoints; count >= 2; count--, coordPtr += 2) { /* * If rounding is done around the first point then compute * the distance between the point and the point. */ if (((linePtr->capStyle == CapRound) && (count == numPoints)) || ((linePtr->joinStyle == JoinRound) && (count != numPoints))) { dist = hypot(coordPtr[0] - pointPtr[0], coordPtr[1] - pointPtr[1]) - linePtr->width/2.0; if (dist <= 0.0) { bestDist = 0.0; goto done; } else if (dist < bestDist) { bestDist = dist; } } /* * Compute the polygonal shape corresponding to this edge, * consisting of two points for the first point of the edge * and two points for the last point of the edge. */ if (count == numPoints) { TkGetButtPoints(coordPtr+2, coordPtr, (double) linePtr->width, linePtr->capStyle == CapProjecting, poly, poly+2); } else if ((linePtr->joinStyle == JoinMiter) && !changedMiterToBevel) { poly[0] = poly[6]; poly[1] = poly[7]; poly[2] = poly[4]; poly[3] = poly[5]; } else { TkGetButtPoints(coordPtr+2, coordPtr, (double) linePtr->width, 0, poly, poly+2); /* * If this line uses beveled joints, then check the distance * to a polygon comprising the last two points of the previous * polygon and the first two from this polygon; this checks * the wedges that fill the mitered joint. */ if ((linePtr->joinStyle == JoinBevel) || changedMiterToBevel) { poly[8] = poly[0]; poly[9] = poly[1]; dist = TkPolygonToPoint(poly, 5, pointPtr); if (dist <= 0.0) { bestDist = 0.0; goto done; } else if (dist < bestDist) { bestDist = dist; } changedMiterToBevel = 0; } } if (count == 2) { TkGetButtPoints(coordPtr, coordPtr+2, (double) linePtr->width, linePtr->capStyle == CapProjecting, poly+4, poly+6); } else if (linePtr->joinStyle == JoinMiter) { if (TkGetMiterPoints(coordPtr, coordPtr+2, coordPtr+4, (double) linePtr->width, poly+4, poly+6) == 0) { changedMiterToBevel = 1; TkGetButtPoints(coordPtr, coordPtr+2, (double) linePtr->width, 0, poly+4, poly+6); } } else { TkGetButtPoints(coordPtr, coordPtr+2, (double) linePtr->width, 0, poly+4, poly+6); } poly[8] = poly[0]; poly[9] = poly[1]; dist = TkPolygonToPoint(poly, 5, pointPtr); if (dist <= 0.0) { bestDist = 0.0; goto done; } else if (dist < bestDist) { bestDist = dist; } } /* * If caps are rounded, check the distance to the cap around the * final end point of the line. */ if (linePtr->capStyle == CapRound) { dist = hypot(coordPtr[0] - pointPtr[0], coordPtr[1] - pointPtr[1]) - linePtr->width/2.0; if (dist <= 0.0) { bestDist = 0.0; goto done; } else if (dist < bestDist) { bestDist = dist; } } /* * If there are arrowheads, check the distance to the arrowheads. */ if (linePtr->arrow != noneUid) { if (linePtr->arrow != lastUid) { dist = TkPolygonToPoint(linePtr->firstArrowPtr, PTS_IN_ARROW, pointPtr); if (dist <= 0.0) { bestDist = 0.0; goto done; } else if (dist < bestDist) { bestDist = dist; } } if (linePtr->arrow != firstUid) { dist = TkPolygonToPoint(linePtr->lastArrowPtr, PTS_IN_ARROW, pointPtr); if (dist <= 0.0) { bestDist = 0.0; goto done; } else if (dist < bestDist) { bestDist = dist; } } } done: if ((linePoints != staticSpace) && (linePoints != linePtr->coordPtr)) { ckfree((char *) linePoints); } return bestDist; } /* *-------------------------------------------------------------- * * LineToArea -- * * This procedure is called to determine whether an item * lies entirely inside, entirely outside, or overlapping * a given rectangular area. * * Results: * -1 is returned if the item is entirely outside the * area, 0 if it overlaps, and 1 if it is entirely * inside the given area. * * Side effects: * None. * *-------------------------------------------------------------- */ /* ARGSUSED */ static int LineToArea(canvas, itemPtr, rectPtr) Tk_Canvas canvas; /* Canvas containing item. */ Tk_Item *itemPtr; /* Item to check against line. */ double *rectPtr; { LineItem *linePtr = (LineItem *) itemPtr; double staticSpace[2*MAX_STATIC_POINTS]; double *linePoints; int numPoints, result; /* * Handle smoothed lines by generating an expanded set of points * against which to do the check. */ if ((linePtr->smooth) && (linePtr->numPoints > 2)) { numPoints = 1 + linePtr->numPoints*linePtr->splineSteps; if (numPoints <= MAX_STATIC_POINTS) { linePoints = staticSpace; } else { linePoints = (double *) ckalloc((unsigned) (2*numPoints*sizeof(double))); } numPoints = TkMakeBezierCurve(canvas, linePtr->coordPtr, linePtr->numPoints, linePtr->splineSteps, (XPoint *) NULL, linePoints); } else { numPoints = linePtr->numPoints; linePoints = linePtr->coordPtr; } /* * Check the segments of the line. */ result = TkThickPolyLineToArea(linePoints, numPoints, (double) linePtr->width, linePtr->capStyle, linePtr->joinStyle, rectPtr); if (result == 0) { goto done; } /* * Check arrowheads, if any. */ if (linePtr->arrow != noneUid) { if (linePtr->arrow != lastUid) { if (TkPolygonToArea(linePtr->firstArrowPtr, PTS_IN_ARROW, rectPtr) != result) { result = 0; goto done; } } if (linePtr->arrow != firstUid) { if (TkPolygonToArea(linePtr->lastArrowPtr, PTS_IN_ARROW, rectPtr) != result) { result = 0; goto done; } } } done: if ((linePoints != staticSpace) && (linePoints != linePtr->coordPtr)) { ckfree((char *) linePoints); } return result; } /* *-------------------------------------------------------------- * * ScaleLine -- * * This procedure is invoked to rescale a line item. * * Results: * None. * * Side effects: * The line referred to by itemPtr is rescaled so that the * following transformation is applied to all point * coordinates: * x' = originX + scaleX*(x-originX) * y' = originY + scaleY*(y-originY) * *-------------------------------------------------------------- */ static void ScaleLine(canvas, itemPtr, originX, originY, scaleX, scaleY) Tk_Canvas canvas; /* Canvas containing line. */ Tk_Item *itemPtr; /* Line to be scaled. */ double originX, originY; /* Origin about which to scale rect. */ double scaleX; /* Amount to scale in X direction. */ double scaleY; /* Amount to scale in Y direction. */ { LineItem *linePtr = (LineItem *) itemPtr; double *coordPtr; int i; /* * Delete any arrowheads before scaling all the points (so that * the end-points of the line get restored). */ if (linePtr->firstArrowPtr != NULL) { linePtr->coordPtr[0] = linePtr->firstArrowPtr[0]; linePtr->coordPtr[1] = linePtr->firstArrowPtr[1]; ckfree((char *) linePtr->firstArrowPtr); linePtr->firstArrowPtr = NULL; } if (linePtr->lastArrowPtr != NULL) { int i; i = 2*(linePtr->numPoints-1); linePtr->coordPtr[i] = linePtr->lastArrowPtr[0]; linePtr->coordPtr[i+1] = linePtr->lastArrowPtr[1]; ckfree((char *) linePtr->lastArrowPtr); linePtr->lastArrowPtr = NULL; } for (i = 0, coordPtr = linePtr->coordPtr; i < linePtr->numPoints; i++, coordPtr += 2) { coordPtr[0] = originX + scaleX*(*coordPtr - originX); coordPtr[1] = originY + scaleY*(coordPtr[1] - originY); } if (linePtr->arrow != noneUid) { ConfigureArrows(canvas, linePtr); } ComputeLineBbox(canvas, linePtr); } /* *-------------------------------------------------------------- * * TranslateLine -- * * This procedure is called to move a line by a given amount. * * Results: * None. * * Side effects: * The position of the line is offset by (xDelta, yDelta), and * the bounding box is updated in the generic part of the item * structure. * *-------------------------------------------------------------- */ static void TranslateLine(canvas, itemPtr, deltaX, deltaY) Tk_Canvas canvas; /* Canvas containing item. */ Tk_Item *itemPtr; /* Item that is being moved. */ double deltaX, deltaY; /* Amount by which item is to be * moved. */ { LineItem *linePtr = (LineItem *) itemPtr; double *coordPtr; int i; for (i = 0, coordPtr = linePtr->coordPtr; i < linePtr->numPoints; i++, coordPtr += 2) { coordPtr[0] += deltaX; coordPtr[1] += deltaY; } if (linePtr->firstArrowPtr != NULL) { for (i = 0, coordPtr = linePtr->firstArrowPtr; i < PTS_IN_ARROW; i++, coordPtr += 2) { coordPtr[0] += deltaX; coordPtr[1] += deltaY; } } if (linePtr->lastArrowPtr != NULL) { for (i = 0, coordPtr = linePtr->lastArrowPtr; i < PTS_IN_ARROW; i++, coordPtr += 2) { coordPtr[0] += deltaX; coordPtr[1] += deltaY; } } ComputeLineBbox(canvas, linePtr); } /* *-------------------------------------------------------------- * * ParseArrowShape -- * * This procedure is called back during option parsing to * parse arrow shape information. * * Results: * The return value is a standard Tcl result: TCL_OK means * that the arrow shape information was parsed ok, and * TCL_ERROR means it couldn't be parsed. * * Side effects: * Arrow information in recordPtr is updated. * *-------------------------------------------------------------- */ /* ARGSUSED */ static int ParseArrowShape(clientData, interp, tkwin, value, recordPtr, offset) ClientData clientData; /* Not used. */ Tcl_Interp *interp; /* Used for error reporting. */ Tk_Window tkwin; /* Not used. */ char *value; /* Textual specification of arrow shape. */ char *recordPtr; /* Pointer to item record in which to * store arrow information. */ int offset; /* Offset of shape information in widget * record. */ { LineItem *linePtr = (LineItem *) recordPtr; double a, b, c; int argc; char **argv = NULL; if (offset != Tk_Offset(LineItem, arrowShapeA)) { panic("ParseArrowShape received bogus offset"); } if (Tcl_SplitList(interp, value, &argc, &argv) != TCL_OK) { syntaxError: Tcl_ResetResult(interp); Tcl_AppendResult(interp, "bad arrow shape \"", value, "\": must be list with three numbers", (char *) NULL); if (argv != NULL) { ckfree((char *) argv); } return TCL_ERROR; } if (argc != 3) { goto syntaxError; } if ((Tk_CanvasGetCoord(interp, linePtr->canvas, argv[0], &a) != TCL_OK) || (Tk_CanvasGetCoord(interp, linePtr->canvas, argv[1], &b) != TCL_OK) || (Tk_CanvasGetCoord(interp, linePtr->canvas, argv[2], &c) != TCL_OK)) { goto syntaxError; } linePtr->arrowShapeA = (float)a; linePtr->arrowShapeB = (float)b; linePtr->arrowShapeC = (float)c; ckfree((char *) argv); return TCL_OK; } /* *-------------------------------------------------------------- * * PrintArrowShape -- * * This procedure is a callback invoked by the configuration * code to return a printable value describing an arrow shape. * * Results: * None. * * Side effects: * None. * *-------------------------------------------------------------- */ /* ARGSUSED */ static char * PrintArrowShape(clientData, tkwin, recordPtr, offset, freeProcPtr) ClientData clientData; /* Not used. */ Tk_Window tkwin; /* Window associated with linePtr's widget. */ char *recordPtr; /* Pointer to item record containing current * shape information. */ int offset; /* Offset of arrow information in record. */ Tcl_FreeProc **freeProcPtr; /* Store address of procedure to call to * free string here. */ { LineItem *linePtr = (LineItem *) recordPtr; char *buffer; buffer = (char *) ckalloc(120); #ifdef STk_CODE sprintf(buffer, "(%.5g %.5g %.5g)", linePtr->arrowShapeA, linePtr->arrowShapeB, linePtr->arrowShapeC); #else sprintf(buffer, "%.5g %.5g %.5g", linePtr->arrowShapeA, linePtr->arrowShapeB, linePtr->arrowShapeC); #endif *freeProcPtr = TCL_DYNAMIC; return buffer; } /* *-------------------------------------------------------------- * * ConfigureArrows -- * * If arrowheads have been requested for a line, this * procedure makes arrangements for the arrowheads. * * Results: * Always returns TCL_OK. * * Side effects: * Information in linePtr is set up for one or two arrowheads. * the firstArrowPtr and lastArrowPtr polygons are allocated * and initialized, if need be, and the end points of the line * are adjusted so that a thick line doesn't stick out past * the arrowheads. * *-------------------------------------------------------------- */ /* ARGSUSED */ static int ConfigureArrows(canvas, linePtr) Tk_Canvas canvas; /* Canvas in which arrows will be * displayed (interp and tkwin * fields are needed). */ LineItem *linePtr; /* Item to configure for arrows. */ { double *poly, *coordPtr; double dx, dy, length, sinTheta, cosTheta, temp; double fracHeight; /* Line width as fraction of * arrowhead width. */ double backup; /* Distance to backup end points * so the line ends in the middle * of the arrowhead. */ double vertX, vertY; /* Position of arrowhead vertex. */ double shapeA, shapeB, shapeC; /* Adjusted coordinates (see * explanation below). */ /* * The code below makes a tiny increase in the shape parameters * for the line. This is a bit of a hack, but it seems to result * in displays that more closely approximate the specified parameters. * Without the adjustment, the arrows come out smaller than expected. */ shapeA = linePtr->arrowShapeA + 0.001; shapeB = linePtr->arrowShapeB + 0.001; shapeC = linePtr->arrowShapeC + linePtr->width/2.0 + 0.001; /* * If there's an arrowhead on the first point of the line, compute * its polygon and adjust the first point of the line so that the * line doesn't stick out past the leading edge of the arrowhead. */ fracHeight = (linePtr->width/2.0)/shapeC; backup = fracHeight*shapeB + shapeA*(1.0 - fracHeight)/2.0; if (linePtr->arrow != lastUid) { poly = linePtr->firstArrowPtr; if (poly == NULL) { poly = (double *) ckalloc((unsigned) (2*PTS_IN_ARROW*sizeof(double))); poly[0] = poly[10] = linePtr->coordPtr[0]; poly[1] = poly[11] = linePtr->coordPtr[1]; linePtr->firstArrowPtr = poly; } dx = poly[0] - linePtr->coordPtr[2]; dy = poly[1] - linePtr->coordPtr[3]; length = hypot(dx, dy); if (length == 0) { sinTheta = cosTheta = 0.0; } else { sinTheta = dy/length; cosTheta = dx/length; } vertX = poly[0] - shapeA*cosTheta; vertY = poly[1] - shapeA*sinTheta; temp = shapeC*sinTheta; poly[2] = poly[0] - shapeB*cosTheta + temp; poly[8] = poly[2] - 2*temp; temp = shapeC*cosTheta; poly[3] = poly[1] - shapeB*sinTheta - temp; poly[9] = poly[3] + 2*temp; poly[4] = poly[2]*fracHeight + vertX*(1.0-fracHeight); poly[5] = poly[3]*fracHeight + vertY*(1.0-fracHeight); poly[6] = poly[8]*fracHeight + vertX*(1.0-fracHeight); poly[7] = poly[9]*fracHeight + vertY*(1.0-fracHeight); /* * Polygon done. Now move the first point towards the second so * that the corners at the end of the line are inside the * arrowhead. */ linePtr->coordPtr[0] = poly[0] - backup*cosTheta; linePtr->coordPtr[1] = poly[1] - backup*sinTheta; } /* * Similar arrowhead calculation for the last point of the line. */ if (linePtr->arrow != firstUid) { coordPtr = linePtr->coordPtr + 2*(linePtr->numPoints-2); poly = linePtr->lastArrowPtr; if (poly == NULL) { poly = (double *) ckalloc((unsigned) (2*PTS_IN_ARROW*sizeof(double))); poly[0] = poly[10] = coordPtr[2]; poly[1] = poly[11] = coordPtr[3]; linePtr->lastArrowPtr = poly; } dx = poly[0] - coordPtr[0]; dy = poly[1] - coordPtr[1]; length = hypot(dx, dy); if (length == 0) { sinTheta = cosTheta = 0.0; } else { sinTheta = dy/length; cosTheta = dx/length; } vertX = poly[0] - shapeA*cosTheta; vertY = poly[1] - shapeA*sinTheta; temp = shapeC*sinTheta; poly[2] = poly[0] - shapeB*cosTheta + temp; poly[8] = poly[2] - 2*temp; temp = shapeC*cosTheta; poly[3] = poly[1] - shapeB*sinTheta - temp; poly[9] = poly[3] + 2*temp; poly[4] = poly[2]*fracHeight + vertX*(1.0-fracHeight); poly[5] = poly[3]*fracHeight + vertY*(1.0-fracHeight); poly[6] = poly[8]*fracHeight + vertX*(1.0-fracHeight); poly[7] = poly[9]*fracHeight + vertY*(1.0-fracHeight); coordPtr[2] = poly[0] - backup*cosTheta; coordPtr[3] = poly[1] - backup*sinTheta; } return TCL_OK; } /* *-------------------------------------------------------------- * * LineToPostscript -- * * This procedure is called to generate Postscript for * line items. * * Results: * The return value is a standard Tcl result. If an error * occurs in generating Postscript then an error message is * left in interp->result, replacing whatever used * to be there. If no error occurs, then Postscript for the * item is appended to the result. * * Side effects: * None. * *-------------------------------------------------------------- */ static int LineToPostscript(interp, canvas, itemPtr, prepass) Tcl_Interp *interp; /* Leave Postscript or error message * here. */ Tk_Canvas canvas; /* Information about overall canvas. */ Tk_Item *itemPtr; /* Item for which Postscript is * wanted. */ int prepass; /* 1 means this is a prepass to * collect font information; 0 means * final Postscript is being created. */ { LineItem *linePtr = (LineItem *) itemPtr; char buffer[200]; char *style; if (linePtr->fg == NULL) { return TCL_OK; } /* * Generate a path for the line's center-line (do this differently * for straight lines and smoothed lines). */ if ((!linePtr->smooth) || (linePtr->numPoints <= 2)) { Tk_CanvasPsPath(interp, canvas, linePtr->coordPtr, linePtr->numPoints); } else { if (linePtr->fillStipple == None) { TkMakeBezierPostscript(interp, canvas, linePtr->coordPtr, linePtr->numPoints); } else { /* * Special hack: Postscript printers don't appear to be able * to turn a path drawn with "curveto"s into a clipping path * without exceeding resource limits, so TkMakeBezierPostscript * won't work for stippled curves. Instead, generate all of * the intermediate points here and output them into the * Postscript file with "lineto"s instead. */ double staticPoints[2*MAX_STATIC_POINTS]; double *pointPtr; int numPoints; numPoints = 1 + linePtr->numPoints*linePtr->splineSteps; pointPtr = staticPoints; if (numPoints > MAX_STATIC_POINTS) { pointPtr = (double *) ckalloc((unsigned) (numPoints * 2 * sizeof(double))); } numPoints = TkMakeBezierCurve(canvas, linePtr->coordPtr, linePtr->numPoints, linePtr->splineSteps, (XPoint *) NULL, pointPtr); Tk_CanvasPsPath(interp, canvas, pointPtr, numPoints); if (pointPtr != staticPoints) { ckfree((char *) pointPtr); } } } /* * Set other line-drawing parameters and stroke out the line. */ sprintf(buffer, "%d setlinewidth\n", linePtr->width); Tcl_AppendResult(interp, buffer, (char *) NULL); style = "0 setlinecap\n"; if (linePtr->capStyle == CapRound) { style = "1 setlinecap\n"; } else if (linePtr->capStyle == CapProjecting) { style = "2 setlinecap\n"; } Tcl_AppendResult(interp, style, (char *) NULL); style = "0 setlinejoin\n"; if (linePtr->joinStyle == JoinRound) { style = "1 setlinejoin\n"; } else if (linePtr->joinStyle == JoinBevel) { style = "2 setlinejoin\n"; } Tcl_AppendResult(interp, style, (char *) NULL); if (Tk_CanvasPsColor(interp, canvas, linePtr->fg) != TCL_OK) { return TCL_ERROR; }; if (linePtr->fillStipple != None) { Tcl_AppendResult(interp, "StrokeClip ", (char *) NULL); if (Tk_CanvasPsStipple(interp, canvas, linePtr->fillStipple) != TCL_OK) { return TCL_ERROR; } } else { Tcl_AppendResult(interp, "stroke\n", (char *) NULL); } /* * Output polygons for the arrowheads, if there are any. */ if (linePtr->firstArrowPtr != NULL) { if (linePtr->fillStipple != None) { Tcl_AppendResult(interp, "grestore gsave\n", (char *) NULL); } if (ArrowheadPostscript(interp, canvas, linePtr, linePtr->firstArrowPtr) != TCL_OK) { return TCL_ERROR; } } if (linePtr->lastArrowPtr != NULL) { if (linePtr->fillStipple != None) { Tcl_AppendResult(interp, "grestore gsave\n", (char *) NULL); } if (ArrowheadPostscript(interp, canvas, linePtr, linePtr->lastArrowPtr) != TCL_OK) { return TCL_ERROR; } } return TCL_OK; } /* *-------------------------------------------------------------- * * ArrowheadPostscript -- * * This procedure is called to generate Postscript for * an arrowhead for a line item. * * Results: * The return value is a standard Tcl result. If an error * occurs in generating Postscript then an error message is * left in interp->result, replacing whatever used * to be there. If no error occurs, then Postscript for the * arrowhead is appended to the result. * * Side effects: * None. * *-------------------------------------------------------------- */ static int ArrowheadPostscript(interp, canvas, linePtr, arrowPtr) Tcl_Interp *interp; /* Leave Postscript or error message * here. */ Tk_Canvas canvas; /* Information about overall canvas. */ LineItem *linePtr; /* Line item for which Postscript is * being generated. */ double *arrowPtr; /* Pointer to first of five points * describing arrowhead polygon. */ { Tk_CanvasPsPath(interp, canvas, arrowPtr, PTS_IN_ARROW); if (linePtr->fillStipple != None) { Tcl_AppendResult(interp, "clip ", (char *) NULL); if (Tk_CanvasPsStipple(interp, canvas, linePtr->fillStipple) != TCL_OK) { return TCL_ERROR; } } else { Tcl_AppendResult(interp, "fill\n", (char *) NULL); } return TCL_OK; }