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authorrjohnson <rjohnson>1998-04-01 09:51:44 (GMT)
committerrjohnson <rjohnson>1998-04-01 09:51:44 (GMT)
commit066ea7fd88d49cb456f74da71dbe875e4fc0aabb (patch)
tree8fb30cb152c4dc191be47fa043d2e6f5ea38c7ba /generic/tkCanvLine.c
parent13242623d2ff3ea02ab6a62bfb48a7dbb5c27e22 (diff)
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diff --git a/generic/tkCanvLine.c b/generic/tkCanvLine.c
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+++ b/generic/tkCanvLine.c
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+/*
+ * 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 <stdio.h>
+#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,
+ "8 10 3", Tk_Offset(LineItem, arrowShapeA),
+ 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,
+ "0", Tk_Offset(LineItem, smooth), TK_CONFIG_DONT_SET_DEFAULT},
+ {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);
+ sprintf(buffer, "%.5g %.5g %.5g", linePtr->arrowShapeA,
+ linePtr->arrowShapeB, linePtr->arrowShapeC);
+ *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;
+}