stk/Tk/generic/tkCanvLine.c

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1996-09-27 06:29:02 -04:00
/*
* 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.
*
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* SCCS: @(#) tkCanvLine.c 1.46 97/04/25 16:51:02
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*/
#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,
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#ifdef SCM_CODE
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"(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,
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#ifdef SCM_CODE
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"#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;
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linePtr->arrowShapeA = (float)8.0;
linePtr->arrowShapeB = (float)10.0;
linePtr->arrowShapeC = (float)3.0;
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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;
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int i, width;
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coordPtr = linePtr->coordPtr;
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linePtr->header.x1 = linePtr->header.x2 = (int) *coordPtr;
linePtr->header.y1 = linePtr->header.y2 = (int) coordPtr[1];
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/*
* 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);
}
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width = linePtr->width;
if (width < 1) {
width = 1;
}
linePtr->header.x1 -= width;
linePtr->header.x2 += width;
linePtr->header.y1 -= width;
linePtr->header.y2 += width;
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/*
* 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,
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(double) width, miter, miter+2)) {
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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.
*/