stk/Tk/generic/tkCanvPoly.c

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/*
* tkCanvPoly.c --
*
* This file implements polygon items for canvas widgets.
*
* Copyright (c) 1991-1994 The Regents of the University of California.
* Copyright (c) 1994-1997 Sun Microsystems, Inc.
*
* See the file "license.terms" for information on usage and redistribution
* of this file, and for a DISCLAIMER OF ALL WARRANTIES.
*
* SCCS: @(#) tkCanvPoly.c 1.37 97/04/29 15:39:16
*/
#include <stdio.h>
#include "tkInt.h"
#include "tkPort.h"
/*
* The structure below defines the record for each polygon item.
*/
typedef struct PolygonItem {
Tk_Item header; /* Generic stuff that's the same for all
* types. MUST BE FIRST IN STRUCTURE. */
int numPoints; /* Number of points in polygon (always >= 3).
* Polygon is always closed. */
int pointsAllocated; /* Number of points for which space is
* allocated at *coordPtr. */
double *coordPtr; /* Pointer to malloc-ed array containing
* x- and y-coords of all points in polygon.
* X-coords are even-valued indices, y-coords
* are corresponding odd-valued indices. */
int width; /* Width of outline. */
XColor *outlineColor; /* Color for outline. */
GC outlineGC; /* Graphics context for drawing outline. */
XColor *fillColor; /* Foreground color for polygon. */
Pixmap fillStipple; /* Stipple bitmap for filling polygon. */
GC fillGC; /* Graphics context for filling polygon. */
int smooth; /* Non-zero means draw shape smoothed (i.e.
* with Bezier splines). */
int splineSteps; /* Number of steps in each spline segment. */
int autoClosed; /* Zero means the given polygon was closed,
one means that we auto closed it. */
} PolygonItem;
/*
* Information used for parsing configuration specs:
*/
static Tk_CustomOption tagsOption = {Tk_CanvasTagsParseProc,
Tk_CanvasTagsPrintProc, (ClientData) NULL
};
static Tk_ConfigSpec configSpecs[] = {
{TK_CONFIG_COLOR, "-fill", (char *) NULL, (char *) NULL,
"black", Tk_Offset(PolygonItem, fillColor), TK_CONFIG_NULL_OK},
{TK_CONFIG_COLOR, "-outline", (char *) NULL, (char *) NULL,
(char *) NULL, Tk_Offset(PolygonItem, outlineColor), TK_CONFIG_NULL_OK},
{TK_CONFIG_BOOLEAN, "-smooth", (char *) NULL, (char *) NULL,
#ifdef SCM_CODE
"#f", Tk_Offset(PolygonItem, smooth), TK_CONFIG_DONT_SET_DEFAULT},
#else
"0", Tk_Offset(PolygonItem, smooth), TK_CONFIG_DONT_SET_DEFAULT},
#endif
{TK_CONFIG_INT, "-splinesteps", (char *) NULL, (char *) NULL,
"12", Tk_Offset(PolygonItem, splineSteps), TK_CONFIG_DONT_SET_DEFAULT},
{TK_CONFIG_BITMAP, "-stipple", (char *) NULL, (char *) NULL,
(char *) NULL, Tk_Offset(PolygonItem, 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(PolygonItem, width), TK_CONFIG_DONT_SET_DEFAULT},
{TK_CONFIG_END, (char *) NULL, (char *) NULL, (char *) NULL,
(char *) NULL, 0, 0}
};
/*
* Prototypes for procedures defined in this file:
*/
static void ComputePolygonBbox _ANSI_ARGS_((Tk_Canvas canvas,
PolygonItem *polyPtr));
static int ConfigurePolygon _ANSI_ARGS_((Tcl_Interp *interp,
Tk_Canvas canvas, Tk_Item *itemPtr, int argc,
char **argv, int flags));
static int CreatePolygon _ANSI_ARGS_((Tcl_Interp *interp,
Tk_Canvas canvas, struct Tk_Item *itemPtr,
int argc, char **argv));
static void DeletePolygon _ANSI_ARGS_((Tk_Canvas canvas,
Tk_Item *itemPtr, Display *display));
static void DisplayPolygon _ANSI_ARGS_((Tk_Canvas canvas,
Tk_Item *itemPtr, Display *display, Drawable dst,
int x, int y, int width, int height));
static int PolygonCoords _ANSI_ARGS_((Tcl_Interp *interp,
Tk_Canvas canvas, Tk_Item *itemPtr,
int argc, char **argv));
static int PolygonToArea _ANSI_ARGS_((Tk_Canvas canvas,
Tk_Item *itemPtr, double *rectPtr));
static double PolygonToPoint _ANSI_ARGS_((Tk_Canvas canvas,
Tk_Item *itemPtr, double *pointPtr));
static int PolygonToPostscript _ANSI_ARGS_((Tcl_Interp *interp,
Tk_Canvas canvas, Tk_Item *itemPtr, int prepass));
static void ScalePolygon _ANSI_ARGS_((Tk_Canvas canvas,
Tk_Item *itemPtr, double originX, double originY,
double scaleX, double scaleY));
static void TranslatePolygon _ANSI_ARGS_((Tk_Canvas canvas,
Tk_Item *itemPtr, double deltaX, double deltaY));
/*
* The structures below defines the polygon item type by means
* of procedures that can be invoked by generic item code.
*/
Tk_ItemType tkPolygonType = {
"polygon", /* name */
sizeof(PolygonItem), /* itemSize */
CreatePolygon, /* createProc */
configSpecs, /* configSpecs */
ConfigurePolygon, /* configureProc */
PolygonCoords, /* coordProc */
DeletePolygon, /* deleteProc */
DisplayPolygon, /* displayProc */
0, /* alwaysRedraw */
PolygonToPoint, /* pointProc */
PolygonToArea, /* areaProc */
PolygonToPostscript, /* postscriptProc */
ScalePolygon, /* scaleProc */
TranslatePolygon, /* 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 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
/*
*--------------------------------------------------------------
*
* CreatePolygon --
*
* This procedure is invoked to create a new polygon 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 polygon item is created.
*
*--------------------------------------------------------------
*/
static int
CreatePolygon(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 polygon. */
{
PolygonItem *polyPtr = (PolygonItem *) itemPtr;
int i;
if (argc < 6) {
Tcl_AppendResult(interp, "wrong # args: should be \"",
Tk_PathName(Tk_CanvasTkwin(canvas)), " create ",
itemPtr->typePtr->name,
" x1 y1 x2 y2 x3 y3 ?x4 y4 ...? ?options?\"", (char *) NULL);
return TCL_ERROR;
}
/*
* Carry out initialization that is needed in order to clean
* up after errors during the the remainder of this procedure.
*/
polyPtr->numPoints = 0;
polyPtr->pointsAllocated = 0;
polyPtr->coordPtr = NULL;
polyPtr->width = 1;
polyPtr->outlineColor = NULL;
polyPtr->outlineGC = None;
polyPtr->fillColor = NULL;
polyPtr->fillStipple = None;
polyPtr->fillGC = None;
polyPtr->smooth = 0;
polyPtr->splineSteps = 12;
polyPtr->autoClosed = 0;
/*
* 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] != '-') || (!isdigit(UCHAR(argv[i][1]))))) {
break;
}
}
if (PolygonCoords(interp, canvas, itemPtr, i, argv) != TCL_OK) {
goto error;
}
if (ConfigurePolygon(interp, canvas, itemPtr, argc-i, argv+i, 0)
== TCL_OK) {
return TCL_OK;
}
error:
DeletePolygon(canvas, itemPtr, Tk_Display(Tk_CanvasTkwin(canvas)));
return TCL_ERROR;
}
/*
*--------------------------------------------------------------
*
* PolygonCoords --
*
* This procedure is invoked to process the "coords" widget
* command on polygons. 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
PolygonCoords(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, ... */
{
PolygonItem *polyPtr = (PolygonItem *) itemPtr;
char buffer[TCL_DOUBLE_SPACE];
int i, numPoints;
if (argc == 0) {
/*
* Print the coords used to create the polygon. If we auto
* closed the polygon then we don't report the last point.
*/
for (i = 0; i < 2*(polyPtr->numPoints - polyPtr->autoClosed); i++) {
Tcl_PrintDouble(interp, polyPtr->coordPtr[i], buffer);
Tcl_AppendElement(interp, buffer);
}
} else if (argc < 6) {
Tcl_AppendResult(interp,
"too few coordinates for polygon: must have at least 6",
(char *) NULL);
return TCL_ERROR;
} else if (argc & 1) {
Tcl_AppendResult(interp,
"odd number of coordinates specified for polygon",
(char *) NULL);
return TCL_ERROR;
} else {
numPoints = argc/2;
if (polyPtr->pointsAllocated <= numPoints) {
if (polyPtr->coordPtr != NULL) {
ckfree((char *) polyPtr->coordPtr);
}
/*
* One extra point gets allocated here, just in case we have
* to add another point to close the polygon.
*/
polyPtr->coordPtr = (double *) ckalloc((unsigned)
(sizeof(double) * (argc+2)));
polyPtr->pointsAllocated = numPoints+1;
}
for (i = argc-1; i >= 0; i--) {
if (Tk_CanvasGetCoord(interp, canvas, argv[i],
&polyPtr->coordPtr[i]) != TCL_OK) {
return TCL_ERROR;
}
}
polyPtr->numPoints = numPoints;
polyPtr->autoClosed = 0;
/*
* Close the polygon if it isn't already closed.
*/
if ((polyPtr->coordPtr[argc-2] != polyPtr->coordPtr[0])
|| (polyPtr->coordPtr[argc-1] != polyPtr->coordPtr[1])) {
polyPtr->autoClosed = 1;
polyPtr->numPoints++;
polyPtr->coordPtr[argc] = polyPtr->coordPtr[0];
polyPtr->coordPtr[argc+1] = polyPtr->coordPtr[1];
}
ComputePolygonBbox(canvas, polyPtr);
}
return TCL_OK;
}
/*
*--------------------------------------------------------------
*
* ConfigurePolygon --
*
* This procedure is invoked to configure various aspects
* of a polygon 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
ConfigurePolygon(interp, canvas, itemPtr, argc, argv, flags)
Tcl_Interp *interp; /* Interpreter for error reporting. */
Tk_Canvas canvas; /* Canvas containing itemPtr. */
Tk_Item *itemPtr; /* Polygon 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. */
{
PolygonItem *polyPtr = (PolygonItem *) itemPtr;
XGCValues gcValues;
GC newGC;
unsigned long mask;
Tk_Window tkwin;
tkwin = Tk_CanvasTkwin(canvas);
if (Tk_ConfigureWidget(interp, tkwin, configSpecs, argc, argv,
(char *) polyPtr, flags) != TCL_OK) {
return TCL_ERROR;
}
/*
* A few of the options require additional processing, such as
* graphics contexts.
*/
if (polyPtr->width < 1) {
polyPtr->width = 1;
}
if (polyPtr->outlineColor == NULL) {
newGC = None;
} else {
gcValues.foreground = polyPtr->outlineColor->pixel;
gcValues.line_width = polyPtr->width;
gcValues.cap_style = CapRound;
gcValues.join_style = JoinRound;
mask = GCForeground|GCLineWidth|GCCapStyle|GCJoinStyle;
newGC = Tk_GetGC(tkwin, mask, &gcValues);
}
if (polyPtr->outlineGC != None) {
Tk_FreeGC(Tk_Display(tkwin), polyPtr->outlineGC);
}
polyPtr->outlineGC = newGC;
if (polyPtr->fillColor == NULL) {
newGC = None;
} else {
gcValues.foreground = polyPtr->fillColor->pixel;
mask = GCForeground;
if (polyPtr->fillStipple != None) {
gcValues.stipple = polyPtr->fillStipple;
gcValues.fill_style = FillStippled;
mask |= GCStipple|GCFillStyle;
}
newGC = Tk_GetGC(tkwin, mask, &gcValues);
}
if (polyPtr->fillGC != None) {
Tk_FreeGC(Tk_Display(tkwin), polyPtr->fillGC);
}
polyPtr->fillGC = newGC;
/*
* Keep spline parameters within reasonable limits.
*/
if (polyPtr->splineSteps < 1) {
polyPtr->splineSteps = 1;
} else if (polyPtr->splineSteps > 100) {
polyPtr->splineSteps = 100;
}
ComputePolygonBbox(canvas, polyPtr);
return TCL_OK;
}
/*
*--------------------------------------------------------------
*
* DeletePolygon --
*
* This procedure is called to clean up the data structure
* associated with a polygon item.
*
* Results:
* None.
*
* Side effects:
* Resources associated with itemPtr are released.
*
*--------------------------------------------------------------
*/
static void
DeletePolygon(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. */
{
PolygonItem *polyPtr = (PolygonItem *) itemPtr;
if (polyPtr->coordPtr != NULL) {
ckfree((char *) polyPtr->coordPtr);
}
if (polyPtr->fillColor != NULL) {
Tk_FreeColor(polyPtr->fillColor);
}
if (polyPtr->fillStipple != None) {
Tk_FreeBitmap(display, polyPtr->fillStipple);
}
if (polyPtr->outlineColor != NULL) {
Tk_FreeColor(polyPtr->outlineColor);
}
if (polyPtr->outlineGC != None) {
Tk_FreeGC(display, polyPtr->outlineGC);
}
if (polyPtr->fillGC != None) {
Tk_FreeGC(display, polyPtr->fillGC);
}
}
/*
*--------------------------------------------------------------
*
* ComputePolygonBbox --
*
* This procedure is invoked to compute the bounding box of
* all the pixels that may be drawn as part of a polygon.
*
* Results:
* None.
*
* Side effects:
* The fields x1, y1, x2, and y2 are updated in the header
* for itemPtr.
*
*--------------------------------------------------------------
*/
static void
ComputePolygonBbox(canvas, polyPtr)
Tk_Canvas canvas; /* Canvas that contains item. */
PolygonItem *polyPtr; /* Item whose bbox is to be
* recomputed. */
{
double *coordPtr;
int i;
coordPtr = polyPtr->coordPtr;
polyPtr->header.x1 = polyPtr->header.x2 = (int) *coordPtr;
polyPtr->header.y1 = polyPtr->header.y2 = (int) coordPtr[1];
for (i = 1, coordPtr = polyPtr->coordPtr+2; i < polyPtr->numPoints;
i++, coordPtr += 2) {
TkIncludePoint((Tk_Item *) polyPtr, coordPtr);
}
/*
* Expand bounding box in all directions to account for the outline,
* which can stick out beyond the polygon. Add one extra pixel of
* fudge, just in case X rounds differently than we do.
*/
i = (polyPtr->width+1)/2 + 1;
polyPtr->header.x1 -= i;
polyPtr->header.x2 += i;
polyPtr->header.y1 -= i;
polyPtr->header.y2 += i;
}
/*
*--------------------------------------------------------------
*
* TkFillPolygon --
*
* This procedure is invoked to convert a polygon to screen
* coordinates and display it using a particular GC.
*
* Results:
* None.
*
* Side effects:
* ItemPtr is drawn in drawable using the transformation
* information in canvas.
*
*--------------------------------------------------------------
*/
void
TkFillPolygon(canvas, coordPtr, numPoints, display, drawable, gc, outlineGC)
Tk_Canvas canvas; /* Canvas whose coordinate system
* is to be used for drawing. */
double *coordPtr; /* Array of coordinates for polygon:
* x1, y1, x2, y2, .... */
int numPoints; /* Twice this many coordinates are
* present at *coordPtr. */
Display *display; /* Display on which to draw polygon. */
Drawable drawable; /* Pixmap or window in which to draw
* polygon. */
GC gc; /* Graphics context for drawing. */
GC outlineGC; /* If not None, use this to draw an
* outline around the polygon after
* filling it. */
{
XPoint staticPoints[MAX_STATIC_POINTS];
XPoint *pointPtr;
XPoint *pPtr;
int i;
/*
* Build up an array of points in screen coordinates. Use a
* static array unless the polygon has an enormous number of points;
* in this case, dynamically allocate an array.
*/
if (numPoints <= MAX_STATIC_POINTS) {
pointPtr = staticPoints;
} else {
pointPtr = (XPoint *) ckalloc((unsigned) (numPoints * sizeof(XPoint)));
}
for (i = 0, pPtr = pointPtr; i < numPoints; i += 1, coordPtr += 2, pPtr++) {
Tk_CanvasDrawableCoords(canvas, coordPtr[0], coordPtr[1], &pPtr->x,
&pPtr->y);
}
/*
* Display polygon, then free up polygon storage if it was dynamically
* allocated.
*/
if (gc != None) {
XFillPolygon(display, drawable, gc, pointPtr, numPoints, Complex,
CoordModeOrigin);
}
if (outlineGC != None) {
XDrawLines(display, drawable, outlineGC, pointPtr,
numPoints, CoordModeOrigin);
}
if (pointPtr != staticPoints) {
ckfree((char *) pointPtr);
}
}
/*
*--------------------------------------------------------------
*
* DisplayPolygon --
*
* This procedure is invoked to draw a polygon item in a given
* drawable.
*
* Results:
* None.
*
* Side effects:
* ItemPtr is drawn in drawable using the transformation
* information in canvas.
*
*--------------------------------------------------------------
*/
static void
DisplayPolygon(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). */
{
PolygonItem *polyPtr = (PolygonItem *) itemPtr;
if ((polyPtr->fillGC == None) && (polyPtr->outlineGC == None)) {
return;
}
/*
* 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 ((polyPtr->fillStipple != None) && (polyPtr->fillGC != None)) {
Tk_CanvasSetStippleOrigin(canvas, polyPtr->fillGC);
}
if (!polyPtr->smooth) {
TkFillPolygon(canvas, polyPtr->coordPtr, polyPtr->numPoints,
display, drawable, polyPtr->fillGC, polyPtr->outlineGC);
} else {
int numPoints;
XPoint staticPoints[MAX_STATIC_POINTS];
XPoint *pointPtr;
/*
* This is a smoothed polygon. Display using a set of generated
* spline points rather than the original points.
*/
numPoints = 1 + polyPtr->numPoints*polyPtr->splineSteps;
if (numPoints <= MAX_STATIC_POINTS) {
pointPtr = staticPoints;
} else {
pointPtr = (XPoint *) ckalloc((unsigned)
(numPoints * sizeof(XPoint)));
}
numPoints = TkMakeBezierCurve(canvas, polyPtr->coordPtr,
polyPtr->numPoints, polyPtr->splineSteps, pointPtr,
(double *) NULL);
if (polyPtr->fillGC != None) {
XFillPolygon(display, drawable, polyPtr->fillGC, pointPtr,
numPoints, Complex, CoordModeOrigin);
}
if (polyPtr->outlineGC != None) {
XDrawLines(display, drawable, polyPtr->outlineGC, pointPtr,
numPoints, CoordModeOrigin);
}
if (pointPtr != staticPoints) {
ckfree((char *) pointPtr);
}
}
if ((polyPtr->fillStipple != None) && (polyPtr->fillGC != None)) {
XSetTSOrigin(display, polyPtr->fillGC, 0, 0);
}
}
/*
*--------------------------------------------------------------
*
* PolygonToPoint --
*
* Computes the distance from a given point to a given
* polygon, 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 polygon. If the
* point isn't inside the polygon then the return value is the
* distance from the point to the polygon.
*
* Side effects:
* None.
*
*--------------------------------------------------------------
*/
/* ARGSUSED */
static double
PolygonToPoint(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. */
{
PolygonItem *polyPtr = (PolygonItem *) itemPtr;
double *coordPtr, distance;
double staticSpace[2*MAX_STATIC_POINTS];
int numPoints;
if (!polyPtr->smooth) {
distance = TkPolygonToPoint(polyPtr->coordPtr, polyPtr->numPoints,
pointPtr);
} else {
/*
* Smoothed polygon. Generate a new set of points and use them
* for comparison.
*/
numPoints = 1 + polyPtr->numPoints*polyPtr->splineSteps;
if (numPoints <= MAX_STATIC_POINTS) {
coordPtr = staticSpace;
} else {
coordPtr = (double *) ckalloc((unsigned)
(2*numPoints*sizeof(double)));
}
numPoints = TkMakeBezierCurve(canvas, polyPtr->coordPtr,
polyPtr->numPoints, polyPtr->splineSteps, (XPoint *) NULL,
coordPtr);
distance = TkPolygonToPoint(coordPtr, numPoints, pointPtr);
if (coordPtr != staticSpace) {
ckfree((char *) coordPtr);
}
}
if (polyPtr->outlineColor != NULL) {
distance -= polyPtr->width/2.0;
if (distance < 0) {
distance = 0;
}
}
return distance;
}
/*
*--------------------------------------------------------------
*
* PolygonToArea --
*
* 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
* given by rectPtr, 0 if it overlaps, and 1 if it is entirely
* inside the given area.
*
* Side effects:
* None.
*
*--------------------------------------------------------------
*/
/* ARGSUSED */
static int
PolygonToArea(canvas, itemPtr, rectPtr)
Tk_Canvas canvas; /* Canvas containing item. */
Tk_Item *itemPtr; /* Item to check against polygon. */
double *rectPtr; /* Pointer to array of four coordinates
* (x1, y1, x2, y2) describing rectangular
* area. */
{
PolygonItem *polyPtr = (PolygonItem *) itemPtr;
double *coordPtr, rect2[4], halfWidth;
double staticSpace[2*MAX_STATIC_POINTS];
int numPoints, result;
/*
* Handle smoothed polygons by generating an expanded set of points
* against which to do the check.
*/
if (polyPtr->smooth) {
numPoints = 1 + polyPtr->numPoints*polyPtr->splineSteps;
if (numPoints <= MAX_STATIC_POINTS) {
coordPtr = staticSpace;
} else {
coordPtr = (double *) ckalloc((unsigned)
(2*numPoints*sizeof(double)));
}
numPoints = TkMakeBezierCurve(canvas, polyPtr->coordPtr,
polyPtr->numPoints, polyPtr->splineSteps, (XPoint *) NULL,
coordPtr);
} else {
numPoints = polyPtr->numPoints;
coordPtr = polyPtr->coordPtr;
}
if (polyPtr->width <= 1) {
/*
* The outline of the polygon doesn't stick out, so we can
* do a simple check.
*/
result = TkPolygonToArea(coordPtr, numPoints, rectPtr);
} else {
/*
* The polygon has a wide outline, so the check is more complicated.
* First, check the line segments to see if they overlap the area.
*/
result = TkThickPolyLineToArea(coordPtr, numPoints,
(double) polyPtr->width, CapRound, JoinRound, rectPtr);
if (result >= 0) {
goto done;
}
/*
* There is no overlap between the polygon's outline and the
* rectangle. This means either the rectangle is entirely outside
* the polygon or entirely inside. To tell the difference,
* see whether the polygon (with 0 outline width) overlaps the
* rectangle bloated by half the outline width.
*/
halfWidth = polyPtr->width/2.0;
rect2[0] = rectPtr[0] - halfWidth;
rect2[1] = rectPtr[1] - halfWidth;
rect2[2] = rectPtr[2] + halfWidth;
rect2[3] = rectPtr[3] + halfWidth;
if (TkPolygonToArea(coordPtr, numPoints, rect2) == -1) {
result = -1;
} else {
result = 0;
}
}
done:
if ((coordPtr != staticSpace) && (coordPtr != polyPtr->coordPtr)) {
ckfree((char *) coordPtr);
}
return result;
}
/*
*--------------------------------------------------------------
*
* ScalePolygon --
*
* This procedure is invoked to rescale a polygon item.
*
* Results:
* None.
*
* Side effects:
* The polygon 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
ScalePolygon(canvas, itemPtr, originX, originY, scaleX, scaleY)
Tk_Canvas canvas; /* Canvas containing polygon. */
Tk_Item *itemPtr; /* Polygon 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. */
{
PolygonItem *polyPtr = (PolygonItem *) itemPtr;
double *coordPtr;
int i;
for (i = 0, coordPtr = polyPtr->coordPtr; i < polyPtr->numPoints;
i++, coordPtr += 2) {
*coordPtr = originX + scaleX*(*coordPtr - originX);
coordPtr[1] = originY + scaleY*(coordPtr[1] - originY);
}
ComputePolygonBbox(canvas, polyPtr);
}
/*
*--------------------------------------------------------------
*
* TranslatePolygon --
*
* This procedure is called to move a polygon by a given
* amount.
*
* Results:
* None.
*
* Side effects:
* The position of the polygon is offset by (xDelta, yDelta),
* and the bounding box is updated in the generic part of the
* item structure.
*
*--------------------------------------------------------------
*/
static void
TranslatePolygon(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. */
{
PolygonItem *polyPtr = (PolygonItem *) itemPtr;
double *coordPtr;
int i;
for (i = 0, coordPtr = polyPtr->coordPtr; i < polyPtr->numPoints;
i++, coordPtr += 2) {
*coordPtr += deltaX;
coordPtr[1] += deltaY;
}
ComputePolygonBbox(canvas, polyPtr);
}
/*
*--------------------------------------------------------------
*
* PolygonToPostscript --
*
* This procedure is called to generate Postscript for
* polygon 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
PolygonToPostscript(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. */
{
char string[100];
PolygonItem *polyPtr = (PolygonItem *) itemPtr;
/*
* Fill the area of the polygon.
*/
if (polyPtr->fillColor != NULL) {
if (!polyPtr->smooth) {
Tk_CanvasPsPath(interp, canvas, polyPtr->coordPtr,
polyPtr->numPoints);
} else {
TkMakeBezierPostscript(interp, canvas, polyPtr->coordPtr,
polyPtr->numPoints);
}
if (Tk_CanvasPsColor(interp, canvas, polyPtr->fillColor) != TCL_OK) {
return TCL_ERROR;
}
if (polyPtr->fillStipple != None) {
Tcl_AppendResult(interp, "eoclip ", (char *) NULL);
if (Tk_CanvasPsStipple(interp, canvas, polyPtr->fillStipple)
!= TCL_OK) {
return TCL_ERROR;
}
if (polyPtr->outlineColor != NULL) {
Tcl_AppendResult(interp, "grestore gsave\n", (char *) NULL);
}
} else {
Tcl_AppendResult(interp, "eofill\n", (char *) NULL);
}
}
/*
* Now draw the outline, if there is one.
*/
if (polyPtr->outlineColor != NULL) {
if (!polyPtr->smooth) {
Tk_CanvasPsPath(interp, canvas, polyPtr->coordPtr,
polyPtr->numPoints);
} else {
TkMakeBezierPostscript(interp, canvas, polyPtr->coordPtr,
polyPtr->numPoints);
}
sprintf(string, "%d setlinewidth\n", polyPtr->width);
Tcl_AppendResult(interp, string,
"1 setlinecap\n1 setlinejoin\n", (char *) NULL);
if (Tk_CanvasPsColor(interp, canvas, polyPtr->outlineColor)
!= TCL_OK) {
return TCL_ERROR;
}
Tcl_AppendResult(interp, "stroke\n", (char *) NULL);
}
return TCL_OK;
}