URL https://opencores.org/ocsvn/or1k/or1k/trunk
Subversion Repositories or1k

[/] [or1k/] [tags/] [start/] [insight/] [tk/] [generic/] [tkCanvPoly.c] - Blame information for rev 1765

Details | Compare with Previous | View Log

/*
 * 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.
 *
 * RCS: @(#) $Id: tkCanvPoly.c,v 1.1.1.1 2002-01-16 10:25:51 markom Exp $
 */
 
#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,
        "0", Tk_Offset(PolygonItem, smooth), TK_CONFIG_DONT_SET_DEFAULT},
    {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_GetGCColor(tkwin, mask, &gcValues, polyPtr->outlineColor,
                              NULL);
    }
    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_GetGCColor(tkwin, mask, &gcValues, polyPtr->fillColor,
                              NULL);
    }
    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;
}
Browse

Tools

Subversion Repositories or1k

[/] [or1k/] [tags/] [start/] [insight/] [tk/] [generic/] [tkCanvPoly.c] - Blame information for rev 1765

Line No.	Rev	Author	Line
1	578	markom	`/*`
2			`* tkCanvPoly.c --`
3			`*`
4			`* This file implements polygon items for canvas widgets.`
5			`*`
6			`* Copyright (c) 1991-1994 The Regents of the University of California.`
7			`* Copyright (c) 1994-1997 Sun Microsystems, Inc.`
8			`*`
9			`* See the file "license.terms" for information on usage and redistribution`
10			`* of this file, and for a DISCLAIMER OF ALL WARRANTIES.`
11			`*`
12			`* RCS: @(#) $Id: tkCanvPoly.c,v 1.1.1.1 2002-01-16 10:25:51 markom Exp $`
13			`*/`
14
15			`#include <stdio.h>`
16			`#include "tkInt.h"`
17			`#include "tkPort.h"`
18
19			`/*`
20			`* The structure below defines the record for each polygon item.`
21			`*/`
22
23			`typedef struct PolygonItem {`
24			`Tk_Item header; /* Generic stuff that's the same for all`
25			`* types. MUST BE FIRST IN STRUCTURE. */`
26			`int numPoints; /* Number of points in polygon (always >= 3).`
27			`* Polygon is always closed. */`
28			`int pointsAllocated; /* Number of points for which space is`
29			`* allocated at coordPtr. /`
30			`double coordPtr; / Pointer to malloc-ed array containing`
31			`* x- and y-coords of all points in polygon.`
32			`* X-coords are even-valued indices, y-coords`
33			`* are corresponding odd-valued indices. */`
34			`int width; /* Width of outline. */`
35			`XColor outlineColor; / Color for outline. */`
36			`GC outlineGC; /* Graphics context for drawing outline. */`
37			`XColor fillColor; / Foreground color for polygon. */`
38			`Pixmap fillStipple; /* Stipple bitmap for filling polygon. */`
39			`GC fillGC; /* Graphics context for filling polygon. */`
40			`int smooth; /* Non-zero means draw shape smoothed (i.e.`