tkcanvline.c

linux系统下的音频通信

 *
 * Side effects:
 *	Configuration information, such as colors and stipple
 *	patterns, may be set for itemPtr.
 *
 *--------------------------------------------------------------
 */

static int
ConfigureLine(interp, canvas, itemPtr, argc, argv, flags)
    Tcl_Interp *interp;		/* Used for error reporting. */
    Tk_Canvas canvas;		/* Canvas containing itemPtr. */
    Tk_Item *itemPtr;		/* Line item to reconfigure. */
    int argc;			/* Number of elements in argv.  */
    char **argv;		/* Arguments describing things to configure. */
    int flags;			/* Flags to pass to Tk_ConfigureWidget. */
{
    LineItem *linePtr = (LineItem *) itemPtr;
    XGCValues gcValues;
    GC newGC, arrowGC;
    unsigned long mask;
    Tk_Window tkwin;

    tkwin = Tk_CanvasTkwin(canvas);
    if (Tk_ConfigureWidget(interp, tkwin, configSpecs, argc, argv,
	    (char *) linePtr, flags) != TCL_OK) {
	return TCL_ERROR;
    }

    /*
     * A few of the options require additional processing, such as
     * graphics contexts.
     */

    if (linePtr->fg == NULL) {
	newGC = arrowGC = None;
    } else {
	gcValues.foreground = linePtr->fg->pixel;
	gcValues.join_style = linePtr->joinStyle;
	if (linePtr->width < 0) {
	    linePtr->width = 1;
	}
	gcValues.line_width = linePtr->width;
	mask = GCForeground|GCJoinStyle|GCLineWidth;
	if (linePtr->fillStipple != None) {
	    gcValues.stipple = linePtr->fillStipple;
	    gcValues.fill_style = FillStippled;
	    mask |= GCStipple|GCFillStyle;
	}
	if (linePtr->arrow == noneUid) {
	    gcValues.cap_style = linePtr->capStyle;
	    mask |= GCCapStyle;
	}
	newGC = Tk_GetGC(tkwin, mask, &gcValues);
	gcValues.line_width = 0;
	arrowGC = Tk_GetGC(tkwin, mask, &gcValues);
    }
    if (linePtr->gc != None) {
	Tk_FreeGC(Tk_Display(tkwin), linePtr->gc);
    }
    if (linePtr->arrowGC != None) {
	Tk_FreeGC(Tk_Display(tkwin), linePtr->arrowGC);
    }
    linePtr->gc = newGC;
    linePtr->arrowGC = arrowGC;

    /*
     * Keep spline parameters within reasonable limits.
     */

    if (linePtr->splineSteps < 1) {
	linePtr->splineSteps = 1;
    } else if (linePtr->splineSteps > 100) {
	linePtr->splineSteps = 100;
    }

    /*
     * Setup arrowheads, if needed.  If arrowheads are turned off,
     * restore the line's endpoints (they were shortened when the
     * arrowheads were added).
     */

    if ((linePtr->firstArrowPtr != NULL) && (linePtr->arrow != firstUid)
	    && (linePtr->arrow != bothUid)) {
	linePtr->coordPtr[0] = linePtr->firstArrowPtr[0];
	linePtr->coordPtr[1] = linePtr->firstArrowPtr[1];
	ckfree((char *) linePtr->firstArrowPtr);
	linePtr->firstArrowPtr = NULL;
    }
    if ((linePtr->lastArrowPtr != NULL) && (linePtr->arrow != lastUid)
	    && (linePtr->arrow != bothUid)) {
	int i;

	i = 2*(linePtr->numPoints-1);
	linePtr->coordPtr[i] = linePtr->lastArrowPtr[0];
	linePtr->coordPtr[i+1] = linePtr->lastArrowPtr[1];
	ckfree((char *) linePtr->lastArrowPtr);
	linePtr->lastArrowPtr = NULL;
    }
    if (linePtr->arrow != noneUid) {
	if ((linePtr->arrow != firstUid) && (linePtr->arrow != lastUid)
		&& (linePtr->arrow != bothUid)) {
	    Tcl_AppendResult(interp, "bad arrow spec \"",
		    linePtr->arrow, "\": must be none, first, last, or both",
		    (char *) NULL);
	    linePtr->arrow = noneUid;
	    return TCL_ERROR;
	}
	ConfigureArrows(canvas, linePtr);
    }

    /*
     * Recompute bounding box for line.
     */

    ComputeLineBbox(canvas, linePtr);

    return TCL_OK;
}

/*
 *--------------------------------------------------------------
 *
 * DeleteLine --
 *
 *	This procedure is called to clean up the data structure
 *	associated with a line item.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Resources associated with itemPtr are released.
 *
 *--------------------------------------------------------------
 */

static void
DeleteLine(canvas, itemPtr, display)
    Tk_Canvas canvas;			/* Info about overall canvas widget. */
    Tk_Item *itemPtr;			/* Item that is being deleted. */
    Display *display;			/* Display containing window for
					 * canvas. */
{
    LineItem *linePtr = (LineItem *) itemPtr;

    if (linePtr->coordPtr != NULL) {
	ckfree((char *) linePtr->coordPtr);
    }
    if (linePtr->fg != NULL) {
	Tk_FreeColor(linePtr->fg);
    }
    if (linePtr->fillStipple != None) {
	Tk_FreeBitmap(display, linePtr->fillStipple);
    }
    if (linePtr->gc != None) {
	Tk_FreeGC(display, linePtr->gc);
    }
    if (linePtr->arrowGC != None) {
	Tk_FreeGC(display, linePtr->arrowGC);
    }
    if (linePtr->firstArrowPtr != NULL) {
	ckfree((char *) linePtr->firstArrowPtr);
    }
    if (linePtr->lastArrowPtr != NULL) {
	ckfree((char *) linePtr->lastArrowPtr);
    }
}

/*
 *--------------------------------------------------------------
 *
 * ComputeLineBbox --
 *
 *	This procedure is invoked to compute the bounding box of
 *	all the pixels that may be drawn as part of a line.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The fields x1, y1, x2, and y2 are updated in the header
 *	for itemPtr.
 *
 *--------------------------------------------------------------
 */

static void
ComputeLineBbox(canvas, linePtr)
    Tk_Canvas canvas;			/* Canvas that contains item. */
    LineItem *linePtr;			/* Item whose bbos is to be
					 * recomputed. */
{
    double *coordPtr;
    int i, width;

    coordPtr = linePtr->coordPtr;
    linePtr->header.x1 = linePtr->header.x2 = (int) *coordPtr;
    linePtr->header.y1 = linePtr->header.y2 = (int) coordPtr[1];

    /*
     * Compute the bounding box of all the points in the line,
     * then expand in all directions by the line's width to take
     * care of butting or rounded corners and projecting or
     * rounded caps.  This expansion is an overestimate (worst-case
     * is square root of two over two) but it's simple.  Don't do
     * anything special for curves.  This causes an additional
     * overestimate in the bounding box, but is faster.
     */

    for (i = 1, coordPtr = linePtr->coordPtr+2; i < linePtr->numPoints;
	    i++, coordPtr += 2) {
	TkIncludePoint((Tk_Item *) linePtr, coordPtr);
    }
    width = linePtr->width;
    if (width < 1) {
	width = 1;
    }
    linePtr->header.x1 -= width;
    linePtr->header.x2 += width;
    linePtr->header.y1 -= width;
    linePtr->header.y2 += width;

    /*
     * For mitered lines, make a second pass through all the points.
     * Compute the locations of the two miter vertex points and add
     * those into the bounding box.
     */

    if (linePtr->joinStyle == JoinMiter) {
	for (i = linePtr->numPoints, coordPtr = linePtr->coordPtr; i >= 3;
		i--, coordPtr += 2) {
	    double miter[4];
	    int j;
    
	    if (TkGetMiterPoints(coordPtr, coordPtr+2, coordPtr+4,
		    (double) width, miter, miter+2)) {
		for (j = 0; j < 4; j += 2) {
		    TkIncludePoint((Tk_Item *) linePtr, miter+j);
		}
	    }
	}
    }

    /*
     * Add in the sizes of arrowheads, if any.
     */

    if (linePtr->arrow != noneUid) {
	if (linePtr->arrow != lastUid) {
	    for (i = 0, coordPtr = linePtr->firstArrowPtr; i < PTS_IN_ARROW;
		    i++, coordPtr += 2) {
		TkIncludePoint((Tk_Item *) linePtr, coordPtr);
	    }
	}
	if (linePtr->arrow != firstUid) {
	    for (i = 0, coordPtr = linePtr->lastArrowPtr; i < PTS_IN_ARROW;
		    i++, coordPtr += 2) {
		TkIncludePoint((Tk_Item *) linePtr, coordPtr);
	    }
	}
    }

    /*
     * Add one more pixel of fudge factor just to be safe (e.g.
     * X may round differently than we do).
     */

    linePtr->header.x1 -= 1;
    linePtr->header.x2 += 1;
    linePtr->header.y1 -= 1;
    linePtr->header.y2 += 1;
}

/*
 *--------------------------------------------------------------
 *
 * DisplayLine --
 *
 *	This procedure is invoked to draw a line item in a given
 *	drawable.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	ItemPtr is drawn in drawable using the transformation
 *	information in canvas.
 *
 *--------------------------------------------------------------
 */

static void
DisplayLine(canvas, itemPtr, display, drawable, x, y, width, height)
    Tk_Canvas canvas;			/* Canvas that contains item. */
    Tk_Item *itemPtr;			/* Item to be displayed. */
    Display *display;			/* Display on which to draw item. */
    Drawable drawable;			/* Pixmap or window in which to draw
					 * item. */
    int x, y, width, height;		/* Describes region of canvas that
					 * must be redisplayed (not used). */
{
    LineItem *linePtr = (LineItem *) itemPtr;
    XPoint staticPoints[MAX_STATIC_POINTS];
    XPoint *pointPtr;
    XPoint *pPtr;
    double *coordPtr;
    int i, numPoints;

    if (linePtr->gc == None) {
	return;
    }

    /*
     * Build up an array of points in screen coordinates.  Use a
     * static array unless the line has an enormous number of points;
     * in this case, dynamically allocate an array.  For smoothed lines,
     * generate the curve points on each redisplay.
     */

    if ((linePtr->smooth) && (linePtr->numPoints > 2)) {
	numPoints = 1 + linePtr->numPoints*linePtr->splineSteps;
    } else {
	numPoints = linePtr->numPoints;
    }

    if (numPoints <= MAX_STATIC_POINTS) {
	pointPtr = staticPoints;
    } else {
	pointPtr = (XPoint *) ckalloc((unsigned) (numPoints * sizeof(XPoint)));
    }

    if ((linePtr->smooth) && (linePtr->numPoints > 2)) {
	numPoints = TkMakeBezierCurve(canvas, linePtr->coordPtr,
		linePtr->numPoints, linePtr->splineSteps, pointPtr,
		(double *) NULL);
    } else {
	for (i = 0, coordPtr = linePtr->coordPtr, pPtr = pointPtr;
		i < linePtr->numPoints;  i += 1, coordPtr += 2, pPtr++) {
	    Tk_CanvasDrawableCoords(canvas, coordPtr[0], coordPtr[1],
		    &pPtr->x, &pPtr->y);
	}
    }

    /*
     * Display line, the free up line storage if it was dynamically
     * allocated.  If we're stippling, then modify the stipple offset
     * in the GC.  Be sure to reset the offset when done, since the
     * GC is supposed to be read-only.
     */

    if (linePtr->fillStipple != None) {
	Tk_CanvasSetStippleOrigin(canvas, linePtr->gc);
	Tk_CanvasSetStippleOrigin(canvas, linePtr->arrowGC);
    }
    XDrawLines(display, drawable, linePtr->gc, pointPtr, numPoints,
	    CoordModeOrigin);
    if (pointPtr != staticPoints) {
	ckfree((char *) pointPtr);
    }

    /*
     * Display arrowheads, if they are wanted.
     */

    if (linePtr->firstArrowPtr != NULL) {
	TkFillPolygon(canvas, linePtr->firstArrowPtr, PTS_IN_ARROW,
		display, drawable, linePtr->gc, NULL);
    }
    if (linePtr->lastArrowPtr != NULL) {
	TkFillPolygon(canvas, linePtr->lastArrowPtr, PTS_IN_ARROW,
		display, drawable, linePtr->gc, NULL);
    }
    if (linePtr->fillStipple != None) {
	XSetTSOrigin(display, linePtr->gc, 0, 0);
	XSetTSOrigin(display, linePtr->arrowGC, 0, 0);
    }
}

/*
 *--------------------------------------------------------------
 *
 * LineToPoint --
 *
 *	Computes the distance from a given point to a given
 *	line, in canvas units.
 *
 * Results:
 *	The return value is 0 if the point whose x and y coordinates
 *	are pointPtr[0] and pointPtr[1] is inside the line.  If the
 *	point isn't inside the line then the return value is the
 *	distance from the point to the line.
 *
 * Side effects:
 *	None.
 *
 *--------------------------------------------------------------
 */

	/* ARGSUSED */
static double
LineToPoint(canvas, itemPtr, pointPtr)
    Tk_Canvas canvas;		/* Canvas containing item. */
    Tk_Item *itemPtr;		/* Item to check against point. */
    double *pointPtr;		/* Pointer to x and y coordinates. */
{