tkcanvpoly.c

linux系统下的音频通信

    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;
}