tkcanvarc.c

linux系统下的音频通信

	angle = atan2(boxWidth*sin1, boxHeight*cos1);
    }
    corner1[0] = arcPtr->center1[0] + cos(angle)*halfWidth;
    corner1[1] = arcPtr->center1[1] + sin(angle)*halfWidth;
    if (((boxWidth*sin2) == 0.0) && ((boxHeight*cos2) == 0.0)) {
	angle = 0.0;
    } else {
	angle = atan2(boxWidth*sin2, boxHeight*cos2);
    }
    corner2[0] = arcPtr->center2[0] + cos(angle)*halfWidth;
    corner2[1] = arcPtr->center2[1] + sin(angle)*halfWidth;

    /*
     * For a chord outline, generate a six-sided polygon with three
     * points for each end of the chord.  The first and third points
     * for each end are butt points generated on either side of the
     * center point.  The second point is the corner point.
     */

    if (arcPtr->style == chordUid) {
	outlinePtr[0] = outlinePtr[12] = corner1[0];
	outlinePtr[1] = outlinePtr[13] = corner1[1];
	TkGetButtPoints(arcPtr->center2, arcPtr->center1,
		(double) arcPtr->width, 0, outlinePtr+10, outlinePtr+2);
	outlinePtr[4] = arcPtr->center2[0] + outlinePtr[2]
		- arcPtr->center1[0];
	outlinePtr[5] = arcPtr->center2[1] + outlinePtr[3]
		- arcPtr->center1[1];
	outlinePtr[6] = corner2[0];
	outlinePtr[7] = corner2[1];
	outlinePtr[8] = arcPtr->center2[0] + outlinePtr[10]
		- arcPtr->center1[0];
	outlinePtr[9] = arcPtr->center2[1] + outlinePtr[11]
		- arcPtr->center1[1];
    } else if (arcPtr->style == pieSliceUid) {
	/*
	 * For pie slices, generate two polygons, one for each side
	 * of the pie slice.  The first arm has a shape like this,
	 * where the center of the oval is X, arcPtr->center1 is at Y, and
	 * corner1 is at Z:
	 *
	 *	 _____________________
	 *	|		      \
	 *	|		       \
	 *	X		     Y  Z
	 *	|		       /
	 *	|_____________________/
	 *
	 */

	TkGetButtPoints(arcPtr->center1, vertex, (double) arcPtr->width, 0,
		outlinePtr, outlinePtr+2);
	outlinePtr[4] = arcPtr->center1[0] + outlinePtr[2] - vertex[0];
	outlinePtr[5] = arcPtr->center1[1] + outlinePtr[3] - vertex[1];
	outlinePtr[6] = corner1[0];
	outlinePtr[7] = corner1[1];
	outlinePtr[8] = arcPtr->center1[0] + outlinePtr[0] - vertex[0];
	outlinePtr[9] = arcPtr->center1[1] + outlinePtr[1] - vertex[1];
	outlinePtr[10] = outlinePtr[0];
	outlinePtr[11] = outlinePtr[1];

	/*
	 * The second arm has a shape like this:
	 *
	 *
	 *	   ______________________
	 *	  /			  \
	 *	 /			   \
	 *	Z  Y			X  /
	 *	 \			  /
	 *	  \______________________/
	 *
	 * Similar to above X is the center of the oval/circle, Y is
	 * arcPtr->center2, and Z is corner2.  The extra jog out to the left
	 * of X is needed in or to produce a butted joint with the
	 * first arm;  the corner to the right of X is one of the
	 * first two points of the first arm, depending on extent.
	 */

	TkGetButtPoints(arcPtr->center2, vertex, (double) arcPtr->width, 0,
		outlinePtr+12, outlinePtr+16);
	if ((arcPtr->extent > 180) ||
		((arcPtr->extent < 0) && (arcPtr->extent > -180))) {
	    outlinePtr[14] = outlinePtr[0];
	    outlinePtr[15] = outlinePtr[1];
	} else {
	    outlinePtr[14] = outlinePtr[2];
	    outlinePtr[15] = outlinePtr[3];
	}
	outlinePtr[18] = arcPtr->center2[0] + outlinePtr[16] - vertex[0];
	outlinePtr[19] = arcPtr->center2[1] + outlinePtr[17] - vertex[1];
	outlinePtr[20] = corner2[0];
	outlinePtr[21] = corner2[1];
	outlinePtr[22] = arcPtr->center2[0] + outlinePtr[12] - vertex[0];
	outlinePtr[23] = arcPtr->center2[1] + outlinePtr[13] - vertex[1];
	outlinePtr[24] = outlinePtr[12];
	outlinePtr[25] = outlinePtr[13];
    }
}

/*
 *--------------------------------------------------------------
 *
 * HorizLineToArc --
 *
 *	Determines whether a horizontal line segment intersects
 *	a given arc.
 *
 * Results:
 *	The return value is 1 if the given line intersects the
 *	infinitely-thin arc section defined by rx, ry, start,
 *	and extent, and 0 otherwise.  Only the perimeter of the
 *	arc is checked: interior areas (e.g. pie-slice or chord)
 *	are not checked.
 *
 * Side effects:
 *	None.
 *
 *--------------------------------------------------------------
 */

static int
HorizLineToArc(x1, x2, y, rx, ry, start, extent)
    double x1, x2;		/* X-coords of endpoints of line segment. 
				 * X1 must be <= x2. */
    double y;			/* Y-coordinate of line segment. */
    double rx, ry;		/* These x- and y-radii define an oval
				 * centered at the origin. */
    double start, extent;	/* Angles that define extent of arc, in
				 * the standard fashion for this module. */
{
    double tmp;
    double tx, ty;		/* Coordinates of intersection point in
				 * transformed coordinate system. */
    double x;

    /*
     * Compute the x-coordinate of one possible intersection point
     * between the arc and the line.  Use a transformed coordinate
     * system where the oval is a unit circle centered at the origin.
     * Then scale back to get actual x-coordinate.
     */

    ty = y/ry;
    tmp = 1 - ty*ty;
    if (tmp < 0) {
	return 0;
    }
    tx = sqrt(tmp);
    x = tx*rx;

    /*
     * Test both intersection points.
     */

    if ((x >= x1) && (x <= x2) && AngleInRange(tx, ty, start, extent)) {
	return 1;
    }
    if ((-x >= x1) && (-x <= x2) && AngleInRange(-tx, ty, start, extent)) {
	return 1;
    }
    return 0;
}

/*
 *--------------------------------------------------------------
 *
 * VertLineToArc --
 *
 *	Determines whether a vertical line segment intersects
 *	a given arc.
 *
 * Results:
 *	The return value is 1 if the given line intersects the
 *	infinitely-thin arc section defined by rx, ry, start,
 *	and extent, and 0 otherwise.  Only the perimeter of the
 *	arc is checked: interior areas (e.g. pie-slice or chord)
 *	are not checked.
 *
 * Side effects:
 *	None.
 *
 *--------------------------------------------------------------
 */

static int
VertLineToArc(x, y1, y2, rx, ry, start, extent)
    double x;			/* X-coordinate of line segment. */
    double y1, y2;		/* Y-coords of endpoints of line segment. 
				 * Y1 must be <= y2. */
    double rx, ry;		/* These x- and y-radii define an oval
				 * centered at the origin. */
    double start, extent;	/* Angles that define extent of arc, in
				 * the standard fashion for this module. */
{
    double tmp;
    double tx, ty;		/* Coordinates of intersection point in
				 * transformed coordinate system. */
    double y;

    /*
     * Compute the y-coordinate of one possible intersection point
     * between the arc and the line.  Use a transformed coordinate
     * system where the oval is a unit circle centered at the origin.
     * Then scale back to get actual y-coordinate.
     */

    tx = x/rx;
    tmp = 1 - tx*tx;
    if (tmp < 0) {
	return 0;
    }
    ty = sqrt(tmp);
    y = ty*ry;

    /*
     * Test both intersection points.
     */

    if ((y > y1) && (y < y2) && AngleInRange(tx, ty, start, extent)) {
	return 1;
    }
    if ((-y > y1) && (-y < y2) && AngleInRange(tx, -ty, start, extent)) {
	return 1;
    }
    return 0;
}

/*
 *--------------------------------------------------------------
 *
 * AngleInRange --
 *
 *	Determine whether the angle from the origin to a given
 *	point is within a given range.
 *
 * Results:
 *	The return value is 1 if the angle from (0,0) to (x,y)
 *	is in the range given by start and extent, where angles
 *	are interpreted in the standard way for ovals (meaning
 *	backwards from normal interpretation).  Otherwise the
 *	return value is 0.
 *
 * Side effects:
 *	None.
 *
 *--------------------------------------------------------------
 */

static int
AngleInRange(x, y, start, extent)
    double x, y;		/* Coordinate of point;  angle measured
				 * from origin to here, relative to x-axis. */
    double start;		/* First angle, degrees, >=0, <=360. */
    double extent;		/* Size of arc in degrees >=-360, <=360. */
{
    double diff;

    if ((x == 0.0) && (y == 0.0)) {
	return 1;
    }
    diff = -atan2(y, x);
    diff = diff*(180.0/PI) - start;
    while (diff > 360.0) {
	diff -= 360.0;
    }
    while (diff < 0.0) {
	diff += 360.0;
    }
    if (extent >= 0) {
	return diff <= extent;
    }
    return (diff-360.0) >= extent;
}

/*
 *--------------------------------------------------------------
 *
 * ArcToPostscript --
 *
 *	This procedure is called to generate Postscript for
 *	arc 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
ArcToPostscript(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. */
{
    ArcItem *arcPtr = (ArcItem *) itemPtr;
    char buffer[400];
    double y1, y2, ang1, ang2;

    y1 = Tk_CanvasPsY(canvas, arcPtr->bbox[1]);
    y2 = Tk_CanvasPsY(canvas, arcPtr->bbox[3]);
    ang1 = arcPtr->start;
    ang2 = ang1 + arcPtr->extent;
    if (ang2 < ang1) {
	ang1 = ang2;
	ang2 = arcPtr->start;
    }

    /*
     * If the arc is filled, output Postscript for the interior region
     * of the arc.
     */

    if (arcPtr->fillGC != None) {
	sprintf(buffer, "matrix currentmatrix\n%.15g %.15g translate %.15g %.15g scale\n",
		(arcPtr->bbox[0] + arcPtr->bbox[2])/2, (y1 + y2)/2,
		(arcPtr->bbox[2] - arcPtr->bbox[0])/2, (y1 - y2)/2);
	Tcl_AppendResult(interp, buffer, (char *) NULL);
	if (arcPtr->style == chordUid) {
	    sprintf(buffer, "0 0 1 %.15g %.15g arc closepath\nsetmatrix\n",
		    ang1, ang2);
	} else {
	    sprintf(buffer,
		    "0 0 moveto 0 0 1 %.15g %.15g arc closepath\nsetmatrix\n",
		    ang1, ang2);
	}
	Tcl_AppendResult(interp, buffer, (char *) NULL);
	if (Tk_CanvasPsColor(interp, canvas, arcPtr->fillColor) != TCL_OK) {
	    return TCL_ERROR;
	};
	if (arcPtr->fillStipple != None) {
	    Tcl_AppendResult(interp, "clip ", (char *) NULL);
	    if (Tk_CanvasPsStipple(interp, canvas, arcPtr->fillStipple)
		    != TCL_OK) {
		return TCL_ERROR;
	    }
	    if (arcPtr->outlineGC != None) {
		Tcl_AppendResult(interp, "grestore gsave\n", (char *) NULL);
	    }
	} else {
	    Tcl_AppendResult(interp, "fill\n", (char *) NULL);
	}
    }

    /*
     * If there's an outline for the arc, draw it.
     */

    if (arcPtr->outlineGC != None) {
	sprintf(buffer, "matrix currentmatrix\n%.15g %.15g translate %.15g %.15g scale\n",
		(arcPtr->bbox[0] + arcPtr->bbox[2])/2, (y1 + y2)/2,
		(arcPtr->bbox[2] - arcPtr->bbox[0])/2, (y1 - y2)/2);
	Tcl_AppendResult(interp, buffer, (char *) NULL);
	sprintf(buffer, "0 0 1 %.15g %.15g arc\nsetmatrix\n", ang1, ang2);
	Tcl_AppendResult(interp, buffer, (char *) NULL);
	sprintf(buffer, "%d setlinewidth\n0 setlinecap\n", arcPtr->width);
	Tcl_AppendResult(interp, buffer, (char *) NULL);
	if (Tk_CanvasPsColor(interp, canvas, arcPtr->outlineColor)
		!= TCL_OK) {
	    return TCL_ERROR;
	}
	if (arcPtr->outlineStipple != None) {
	    Tcl_AppendResult(interp, "StrokeClip ", (char *) NULL);
	    if (Tk_CanvasPsStipple(interp, canvas,
		    arcPtr->outlineStipple) != TCL_OK) {
		return TCL_ERROR;
	    }
	} else {
	    Tcl_AppendResult(interp, "stroke\n", (char *) NULL);
	}
	if (arcPtr->style != arcUid) {
	    Tcl_AppendResult(interp, "grestore gsave\n", (char *) NULL);
	    if (arcPtr->style == chordUid) {
		Tk_CanvasPsPath(interp, canvas, arcPtr->outlinePtr,
			CHORD_OUTLINE_PTS);
	    } else {
		Tk_CanvasPsPath(interp, canvas, arcPtr->outlinePtr,
			PIE_OUTLINE1_PTS);
		if (Tk_CanvasPsColor(interp, canvas, arcPtr->outlineColor)
			!= TCL_OK) {
		    return TCL_ERROR;
		}
		if (arcPtr->outlineStipple != None) {
		    Tcl_AppendResult(interp, "clip ", (char *) NULL);
		    if (Tk_CanvasPsStipple(interp, canvas,
			    arcPtr->outlineStipple) != TCL_OK) {
			return TCL_ERROR;
		    }
		} else {
		    Tcl_AppendResult(interp, "fill\n", (char *) NULL);
		}
		Tcl_AppendResult(interp, "grestore gsave\n", (char *) NULL);
		Tk_CanvasPsPath(interp, canvas,
			arcPtr->outlinePtr + 2*PIE_OUTLINE1_PTS,
			PIE_OUTLINE2_PTS);
	    }
	    if (Tk_CanvasPsColor(interp, canvas, arcPtr->outlineColor)
		    != TCL_OK) {
		return TCL_ERROR;
	    }
	    if (arcPtr->outlineStipple != None) {
		Tcl_AppendResult(interp, "clip ", (char *) NULL);
		if (Tk_CanvasPsStipple(interp, canvas,
			arcPtr->outlineStipple) != TCL_OK) {
		    return TCL_ERROR;
		}
	    } else {
		Tcl_AppendResult(interp, "fill\n", (char *) NULL);
	    }
	}
    }

    return TCL_OK;
}