/*
* tkCanvArc.c --
*
* This file implements arc items for canvas widgets.
*
* Copyright (c) 1992-1994 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.
*/
#include "tkInt.h"
#include "tkCanvas.h"
#include "default.h"
/*
* The structure below defines the record for each arc item.
*/
typedef enum {
PIESLICE_STYLE, CHORD_STYLE, ARC_STYLE
} Style;
typedef struct ArcItem {
Tk_Item header; /* Generic stuff that's the same for all
* types. MUST BE FIRST IN STRUCTURE. */
Tk_Outline outline; /* Outline structure */
double bbox[4]; /* Coordinates (x1, y1, x2, y2) of bounding
* box for oval of which arc is a piece. */
double start; /* Angle at which arc begins, in degrees
* between 0 and 360. */
double extent; /* Extent of arc (angular distance from start
* to end of arc) in degrees between -360 and
* 360. */
double *outlinePtr; /* Points to (x,y) coordinates for points that
* define one or two closed polygons
* representing the portion of the outline
* that isn't part of the arc (the V-shape for
* a pie slice or a line-like segment for a
* chord). Malloc'ed. */
int numOutlinePoints; /* Number of points at outlinePtr. Zero means
* no space allocated. */
Tk_TSOffset tsoffset;
XColor *fillColor; /* Color for filling arc (used for drawing
* outline too when style is "arc"). NULL
* means don't fill arc. */
XColor *activeFillColor; /* Color for filling arc (used for drawing
* outline too when style is "arc" and state
* is "active"). NULL means use fillColor. */
XColor *disabledFillColor; /* Color for filling arc (used for drawing
* outline too when style is "arc" and state
* is "disabled". NULL means use fillColor */
Pixmap fillStipple; /* Stipple bitmap for filling item. */
Pixmap activeFillStipple; /* Stipple bitmap for filling item if state is
* active. */
Pixmap disabledFillStipple; /* Stipple bitmap for filling item if state is
* disabled. */
Style style; /* How to draw arc: arc, chord, or
* pieslice. */
GC fillGC; /* Graphics context for filling item. */
double center1[2]; /* Coordinates of center of arc outline at
* start (see ComputeArcOutline). */
double center2[2]; /* Coordinates of center of arc outline at
* start+extent (see ComputeArcOutline). */
} ArcItem;
/*
* The definitions below define the sizes of the polygons used to display
* outline information for various styles of arcs:
*/
#define CHORD_OUTLINE_PTS 7
#define PIE_OUTLINE1_PTS 6
#define PIE_OUTLINE2_PTS 7
/*
* Information used for parsing configuration specs:
*/
static int StyleParseProc(ClientData clientData, Tcl_Interp *interp,
Tk_Window tkwin, const char *value,
char *widgRec, int offset);
static const char * StylePrintProc(ClientData clientData, Tk_Window tkwin,
char *widgRec, int offset, Tcl_FreeProc **freeProcPtr);
static const Tk_CustomOption stateOption = {
TkStateParseProc, TkStatePrintProc, INT2PTR(2)
};
static const Tk_CustomOption styleOption = {
StyleParseProc, StylePrintProc, NULL
};
static const Tk_CustomOption tagsOption = {
Tk_CanvasTagsParseProc, Tk_CanvasTagsPrintProc, NULL
};
static const Tk_CustomOption dashOption = {
TkCanvasDashParseProc, TkCanvasDashPrintProc, NULL
};
static const Tk_CustomOption offsetOption = {
TkOffsetParseProc, TkOffsetPrintProc, INT2PTR(TK_OFFSET_RELATIVE)
};
static const Tk_CustomOption pixelOption = {
TkPixelParseProc, TkPixelPrintProc, NULL
};
static const Tk_ConfigSpec configSpecs[] = {
{TK_CONFIG_CUSTOM, "-activedash", NULL, NULL,
NULL, Tk_Offset(ArcItem, outline.activeDash),
TK_CONFIG_NULL_OK, &dashOption},
{TK_CONFIG_COLOR, "-activefill", NULL, NULL,
NULL, Tk_Offset(ArcItem, activeFillColor), TK_CONFIG_NULL_OK, NULL},
{TK_CONFIG_COLOR, "-activeoutline", NULL, NULL,
NULL, Tk_Offset(ArcItem, outline.activeColor), TK_CONFIG_NULL_OK, NULL},
{TK_CONFIG_BITMAP, "-activeoutlinestipple", NULL, NULL,
NULL, Tk_Offset(ArcItem, outline.activeStipple), TK_CONFIG_NULL_OK, NULL},
{TK_CONFIG_BITMAP, "-activestipple", NULL, NULL,
NULL, Tk_Offset(ArcItem, activeFillStipple), TK_CONFIG_NULL_OK, NULL},
{TK_CONFIG_CUSTOM, "-activewidth", NULL, NULL,
"0.0", Tk_Offset(ArcItem, outline.activeWidth),
TK_CONFIG_DONT_SET_DEFAULT, &pixelOption},
{TK_CONFIG_CUSTOM, "-dash", NULL, NULL,
NULL, Tk_Offset(ArcItem, outline.dash),
TK_CONFIG_NULL_OK, &dashOption},
{TK_CONFIG_PIXELS, "-dashoffset", NULL, NULL,
"0", Tk_Offset(ArcItem, outline.offset), TK_CONFIG_DONT_SET_DEFAULT, NULL},
{TK_CONFIG_CUSTOM, "-disableddash", NULL, NULL,
NULL, Tk_Offset(ArcItem, outline.disabledDash),
TK_CONFIG_NULL_OK, &dashOption},
{TK_CONFIG_COLOR, "-disabledfill", NULL, NULL,
NULL, Tk_Offset(ArcItem, disabledFillColor), TK_CONFIG_NULL_OK, NULL},
{TK_CONFIG_COLOR, "-disabledoutline", NULL, NULL,
NULL, Tk_Offset(ArcItem, outline.disabledColor), TK_CONFIG_NULL_OK, NULL},
{TK_CONFIG_BITMAP, "-disabledoutlinestipple", NULL, NULL,
NULL, Tk_Offset(ArcItem, outline.disabledStipple), TK_CONFIG_NULL_OK, NULL},
{TK_CONFIG_BITMAP, "-disabledstipple", NULL, NULL,
NULL, Tk_Offset(ArcItem, disabledFillStipple), TK_CONFIG_NULL_OK, NULL},
{TK_CONFIG_CUSTOM, "-disabledwidth", NULL, NULL,
"0.0", Tk_Offset(ArcItem, outline.disabledWidth),
TK_CONFIG_DONT_SET_DEFAULT, &pixelOption},
{TK_CONFIG_DOUBLE, "-extent", NULL, NULL,
"90", Tk_Offset(ArcItem, extent), TK_CONFIG_DONT_SET_DEFAULT, NULL},
{TK_CONFIG_COLOR, "-fill", NULL, NULL,
NULL, Tk_Offset(ArcItem, fillColor), TK_CONFIG_NULL_OK, NULL},
{TK_CONFIG_CUSTOM, "-offset", NULL, NULL,
"0,0", Tk_Offset(ArcItem, tsoffset),
TK_CONFIG_DONT_SET_DEFAULT, &offsetOption},
{TK_CONFIG_COLOR, "-outline", NULL, NULL,
DEF_CANVITEM_OUTLINE, Tk_Offset(ArcItem, outline.color), TK_CONFIG_NULL_OK, NULL},
{TK_CONFIG_CUSTOM, "-outlineoffset", NULL, NULL,
"0,0", Tk_Offset(ArcItem, outline.tsoffset),
TK_CONFIG_DONT_SET_DEFAULT, &offsetOption},
{TK_CONFIG_BITMAP, "-outlinestipple", NULL, NULL,
NULL, Tk_Offset(ArcItem, outline.stipple), TK_CONFIG_NULL_OK, NULL},
{TK_CONFIG_DOUBLE, "-start", NULL, NULL,
"0", Tk_Offset(ArcItem, start), TK_CONFIG_DONT_SET_DEFAULT, NULL},
{TK_CONFIG_CUSTOM, "-state", NULL, NULL,
NULL, Tk_Offset(Tk_Item, state), TK_CONFIG_NULL_OK, &stateOption},
{TK_CONFIG_BITMAP, "-stipple", NULL, NULL,
NULL, Tk_Offset(ArcItem, fillStipple), TK_CONFIG_NULL_OK, NULL},
{TK_CONFIG_CUSTOM, "-style", NULL, NULL,
NULL, Tk_Offset(ArcItem, style), TK_CONFIG_DONT_SET_DEFAULT,
&styleOption},
{TK_CONFIG_CUSTOM, "-tags", NULL, NULL,
NULL, 0, TK_CONFIG_NULL_OK, &tagsOption},
{TK_CONFIG_CUSTOM, "-width", NULL, NULL,
"1.0", Tk_Offset(ArcItem, outline.width), TK_CONFIG_DONT_SET_DEFAULT,
&pixelOption},
{TK_CONFIG_END, NULL, NULL, NULL, NULL, 0, 0, NULL}
};
/*
* Prototypes for functions defined in this file:
*/
static void ComputeArcBbox(Tk_Canvas canvas, ArcItem *arcPtr);
static int ConfigureArc(Tcl_Interp *interp,
Tk_Canvas canvas, Tk_Item *itemPtr, int objc,
Tcl_Obj *const objv[], int flags);
static int CreateArc(Tcl_Interp *interp,
Tk_Canvas canvas, struct Tk_Item *itemPtr,
int objc, Tcl_Obj *const objv[]);
static void DeleteArc(Tk_Canvas canvas,
Tk_Item *itemPtr, Display *display);
static void DisplayArc(Tk_Canvas canvas,
Tk_Item *itemPtr, Display *display, Drawable dst,
int x, int y, int width, int height);
static int ArcCoords(Tcl_Interp *interp, Tk_Canvas canvas,
Tk_Item *itemPtr, int objc, Tcl_Obj *const objv[]);
static int ArcToArea(Tk_Canvas canvas,
Tk_Item *itemPtr, double *rectPtr);
static double ArcToPoint(Tk_Canvas canvas,
Tk_Item *itemPtr, double *coordPtr);
static int ArcToPostscript(Tcl_Interp *interp,
Tk_Canvas canvas, Tk_Item *itemPtr, int prepass);
static void ScaleArc(Tk_Canvas canvas,
Tk_Item *itemPtr, double originX, double originY,
double scaleX, double scaleY);
static void TranslateArc(Tk_Canvas canvas,
Tk_Item *itemPtr, double deltaX, double deltaY);
static int AngleInRange(double x, double y,
double start, double extent);
static void ComputeArcOutline(Tk_Canvas canvas, ArcItem *arcPtr);
static int HorizLineToArc(double x1, double x2,
double y, double rx, double ry,
double start, double extent);
static int VertLineToArc(double x, double y1,
double y2, double rx, double ry,
double start, double extent);
/*
* The structures below defines the arc item types by means of functions that
* can be invoked by generic item code.
*/
Tk_ItemType tkArcType = {
"arc", /* name */
sizeof(ArcItem), /* itemSize */
CreateArc, /* createProc */
configSpecs, /* configSpecs */
ConfigureArc, /* configureProc */
ArcCoords, /* coordProc */
DeleteArc, /* deleteProc */
DisplayArc, /* displayProc */
TK_CONFIG_OBJS, /* flags */
ArcToPoint, /* pointProc */
ArcToArea, /* areaProc */
ArcToPostscript, /* postscriptProc */
ScaleArc, /* scaleProc */
TranslateArc, /* translateProc */
NULL, /* indexProc */
NULL, /* icursorProc */
NULL, /* selectionProc */
NULL, /* insertProc */
NULL, /* dTextProc */
NULL, /* nextPtr */
NULL, 0, NULL, NULL
};
/*
*--------------------------------------------------------------
*
* CreateArc --
*
* This function is invoked to create a new arc 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 the interp's result; in this
* case itemPtr is left uninitialized, so it can be safely freed by the
* caller.
*
* Side effects:
* A new arc item is created.
*
*--------------------------------------------------------------
*/
static int
CreateArc(
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 objc, /* Number of arguments in objv. */
Tcl_Obj *const objv[]) /* Arguments describing arc. */
{
ArcItem *arcPtr = (ArcItem *) itemPtr;
int i;
if (objc == 0) {
Tcl_Panic("canvas did not pass any coords");
}
/*
* Carry out initialization that is needed in order to clean up after
* errors during the the remainder of this function.
*/
Tk_CreateOutline(&(arcPtr->outline));
arcPtr->start = 0;
arcPtr->extent = 90;
arcPtr->outlinePtr = NULL;
arcPtr->numOutlinePoints = 0;
arcPtr->tsoffset.flags = 0;
arcPtr->tsoffset.xoffset = 0;
arcPtr->tsoffset.yoffset = 0;
arcPtr->fillColor = NULL;
arcPtr->activeFillColor = NULL;
arcPtr->disabledFillColor = NULL;
arcPtr->fillStipple = None;
arcPtr->activeFillStipple = None;
arcPtr->disabledFillStipple = None;
arcPtr->style = PIESLICE_STYLE;
arcPtr->fillGC = NULL;
/*
* Process the arguments to fill in the item record.
*/
for (i = 1; i < objc; i++) {
const char *arg = Tcl_GetString(objv[i]);
if ((arg[0] == '-') && (arg[1] >= 'a') && (arg[1] <= 'z')) {
break;
}
}
if (ArcCoords(interp, canvas, itemPtr, i, objv) != TCL_OK) {
goto error;
}
if (ConfigureArc(interp, canvas, itemPtr, objc-i, objv+i, 0) == TCL_OK) {
return TCL_OK;
}
error:
DeleteArc(canvas, itemPtr, Tk_Display(Tk_CanvasTkwin(canvas)));
return TCL_ERROR;
}
/*
*--------------------------------------------------------------
*
* ArcCoords --
*
* This function is invoked to process the "coords" widget command on
* arcs. See the user documentation for details on what it does.
*
* Results:
* Returns TCL_OK or TCL_ERROR, and sets the interp's result.
*
* Side effects:
* The coordinates for the given item may be changed.
*
*--------------------------------------------------------------
*/
static int
ArcCoords(
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 objc, /* Number of coordinates supplied in objv. */
Tcl_Obj *const objv[]) /* Array of coordinates: x1, y1, x2, y2, ... */
{
ArcItem *arcPtr = (ArcItem *) itemPtr;
if (objc == 0) {
Tcl_Obj *objs[4];
objs[0] = Tcl_NewDoubleObj(arcPtr->bbox[0]);
objs[1] = Tcl_NewDoubleObj(arcPtr->bbox[1]);
objs[2] = Tcl_NewDoubleObj(arcPtr->bbox[2]);
objs[3] = Tcl_NewDoubleObj(arcPtr->bbox[3]);
Tcl_SetObjResult(interp, Tcl_NewListObj(4, objs));
} else if ((objc == 1) || (objc == 4)) {
if (objc == 1) {
if (Tcl_ListObjGetElements(interp, objv[0], &objc,
(Tcl_Obj ***) &objv) != TCL_OK) {
return TCL_ERROR;
} else if (objc != 4) {
Tcl_SetObjResult(interp, Tcl_ObjPrintf(
"wrong # coordinates: expected 4, got %d", objc));
Tcl_SetErrorCode(interp, "TK", "CANVAS", "COORDS", "ARC",
NULL);
return TCL_ERROR;
}
}
if ((Tk_CanvasGetCoordFromObj(interp, canvas, objv[0],
&arcPtr->bbox[0]) != TCL_OK)
|| (Tk_CanvasGetCoordFromObj(interp, canvas, objv[1],
&arcPtr->bbox[1]) != TCL_OK)
|| (Tk_CanvasGetCoordFromObj(interp, canvas, objv[2],
&arcPtr->bbox[2]) != TCL_OK)
|| (Tk_CanvasGetCoordFromObj(interp, canvas, objv[3],
&arcPtr->bbox[3]) != TCL_OK)) {
return TCL_ERROR;
}
ComputeArcBbox(canvas, arcPtr);
} else {
Tcl_SetObjResult(interp, Tcl_ObjPrintf(
"wrong # coordinates: expected 0 or 4, got %d", objc));
Tcl_SetErrorCode(interp, "TK", "CANVAS", "COORDS", "ARC", NULL);
return TCL_ERROR;
}
return TCL_OK;
}
/*
*--------------------------------------------------------------
*
* ConfigureArc --
*
* This function is invoked to configure various aspects of a arc item,
* such as its outline and fill colors.
*
* Results:
* A standard Tcl result code. If an error occurs, then an error message
* is left in the interp's result.
*
* Side effects:
* Configuration information, such as colors and stipple patterns, may be
* set for itemPtr.
*
*--------------------------------------------------------------
*/
static int
ConfigureArc(
Tcl_Interp *interp, /* Used for error reporting. */
Tk_Canvas canvas, /* Canvas containing itemPtr. */
Tk_Item *itemPtr, /* Arc item to reconfigure. */
int objc, /* Number of elements in objv. */
Tcl_Obj *const objv[], /* Arguments describing things to configure. */
int flags) /* Flags to pass to Tk_ConfigureWidget. */
{
ArcItem *arcPtr = (ArcItem *) itemPtr;
XGCValues gcValues;
GC newGC;
unsigned long mask;
int i;
Tk_Window tkwin;
Tk_TSOffset *tsoffset;
XColor *color;
Pixmap stipple;
Tk_State state;
tkwin = Tk_CanvasTkwin(canvas);
if (TCL_OK != Tk_ConfigureWidget(interp, tkwin, configSpecs, objc,
(const char **) objv, (char *) arcPtr, flags|TK_CONFIG_OBJS)) {
return TCL_ERROR;
}
state = itemPtr->state;
/*
* A few of the options require additional processing, such as style and
* graphics contexts.
*/
if (arcPtr->outline.activeWidth > arcPtr->outline.width ||
arcPtr->outline.activeDash.number != 0 ||
arcPtr->outline.activeColor != NULL ||
arcPtr->outline.activeStipple != None ||
arcPtr->activeFillColor != NULL ||
arcPtr->activeFillStipple != None) {
itemPtr->redraw_flags |= TK_ITEM_STATE_DEPENDANT;
} else {
itemPtr->redraw_flags &= ~TK_ITEM_STATE_DEPENDANT;
}
tsoffset = &arcPtr->outline.tsoffset;
flags = tsoffset->flags;
if (flags & TK_OFFSET_LEFT) {
tsoffset->xoffset = (int) (arcPtr->bbox[0] + 0.5);
} else if (flags & TK_OFFSET_CENTER) {
tsoffset->xoffset = (int) ((arcPtr->bbox[0]+arcPtr->bbox[2]+1)/2);
} else if (flags & TK_OFFSET_RIGHT) {
tsoffset->xoffset = (int) (arcPtr->bbox[2] + 0.5);
}
if (flags & TK_OFFSET_TOP) {
tsoffset->yoffset = (int) (arcPtr->bbox[1] + 0.5);
} else if (flags & TK_OFFSET_MIDDLE) {
tsoffset->yoffset = (int) ((arcPtr->bbox[1]+arcPtr->bbox[3]+1)/2);
} else if (flags & TK_OFFSET_BOTTOM) {
tsoffset->yoffset = (int) (arcPtr->bbox[2] + 0.5);
}
i = (int) (arcPtr->start/360.0);
arcPtr->start -= i*360.0;
if (arcPtr->start < 0) {
arcPtr->start += 360.0;
}
i = (int) (arcPtr->extent/360.0);
arcPtr->extent -= i*360.0;
mask = Tk_ConfigOutlineGC(&gcValues, canvas, itemPtr, &(arcPtr->outline));
if (mask) {
gcValues.cap_style = CapButt;
mask |= GCCapStyle;
newGC = Tk_GetGC(tkwin, mask, &gcValues);
} else {
newGC = NULL;
}
if (arcPtr->outline.gc != NULL) {
Tk_FreeGC(Tk_Display(tkwin), arcPtr->outline.gc);
}
arcPtr->outline.gc = newGC;
if(state == TK_STATE_NULL) {
state = Canvas(canvas)->canvas_state;
}
if (state==TK_STATE_HIDDEN) {
ComputeArcBbox(canvas, arcPtr);
return TCL_OK;
}
color = arcPtr->fillColor;
stipple = arcPtr->fillStipple;
if (Canvas(canvas)->currentItemPtr == itemPtr) {
if (arcPtr->activeFillColor!=NULL) {
color = arcPtr->activeFillColor;
}
if (arcPtr->activeFillStipple!=None) {
stipple = arcPtr->activeFillStipple;
}
} else if (state==TK_STATE_DISABLED) {
if (arcPtr->disabledFillColor!=NULL) {
color = arcPtr->disabledFillColor;
}
if (arcPtr->disabledFillStipple!=None) {
stipple = arcPtr->disabledFillStipple;
}
}
if (arcPtr->style == ARC_STYLE) {
newGC = NULL;
} else if (color == NULL) {
newGC = NULL;
} else {
gcValues.foreground = color->pixel;
if (arcPtr->style == CHORD_STYLE) {
gcValues.arc_mode = ArcChord;
} else {
gcValues.arc_mode = ArcPieSlice;
}
mask = GCForeground|GCArcMode;
if (stipple != None) {
gcValues.stipple = stipple;
gcValues.fill_style = FillStippled;
mask |= GCStipple|GCFillStyle;
}
newGC = Tk_GetGC(tkwin, mask, &gcValues);
}
if (arcPtr->fillGC != NULL) {
Tk_FreeGC(Tk_Display(tkwin), arcPtr->fillGC);
}
arcPtr->fillGC = newGC;
tsoffset = &arcPtr->tsoffset;
flags = tsoffset->flags;
if (flags & TK_OFFSET_LEFT) {
tsoffset->xoffset = (int) (arcPtr->bbox[0] + 0.5);
} else if (flags & TK_OFFSET_CENTER) {
tsoffset->xoffset = (int) ((arcPtr->bbox[0]+arcPtr->bbox[2]+1)/2);
} else if (flags & TK_OFFSET_RIGHT) {
tsoffset->xoffset = (int) (arcPtr->bbox[2] + 0.5);
}
if (flags & TK_OFFSET_TOP) {
tsoffset->yoffset = (int) (arcPtr->bbox[1] + 0.5);
} else if (flags & TK_OFFSET_MIDDLE) {
tsoffset->yoffset = (int) ((arcPtr->bbox[1]+arcPtr->bbox[3]+1)/2);
} else if (flags & TK_OFFSET_BOTTOM) {
tsoffset->yoffset = (int) (arcPtr->bbox[3] + 0.5);
}
ComputeArcBbox(canvas, arcPtr);
return TCL_OK;
}
/*
*--------------------------------------------------------------
*
* DeleteArc --
*
* This function is called to clean up the data structure associated with
* an arc item.
*
* Results:
* None.
*
* Side effects:
* Resources associated with itemPtr are released.
*
*--------------------------------------------------------------
*/
static void
DeleteArc(
TCL_UNUSED(Tk_Canvas), /* Info about overall canvas. */
Tk_Item *itemPtr, /* Item that is being deleted. */
Display *display) /* Display containing window for canvas. */
{
ArcItem *arcPtr = (ArcItem *)itemPtr;
Tk_DeleteOutline(display, &(arcPtr->outline));
if (arcPtr->numOutlinePoints != 0) {
ckfree(arcPtr->outlinePtr);
}
if (arcPtr->fillColor != NULL) {
Tk_FreeColor(arcPtr->fillColor);
}
if (arcPtr->activeFillColor != NULL) {
Tk_FreeColor(arcPtr->activeFillColor);
}
if (arcPtr->disabledFillColor != NULL) {
Tk_FreeColor(arcPtr->disabledFillColor);
}
if (arcPtr->fillStipple != None) {
Tk_FreeBitmap(display, arcPtr->fillStipple);
}
if (arcPtr->activeFillStipple != None) {
Tk_FreeBitmap(display, arcPtr->activeFillStipple);
}
if (arcPtr->disabledFillStipple != None) {
Tk_FreeBitmap(display, arcPtr->disabledFillStipple);
}
if (arcPtr->fillGC != NULL) {
Tk_FreeGC(display, arcPtr->fillGC);
}
}
/*
*--------------------------------------------------------------
*
* ComputeArcBbox --
*
* This function is invoked to compute the bounding box of all the pixels
* that may be drawn as part of an arc.
*
* Results:
* None.
*
* Side effects:
* The fields x1, y1, x2, and y2 are updated in the header for itemPtr.
*
*--------------------------------------------------------------
*/
static void
ComputeArcBbox(
Tk_Canvas canvas, /* Canvas that contains item. */
ArcItem *arcPtr) /* Item whose bbox is to be recomputed. */
{
double tmp, center[2], point[2];
double width;
Tk_State state = arcPtr->header.state;
if (state == TK_STATE_NULL) {
state = Canvas(canvas)->canvas_state;
}
width = arcPtr->outline.width;
if (width < 1.0) {
width = 1.0;
}
if (state==TK_STATE_HIDDEN) {
arcPtr->header.x1 = arcPtr->header.x2 =
arcPtr->header.y1 = arcPtr->header.y2 = -1;
return;
} else if (Canvas(canvas)->currentItemPtr == (Tk_Item *) arcPtr) {
if (arcPtr->outline.activeWidth>width) {
width = arcPtr->outline.activeWidth;
}
} else if (state==TK_STATE_DISABLED) {
if (arcPtr->outline.disabledWidth>0) {
width = arcPtr->outline.disabledWidth;
}
}
/*
* Make sure that the first coordinates are the lowest ones.
*/
if (arcPtr->bbox[1] > arcPtr->bbox[3]) {
tmp = arcPtr->bbox[3];
arcPtr->bbox[3] = arcPtr->bbox[1];
arcPtr->bbox[1] = tmp;
}
if (arcPtr->bbox[0] > arcPtr->bbox[2]) {
tmp = arcPtr->bbox[2];
arcPtr->bbox[2] = arcPtr->bbox[0];
arcPtr->bbox[0] = tmp;
}
ComputeArcOutline(canvas,arcPtr);
/*
* To compute the bounding box, start with the bbox formed by the two
* endpoints of the arc. Then add in the center of the arc's oval (if
* relevant) and the 3-o'clock, 6-o'clock, 9-o'clock, and 12-o'clock
* positions, if they are relevant.
*/
arcPtr->header.x1 = arcPtr->header.x2 = (int) arcPtr->center1[0];
arcPtr->header.y1 = arcPtr->header.y2 = (int) arcPtr->center1[1];
TkIncludePoint((Tk_Item *) arcPtr, arcPtr->center2);
center[0] = (arcPtr->bbox[0] + arcPtr->bbox[2])/2;
center[1] = (arcPtr->bbox[1] + arcPtr->bbox[3])/2;
if (arcPtr->style == PIESLICE_STYLE) {
TkIncludePoint((Tk_Item *) arcPtr, center);
}
tmp = -arcPtr->start;
if (tmp < 0) {
tmp += 360.0;
}
if ((tmp < arcPtr->extent) || ((tmp-360) > arcPtr->extent)) {
point[0] = arcPtr->bbox[2];
point[1] = center[1];
TkIncludePoint((Tk_Item *) arcPtr, point);
}
tmp = 90.0 - arcPtr->start;
if (tmp < 0) {
tmp += 360.0;
}
if ((tmp < arcPtr->extent) || ((tmp-360) > arcPtr->extent)) {
point[0] = center[0];
point[1] = arcPtr->bbox[1];
TkIncludePoint((Tk_Item *) arcPtr, point);
}
tmp = 180.0 - arcPtr->start;
if (tmp < 0) {
tmp += 360.0;
}
if ((tmp < arcPtr->extent) || ((tmp-360) > arcPtr->extent)) {
point[0] = arcPtr->bbox[0];
point[1] = center[1];
TkIncludePoint((Tk_Item *) arcPtr, point);
}
tmp = 270.0 - arcPtr->start;
if (tmp < 0) {
tmp += 360.0;
}
if ((tmp < arcPtr->extent) || ((tmp-360) > arcPtr->extent)) {
point[0] = center[0];
point[1] = arcPtr->bbox[3];
TkIncludePoint((Tk_Item *) arcPtr, point);
}
/*
* Lastly, expand by the width of the arc (if the arc's outline is being
* drawn) and add one extra pixel just for safety.
*/
if (arcPtr->outline.gc == NULL) {
tmp = 1;
} else {
tmp = (int) ((width + 1.0)/2.0 + 1);
}
arcPtr->header.x1 -= (int) tmp;
arcPtr->header.y1 -= (int) tmp;
arcPtr->header.x2 += (int) tmp;
arcPtr->header.y2 += (int) tmp;
}
/*
*--------------------------------------------------------------
*
* DisplayArc --
*
* This function is invoked to draw an arc item in a given drawable.
*
* Results:
* None.
*
* Side effects:
* ItemPtr is drawn in drawable using the transformation information in
* canvas.
*
*--------------------------------------------------------------
*/
static void
DisplayArc(
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. */
TCL_UNUSED(int), /* Describes region of canvas that must be */
TCL_UNUSED(int), /* redisplayed (not used). */
TCL_UNUSED(int),
TCL_UNUSED(int))
{
ArcItem *arcPtr = (ArcItem *) itemPtr;
short x1, y1, x2, y2;
int start, extent, dashnumber;
double lineWidth;
Tk_State state = itemPtr->state;
Pixmap stipple;
if (state == TK_STATE_NULL) {
state = Canvas(canvas)->canvas_state;
}
lineWidth = arcPtr->outline.width;
if (lineWidth < 1.0) {
lineWidth = 1.0;
}
dashnumber = arcPtr->outline.dash.number;
stipple = arcPtr->fillStipple;
if (Canvas(canvas)->currentItemPtr == itemPtr) {
if (arcPtr->outline.activeWidth>lineWidth) {
lineWidth = arcPtr->outline.activeWidth;
}
if (arcPtr->outline.activeDash.number != 0) {
dashnumber = arcPtr->outline.activeDash.number;
}
if (arcPtr->activeFillStipple != None) {
stipple = arcPtr->activeFillStipple;
}
} else if (state == TK_STATE_DISABLED) {
if (arcPtr->outline.disabledWidth > 0) {
lineWidth = arcPtr->outline.disabledWidth;
}
if (arcPtr->outline.disabledDash.number != 0) {
dashnumber = arcPtr->outline.disabledDash.number;
}
if (arcPtr->disabledFillStipple != None) {
stipple = arcPtr->disabledFillStipple;
}
}
/*
* Compute the screen coordinates of the bounding box for the item, plus
* integer values for the angles.
*/
Tk_CanvasDrawableCoords(canvas, arcPtr->bbox[0], arcPtr->bbox[1],
&x1, &y1);
Tk_CanvasDrawableCoords(canvas, arcPtr->bbox[2], arcPtr->bbox[3],
&x2, &y2);
if (x2 <= x1) {
x2 = x1+1;
}
if (y2 <= y1) {
y2 = y1+1;
}
start = (int) ((64*arcPtr->start) + 0.5);
extent = (int) ((64*arcPtr->extent) + 0.5);
/*
* Display filled arc first (if wanted), then outline. If the extent is
* zero then don't invoke XFillArc or XDrawArc, since this causes some
* window servers to crash and should be a no-op anyway.
*/
if ((arcPtr->fillGC != NULL) && (extent != 0)) {
if (stipple != None) {
int w = 0;
int h = 0;
Tk_TSOffset *tsoffset = &arcPtr->tsoffset;
int flags = tsoffset->flags;
if (flags & (TK_OFFSET_CENTER|TK_OFFSET_MIDDLE)) {
Tk_SizeOfBitmap(display, stipple, &w, &h);
if (flags & TK_OFFSET_CENTER) {
w /= 2;
} else {
w = 0;
}
if (flags & TK_OFFSET_MIDDLE) {
h /= 2;
} else {
h = 0;
}
}
tsoffset->xoffset -= w;
tsoffset->yoffset -= h;
Tk_CanvasSetOffset(canvas, arcPtr->fillGC, tsoffset);
if (tsoffset) {
tsoffset->xoffset += w;
tsoffset->yoffset += h;
}
}
XFillArc(display, drawable, arcPtr->fillGC, x1, y1, (unsigned) (x2-x1),
(unsigned) (y2-y1), start, extent);
if (stipple != None) {
XSetTSOrigin(display, arcPtr->fillGC, 0, 0);
}
}
if (arcPtr->outline.gc != NULL) {
Tk_ChangeOutlineGC(canvas, itemPtr, &(arcPtr->outline));
if (extent != 0) {
XDrawArc(display, drawable, arcPtr->outline.gc, x1, y1,
(unsigned) (x2-x1), (unsigned) (y2-y1), start, extent);
}
/*
* If the outline width is very thin, don't use polygons to draw the
* linear parts of the outline (this often results in nothing being
* displayed); just draw lines instead. The same is done if the
* outline is dashed, because then polygons don't work.
*/
if (lineWidth < 1.5 || dashnumber != 0) {
Tk_CanvasDrawableCoords(canvas, arcPtr->center1[0],
arcPtr->center1[1], &x1, &y1);
Tk_CanvasDrawableCoords(canvas, arcPtr->center2[0],
arcPtr->center2[1], &x2, &y2);
if (arcPtr->style == CHORD_STYLE) {
XDrawLine(display, drawable, arcPtr->outline.gc,
x1, y1, x2, y2);
} else if (arcPtr->style == PIESLICE_STYLE) {
short cx, cy;
Tk_CanvasDrawableCoords(canvas,
(arcPtr->bbox[0] + arcPtr->bbox[2])/2.0,
(arcPtr->bbox[1] + arcPtr->bbox[3])/2.0, &cx, &cy);
XDrawLine(display, drawable, arcPtr->outline.gc,
cx, cy, x1, y1);
XDrawLine(display, drawable, arcPtr->outline.gc,
cx, cy, x2, y2);
}
} else {
if (arcPtr->style == CHORD_STYLE) {
TkFillPolygon(canvas, arcPtr->outlinePtr, CHORD_OUTLINE_PTS,
display, drawable, arcPtr->outline.gc, NULL);
} else if (arcPtr->style == PIESLICE_STYLE) {
TkFillPolygon(canvas, arcPtr->outlinePtr, PIE_OUTLINE1_PTS,
display, drawable, arcPtr->outline.gc, NULL);
TkFillPolygon(canvas, arcPtr->outlinePtr + 2*PIE_OUTLINE1_PTS,
PIE_OUTLINE2_PTS, display, drawable,
arcPtr->outline.gc, NULL);
}
}
Tk_ResetOutlineGC(canvas, itemPtr, &(arcPtr->outline));
}
}
/*
*--------------------------------------------------------------
*
* ArcToPoint --
*
* Computes the distance from a given point to a given arc, in canvas
* units.
*
* Results:
* The return value is 0 if the point whose x and y coordinates are
* coordPtr[0] and coordPtr[1] is inside the arc. If the point isn't
* inside the arc then the return value is the distance from the point to
* the arc. If itemPtr is filled, then anywhere in the interior is
* considered "inside"; if itemPtr isn't filled, then "inside" means only
* the area occupied by the outline.
*
* Side effects:
* None.
*
*--------------------------------------------------------------
*/
static double
ArcToPoint(
Tk_Canvas canvas, /* Canvas containing item. */
Tk_Item *itemPtr, /* Item to check against point. */
double *pointPtr) /* Pointer to x and y coordinates. */
{
ArcItem *arcPtr = (ArcItem *) itemPtr;
double vertex[2], pointAngle, diff, dist, newDist;
double poly[8], polyDist, width, t1, t2;
int filled, angleInRange;
Tk_State state = itemPtr->state;
if (state == TK_STATE_NULL) {
state = Canvas(canvas)->canvas_state;
}
width = (double) arcPtr->outline.width;
if (Canvas(canvas)->currentItemPtr == itemPtr) {
if (arcPtr->outline.activeWidth>width) {
width = (double) arcPtr->outline.activeWidth;
}
} else if (state == TK_STATE_DISABLED) {
if (arcPtr->outline.disabledWidth>0) {
width = (double) arcPtr->outline.disabledWidth;
}
}
/*
* See if the point is within the angular range of the arc. Remember, X
* angles are backwards from the way we'd normally think of them. Also,
* compensate for any eccentricity of the oval.
*/
vertex[0] = (arcPtr->bbox[0] + arcPtr->bbox[2])/2.0;
vertex[1] = (arcPtr->bbox[1] + arcPtr->bbox[3])/2.0;
t1 = arcPtr->bbox[3] - arcPtr->bbox[1];
if (t1 != 0.0) {
t1 = (pointPtr[1] - vertex[1]) / t1;
}
t2 = arcPtr->bbox[2] - arcPtr->bbox[0];
if (t2 != 0.0) {
t2 = (pointPtr[0] - vertex[0]) / t2;
}
if ((t1 == 0.0) && (t2 == 0.0)) {
pointAngle = 0;
} else {
pointAngle = -atan2(t1, t2)*180/PI;
}
diff = pointAngle - arcPtr->start;
diff -= ((int) (diff/360.0) * 360.0);
if (diff < 0) {
diff += 360.0;
}
angleInRange = (diff <= arcPtr->extent) ||
((arcPtr->extent < 0) && ((diff - 360.0) >= arcPtr->extent));
/*
* Now perform different tests depending on what kind of arc we're dealing
* with.
*/
if (arcPtr->style == ARC_STYLE) {
if (angleInRange) {
return TkOvalToPoint(arcPtr->bbox, width, 0, pointPtr);
}
dist = hypot(pointPtr[0] - arcPtr->center1[0],
pointPtr[1] - arcPtr->center1[1]);
newDist = hypot(pointPtr[0] - arcPtr->center2[0],
pointPtr[1] - arcPtr->center2[1]);
if (newDist < dist) {
return newDist;
}
return dist;
}
if ((arcPtr->fillGC != NULL) || (arcPtr->outline.gc == NULL)) {
filled = 1;
} else {
filled = 0;
}
if (arcPtr->outline.gc == NULL) {
width = 0.0;
}
if (arcPtr->style == PIESLICE_STYLE) {
if (width > 1.0) {
dist = TkPolygonToPoint(arcPtr->outlinePtr, PIE_OUTLINE1_PTS,
pointPtr);
newDist = TkPolygonToPoint(arcPtr->outlinePtr + 2*PIE_OUTLINE1_PTS,
PIE_OUTLINE2_PTS, pointPtr);
} else {
dist = TkLineToPoint(vertex, arcPtr->center1, pointPtr);
newDist = TkLineToPoint(vertex, arcPtr->center2, pointPtr);
}
if (newDist < dist) {
dist = newDist;
}
if (angleInRange) {
newDist = TkOvalToPoint(arcPtr->bbox, width, filled, pointPtr);
if (newDist < dist) {
dist = newDist;
}
}
return dist;
}
/*
* This is a chord-style arc. We have to deal specially with the
* triangular piece that represents the difference between a chord-style
* arc and a pie-slice arc (for small angles this piece is excluded here
* where it would be included for pie slices; for large angles the piece
* is included here but would be excluded for pie slices).
*/
if (width > 1.0) {
dist = TkPolygonToPoint(arcPtr->outlinePtr, CHORD_OUTLINE_PTS,
pointPtr);
} else {
dist = TkLineToPoint(arcPtr->center1, arcPtr->center2, pointPtr);
}
poly[0] = poly[6] = vertex[0];
poly[1] = poly[7] = vertex[1];
poly[2] = arcPtr->center1[0];
poly[3] = arcPtr->center1[1];
poly[4] = arcPtr->center2[0];
poly[5] = arcPtr->center2[1];
polyDist = TkPolygonToPoint(poly, 4, pointPtr);
if (angleInRange) {
if ((arcPtr->extent < -180.0) || (arcPtr->extent > 180.0)
|| (polyDist > 0.0)) {
newDist = TkOvalToPoint(arcPtr->bbox, width, filled, pointPtr);
if (newDist < dist) {
dist = newDist;
}
}
} else {
if ((arcPtr->extent < -180.0) || (arcPtr->extent > 180.0)) {
if (filled && (polyDist < dist)) {
dist = polyDist;
}
}
}
return dist;
}
/*
*--------------------------------------------------------------
*
* ArcToArea --
*
* This function is called to determine whether an item lies entirely
* inside, entirely outside, or overlapping a given 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.
*
*--------------------------------------------------------------
*/
static int
ArcToArea(
Tk_Canvas canvas, /* Canvas containing item. */
Tk_Item *itemPtr, /* Item to check against arc. */
double *rectPtr) /* Pointer to array of four coordinates (x1,
* y1, x2, y2) describing rectangular area. */
{
ArcItem *arcPtr = (ArcItem *) itemPtr;
double rx, ry; /* Radii for transformed oval: these define an
* oval centered at the origin. */
double tRect[4]; /* Transformed version of x1, y1, x2, y2, for
* coord. system where arc is centered on the
* origin. */
double center[2], width, angle, tmp;
double points[20], *pointPtr;
int numPoints, filled;
int inside; /* Non-zero means every test so far suggests
* that arc is inside rectangle. 0 means every
* test so far shows arc to be outside of
* rectangle. */
int newInside;
Tk_State state = itemPtr->state;
if(state == TK_STATE_NULL) {
state = Canvas(canvas)->canvas_state;
}
width = (double) arcPtr->outline.width;
if (Canvas(canvas)->currentItemPtr == itemPtr) {
if (arcPtr->outline.activeWidth>width) {
width = (double) arcPtr->outline.activeWidth;
}
} else if (state == TK_STATE_DISABLED) {
if (arcPtr->outline.disabledWidth>0) {
width = (double) arcPtr->outline.disabledWidth;
}
}
if ((arcPtr->fillGC != NULL) || (arcPtr->outline.gc == NULL)) {
filled = 1;
} else {
filled = 0;
}
if (arcPtr->outline.gc == NULL) {
width = 0.0;
}
/*
* Transform both the arc and the rectangle so that the arc's oval is
* centered on the origin.
*/
center[0] = (arcPtr->bbox[0] + arcPtr->bbox[2])/2.0;
center[1] = (arcPtr->bbox[1] + arcPtr->bbox[3])/2.0;
tRect[0] = rectPtr[0] - center[0];
tRect[1] = rectPtr[1] - center[1];
tRect[2] = rectPtr[2] - center[0];
tRect[3] = rectPtr[3] - center[1];
rx = arcPtr->bbox[2] - center[0] + width/2.0;
ry = arcPtr->bbox[3] - center[1] + width/2.0;
/*
* Find the extreme points of the arc and see whether these are all inside
* the rectangle (in which case we're done), partly in and partly out (in
* which case we're done), or all outside (in which case we have more work
* to do). The extreme points include the following, which are checked in
* order:
*
* 1. The outside points of the arc, corresponding to start and extent.
* 2. The center of the arc (but only in pie-slice mode).
* 3. The 12, 3, 6, and 9-o'clock positions (but only if the arc includes
* those angles).
*/
pointPtr = points;
angle = -arcPtr->start*(PI/180.0);
pointPtr[0] = rx*cos(angle);
pointPtr[1] = ry*sin(angle);
angle += -arcPtr->extent*(PI/180.0);
pointPtr[2] = rx*cos(angle);
pointPtr[3] = ry*sin(angle);
numPoints = 2;
pointPtr += 4;
if ((arcPtr->style == PIESLICE_STYLE) && (arcPtr->extent < 180.0)) {
pointPtr[0] = 0.0;
pointPtr[1] = 0.0;
numPoints++;
pointPtr += 2;
}
tmp = -arcPtr->start;
if (tmp < 0) {
tmp += 360.0;
}
if ((tmp < arcPtr->extent) || ((tmp-360) > arcPtr->extent)) {
pointPtr[0] = rx;
pointPtr[1] = 0.0;
numPoints++;
pointPtr += 2;
}
tmp = 90.0 - arcPtr->start;
if (tmp < 0) {
tmp += 360.0;
}
if ((tmp < arcPtr->extent) || ((tmp-360) > arcPtr->extent)) {
pointPtr[0] = 0.0;
pointPtr[1] = -ry;
numPoints++;
pointPtr += 2;
}
tmp = 180.0 - arcPtr->start;
if (tmp < 0) {
tmp += 360.0;
}
if ((tmp < arcPtr->extent) || ((tmp-360) > arcPtr->extent)) {
pointPtr[0] = -rx;
pointPtr[1] = 0.0;
numPoints++;
pointPtr += 2;
}
tmp = 270.0 - arcPtr->start;
if (tmp < 0) {
tmp += 360.0;
}
if ((tmp < arcPtr->extent) || ((tmp-360) > arcPtr->extent)) {
pointPtr[0] = 0.0;
pointPtr[1] = ry;
numPoints++;
}
/*
* Now that we've located the extreme points, loop through them all to see
* which are inside the rectangle.
*/
inside = (points[0] > tRect[0]) && (points[0] < tRect[2])
&& (points[1] > tRect[1]) && (points[1] < tRect[3]);
for (pointPtr = points+2; numPoints > 1; pointPtr += 2, numPoints--) {
newInside = (pointPtr[0] > tRect[0]) && (pointPtr[0] < tRect[2])
&& (pointPtr[1] > tRect[1]) && (pointPtr[1] < tRect[3]);
if (newInside != inside) {
return 0;
}
}
if (inside) {
return 1;
}
/*
* So far, oval appears to be outside rectangle, but can't yet tell for
* sure. Next, test each of the four sides of the rectangle against the
* bounding region for the arc. If any intersections are found, then
* return "overlapping". First, test against the polygon(s) forming the
* sides of a chord or pie-slice.
*/
if (arcPtr->style == PIESLICE_STYLE) {
if (width >= 1.0) {
if (TkPolygonToArea(arcPtr->outlinePtr, PIE_OUTLINE1_PTS,
rectPtr) != -1) {
return 0;
}
if (TkPolygonToArea(arcPtr->outlinePtr + 2*PIE_OUTLINE1_PTS,
PIE_OUTLINE2_PTS, rectPtr) != -1) {
return 0;
}
} else {
if ((TkLineToArea(center, arcPtr->center1, rectPtr) != -1) ||
(TkLineToArea(center, arcPtr->center2, rectPtr) != -1)) {
return 0;
}
}
} else if (arcPtr->style == CHORD_STYLE) {
if (width >= 1.0) {
if (TkPolygonToArea(arcPtr->outlinePtr, CHORD_OUTLINE_PTS,
rectPtr) != -1) {
return 0;
}
} else {
if (TkLineToArea(arcPtr->center1, arcPtr->center2,
rectPtr) != -1) {
return 0;
}
}
}
/*
* Next check for overlap between each of the four sides and the outer
* perimiter of the arc. If the arc isn't filled, then also check the
* inner perimeter of the arc.
*/
if (HorizLineToArc(tRect[0], tRect[2], tRect[1], rx, ry, arcPtr->start,
arcPtr->extent)
|| HorizLineToArc(tRect[0], tRect[2], tRect[3], rx, ry,
arcPtr->start, arcPtr->extent)
|| VertLineToArc(tRect[0], tRect[1], tRect[3], rx, ry,
arcPtr->start, arcPtr->extent)
|| VertLineToArc(tRect[2], tRect[1], tRect[3], rx, ry,
arcPtr->start, arcPtr->extent)) {
return 0;
}
if ((width > 1.0) && !filled) {
rx -= width;
ry -= width;
if (HorizLineToArc(tRect[0], tRect[2], tRect[1], rx, ry, arcPtr->start,
arcPtr->extent)
|| HorizLineToArc(tRect[0], tRect[2], tRect[3], rx, ry,
arcPtr->start, arcPtr->extent)
|| VertLineToArc(tRect[0], tRect[1], tRect[3], rx, ry,
arcPtr->start, arcPtr->extent)
|| VertLineToArc(tRect[2], tRect[1], tRect[3], rx, ry,
arcPtr->start, arcPtr->extent)) {
return 0;
}
}
/*
* The arc still appears to be totally disjoint from the rectangle, but
* it's also possible that the rectangle is totally inside the arc. Do one
* last check, which is to check one point of the rectangle to see if it's
* inside the arc. If it is, we've got overlap. If it isn't, the arc's
* really outside the rectangle.
*/
if (ArcToPoint(canvas, itemPtr, rectPtr) == 0.0) {
return 0;
}
return -1;
}
/*
*--------------------------------------------------------------
*
* ScaleArc --
*
* This function is invoked to rescale an arc item.
*
* Results:
* None.
*
* Side effects:
* The arc 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
ScaleArc(
Tk_Canvas canvas, /* Canvas containing arc. */
Tk_Item *itemPtr, /* Arc to be scaled. */
double originX, /* Origin about which to scale rect. */
double originY,
double scaleX, /* Amount to scale in X direction. */
double scaleY) /* Amount to scale in Y direction. */
{
ArcItem *arcPtr = (ArcItem *) itemPtr;
arcPtr->bbox[0] = originX + scaleX*(arcPtr->bbox[0] - originX);
arcPtr->bbox[1] = originY + scaleY*(arcPtr->bbox[1] - originY);
arcPtr->bbox[2] = originX + scaleX*(arcPtr->bbox[2] - originX);
arcPtr->bbox[3] = originY + scaleY*(arcPtr->bbox[3] - originY);
ComputeArcBbox(canvas, arcPtr);
}
/*
*--------------------------------------------------------------
*
* TranslateArc --
*
* This function is called to move an arc by a given amount.
*
* Results:
* None.
*
* Side effects:
* The position of the arc is offset by (xDelta, yDelta), and the
* bounding box is updated in the generic part of the item structure.
*
*--------------------------------------------------------------
*/
static void
TranslateArc(
Tk_Canvas canvas, /* Canvas containing item. */
Tk_Item *itemPtr, /* Item that is being moved. */
double deltaX, /* Amount by which item is to be moved. */
double deltaY)
{
ArcItem *arcPtr = (ArcItem *) itemPtr;
arcPtr->bbox[0] += deltaX;
arcPtr->bbox[1] += deltaY;
arcPtr->bbox[2] += deltaX;
arcPtr->bbox[3] += deltaY;
ComputeArcBbox(canvas, arcPtr);
}
/*
*--------------------------------------------------------------
*
* ComputeArcOutline --
*
* This function creates a polygon describing everything in the outline
* for an arc except what's in the curved part. For a "pie slice" arc
* this is a V-shaped chunk, and for a "chord" arc this is a linear chunk
* (with cutaway corners). For "arc" arcs, this stuff isn't relevant.
*
* Results:
* None.
*
* Side effects:
* The information at arcPtr->outlinePtr gets modified, and storage for
* arcPtr->outlinePtr may be allocated or freed.
*
*--------------------------------------------------------------
*/
static void
ComputeArcOutline(
Tk_Canvas canvas, /* Information about overall canvas. */
ArcItem *arcPtr) /* Information about arc. */
{
double sin1, cos1, sin2, cos2, angle, width, halfWidth;
double boxWidth, boxHeight;
double vertex[2], corner1[2], corner2[2];
double *outlinePtr;
Tk_State state = arcPtr->header.state;
/*
* Make sure that the outlinePtr array is large enough to hold either a
* chord or pie-slice outline.
*/
if (arcPtr->numOutlinePoints == 0) {
arcPtr->outlinePtr = (double *)ckalloc(26 * sizeof(double));
arcPtr->numOutlinePoints = 22;
}
outlinePtr = arcPtr->outlinePtr;
if (state == TK_STATE_NULL) {
state = Canvas(canvas)->canvas_state;
}
/*
* First compute the two points that lie at the centers of the ends of the
* curved arc segment, which are marked with X's in the figure below:
*
*
* * * *
* * *
* * * * *
* * * * *
* * * * *
* X * * X
*
* The code is tricky because the arc can be ovular in shape. It computes
* the position for a unit circle, and then scales to fit the shape of the
* arc's bounding box.
*
* Also, watch out because angles go counter-clockwise like you might
* expect, but the y-coordinate system is inverted. To handle this, just
* negate the angles in all the computations.
*/
boxWidth = arcPtr->bbox[2] - arcPtr->bbox[0];
boxHeight = arcPtr->bbox[3] - arcPtr->bbox[1];
angle = -arcPtr->start*PI/180.0;
sin1 = sin(angle);
cos1 = cos(angle);
angle -= arcPtr->extent*PI/180.0;
sin2 = sin(angle);
cos2 = cos(angle);
vertex[0] = (arcPtr->bbox[0] + arcPtr->bbox[2])/2.0;
vertex[1] = (arcPtr->bbox[1] + arcPtr->bbox[3])/2.0;
arcPtr->center1[0] = vertex[0] + cos1*boxWidth/2.0;
arcPtr->center1[1] = vertex[1] + sin1*boxHeight/2.0;
arcPtr->center2[0] = vertex[0] + cos2*boxWidth/2.0;
arcPtr->center2[1] = vertex[1] + sin2*boxHeight/2.0;
/*
* Next compute the "outermost corners" of the arc, which are marked with
* X's in the figure below:
*
* * * *
* * *
* * * * *
* * * * *
* X * * X
* * *
*
* The code below is tricky because it has to handle eccentricity in the
* shape of the oval. The key in the code below is to realize that the
* slope of the line from arcPtr->center1 to corner1 is (boxWidth*sin1)
* divided by (boxHeight*cos1), and similarly for arcPtr->center2 and
* corner2. These formulas can be computed from the formula for the oval.
*/
width = arcPtr->outline.width;
if (Canvas(canvas)->currentItemPtr == (Tk_Item *) arcPtr) {
if (arcPtr->outline.activeWidth>arcPtr->outline.width) {
width = arcPtr->outline.activeWidth;
}
} else if (state == TK_STATE_DISABLED) {
if (arcPtr->outline.disabledWidth>arcPtr->outline.width) {
width = arcPtr->outline.disabledWidth;
}
}
halfWidth = width/2.0;
if (((boxWidth*sin1) == 0.0) && ((boxHeight*cos1) == 0.0)) {
angle = 0.0;
} else {
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 == CHORD_STYLE) {
outlinePtr[0] = outlinePtr[12] = corner1[0];
outlinePtr[1] = outlinePtr[13] = corner1[1];
TkGetButtPoints(arcPtr->center2, arcPtr->center1,
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 == PIESLICE_STYLE) {
/*
* 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, 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, 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. chord
* or pie-slice) are not checked.
*
* Side effects:
* None.
*
*--------------------------------------------------------------
*/
static int
HorizLineToArc(
double x1, double x2, /* X-coords of endpoints of line segment. X1
* must be <= x2. */
double y, /* Y-coordinate of line segment. */
double rx, double ry, /* These x- and y-radii define an oval
* centered at the origin. */
double start, double extent)/* Angles that define extent of arc, in the
* standard fashion for this module. */
{
double tmp, x;
double tx, ty; /* Coordinates of intersection point in
* transformed coordinate system. */
/*
* 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. chord
* or pie-slice) are not checked.
*
* Side effects:
* None.
*
*--------------------------------------------------------------
*/
static int
VertLineToArc(
double x, /* X-coordinate of line segment. */
double y1, double y2, /* Y-coords of endpoints of line segment. Y1
* must be <= y2. */
double rx, double ry, /* These x- and y-radii define an oval
* centered at the origin. */
double start, double extent)/* Angles that define extent of arc, in the
* standard fashion for this module. */
{
double tmp, y;
double tx, ty; /* Coordinates of intersection point in
* transformed coordinate system. */
/*
* 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(
double x, double 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 function 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 the interp's
* 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(
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. */
TCL_UNUSED(int)) /* 1 means this is a prepass to collect font
* information; 0 means final Postscript is
* being created. */
{
ArcItem *arcPtr = (ArcItem *) itemPtr;
double y1, y2, ang1, ang2;
XColor *color;
Pixmap stipple;
XColor *fillColor;
Pixmap fillStipple;
Tk_State state = itemPtr->state;
Tcl_Obj *psObj;
Tcl_InterpState interpState;
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 (state == TK_STATE_NULL) {
state = Canvas(canvas)->canvas_state;
}
color = arcPtr->outline.color;
stipple = arcPtr->outline.stipple;
fillColor = arcPtr->fillColor;
fillStipple = arcPtr->fillStipple;
if (Canvas(canvas)->currentItemPtr == itemPtr) {
if (arcPtr->outline.activeColor!=NULL) {
color = arcPtr->outline.activeColor;
}
if (arcPtr->outline.activeStipple!=None) {
stipple = arcPtr->outline.activeStipple;
}
if (arcPtr->activeFillColor!=NULL) {
fillColor = arcPtr->activeFillColor;
}
if (arcPtr->activeFillStipple!=None) {
fillStipple = arcPtr->activeFillStipple;
}
} else if (state == TK_STATE_DISABLED) {
if (arcPtr->outline.disabledColor!=NULL) {
color = arcPtr->outline.disabledColor;
}
if (arcPtr->outline.disabledStipple!=None) {
stipple = arcPtr->outline.disabledStipple;
}
if (arcPtr->disabledFillColor!=NULL) {
fillColor = arcPtr->disabledFillColor;
}
if (arcPtr->disabledFillStipple!=None) {
fillStipple = arcPtr->disabledFillStipple;
}
}
/*
* Make our working space.
*/
psObj = Tcl_NewObj();
interpState = Tcl_SaveInterpState(interp, TCL_OK);
/*
* If the arc is filled, output Postscript for the interior region of the
* arc.
*/
if (arcPtr->fillGC != NULL) {
Tcl_AppendPrintfToObj(psObj,
"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);
if (arcPtr->style != CHORD_STYLE) {
Tcl_AppendToObj(psObj, "0 0 moveto ", -1);
}
Tcl_AppendPrintfToObj(psObj,
"0 0 1 %.15g %.15g arc closepath\nsetmatrix\n",
ang1, ang2);
Tcl_ResetResult(interp);
if (Tk_CanvasPsColor(interp, canvas, fillColor) != TCL_OK) {
goto error;
}
Tcl_AppendObjToObj(psObj, Tcl_GetObjResult(interp));
if (fillStipple != None) {
Tcl_AppendToObj(psObj, "clip ", -1);
Tcl_ResetResult(interp);
if (Tk_CanvasPsStipple(interp, canvas, fillStipple) != TCL_OK) {
goto error;
}
Tcl_AppendObjToObj(psObj, Tcl_GetObjResult(interp));
if (arcPtr->outline.gc != NULL) {
Tcl_AppendToObj(psObj, "grestore gsave\n", -1);
}
} else {
Tcl_AppendToObj(psObj, "fill\n", -1);
}
}
/*
* If there's an outline for the arc, draw it.
*/
if (arcPtr->outline.gc != NULL) {
Tcl_AppendPrintfToObj(psObj,
"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_AppendPrintfToObj(psObj,
"0 0 1 %.15g %.15g arc\nsetmatrix\n0 setlinecap\n",
ang1, ang2);
Tcl_ResetResult(interp);
if (Tk_CanvasPsOutline(canvas, itemPtr, &arcPtr->outline) != TCL_OK) {
goto error;
}
Tcl_AppendObjToObj(psObj, Tcl_GetObjResult(interp));
if (arcPtr->style != ARC_STYLE) {
Tcl_AppendToObj(psObj, "grestore gsave\n", -1);
Tcl_ResetResult(interp);
if (arcPtr->style == CHORD_STYLE) {
Tk_CanvasPsPath(interp, canvas, arcPtr->outlinePtr,
CHORD_OUTLINE_PTS);
} else {
Tk_CanvasPsPath(interp, canvas, arcPtr->outlinePtr,
PIE_OUTLINE1_PTS);
if (Tk_CanvasPsColor(interp, canvas, color) != TCL_OK) {
goto error;
}
Tcl_AppendObjToObj(psObj, Tcl_GetObjResult(interp));
if (stipple != None) {
Tcl_AppendToObj(psObj, "clip ", -1);
Tcl_ResetResult(interp);
if (Tk_CanvasPsStipple(interp, canvas, stipple) !=TCL_OK){
goto error;
}
Tcl_AppendObjToObj(psObj, Tcl_GetObjResult(interp));
} else {
Tcl_AppendToObj(psObj, "fill\n", -1);
}
Tcl_AppendToObj(psObj, "grestore gsave\n", -1);
Tcl_ResetResult(interp);
Tk_CanvasPsPath(interp, canvas,
arcPtr->outlinePtr + 2*PIE_OUTLINE1_PTS,
PIE_OUTLINE2_PTS);
}
if (Tk_CanvasPsColor(interp, canvas, color) != TCL_OK) {
goto error;
}
Tcl_AppendObjToObj(psObj, Tcl_GetObjResult(interp));
if (stipple != None) {
Tcl_AppendToObj(psObj, "clip ", -1);
Tcl_ResetResult(interp);
if (Tk_CanvasPsStipple(interp, canvas, stipple) != TCL_OK) {
goto error;
}
Tcl_AppendObjToObj(psObj, Tcl_GetObjResult(interp));
} else {
Tcl_AppendToObj(psObj, "fill\n", -1);
}
}
}
/*
* Plug the accumulated postscript back into the result.
*/
(void) Tcl_RestoreInterpState(interp, interpState);
Tcl_AppendObjToObj(Tcl_GetObjResult(interp), psObj);
Tcl_DecrRefCount(psObj);
return TCL_OK;
error:
Tcl_DiscardInterpState(interpState);
Tcl_DecrRefCount(psObj);
return TCL_ERROR;
}
/*
*--------------------------------------------------------------
*
* StyleParseProc --
*
* This function is invoked during option processing to handle the
* "-style" option.
*
* Results:
* A standard Tcl return value.
*
* Side effects:
* The state for a given item gets replaced by the state indicated in the
* value argument.
*
*--------------------------------------------------------------
*/
static int
StyleParseProc(
TCL_UNUSED(void *),
Tcl_Interp *interp, /* Used for reporting errors. */
TCL_UNUSED(Tk_Window), /* Window containing canvas widget. */
const char *value, /* Value of option. */
char *widgRec, /* Pointer to record for item. */
int offset) /* Offset into item. */
{
int c;
size_t length;
Style *stylePtr = (Style *) (widgRec + offset);
if (value == NULL || *value == 0) {
*stylePtr = PIESLICE_STYLE;
return TCL_OK;
}
c = value[0];
length = strlen(value);
if ((c == 'a') && (strncmp(value, "arc", length) == 0)) {
*stylePtr = ARC_STYLE;
return TCL_OK;
}
if ((c == 'c') && (strncmp(value, "chord", length) == 0)) {
*stylePtr = CHORD_STYLE;
return TCL_OK;
}
if ((c == 'p') && (strncmp(value, "pieslice", length) == 0)) {
*stylePtr = PIESLICE_STYLE;
return TCL_OK;
}
Tcl_SetObjResult(interp, Tcl_ObjPrintf(
"bad -style option \"%s\": must be arc, chord, or pieslice",
value));
Tcl_SetErrorCode(interp, "TK", "CANVAS", "ARC_STYLE", NULL);
*stylePtr = PIESLICE_STYLE;
return TCL_ERROR;
}
/*
*--------------------------------------------------------------
*
* StylePrintProc --
*
* This function is invoked by the Tk configuration code to produce a
* printable string for the "-style" configuration option.
*
* Results:
* The return value is a string describing the state for the item
* referred to by "widgRec". In addition, *freeProcPtr is filled in with
* the address of a function to call to free the result string when it's
* no longer needed (or NULL to indicate that the string doesn't need to
* be freed).
*
* Side effects:
* None.
*
*--------------------------------------------------------------
*/
static const char *
StylePrintProc(
TCL_UNUSED(void *), /* Ignored. */
TCL_UNUSED(Tk_Window), /* Ignored. */
char *widgRec, /* Pointer to record for item. */
int offset, /* Offset into item. */
TCL_UNUSED(Tcl_FreeProc **)) /* Pointer to variable to fill in with
* information about how to reclaim storage
* for return string. */
{
Style *stylePtr = (Style *) (widgRec + offset);
if (*stylePtr == ARC_STYLE) {
return "arc";
} else if (*stylePtr == CHORD_STYLE) {
return "chord";
} else {
return "pieslice";
}
}
/*
* Local Variables:
* mode: c
* c-basic-offset: 4
* fill-column: 78
* End:
*/