/* * 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" #include "float.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). */ double height; /* Distance from the arc's chord to its * mid-point. */ double startPoint[2]; /* Start point of arc used when specifying * height. */ double endPoint[2]; /* End point of arc used when specifying * height. */ } 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, offsetof(ArcItem, outline.activeDash), TK_CONFIG_NULL_OK, &dashOption}, {TK_CONFIG_COLOR, "-activefill", NULL, NULL, NULL, offsetof(ArcItem, activeFillColor), TK_CONFIG_NULL_OK, NULL}, {TK_CONFIG_COLOR, "-activeoutline", NULL, NULL, NULL, offsetof(ArcItem, outline.activeColor), TK_CONFIG_NULL_OK, NULL}, {TK_CONFIG_BITMAP, "-activeoutlinestipple", NULL, NULL, NULL, offsetof(ArcItem, outline.activeStipple), TK_CONFIG_NULL_OK, NULL}, {TK_CONFIG_BITMAP, "-activestipple", NULL, NULL, NULL, offsetof(ArcItem, activeFillStipple), TK_CONFIG_NULL_OK, NULL}, {TK_CONFIG_CUSTOM, "-activewidth", NULL, NULL, "0.0", offsetof(ArcItem, outline.activeWidth), TK_CONFIG_DONT_SET_DEFAULT, &pixelOption}, {TK_CONFIG_CUSTOM, "-dash", NULL, NULL, NULL, offsetof(ArcItem, outline.dash), TK_CONFIG_NULL_OK, &dashOption}, {TK_CONFIG_PIXELS, "-dashoffset", NULL, NULL, "0", offsetof(ArcItem, outline.offset), TK_CONFIG_DONT_SET_DEFAULT, NULL}, {TK_CONFIG_CUSTOM, "-disableddash", NULL, NULL, NULL, offsetof(ArcItem, outline.disabledDash), TK_CONFIG_NULL_OK, &dashOption}, {TK_CONFIG_COLOR, "-disabledfill", NULL, NULL, NULL, offsetof(ArcItem, disabledFillColor), TK_CONFIG_NULL_OK, NULL}, {TK_CONFIG_COLOR, "-disabledoutline", NULL, NULL, NULL, offsetof(ArcItem, outline.disabledColor), TK_CONFIG_NULL_OK, NULL}, {TK_CONFIG_BITMAP, "-disabledoutlinestipple", NULL, NULL, NULL, offsetof(ArcItem, outline.disabledStipple), TK_CONFIG_NULL_OK, NULL}, {TK_CONFIG_BITMAP, "-disabledstipple", NULL, NULL, NULL, offsetof(ArcItem, disabledFillStipple), TK_CONFIG_NULL_OK, NULL}, {TK_CONFIG_CUSTOM, "-disabledwidth", NULL, NULL, "0.0", offsetof(ArcItem, outline.disabledWidth), TK_CONFIG_DONT_SET_DEFAULT, &pixelOption}, {TK_CONFIG_DOUBLE, "-extent", NULL, NULL, "90", offsetof(ArcItem, extent), TK_CONFIG_DONT_SET_DEFAULT, NULL}, {TK_CONFIG_COLOR, "-fill", NULL, NULL, NULL, offsetof(ArcItem, fillColor), TK_CONFIG_NULL_OK, NULL}, {TK_CONFIG_DOUBLE, "-height", NULL, NULL, 0, offsetof(ArcItem, height), TK_CONFIG_DONT_SET_DEFAULT, NULL}, {TK_CONFIG_CUSTOM, "-offset", NULL, NULL, "0,0", offsetof(ArcItem, tsoffset), TK_CONFIG_DONT_SET_DEFAULT, &offsetOption}, {TK_CONFIG_COLOR, "-outline", NULL, NULL, DEF_CANVITEM_OUTLINE, offsetof(ArcItem, outline.color), TK_CONFIG_NULL_OK, NULL}, {TK_CONFIG_CUSTOM, "-outlineoffset", NULL, NULL, "0,0", offsetof(ArcItem, outline.tsoffset), TK_CONFIG_DONT_SET_DEFAULT, &offsetOption}, {TK_CONFIG_BITMAP, "-outlinestipple", NULL, NULL, NULL, offsetof(ArcItem, outline.stipple), TK_CONFIG_NULL_OK, NULL}, {TK_CONFIG_DOUBLE, "-start", NULL, NULL, "0", offsetof(ArcItem, start), TK_CONFIG_DONT_SET_DEFAULT, NULL}, {TK_CONFIG_CUSTOM, "-state", NULL, NULL, NULL, offsetof(Tk_Item, state), TK_CONFIG_NULL_OK, &stateOption}, {TK_CONFIG_BITMAP, "-stipple", NULL, NULL, NULL, offsetof(ArcItem, fillStipple), TK_CONFIG_NULL_OK, NULL}, {TK_CONFIG_CUSTOM, "-style", NULL, NULL, NULL, offsetof(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", offsetof(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 void ComputeArcParametersFromHeight(ArcItem *arcPtr); 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); static void RotateArc(Tk_Canvas canvas, Tk_Item *itemPtr, double originX, double originY, double angleRad); /* * 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 */ RotateArc, /* rotateProc */ 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; arcPtr->height = 0; /* * 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; } /* * Store bbox as start and end points so they can be used if either * radius or height is specified. */ arcPtr->startPoint[0] = arcPtr->bbox[0]; arcPtr->startPoint[1] = arcPtr->bbox[1]; arcPtr->endPoint[0] = arcPtr->bbox[2]; arcPtr->endPoint[1] = arcPtr->bbox[3]; 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; } /* * Override the start and extent if the height is given. */ ComputeArcParametersFromHeight(arcPtr); ComputeArcBbox(canvas, arcPtr); 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; 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); } 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; } /* *-------------------------------------------------------------- * * ComputeArcParametersFromHeight -- * * This function calculates the arc parameters given start-point, * end-point and height (!= 0). * * Results: * None. * * Side effects: * The height parameter is set to 0 on exit. * *-------------------------------------------------------------- */ static void ComputeArcParametersFromHeight( ArcItem* arcPtr) { double chordLen, chordDir[2], chordCen[2], arcCen[2], d, radToDeg, radius; /* * Do nothing if no height has been specified. */ if (arcPtr->height == 0) return; /* * Calculate the chord length, return early if it is too small. */ chordLen = hypot(arcPtr->endPoint[1] - arcPtr->startPoint[1], arcPtr->startPoint[0] - arcPtr->endPoint[0]); if (chordLen < DBL_EPSILON) { arcPtr->start = arcPtr->extent = arcPtr->height = 0; return; } chordDir[0] = (arcPtr->endPoint[0] - arcPtr->startPoint[0]) / chordLen; chordDir[1] = (arcPtr->endPoint[1] - arcPtr->startPoint[1]) / chordLen; chordCen[0] = (arcPtr->startPoint[0] + arcPtr->endPoint[0]) / 2; chordCen[1] = (arcPtr->startPoint[1] + arcPtr->endPoint[1]) / 2; /* * Calculate the radius (assumes height != 0). */ radius = (4*pow(arcPtr->height, 2) + pow(chordLen, 2)) / (8 * arcPtr->height); /* * The arc centre. */ d = radius - arcPtr->height; arcCen[0] = chordCen[0] - d * chordDir[1]; arcCen[1] = chordCen[1] + d * chordDir[0]; /* * The arc start and span. Angles are negated because the coordinate * system is left-handed. */ radToDeg = 45 / atan(1); arcPtr->start = atan2(arcCen[1] - arcPtr->startPoint[1], arcPtr->startPoint[0] - arcCen[0]) * radToDeg; arcPtr->extent = -2 * asin(chordLen / (2 * radius)) * radToDeg; /* * Handle spans > 180. */ if (fabs(2 * arcPtr->height) > chordLen) { arcPtr->extent = arcPtr->extent > 0 ? (360 - arcPtr->extent) : -(360 + arcPtr->extent); } /* * Create the bounding box. */ arcPtr->bbox[0] = arcCen[0] - radius; arcPtr->bbox[1] = arcCen[1] - radius; arcPtr->bbox[2] = arcCen[0] + radius; arcPtr->bbox[3] = arcCen[1] + radius; /* * Set the height to 0 so that itemcget -height returns 0. */ arcPtr->height = 0; } /* *-------------------------------------------------------------- * * 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( Tk_Canvas canvas, /* Info about overall canvas. */ Tk_Item *itemPtr, /* Item that is being deleted. */ Display *display) /* Display containing window for canvas. */ { ArcItem *arcPtr = (ArcItem *) itemPtr; (void)canvas; 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]) { double tmp = arcPtr->bbox[3]; arcPtr->bbox[3] = arcPtr->bbox[1]; arcPtr->bbox[1] = tmp; } if (arcPtr->bbox[0] > arcPtr->bbox[2]) { double 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. */ int x, int y, /* Describes region of canvas that must be */ int width, int height) /* redisplayed (not used). */ { ArcItem *arcPtr = (ArcItem *) itemPtr; short x1, y1, x2, y2; int start, extent, dashnumber; double lineWidth; Tk_State state = itemPtr->state; Pixmap stipple; (void)x; (void)y; (void)width; (void)height; 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); } /* *-------------------------------------------------------------- * * RotateArc -- * * This function is called to rotate an arc by a given amount. * * Results: * None. * * Side effects: * The position of the arc is rotated by angleRad radians about (originX, * originY), and the bounding box is updated in the generic part of the * item structure. * *-------------------------------------------------------------- */ static void RotateArc( Tk_Canvas canvas, Tk_Item *itemPtr, double originX, double originY, double angleRad) { ArcItem *arcPtr = (ArcItem *) itemPtr; double newX, newY, oldX, oldY; /* * Compute the centre of the box, then rotate that about the origin. */ newX = oldX = (arcPtr->bbox[0] + arcPtr->bbox[2]) / 2.0; newY = oldY = (arcPtr->bbox[1] + arcPtr->bbox[3]) / 2.0; TkRotatePoint(originX, originY, sin(angleRad), cos(angleRad), &newX, &newY); /* * Apply the translation to the box. */ arcPtr->bbox[0] += newX - oldX; arcPtr->bbox[1] += newY - oldY; arcPtr->bbox[2] += newX - oldX; arcPtr->bbox[3] += newY - oldY; /* * TODO: update the arc endpoints? */ 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. */ int prepass) /* 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; (void)prepass; 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( ClientData dummy, /* some flags.*/ Tcl_Interp *interp, /* Used for reporting errors. */ Tk_Window tkwin, /* 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); (void)dummy; (void)tkwin; 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( ClientData dummy, /* Ignored. */ Tk_Window tkwin, /* Ignored. */ char *widgRec, /* Pointer to record for item. */ int offset, /* Offset into item. */ Tcl_FreeProc **freeProcPtr) /* Pointer to variable to fill in with * information about how to reclaim storage * for return string. */ { Style *stylePtr = (Style *) (widgRec + offset); (void)dummy; (void)tkwin; (void)freeProcPtr; 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: */