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Diffstat (limited to 'generic/tkCanvArc.c')
| -rw-r--r-- | generic/tkCanvArc.c | 1716 |
1 files changed, 1716 insertions, 0 deletions
diff --git a/generic/tkCanvArc.c b/generic/tkCanvArc.c new file mode 100644 index 0000000..26b62e7 --- /dev/null +++ b/generic/tkCanvArc.c @@ -0,0 +1,1716 @@ +/* + * tkCanvArc.c -- + * + * This file implements arc items for canvas widgets. + * + * Copyright (c) 1992-1994 The Regents of the University of California. + * Copyright (c) 1994-1995 Sun Microsystems, Inc. + * + * See the file "license.terms" for information on usage and redistribution + * of this file, and for a DISCLAIMER OF ALL WARRANTIES. + * + * SCCS: @(#) tkCanvArc.c 1.34 97/04/25 16:50:56 + */ + +#include <stdio.h> +#include "tkPort.h" +#include "tkInt.h" + +/* + * The structure below defines the record for each arc item. + */ + +typedef struct ArcItem { + Tk_Item header; /* Generic stuff that's the same for all + * types. MUST BE FIRST IN 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. */ + int width; /* Width of outline (in pixels). */ + XColor *outlineColor; /* Color for outline. NULL means don't + * draw outline. */ + XColor *fillColor; /* Color for filling arc (used for drawing + * outline too when style is "arc"). NULL + * means don't fill arc. */ + Pixmap fillStipple; /* Stipple bitmap for filling item. */ + Pixmap outlineStipple; /* Stipple bitmap for outline. */ + Tk_Uid style; /* How to draw arc: arc, chord, or pieslice. */ + GC outlineGC; /* Graphics context for outline. */ + 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 Tk_CustomOption tagsOption = {Tk_CanvasTagsParseProc, + Tk_CanvasTagsPrintProc, (ClientData) NULL +}; + +static Tk_ConfigSpec configSpecs[] = { + {TK_CONFIG_DOUBLE, "-extent", (char *) NULL, (char *) NULL, + "90", Tk_Offset(ArcItem, extent), TK_CONFIG_DONT_SET_DEFAULT}, + {TK_CONFIG_COLOR, "-fill", (char *) NULL, (char *) NULL, + (char *) NULL, Tk_Offset(ArcItem, fillColor), TK_CONFIG_NULL_OK}, + {TK_CONFIG_COLOR, "-outline", (char *) NULL, (char *) NULL, + "black", Tk_Offset(ArcItem, outlineColor), TK_CONFIG_NULL_OK}, + {TK_CONFIG_BITMAP, "-outlinestipple", (char *) NULL, (char *) NULL, + (char *) NULL, Tk_Offset(ArcItem, outlineStipple), TK_CONFIG_NULL_OK}, + {TK_CONFIG_DOUBLE, "-start", (char *) NULL, (char *) NULL, + "0", Tk_Offset(ArcItem, start), TK_CONFIG_DONT_SET_DEFAULT}, + {TK_CONFIG_BITMAP, "-stipple", (char *) NULL, (char *) NULL, + (char *) NULL, Tk_Offset(ArcItem, fillStipple), TK_CONFIG_NULL_OK}, + {TK_CONFIG_UID, "-style", (char *) NULL, (char *) NULL, + "pieslice", Tk_Offset(ArcItem, style), TK_CONFIG_DONT_SET_DEFAULT}, + {TK_CONFIG_CUSTOM, "-tags", (char *) NULL, (char *) NULL, + (char *) NULL, 0, TK_CONFIG_NULL_OK, &tagsOption}, + {TK_CONFIG_PIXELS, "-width", (char *) NULL, (char *) NULL, + "1", Tk_Offset(ArcItem, width), TK_CONFIG_DONT_SET_DEFAULT}, + {TK_CONFIG_END, (char *) NULL, (char *) NULL, (char *) NULL, + (char *) NULL, 0, 0} +}; + +/* + * Prototypes for procedures defined in this file: + */ + +static void ComputeArcBbox _ANSI_ARGS_((Tk_Canvas canvas, + ArcItem *arcPtr)); +static int ConfigureArc _ANSI_ARGS_((Tcl_Interp *interp, + Tk_Canvas canvas, Tk_Item *itemPtr, int argc, + char **argv, int flags)); +static int CreateArc _ANSI_ARGS_((Tcl_Interp *interp, + Tk_Canvas canvas, struct Tk_Item *itemPtr, + int argc, char **argv)); +static void DeleteArc _ANSI_ARGS_((Tk_Canvas canvas, + Tk_Item *itemPtr, Display *display)); +static void DisplayArc _ANSI_ARGS_((Tk_Canvas canvas, + Tk_Item *itemPtr, Display *display, Drawable dst, + int x, int y, int width, int height)); +static int ArcCoords _ANSI_ARGS_((Tcl_Interp *interp, + Tk_Canvas canvas, Tk_Item *itemPtr, int argc, + char **argv)); +static int ArcToArea _ANSI_ARGS_((Tk_Canvas canvas, + Tk_Item *itemPtr, double *rectPtr)); +static double ArcToPoint _ANSI_ARGS_((Tk_Canvas canvas, + Tk_Item *itemPtr, double *coordPtr)); +static int ArcToPostscript _ANSI_ARGS_((Tcl_Interp *interp, + Tk_Canvas canvas, Tk_Item *itemPtr, int prepass)); +static void ScaleArc _ANSI_ARGS_((Tk_Canvas canvas, + Tk_Item *itemPtr, double originX, double originY, + double scaleX, double scaleY)); +static void TranslateArc _ANSI_ARGS_((Tk_Canvas canvas, + Tk_Item *itemPtr, double deltaX, double deltaY)); +static int AngleInRange _ANSI_ARGS_((double x, double y, + double start, double extent)); +static void ComputeArcOutline _ANSI_ARGS_((ArcItem *arcPtr)); +static int HorizLineToArc _ANSI_ARGS_((double x1, double x2, + double y, double rx, double ry, + double start, double extent)); +static int VertLineToArc _ANSI_ARGS_((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 procedures + * 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 */ + 0, /* alwaysRedraw */ + ArcToPoint, /* pointProc */ + ArcToArea, /* areaProc */ + ArcToPostscript, /* postscriptProc */ + ScaleArc, /* scaleProc */ + TranslateArc, /* translateProc */ + (Tk_ItemIndexProc *) NULL, /* indexProc */ + (Tk_ItemCursorProc *) NULL, /* icursorProc */ + (Tk_ItemSelectionProc *) NULL, /* selectionProc */ + (Tk_ItemInsertProc *) NULL, /* insertProc */ + (Tk_ItemDCharsProc *) NULL, /* dTextProc */ + (Tk_ItemType *) NULL /* nextPtr */ +}; + +#ifndef PI +# define PI 3.14159265358979323846 +#endif + +/* + * The uid's below comprise the legal values for the "-style" + * option for arcs. + */ + +static Tk_Uid arcUid = NULL; +static Tk_Uid chordUid = NULL; +static Tk_Uid pieSliceUid = NULL; + +/* + *-------------------------------------------------------------- + * + * CreateArc -- + * + * This procedure 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 + * interp->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(interp, canvas, itemPtr, argc, argv) + 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 argc; /* Number of arguments in argv. */ + char **argv; /* Arguments describing arc. */ +{ + ArcItem *arcPtr = (ArcItem *) itemPtr; + + if (argc < 4) { + Tcl_AppendResult(interp, "wrong # args: should be \"", + Tk_PathName(Tk_CanvasTkwin(canvas)), " create ", + itemPtr->typePtr->name, " x1 y1 x2 y2 ?options?\"", + (char *) NULL); + return TCL_ERROR; + } + + /* + * Carry out once-only initialization. + */ + + if (arcUid == NULL) { + arcUid = Tk_GetUid("arc"); + chordUid = Tk_GetUid("chord"); + pieSliceUid = Tk_GetUid("pieslice"); + } + + /* + * Carry out initialization that is needed in order to clean + * up after errors during the the remainder of this procedure. + */ + + arcPtr->start = 0; + arcPtr->extent = 90; + arcPtr->outlinePtr = NULL; + arcPtr->numOutlinePoints = 0; + arcPtr->width = 1; + arcPtr->outlineColor = NULL; + arcPtr->fillColor = NULL; + arcPtr->fillStipple = None; + arcPtr->outlineStipple = None; + arcPtr->style = pieSliceUid; + arcPtr->outlineGC = None; + arcPtr->fillGC = None; + + /* + * Process the arguments to fill in the item record. + */ + + if ((Tk_CanvasGetCoord(interp, canvas, argv[0], &arcPtr->bbox[0]) != TCL_OK) + || (Tk_CanvasGetCoord(interp, canvas, argv[1], + &arcPtr->bbox[1]) != TCL_OK) + || (Tk_CanvasGetCoord(interp, canvas, argv[2], + &arcPtr->bbox[2]) != TCL_OK) + || (Tk_CanvasGetCoord(interp, canvas, argv[3], + &arcPtr->bbox[3]) != TCL_OK)) { + return TCL_ERROR; + } + + if (ConfigureArc(interp, canvas, itemPtr, argc-4, argv+4, 0) != TCL_OK) { + DeleteArc(canvas, itemPtr, Tk_Display(Tk_CanvasTkwin(canvas))); + return TCL_ERROR; + } + return TCL_OK; +} + +/* + *-------------------------------------------------------------- + * + * ArcCoords -- + * + * This procedure 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 interp->result. + * + * Side effects: + * The coordinates for the given item may be changed. + * + *-------------------------------------------------------------- + */ + +static int +ArcCoords(interp, canvas, itemPtr, argc, argv) + 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 argc; /* Number of coordinates supplied in + * argv. */ + char **argv; /* Array of coordinates: x1, y1, + * x2, y2, ... */ +{ + ArcItem *arcPtr = (ArcItem *) itemPtr; + char c0[TCL_DOUBLE_SPACE], c1[TCL_DOUBLE_SPACE]; + char c2[TCL_DOUBLE_SPACE], c3[TCL_DOUBLE_SPACE]; + + if (argc == 0) { + Tcl_PrintDouble(interp, arcPtr->bbox[0], c0); + Tcl_PrintDouble(interp, arcPtr->bbox[1], c1); + Tcl_PrintDouble(interp, arcPtr->bbox[2], c2); + Tcl_PrintDouble(interp, arcPtr->bbox[3], c3); + Tcl_AppendResult(interp, c0, " ", c1, " ", c2, " ", c3, + (char *) NULL); + } else if (argc == 4) { + if ((Tk_CanvasGetCoord(interp, canvas, argv[0], + &arcPtr->bbox[0]) != TCL_OK) + || (Tk_CanvasGetCoord(interp, canvas, argv[1], + &arcPtr->bbox[1]) != TCL_OK) + || (Tk_CanvasGetCoord(interp, canvas, argv[2], + &arcPtr->bbox[2]) != TCL_OK) + || (Tk_CanvasGetCoord(interp, canvas, argv[3], + &arcPtr->bbox[3]) != TCL_OK)) { + return TCL_ERROR; + } + ComputeArcBbox(canvas, arcPtr); + } else { + sprintf(interp->result, + "wrong # coordinates: expected 0 or 4, got %d", + argc); + return TCL_ERROR; + } + return TCL_OK; +} + +/* + *-------------------------------------------------------------- + * + * ConfigureArc -- + * + * This procedure 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 interp->result. + * + * Side effects: + * Configuration information, such as colors and stipple + * patterns, may be set for itemPtr. + * + *-------------------------------------------------------------- + */ + +static int +ConfigureArc(interp, canvas, itemPtr, argc, argv, flags) + Tcl_Interp *interp; /* Used for error reporting. */ + Tk_Canvas canvas; /* Canvas containing itemPtr. */ + Tk_Item *itemPtr; /* Arc item to reconfigure. */ + int argc; /* Number of elements in argv. */ + char **argv; /* Arguments describing things to configure. */ + int flags; /* Flags to pass to Tk_ConfigureWidget. */ +{ + ArcItem *arcPtr = (ArcItem *) itemPtr; + XGCValues gcValues; + GC newGC; + unsigned long mask; + int i; + Tk_Window tkwin; + + tkwin = Tk_CanvasTkwin(canvas); + if (Tk_ConfigureWidget(interp, tkwin, configSpecs, argc, argv, + (char *) arcPtr, flags) != TCL_OK) { + return TCL_ERROR; + } + + /* + * A few of the options require additional processing, such as + * style and graphics contexts. + */ + + 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; + + if ((arcPtr->style != arcUid) && (arcPtr->style != chordUid) + && (arcPtr->style != pieSliceUid)) { + Tcl_AppendResult(interp, "bad -style option \"", + arcPtr->style, "\": must be arc, chord, or pieslice", + (char *) NULL); + arcPtr->style = pieSliceUid; + return TCL_ERROR; + } + + if (arcPtr->width < 0) { + arcPtr->width = 1; + } + if (arcPtr->outlineColor == NULL) { + newGC = None; + } else { + gcValues.foreground = arcPtr->outlineColor->pixel; + gcValues.cap_style = CapButt; + gcValues.line_width = arcPtr->width; + mask = GCForeground|GCCapStyle|GCLineWidth; + if (arcPtr->outlineStipple != None) { + gcValues.stipple = arcPtr->outlineStipple; + gcValues.fill_style = FillStippled; + mask |= GCStipple|GCFillStyle; + } + newGC = Tk_GetGC(tkwin, mask, &gcValues); + } + if (arcPtr->outlineGC != None) { + Tk_FreeGC(Tk_Display(tkwin), arcPtr->outlineGC); + } + arcPtr->outlineGC = newGC; + + if ((arcPtr->fillColor == NULL) || (arcPtr->style == arcUid)) { + newGC = None; + } else { + gcValues.foreground = arcPtr->fillColor->pixel; + if (arcPtr->style == chordUid) { + gcValues.arc_mode = ArcChord; + } else { + gcValues.arc_mode = ArcPieSlice; + } + mask = GCForeground|GCArcMode; + if (arcPtr->fillStipple != None) { + gcValues.stipple = arcPtr->fillStipple; + gcValues.fill_style = FillStippled; + mask |= GCStipple|GCFillStyle; + } + newGC = Tk_GetGC(tkwin, mask, &gcValues); + } + if (arcPtr->fillGC != None) { + Tk_FreeGC(Tk_Display(tkwin), arcPtr->fillGC); + } + arcPtr->fillGC = newGC; + + ComputeArcBbox(canvas, arcPtr); + return TCL_OK; +} + +/* + *-------------------------------------------------------------- + * + * DeleteArc -- + * + * This procedure is called to clean up the data structure + * associated with a arc item. + * + * Results: + * None. + * + * Side effects: + * Resources associated with itemPtr are released. + * + *-------------------------------------------------------------- + */ + +static void +DeleteArc(canvas, itemPtr, display) + 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; + + if (arcPtr->numOutlinePoints != 0) { + ckfree((char *) arcPtr->outlinePtr); + } + if (arcPtr->outlineColor != NULL) { + Tk_FreeColor(arcPtr->outlineColor); + } + if (arcPtr->fillColor != NULL) { + Tk_FreeColor(arcPtr->fillColor); + } + if (arcPtr->fillStipple != None) { + Tk_FreeBitmap(display, arcPtr->fillStipple); + } + if (arcPtr->outlineStipple != None) { + Tk_FreeBitmap(display, arcPtr->outlineStipple); + } + if (arcPtr->outlineGC != None) { + Tk_FreeGC(display, arcPtr->outlineGC); + } + if (arcPtr->fillGC != None) { + Tk_FreeGC(display, arcPtr->fillGC); + } +} + +/* + *-------------------------------------------------------------- + * + * ComputeArcBbox -- + * + * This procedure 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. + * + *-------------------------------------------------------------- + */ + + /* ARGSUSED */ +static void +ComputeArcBbox(canvas, arcPtr) + Tk_Canvas canvas; /* Canvas that contains item. */ + ArcItem *arcPtr; /* Item whose bbox is to be + * recomputed. */ +{ + double tmp, center[2], point[2]; + + /* + * Make sure that the first coordinates are the lowest ones. + */ + + if (arcPtr->bbox[1] > arcPtr->bbox[3]) { + double tmp; + tmp = arcPtr->bbox[3]; + arcPtr->bbox[3] = arcPtr->bbox[1]; + arcPtr->bbox[1] = tmp; + } + if (arcPtr->bbox[0] > arcPtr->bbox[2]) { + double tmp; + tmp = arcPtr->bbox[2]; + arcPtr->bbox[2] = arcPtr->bbox[0]; + arcPtr->bbox[0] = tmp; + } + + ComputeArcOutline(arcPtr); + + /* + * To compute the bounding box, start with the 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 != arcUid) { + 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->outlineColor == NULL) { + tmp = 1; + } else { + tmp = (arcPtr->width + 1)/2 + 1; + } + arcPtr->header.x1 -= (int) tmp; + arcPtr->header.y1 -= (int) tmp; + arcPtr->header.x2 += (int) tmp; + arcPtr->header.y2 += (int) tmp; +} + +/* + *-------------------------------------------------------------- + * + * DisplayArc -- + * + * This procedure 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(canvas, itemPtr, display, drawable, x, y, width, height) + Tk_Canvas canvas; /* Canvas that contains item. */ + Tk_Item *itemPtr; /* Item to be displayed. */ + Display *display; /* Display on which to draw item. */ + Drawable drawable; /* Pixmap or window in which to draw + * item. */ + int x, y, width, height; /* Describes region of canvas that + * must be redisplayed (not used). */ +{ + ArcItem *arcPtr = (ArcItem *) itemPtr; + short x1, y1, x2, y2; + int start, extent; + + /* + * 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 != None) && (extent != 0)) { + if (arcPtr->fillStipple != None) { + Tk_CanvasSetStippleOrigin(canvas, arcPtr->fillGC); + } + XFillArc(display, drawable, arcPtr->fillGC, x1, y1, (unsigned) (x2-x1), + (unsigned) (y2-y1), start, extent); + if (arcPtr->fillStipple != None) { + XSetTSOrigin(display, arcPtr->fillGC, 0, 0); + } + } + if (arcPtr->outlineGC != None) { + if (arcPtr->outlineStipple != None) { + Tk_CanvasSetStippleOrigin(canvas, arcPtr->outlineGC); + } + if (extent != 0) { + XDrawArc(display, drawable, arcPtr->outlineGC, 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. + */ + + if (arcPtr->width <= 2) { + 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 == chordUid) { + XDrawLine(display, drawable, arcPtr->outlineGC, + x1, y1, x2, y2); + } else if (arcPtr->style == pieSliceUid) { + 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->outlineGC, + cx, cy, x1, y1); + XDrawLine(display, drawable, arcPtr->outlineGC, + cx, cy, x2, y2); + } + } else { + if (arcPtr->style == chordUid) { + TkFillPolygon(canvas, arcPtr->outlinePtr, CHORD_OUTLINE_PTS, + display, drawable, arcPtr->outlineGC, None); + } else if (arcPtr->style == pieSliceUid) { + TkFillPolygon(canvas, arcPtr->outlinePtr, PIE_OUTLINE1_PTS, + display, drawable, arcPtr->outlineGC, None); + TkFillPolygon(canvas, arcPtr->outlinePtr + 2*PIE_OUTLINE1_PTS, + PIE_OUTLINE2_PTS, display, drawable, arcPtr->outlineGC, + None); + } + } + if (arcPtr->outlineStipple != None) { + XSetTSOrigin(display, arcPtr->outlineGC, 0, 0); + } + } +} + +/* + *-------------------------------------------------------------- + * + * 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. + * + *-------------------------------------------------------------- + */ + + /* ARGSUSED */ +static double +ArcToPoint(canvas, itemPtr, pointPtr) + Tk_Canvas canvas; /* Canvas containing item. */ + Tk_Item *itemPtr; /* Item to check against point. */ + double *pointPtr; /* Pointer to x and y coordinates. */ +{ + ArcItem *arcPtr = (ArcItem *) itemPtr; + double vertex[2], pointAngle, diff, dist, newDist; + double poly[8], polyDist, width, t1, t2; + int filled, angleInRange; + + /* + * 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 = (pointPtr[1] - vertex[1])/(arcPtr->bbox[3] - arcPtr->bbox[1]); + t2 = (pointPtr[0] - vertex[0])/(arcPtr->bbox[2] - arcPtr->bbox[0]); + 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 == arcUid) { + if (angleInRange) { + return TkOvalToPoint(arcPtr->bbox, (double) arcPtr->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 != None) || (arcPtr->outlineGC == None)) { + filled = 1; + } else { + filled = 0; + } + if (arcPtr->outlineGC == None) { + width = 0.0; + } else { + width = arcPtr->width; + } + + if (arcPtr->style == pieSliceUid) { + 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 procedure 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. + * + *-------------------------------------------------------------- + */ + + /* ARGSUSED */ +static int +ArcToArea(canvas, itemPtr, rectPtr) + 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; + + if ((arcPtr->fillGC != None) || (arcPtr->outlineGC == None)) { + filled = 1; + } else { + filled = 0; + } + if (arcPtr->outlineGC == None) { + width = 0.0; + } else { + width = arcPtr->width; + } + + /* + * 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 == pieSliceUid) && (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 == pieSliceUid) { + 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 == chordUid) { + 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 procedure 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(canvas, itemPtr, originX, originY, scaleX, scaleY) + Tk_Canvas canvas; /* Canvas containing arc. */ + Tk_Item *itemPtr; /* Arc to be scaled. */ + double originX, originY; /* Origin about which to scale rect. */ + double scaleX; /* Amount to scale in X direction. */ + double scaleY; /* Amount to scale in Y direction. */ +{ + 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 procedure 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(canvas, itemPtr, deltaX, deltaY) + Tk_Canvas canvas; /* Canvas containing item. */ + Tk_Item *itemPtr; /* Item that is being moved. */ + double deltaX, deltaY; /* Amount by which item is to be + * moved. */ +{ + 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 procedure 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(arcPtr) + ArcItem *arcPtr; /* Information about arc. */ +{ + double sin1, cos1, sin2, cos2, angle, halfWidth; + double boxWidth, boxHeight; + double vertex[2], corner1[2], corner2[2]; + double *outlinePtr; + + /* + * 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((unsigned) + (26 * sizeof(double))); + arcPtr->numOutlinePoints = 22; + } + outlinePtr = arcPtr->outlinePtr; + + /* + * 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)/(boxHeight*cos1), and similarly for arcPtr->center2 + * and corner2. These formulas can be computed from the formula for + * the oval. + */ + + halfWidth = arcPtr->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 == chordUid) { + outlinePtr[0] = outlinePtr[12] = corner1[0]; + outlinePtr[1] = outlinePtr[13] = corner1[1]; + TkGetButtPoints(arcPtr->center2, arcPtr->center1, + (double) arcPtr->width, 0, outlinePtr+10, outlinePtr+2); + outlinePtr[4] = arcPtr->center2[0] + outlinePtr[2] + - arcPtr->center1[0]; + outlinePtr[5] = arcPtr->center2[1] + outlinePtr[3] + - arcPtr->center1[1]; + outlinePtr[6] = corner2[0]; + outlinePtr[7] = corner2[1]; + outlinePtr[8] = arcPtr->center2[0] + outlinePtr[10] + - arcPtr->center1[0]; + outlinePtr[9] = arcPtr->center2[1] + outlinePtr[11] + - arcPtr->center1[1]; + } else if (arcPtr->style == pieSliceUid) { + /* + * For pie slices, generate two polygons, one for each side + * of the pie slice. The first arm has a shape like this, + * where the center of the oval is X, arcPtr->center1 is at Y, and + * corner1 is at Z: + * + * _____________________ + * | \ + * | \ + * X Y Z + * | / + * |_____________________/ + * + */ + + TkGetButtPoints(arcPtr->center1, vertex, (double) arcPtr->width, 0, + outlinePtr, outlinePtr+2); + outlinePtr[4] = arcPtr->center1[0] + outlinePtr[2] - vertex[0]; + outlinePtr[5] = arcPtr->center1[1] + outlinePtr[3] - vertex[1]; + outlinePtr[6] = corner1[0]; + outlinePtr[7] = corner1[1]; + outlinePtr[8] = arcPtr->center1[0] + outlinePtr[0] - vertex[0]; + outlinePtr[9] = arcPtr->center1[1] + outlinePtr[1] - vertex[1]; + outlinePtr[10] = outlinePtr[0]; + outlinePtr[11] = outlinePtr[1]; + + /* + * The second arm has a shape like this: + * + * + * ______________________ + * / \ + * / \ + * Z Y X / + * \ / + * \______________________/ + * + * Similar to above X is the center of the oval/circle, Y is + * arcPtr->center2, and Z is corner2. The extra jog out to the left + * of X is needed in or to produce a butted joint with the + * first arm; the corner to the right of X is one of the + * first two points of the first arm, depending on extent. + */ + + TkGetButtPoints(arcPtr->center2, vertex, (double) arcPtr->width, 0, + outlinePtr+12, outlinePtr+16); + if ((arcPtr->extent > 180) || + ((arcPtr->extent < 0) && (arcPtr->extent > -180))) { + outlinePtr[14] = outlinePtr[0]; + outlinePtr[15] = outlinePtr[1]; + } else { + outlinePtr[14] = outlinePtr[2]; + outlinePtr[15] = outlinePtr[3]; + } + outlinePtr[18] = arcPtr->center2[0] + outlinePtr[16] - vertex[0]; + outlinePtr[19] = arcPtr->center2[1] + outlinePtr[17] - vertex[1]; + outlinePtr[20] = corner2[0]; + outlinePtr[21] = corner2[1]; + outlinePtr[22] = arcPtr->center2[0] + outlinePtr[12] - vertex[0]; + outlinePtr[23] = arcPtr->center2[1] + outlinePtr[13] - vertex[1]; + outlinePtr[24] = outlinePtr[12]; + outlinePtr[25] = outlinePtr[13]; + } +} + +/* + *-------------------------------------------------------------- + * + * HorizLineToArc -- + * + * Determines whether a horizontal line segment intersects + * a given arc. + * + * Results: + * The return value is 1 if the given line intersects the + * infinitely-thin arc section defined by rx, ry, start, + * and extent, and 0 otherwise. Only the perimeter of the + * arc is checked: interior areas (e.g. pie-slice or chord) + * are not checked. + * + * Side effects: + * None. + * + *-------------------------------------------------------------- + */ + +static int +HorizLineToArc(x1, x2, y, rx, ry, start, extent) + double x1, x2; /* X-coords of endpoints of line segment. + * X1 must be <= x2. */ + double y; /* Y-coordinate of line segment. */ + double rx, ry; /* These x- and y-radii define an oval + * centered at the origin. */ + double start, extent; /* Angles that define extent of arc, in + * the standard fashion for this module. */ +{ + double tmp; + double tx, ty; /* Coordinates of intersection point in + * transformed coordinate system. */ + double x; + + /* + * Compute the x-coordinate of one possible intersection point + * between the arc and the line. Use a transformed coordinate + * system where the oval is a unit circle centered at the origin. + * Then scale back to get actual x-coordinate. + */ + + ty = y/ry; + tmp = 1 - ty*ty; + if (tmp < 0) { + return 0; + } + tx = sqrt(tmp); + x = tx*rx; + + /* + * Test both intersection points. + */ + + if ((x >= x1) && (x <= x2) && AngleInRange(tx, ty, start, extent)) { + return 1; + } + if ((-x >= x1) && (-x <= x2) && AngleInRange(-tx, ty, start, extent)) { + return 1; + } + return 0; +} + +/* + *-------------------------------------------------------------- + * + * VertLineToArc -- + * + * Determines whether a vertical line segment intersects + * a given arc. + * + * Results: + * The return value is 1 if the given line intersects the + * infinitely-thin arc section defined by rx, ry, start, + * and extent, and 0 otherwise. Only the perimeter of the + * arc is checked: interior areas (e.g. pie-slice or chord) + * are not checked. + * + * Side effects: + * None. + * + *-------------------------------------------------------------- + */ + +static int +VertLineToArc(x, y1, y2, rx, ry, start, extent) + double x; /* X-coordinate of line segment. */ + double y1, y2; /* Y-coords of endpoints of line segment. + * Y1 must be <= y2. */ + double rx, ry; /* These x- and y-radii define an oval + * centered at the origin. */ + double start, extent; /* Angles that define extent of arc, in + * the standard fashion for this module. */ +{ + double tmp; + double tx, ty; /* Coordinates of intersection point in + * transformed coordinate system. */ + double y; + + /* + * Compute the y-coordinate of one possible intersection point + * between the arc and the line. Use a transformed coordinate + * system where the oval is a unit circle centered at the origin. + * Then scale back to get actual y-coordinate. + */ + + tx = x/rx; + tmp = 1 - tx*tx; + if (tmp < 0) { + return 0; + } + ty = sqrt(tmp); + y = ty*ry; + + /* + * Test both intersection points. + */ + + if ((y > y1) && (y < y2) && AngleInRange(tx, ty, start, extent)) { + return 1; + } + if ((-y > y1) && (-y < y2) && AngleInRange(tx, -ty, start, extent)) { + return 1; + } + return 0; +} + +/* + *-------------------------------------------------------------- + * + * AngleInRange -- + * + * Determine whether the angle from the origin to a given + * point is within a given range. + * + * Results: + * The return value is 1 if the angle from (0,0) to (x,y) + * is in the range given by start and extent, where angles + * are interpreted in the standard way for ovals (meaning + * backwards from normal interpretation). Otherwise the + * return value is 0. + * + * Side effects: + * None. + * + *-------------------------------------------------------------- + */ + +static int +AngleInRange(x, y, start, extent) + double x, y; /* Coordinate of point; angle measured + * from origin to here, relative to x-axis. */ + double start; /* First angle, degrees, >=0, <=360. */ + double extent; /* Size of arc in degrees >=-360, <=360. */ +{ + double diff; + + if ((x == 0.0) && (y == 0.0)) { + return 1; + } + diff = -atan2(y, x); + diff = diff*(180.0/PI) - start; + while (diff > 360.0) { + diff -= 360.0; + } + while (diff < 0.0) { + diff += 360.0; + } + if (extent >= 0) { + return diff <= extent; + } + return (diff-360.0) >= extent; +} + +/* + *-------------------------------------------------------------- + * + * ArcToPostscript -- + * + * This procedure is called to generate Postscript for + * arc items. + * + * Results: + * The return value is a standard Tcl result. If an error + * occurs in generating Postscript then an error message is + * left in interp->result, replacing whatever used + * to be there. If no error occurs, then Postscript for the + * item is appended to the result. + * + * Side effects: + * None. + * + *-------------------------------------------------------------- + */ + +static int +ArcToPostscript(interp, canvas, itemPtr, prepass) + Tcl_Interp *interp; /* Leave Postscript or error message + * here. */ + Tk_Canvas canvas; /* Information about overall canvas. */ + Tk_Item *itemPtr; /* Item for which Postscript is + * wanted. */ + int prepass; /* 1 means this is a prepass to + * collect font information; 0 means + * final Postscript is being created. */ +{ + ArcItem *arcPtr = (ArcItem *) itemPtr; + char buffer[400]; + double y1, y2, ang1, ang2; + + y1 = Tk_CanvasPsY(canvas, arcPtr->bbox[1]); + y2 = Tk_CanvasPsY(canvas, arcPtr->bbox[3]); + ang1 = arcPtr->start; + ang2 = ang1 + arcPtr->extent; + if (ang2 < ang1) { + ang1 = ang2; + ang2 = arcPtr->start; + } + + /* + * If the arc is filled, output Postscript for the interior region + * of the arc. + */ + + if (arcPtr->fillGC != None) { + sprintf(buffer, "matrix currentmatrix\n%.15g %.15g translate %.15g %.15g scale\n", + (arcPtr->bbox[0] + arcPtr->bbox[2])/2, (y1 + y2)/2, + (arcPtr->bbox[2] - arcPtr->bbox[0])/2, (y1 - y2)/2); + Tcl_AppendResult(interp, buffer, (char *) NULL); + if (arcPtr->style == chordUid) { + sprintf(buffer, "0 0 1 %.15g %.15g arc closepath\nsetmatrix\n", + ang1, ang2); + } else { + sprintf(buffer, + "0 0 moveto 0 0 1 %.15g %.15g arc closepath\nsetmatrix\n", + ang1, ang2); + } + Tcl_AppendResult(interp, buffer, (char *) NULL); + if (Tk_CanvasPsColor(interp, canvas, arcPtr->fillColor) != TCL_OK) { + return TCL_ERROR; + }; + if (arcPtr->fillStipple != None) { + Tcl_AppendResult(interp, "clip ", (char *) NULL); + if (Tk_CanvasPsStipple(interp, canvas, arcPtr->fillStipple) + != TCL_OK) { + return TCL_ERROR; + } + if (arcPtr->outlineGC != None) { + Tcl_AppendResult(interp, "grestore gsave\n", (char *) NULL); + } + } else { + Tcl_AppendResult(interp, "fill\n", (char *) NULL); + } + } + + /* + * If there's an outline for the arc, draw it. + */ + + if (arcPtr->outlineGC != None) { + sprintf(buffer, "matrix currentmatrix\n%.15g %.15g translate %.15g %.15g scale\n", + (arcPtr->bbox[0] + arcPtr->bbox[2])/2, (y1 + y2)/2, + (arcPtr->bbox[2] - arcPtr->bbox[0])/2, (y1 - y2)/2); + Tcl_AppendResult(interp, buffer, (char *) NULL); + sprintf(buffer, "0 0 1 %.15g %.15g arc\nsetmatrix\n", ang1, ang2); + Tcl_AppendResult(interp, buffer, (char *) NULL); + sprintf(buffer, "%d setlinewidth\n0 setlinecap\n", arcPtr->width); + Tcl_AppendResult(interp, buffer, (char *) NULL); + if (Tk_CanvasPsColor(interp, canvas, arcPtr->outlineColor) + != TCL_OK) { + return TCL_ERROR; + } + if (arcPtr->outlineStipple != None) { + Tcl_AppendResult(interp, "StrokeClip ", (char *) NULL); + if (Tk_CanvasPsStipple(interp, canvas, + arcPtr->outlineStipple) != TCL_OK) { + return TCL_ERROR; + } + } else { + Tcl_AppendResult(interp, "stroke\n", (char *) NULL); + } + if (arcPtr->style != arcUid) { + Tcl_AppendResult(interp, "grestore gsave\n", (char *) NULL); + if (arcPtr->style == chordUid) { + Tk_CanvasPsPath(interp, canvas, arcPtr->outlinePtr, + CHORD_OUTLINE_PTS); + } else { + Tk_CanvasPsPath(interp, canvas, arcPtr->outlinePtr, + PIE_OUTLINE1_PTS); + if (Tk_CanvasPsColor(interp, canvas, arcPtr->outlineColor) + != TCL_OK) { + return TCL_ERROR; + } + if (arcPtr->outlineStipple != None) { + Tcl_AppendResult(interp, "clip ", (char *) NULL); + if (Tk_CanvasPsStipple(interp, canvas, + arcPtr->outlineStipple) != TCL_OK) { + return TCL_ERROR; + } + } else { + Tcl_AppendResult(interp, "fill\n", (char *) NULL); + } + Tcl_AppendResult(interp, "grestore gsave\n", (char *) NULL); + Tk_CanvasPsPath(interp, canvas, + arcPtr->outlinePtr + 2*PIE_OUTLINE1_PTS, + PIE_OUTLINE2_PTS); + } + if (Tk_CanvasPsColor(interp, canvas, arcPtr->outlineColor) + != TCL_OK) { + return TCL_ERROR; + } + if (arcPtr->outlineStipple != None) { + Tcl_AppendResult(interp, "clip ", (char *) NULL); + if (Tk_CanvasPsStipple(interp, canvas, + arcPtr->outlineStipple) != TCL_OK) { + return TCL_ERROR; + } + } else { + Tcl_AppendResult(interp, "fill\n", (char *) NULL); + } + } + } + + return TCL_OK; +} |