/* * Smithsonian Astrophysical Observatory, Cambridge, MA, USA * This code has been modified under the terms listed below and is made * available under the same terms. */ /* * bltGrMisc.c -- * * This module implements miscellaneous routines for the BLT graph widget. * * Copyright 1993-2004 George A Howlett. * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #include #include #include #include #include "bltInt.h" #include "bltGraph.h" static Blt_OptionParseProc ObjToPoint; static Blt_OptionPrintProc PointToObj; Blt_CustomOption bltPointOption = { ObjToPoint, PointToObj, NULL, (ClientData)0 }; /* *--------------------------------------------------------------------------- * Custom option parse and print procedures *--------------------------------------------------------------------------- */ /* *--------------------------------------------------------------------------- * * Blt_GetXY -- * * Converts a string in the form "@x,y" into an XPoint structure of the x * and y coordinates. * * Results: * A standard TCL result. If the string represents a valid position * *pointPtr* will contain the converted x and y coordinates and TCL_OK * is returned. Otherwise, TCL_ERROR is returned and interp->result will * contain an error message. * *--------------------------------------------------------------------------- */ int Blt_GetXY(Tcl_Interp *interp, Tk_Window tkwin, const char *string, int *xPtr, int *yPtr) { char *comma; int result; int x, y; if ((string == NULL) || (*string == '\0')) { *xPtr = *yPtr = -SHRT_MAX; return TCL_OK; } if (*string != '@') { goto badFormat; } comma = strchr(string + 1, ','); if (comma == NULL) { goto badFormat; } *comma = '\0'; result = ((Tk_GetPixels(interp, tkwin, string + 1, &x) == TCL_OK) && (Tk_GetPixels(interp, tkwin, comma + 1, &y) == TCL_OK)); *comma = ','; if (!result) { Tcl_AppendResult(interp, ": can't parse position \"", string, "\"", (char *)NULL); return TCL_ERROR; } *xPtr = x, *yPtr = y; return TCL_OK; badFormat: Tcl_AppendResult(interp, "bad position \"", string, "\": should be \"@x,y\"", (char *)NULL); return TCL_ERROR; } /* *--------------------------------------------------------------------------- * * ObjToPoint -- * * Convert the string representation of a legend XY position into window * coordinates. The form of the string must be "@x,y" or none. * * Results: * A standard TCL result. The symbol type is written into the * widget record. * *--------------------------------------------------------------------------- */ /*ARGSUSED*/ static int ObjToPoint( ClientData clientData, /* Not used. */ Tcl_Interp *interp, /* Interpreter to send results back to */ Tk_Window tkwin, /* Not used. */ Tcl_Obj *objPtr, /* New legend position string */ char *widgRec, /* Widget record */ int offset, /* Offset to field in structure */ int flags) /* Not used. */ { XPoint *pointPtr = (XPoint *)(widgRec + offset); int x, y; if (Blt_GetXY(interp, tkwin, Tcl_GetString(objPtr), &x, &y) != TCL_OK) { return TCL_ERROR; } pointPtr->x = x, pointPtr->y = y; return TCL_OK; } /* *--------------------------------------------------------------------------- * * PointToObj -- * * Convert the window coordinates into a string. * * Results: * The string representing the coordinate position is returned. * *--------------------------------------------------------------------------- */ /*ARGSUSED*/ static Tcl_Obj * PointToObj( ClientData clientData, /* Not used. */ Tcl_Interp *interp, /* Not used. */ Tk_Window tkwin, /* Not used. */ char *widgRec, /* Widget record */ int offset, /* Offset to field in structure */ int flags) /* Not used. */ { XPoint *pointPtr = (XPoint *)(widgRec + offset); Tcl_Obj *objPtr; if ((pointPtr->x != -SHRT_MAX) && (pointPtr->y != -SHRT_MAX)) { char string[200]; sprintf_s(string, 200, "@%d,%d", pointPtr->x, pointPtr->y); objPtr = Tcl_NewStringObj(string, -1); } else { objPtr = Tcl_NewStringObj("", -1); } return objPtr; } int Blt_PointInSegments( Point2d *samplePtr, Segment2d *segments, int nSegments, double halo) { Segment2d *sp, *send; double minDist; minDist = DBL_MAX; for (sp = segments, send = sp + nSegments; sp < send; sp++) { double dist; double left, right, top, bottom; Point2d p, t; t = Blt_GetProjection((int)samplePtr->x, (int)samplePtr->y, &sp->p, &sp->q); if (sp->p.x > sp->q.x) { right = sp->p.x, left = sp->q.x; } else { right = sp->q.x, left = sp->p.x; } if (sp->p.y > sp->q.y) { bottom = sp->p.y, top = sp->q.y; } else { bottom = sp->q.y, top = sp->p.y; } p.x = BOUND(t.x, left, right); p.y = BOUND(t.y, top, bottom); dist = hypot(p.x - samplePtr->x, p.y - samplePtr->y); if (dist < minDist) { minDist = dist; } } return (minDist < halo); } int Blt_PointInPolygon( Point2d *s, /* Sample point. */ Point2d *points, /* Points representing the polygon. */ int nPoints) /* # of points in above array. */ { Point2d *p, *q, *qend; int count; count = 0; for (p = points, q = p + 1, qend = p + nPoints; q < qend; p++, q++) { if (((p->y <= s->y) && (s->y < q->y)) || ((q->y <= s->y) && (s->y < p->y))) { double b; b = (q->x - p->x) * (s->y - p->y) / (q->y - p->y) + p->x; if (s->x < b) { count++; /* Count the number of intersections. */ } } } return (count & 0x01); } int Blt_RegionInPolygon( Region2d *regionPtr, Point2d *points, int nPoints, int enclosed) { Point2d *pp, *pend; if (enclosed) { /* * All points of the polygon must be inside the rectangle. */ for (pp = points, pend = pp + nPoints; pp < pend; pp++) { if ((pp->x < regionPtr->left) || (pp->x > regionPtr->right) || (pp->y < regionPtr->top) || (pp->y > regionPtr->bottom)) { return FALSE; /* One point is exterior. */ } } return TRUE; } else { Point2d r; /* * If any segment of the polygon clips the bounding region, the * polygon overlaps the rectangle. */ points[nPoints] = points[0]; for (pp = points, pend = pp + nPoints; pp < pend; pp++) { Point2d p, q; p = *pp; q = *(pp + 1); if (Blt_LineRectClip(regionPtr, &p, &q)) { return TRUE; } } /* * Otherwise the polygon and rectangle are either disjoint or * enclosed. Check if one corner of the rectangle is inside the * polygon. */ r.x = regionPtr->left; r.y = regionPtr->top; return Blt_PointInPolygon(&r, points, nPoints); } } /* *--------------------------------------------------------------------------- * * Blt_GraphExtents -- * * Generates a bounding box representing the plotting area of the * graph. This data structure is used to clip the points and line * segments of the line element. * * The clip region is the plotting area plus such arbitrary extra space. * The reason we clip with a bounding box larger than the plot area is so * that symbols will be drawn even if their center point isn't in the * plotting area. * * Results: * None. * * Side Effects: * The bounding box is filled with the dimensions of the plotting area. * *--------------------------------------------------------------------------- */ void Blt_GraphExtents(Graph *graphPtr, Region2d *regionPtr) { regionPtr->left = (double)(graphPtr->hOffset - graphPtr->xPad); regionPtr->top = (double)(graphPtr->vOffset - graphPtr->yPad); regionPtr->right = (double)(graphPtr->hOffset + graphPtr->hRange + graphPtr->xPad); regionPtr->bottom = (double)(graphPtr->vOffset + graphPtr->vRange + graphPtr->yPad); } static int ClipTest (double ds, double dr, double *t1, double *t2) { double t; if (ds < 0.0) { t = dr / ds; if (t > *t2) { return FALSE; } if (t > *t1) { *t1 = t; } } else if (ds > 0.0) { t = dr / ds; if (t < *t1) { return FALSE; } if (t < *t2) { *t2 = t; } } else { /* d = 0, so line is parallel to this clipping edge */ if (dr < 0.0) { /* Line is outside clipping edge */ return FALSE; } } return TRUE; } /* *--------------------------------------------------------------------------- * * Blt_LineRectClip -- * * Clips the given line segment to a rectangular region. The coordinates * of the clipped line segment are returned. The original coordinates * are overwritten. * * Reference: * Liang, Y-D., and B. Barsky, A new concept and method for * Line Clipping, ACM, TOG,3(1), 1984, pp.1-22. * * Results: * Returns if line segment is visible within the region. The coordinates * of the original line segment are overwritten by the clipped * coordinates. * *--------------------------------------------------------------------------- */ int Blt_LineRectClip( Region2d *regionPtr, /* Rectangular region to clip. */ Point2d *p, Point2d *q) /* (in/out) Coordinates of original and * clipped line segment. */ { double t1, t2; double dx, dy; t1 = 0.0, t2 = 1.0; dx = q->x - p->x; if ((ClipTest (-dx, p->x - regionPtr->left, &t1, &t2)) && (ClipTest (dx, regionPtr->right - p->x, &t1, &t2))) { dy = q->y - p->y; if ((ClipTest (-dy, p->y - regionPtr->top, &t1, &t2)) && (ClipTest (dy, regionPtr->bottom - p->y, &t1, &t2))) { if (t2 < 1.0) { q->x = p->x + t2 * dx; q->y = p->y + t2 * dy; } if (t1 > 0.0) { p->x += t1 * dx; p->y += t1 * dy; } return TRUE; } } return FALSE; } /* *--------------------------------------------------------------------------- * * Blt_PolyRectClip -- * * Clips the given polygon to a rectangular region. The resulting * polygon is returned. Note that the resulting polyon may be complex, * connected by zero width/height segments. The drawing routine (such as * XFillPolygon) will not draw a connecting segment. * * Reference: * Liang Y. D. and Brian A. Barsky, "Analysis and Algorithm for * Polygon Clipping", Communications of ACM, Vol. 26, * p.868-877, 1983 * * Results: * Returns the number of points in the clipped polygon. The points of the * clipped polygon are stored in *outputPts*. * *--------------------------------------------------------------------------- */ #define EPSILON FLT_EPSILON #define AddVertex(vx, vy) r->x=(vx), r->y=(vy), r++, count++ #define LastVertex(vx, vy) r->x=(vx), r->y=(vy), count++ int Blt_PolyRectClip( Region2d *regionPtr, /* Rectangular region clipping the polygon. */ Point2d *points, /* Points of polygon to be clipped. */ int nPoints, /* # of points in polygon. */ Point2d *clipPts) /* (out) Points of clipped polygon. */ { Point2d *p; /* First vertex of input polygon edge. */ Point2d *pend; Point2d *q; /* Last vertex of input polygon edge. */ Point2d *r; int count; r = clipPts; count = 0; /* Counts # of vertices in output polygon. */ points[nPoints] = points[0]; for (p = points, q = p + 1, pend = p + nPoints; p < pend; p++, q++) { double dx, dy; double tin1, tin2, tinx, tiny; double xin, yin, xout, yout; dx = q->x - p->x; /* X-direction */ dy = q->y - p->y; /* Y-direction */ if (fabs(dx) < EPSILON) { dx = (p->x > regionPtr->left) ? -EPSILON : EPSILON ; } if (fabs(dy) < EPSILON) { dy = (p->y > regionPtr->top) ? -EPSILON : EPSILON ; } if (dx > 0.0) { /* Left */ xin = regionPtr->left; xout = regionPtr->right + 1.0; } else { /* Right */ xin = regionPtr->right + 1.0; xout = regionPtr->left; } if (dy > 0.0) { /* Top */ yin = regionPtr->top; yout = regionPtr->bottom + 1.0; } else { /* Bottom */ yin = regionPtr->bottom + 1.0; yout = regionPtr->top; } tinx = (xin - p->x) / dx; tiny = (yin - p->y) / dy; if (tinx < tiny) { /* Hits x first */ tin1 = tinx; tin2 = tiny; } else { /* Hits y first */ tin1 = tiny; tin2 = tinx; } if (tin1 <= 1.0) { if (tin1 > 0.0) { AddVertex(xin, yin); } if (tin2 <= 1.0) { double toutx, touty, tout1; toutx = (xout - p->x) / dx; touty = (yout - p->y) / dy; tout1 = MIN(toutx, touty); if ((tin2 > 0.0) || (tout1 > 0.0)) { if (tin2 <= tout1) { if (tin2 > 0.0) { if (tinx > tiny) { AddVertex(xin, p->y + tinx * dy); } else { AddVertex(p->x + tiny * dx, yin); } } if (tout1 < 1.0) { if (toutx < touty) { AddVertex(xout, p->y + toutx * dy); } else { AddVertex(p->x + touty * dx, yout); } } else { AddVertex(q->x, q->y); } } else { if (tinx > tiny) { AddVertex(xin, yout); } else { AddVertex(xout, yin); } } } } } } if (count > 0) { LastVertex(clipPts[0].x, clipPts[0].y); } return count; } /* *--------------------------------------------------------------------------- * * Blt_GetProjection -- * * Computes the projection of a point on a line. The line (given by two * points), is assumed the be infinite. * * Compute the slope (angle) of the line and rotate it 90 degrees. Using * the slope-intercept method (we know the second line from the sample * test point and the computed slope), then find the intersection of both * lines. This will be the projection of the sample point on the first * line. * * Results: * Returns the coordinates of the projection on the line. * *--------------------------------------------------------------------------- */ Point2d Blt_GetProjection( int x, int y, /* Screen coordinates of the sample point. */ Point2d *p, Point2d *q) /* Line segment to project point onto */ { double dx, dy; Point2d t; dx = p->x - q->x; dy = p->y - q->y; /* Test for horizontal and vertical lines */ if (fabs(dx) < DBL_EPSILON) { t.x = p->x, t.y = (double)y; } else if (fabs(dy) < DBL_EPSILON) { t.x = (double)x, t.y = p->y; } else { double m1, m2; /* Slope of both lines */ double b1, b2; /* y-intercepts */ double midX, midY; /* Midpoint of line segment. */ double ax, ay, bx, by; /* Compute the slope and intercept of PQ. */ m1 = (dy / dx); b1 = p->y - (p->x * m1); /* * Compute the slope and intercept of a second line segment: one that * intersects through sample X-Y coordinate with a slope perpendicular * to original line. */ /* Find midpoint of PQ. */ midX = (p->x + q->x) * 0.5; midY = (p->y + q->y) * 0.5; /* Rotate the line 90 degrees */ ax = midX - (0.5 * dy); ay = midY - (0.5 * -dx); bx = midX + (0.5 * dy); by = midY + (0.5 * -dx); m2 = (ay - by) / (ax - bx); b2 = y - (x * m2); /* * Given the equations of two lines which contain the same point, * * y = m1 * x + b1 * y = m2 * x + b2 * * solve for the intersection. * * x = (b2 - b1) / (m1 - m2) * y = m1 * x + b1 * */ t.x = (b2 - b1) / (m1 - m2); t.y = m1 * t.x + b1; } return t; } /* *--------------------------------------------------------------------------- * * Blt_UpdateScrollbar -- * * Invoke a TCL command to the scrollbar, defining the new position and * length of the scroll. See the Tk documentation for further information * on the scrollbar. It is assumed the scrollbar command prefix is * valid. * * Results: * None. * * Side Effects: * Scrollbar is commanded to change position and/or size. * *--------------------------------------------------------------------------- */ void Blt_UpdateScrollbar( Tcl_Interp *interp, Tcl_Obj *scrollCmdObjPtr, /* Scrollbar command prefix. May be * several words */ int first, int last, int width) { Tcl_Obj *cmdObjPtr; double firstFract, lastFract; firstFract = 0.0, lastFract = 1.0; if (width > 0) { firstFract = (double)first / (double)width; lastFract = (double)last / (double)width; } cmdObjPtr = Tcl_DuplicateObj(scrollCmdObjPtr); Tcl_ListObjAppendElement(interp, cmdObjPtr, Tcl_NewDoubleObj(firstFract)); Tcl_ListObjAppendElement(interp, cmdObjPtr, Tcl_NewDoubleObj(lastFract)); Tcl_IncrRefCount(cmdObjPtr); if (Tcl_EvalObjEx(interp, cmdObjPtr, TCL_EVAL_GLOBAL) != TCL_OK) { Tcl_BackgroundError(interp); } Tcl_DecrRefCount(cmdObjPtr); } /* *--------------------------------------------------------------------------- * * Blt_GetPrivateGC -- * * Like Tk_GetGC, but doesn't share the GC with any other widget. This * is needed because the certain GC parameters (like dashes) can not be * set via XCreateGC, therefore there is no way for Tk's hashing * mechanism to recognize that two such GCs differ. * * Results: * A new GC is returned. * *--------------------------------------------------------------------------- */ GC Blt_GetPrivateGC(Tk_Window tkwin, unsigned long gcMask, XGCValues *valuePtr) { GC gc; Pixmap pixmap; Drawable drawable; Display *display; pixmap = None; drawable = Tk_WindowId(tkwin); display = Tk_Display(tkwin); if (drawable == None) { Drawable root; int depth; root = Tk_RootWindow(tkwin); depth = Tk_Depth(tkwin); if (depth == DefaultDepth(display, Tk_ScreenNumber(tkwin))) { drawable = root; } else { pixmap = Tk_GetPixmap(display, root, 1, 1, depth); drawable = pixmap; Blt_SetDrawableAttribs(display, drawable, 1, 1, depth, Tk_Colormap(tkwin), Tk_Visual(tkwin)); } } gc = XCreateGC(display, drawable, gcMask, valuePtr); if (pixmap != None) { Tk_FreePixmap(display, pixmap); } return gc; } void Blt_FreePrivateGC(Display *display, GC gc) { Tk_FreeXId(display, (XID) XGContextFromGC(gc)); XFreeGC(display, gc); } void Blt_SetDashes(Display *display, GC gc, Blt_Dashes *dashesPtr) { XSetDashes(display, gc, dashesPtr->offset, (const char *)dashesPtr->values, (int)strlen((char *)dashesPtr->values)); } void Blt_Draw2DSegments( Display *display, Drawable drawable, GC gc, Segment2d *segments, int nSegments) { XSegment *dp, *xsegments; Segment2d *sp, *send; xsegments = malloc(nSegments * sizeof(XSegment)); if (xsegments == NULL) { return; } dp = xsegments; for (sp = segments, send = sp + nSegments; sp < send; sp++) { dp->x1 = (short int)sp->p.x; dp->y1 = (short int)sp->p.y; dp->x2 = (short int)sp->q.x; dp->y2 = (short int)sp->q.y; dp++; } XDrawSegments(display, drawable, gc, xsegments, nSegments); free(xsegments); } long Blt_MaxRequestSize(Display *display, size_t elemSize) { static long maxSizeBytes = 0L; if (maxSizeBytes == 0L) { long size; size = XExtendedMaxRequestSize(display); if (size == 0) { size = XMaxRequestSize(display); } size -= (4 * elemSize); /* maxSizeBytes = (size * 4); */ maxSizeBytes = size; } return (maxSizeBytes / elemSize); }