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r34.1/plot/graphics.c
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#ifndef lint static char *RCSid = "$Id: graphics.c,v 3.26 92/03/24 22:34:25 woo Exp Locker: woo $"; #endif /* GNUPLOT - graphics.c */ /* * Copyright (C) 1986, 1987, 1990, 1991, 1992 Thomas Williams, Colin Kelley * * Permission to use, copy, and distribute this software and its * documentation for any purpose with or without fee is hereby granted, * provided that the above copyright notice appear in all copies and * that both that copyright notice and this permission notice appear * in supporting documentation. * * Permission to modify the software is granted, but not the right to * distribute the modified code. Modifications are to be distributed * as patches to released version. * * This software is provided "as is" without express or implied warranty. * * * AUTHORS * * Original Software: * Thomas Williams, Colin Kelley. * * Gnuplot 2.0 additions: * Russell Lang, Dave Kotz, John Campbell. * * Gnuplot 3.0 additions: * Gershon Elber and many others. * * Send your comments or suggestions to * info-gnuplot@ames.arc.nasa.gov. * This is a mailing list; to join it send a note to * info-gnuplot-request@ames.arc.nasa.gov. * Send bug reports to * bug-gnuplot@ames.arc.nasa.gov. */ #include <stdio.h> #include <math.h> #include <assert.h> #include <time.h> #include "plot.h" #include "setshow.h" extern char *strcpy(),*strncpy(),*strcat(),*ctime(); char *tdate; #ifdef AMIGA_AC_5 time_t dated; #else #ifdef VMS time_t dated,time(); #else long dated,time(); #endif #endif void plot_impulses(); void plot_lines(); void plot_points(); void plot_dots(); void plot_bars(); void edge_intersect(); BOOLEAN two_edge_intersect(); /* for plotting error bars */ #define ERRORBARTIC (t->h_tic/2) /* half the width of error bar tic mark */ #ifndef max /* Lattice C has max() in math.h, but shouldn't! */ #define max(a,b) ((a > b) ? a : b) #endif #ifndef min #define min(a,b) ((a < b) ? a : b) #endif #define inrange(z,min,max) ((min<max) ? ((z>=min)&&(z<=max)) : ((z>=max)&&(z<=min)) ) /* True if a and b have the same sign or zero (positive or negative) */ #define samesign(a,b) ((a) * (b) >= 0) /* Define the boundary of the plot * These are computed at each call to do_plot, and are constant over * the period of one do_plot. They actually only change when the term * type changes and when the 'set size' factors change. */ static int xleft, xright, ybot, ytop; /* Boundary and scale factors, in user coordinates */ /* x_min, x_max, y_min, y_max are local to this file and * are not the same as variables of the same names in other files */ static double x_min, x_max, y_min, y_max; static double xscale, yscale; /* And the functions to map from user to terminal coordinates */ #define map_x(x) (int)(xleft+(x-x_min)*xscale+0.5) /* maps floating point x to screen */ #define map_y(y) (int)(ybot+(y-y_min)*yscale+0.5) /* same for y */ /* (DFK) Watch for cancellation error near zero on axes labels */ #define SIGNIF (0.01) /* less than one hundredth of a tic mark */ #define CheckZero(x,tic) (fabs(x) < ((tic) * SIGNIF) ? 0.0 : (x)) #define NearlyEqual(x,y,tic) (fabs((x)-(y)) < ((tic) * SIGNIF)) /* (DFK) For some reason, the Sun386i compiler screws up with the CheckLog * macro, so I write it as a function on that machine. */ #ifndef sun386 /* (DFK) Use 10^x if logscale is in effect, else x */ #define CheckLog(log, x) ((log) ? pow(10., (x)) : (x)) #else static double CheckLog(log, x) BOOLEAN log; double x; { if (log) return(pow(10., x)); else return(x); } #endif /* sun386 */ double LogScale(coord, islog, what, axis) double coord; /* the value */ BOOLEAN islog; /* is this axis in logscale? */ char *what; /* what is the coord for? */ char *axis; /* which axis is this for ("x" or "y")? */ { if (islog) { if (coord <= 0.0) { char errbuf[100]; /* place to write error message */ (void) sprintf(errbuf,"%s has %s coord of %g; must be above 0 for log scale!", what, axis, coord); (*term_tbl[term].text)(); (void) fflush(outfile); int_error(errbuf, NO_CARET); } else return(log10(coord)); } return(coord); } /* borders of plotting area */ /* computed once on every call to do_plot */ boundary(scaling) BOOLEAN scaling; /* TRUE if terminal is doing the scaling */ { register struct termentry *t = &term_tbl[term]; xleft = (t->h_char)*12; xright = (scaling ? 1 : xsize) * (t->xmax) - (t->h_char)*2 - (t->h_tic); ybot = (t->v_char)*7/2 + 1; ytop = (scaling ? 1 : ysize) * (t->ymax) - (t->v_char)*5/2 - 1; } double dbl_raise(x,y) double x; int y; { register int i; double val; val = 1.0; for (i=0; i < abs(y); i++) val *= x; if (y < 0 ) return (1.0/val); return(val); } double make_tics(tmin,tmax,logscale) double tmin,tmax; BOOLEAN logscale; { register double xr,xnorm,tics,tic,l10; xr = fabs(tmin-tmax); l10 = log10(xr); if (logscale) { tic = dbl_raise(10.0,(l10 >= 0.0 ) ? (int)l10 : ((int)l10-1)); if (tic < 1.0) tic = 1.0; } else { xnorm = pow(10.0,l10-(double)((l10 >= 0.0 ) ? (int)l10 : ((int)l10-1))); if (xnorm <= 2) tics = 0.2; else if (xnorm <= 5) tics = 0.5; else tics = 1.0; tic = tics * dbl_raise(10.0,(l10 >= 0.0 ) ? (int)l10 : ((int)l10-1)); } return(tic); } do_plot(plots, pcount, min_x, max_x, min_y, max_y) struct curve_points *plots; int pcount; /* count of plots in linked list */ double min_x, max_x; double min_y, max_y; { register struct termentry *t = &term_tbl[term]; register int curve, xaxis_y, yaxis_x; register struct curve_points *this_plot; register double ytic, xtic; register int xl, yl; /* only a Pyramid would have this many registers! */ double xtemp, ytemp; struct text_label *this_label; struct arrow_def *this_arrow; BOOLEAN scaling; /* store these in variables global to this file */ /* otherwise, we have to pass them around a lot */ x_min = min_x; x_max = max_x; y_min = min_y; y_max = max_y; if (polar) { /* will possibly change x_min, x_max, y_min, y_max */ polar_xform(plots,pcount); } if (y_min == VERYLARGE || y_max == -VERYLARGE || x_min == VERYLARGE || x_max == -VERYLARGE) int_error("all points undefined!", NO_CARET); /* Apply the desired viewport offsets. */ if (y_min < y_max) { y_min -= boff; y_max += toff; } else { y_max -= boff; y_min += toff; } if (x_min < x_max) { x_min -= loff; x_max += roff; } else { x_max -= loff; x_min += roff; } /* SETUP RANGES, SCALES AND TIC PLACES */ if (ytics && yticdef.type == TIC_COMPUTED) { ytic = make_tics(y_min,y_max,log_y); if (autoscale_ly) { if (y_min < y_max) { y_min = ytic * floor(y_min/ytic); y_max = ytic * ceil(y_max/ytic); } else { /* reverse axis */ y_min = ytic * ceil(y_min/ytic); y_max = ytic * floor(y_max/ytic); } } } if (xtics && xticdef.type == TIC_COMPUTED) { xtic = make_tics(x_min,x_max,log_x); if (autoscale_lx) { if (x_min < x_max) { x_min = xtic * floor(x_min/xtic); x_max = xtic * ceil(x_max/xtic); } else { x_min = xtic * ceil(x_min/xtic); x_max = xtic * floor(x_max/xtic); } } } /* This used be x_max == x_min, but that caused an infinite loop once. */ if (fabs(x_max - x_min) < zero) int_error("x_min should not equal x_max!",NO_CARET); if (fabs(y_max - y_min) < zero) int_error("y_min should not equal y_max!",NO_CARET); /* INITIALIZE TERMINAL */ if (!term_init) { (*t->init)(); term_init = TRUE; } screen_ok = FALSE; #ifdef AMIGA_LC_5_1 scaling = (*t->scale)((double)xsize, (double)ysize); #else scaling = (*t->scale)(xsize, ysize); #endif (*t->graphics)(); /* now compute boundary for plot (xleft, xright, ytop, ybot) */ boundary(scaling); /* SCALE FACTORS */ yscale = (ytop - ybot)/(y_max - y_min); xscale = (xright - xleft)/(x_max - x_min); /* DRAW AXES */ (*t->linetype)(-1); /* axis line type */ xaxis_y = map_y(0.0); yaxis_x = map_x(0.0); if (xaxis_y < ybot) xaxis_y = ybot; /* save for impulse plotting */ else if (xaxis_y >= ytop) xaxis_y = ytop ; else if (xzeroaxis && !log_y) { (*t->move)(xleft,xaxis_y); (*t->vector)(xright,xaxis_y); } if (yzeroaxis && !log_x && yaxis_x >= xleft && yaxis_x < xright ) { (*t->move)(yaxis_x,ybot); (*t->vector)(yaxis_x,ytop); } /* DRAW TICS */ (*t->linetype)(-2); /* border linetype */ /* label y axis tics */ if (ytics) { switch (yticdef.type) { case TIC_COMPUTED: { if (y_min < y_max) draw_ytics(ytic * floor(y_min/ytic), ytic, ytic * ceil(y_max/ytic)); else draw_ytics(ytic * floor(y_max/ytic), ytic, ytic * ceil(y_min/ytic)); break; } case TIC_SERIES: { draw_series_ytics(yticdef.def.series.start, yticdef.def.series.incr, yticdef.def.series.end); break; } case TIC_USER: { draw_set_ytics(yticdef.def.user); break; } default: { (*t->text)(); (void) fflush(outfile); int_error("unknown tic type in yticdef in do_plot", NO_CARET); break; /* NOTREACHED */ } } } /* label x axis tics */ if (xtics) { switch (xticdef.type) { case TIC_COMPUTED: { if (x_min < x_max) draw_xtics(xtic * floor(x_min/xtic), xtic, xtic * ceil(x_max/xtic)); else draw_xtics(xtic * floor(x_max/xtic), xtic, xtic * ceil(x_min/xtic)); break; } case TIC_SERIES: { draw_series_xtics(xticdef.def.series.start, xticdef.def.series.incr, xticdef.def.series.end); break; } case TIC_USER: { draw_set_xtics(xticdef.def.user); break; } default: { (*t->text)(); (void) fflush(outfile); int_error("unknown tic type in xticdef in do_plot", NO_CARET); break; /* NOTREACHED */ } } } /* DRAW PLOT BORDER */ (*t->linetype)(-2); /* border linetype */ if (draw_border) { (*t->move)(xleft,ybot); (*t->vector)(xright,ybot); (*t->vector)(xright,ytop); (*t->vector)(xleft,ytop); (*t->vector)(xleft,ybot); } /* PLACE YLABEL */ if (strlen(ylabel) > 0) { int x, y; x = ylabel_xoffset * t->h_char; y = ylabel_yoffset * t->v_char; if ((*t->text_angle)(1)) { if ((*t->justify_text)(CENTRE)) { (*t->put_text)(x+(t->v_char), y+(ytop+ybot)/2, ylabel); } else { (*t->put_text)(x+(t->v_char), y+(ytop+ybot)/2-(t->h_char)*strlen(ylabel)/2, ylabel); } } else { (void)(*t->justify_text)(LEFT); (*t->put_text)(x,y+ytop+(t->v_char), ylabel); } (void)(*t->text_angle)(0); } /* PLACE XLABEL */ if (strlen(xlabel) > 0) { int x, y; x = xlabel_xoffset * t->h_char; y = xlabel_yoffset * t->v_char; if ((*t->justify_text)(CENTRE)) (*t->put_text)(x+(xleft+xright)/2, y+ybot-2*(t->v_char), xlabel); else (*t->put_text)(x+(xleft+xright)/2 - strlen(xlabel)*(t->h_char)/2, y+ybot-2*(t->v_char), xlabel); } /* PLACE TITLE */ if (strlen(title) > 0) { int x, y; x = title_xoffset * t->h_char; y = title_yoffset * t->v_char; if ((*t->justify_text)(CENTRE)) (*t->put_text)(x+(xleft+xright)/2, y+ytop+(t->v_char), title); else (*t->put_text)(x+(xleft+xright)/2 - strlen(title)*(t->h_char)/2, y+ytop+(t->v_char), title); } /* PLACE TIMEDATE */ if (timedate) { int x, y; x = time_xoffset * t->h_char; y = time_yoffset * t->v_char; dated = time( (long *) 0); tdate = ctime( &dated); tdate[24]='\0'; if ((*t->text_angle)(1)) { if ((*t->justify_text)(CENTRE)) { (*t->put_text)(x+(t->v_char), y+ybot+4*(t->v_char), tdate); } else { (*t->put_text)(x+(t->v_char), y+ybot+4*(t->v_char)-(t->h_char)*strlen(ylabel)/2, tdate); } } else { (void)(*t->justify_text)(LEFT); (*t->put_text)(x, y+ybot-3*(t->v_char), tdate); } (void)(*t->text_angle)(0); } /* PLACE LABELS */ for (this_label = first_label; this_label!=NULL; this_label=this_label->next ) { xtemp = LogScale(this_label->x, log_x, "label", "x"); ytemp = LogScale(this_label->y, log_y, "label", "y"); if ((*t->justify_text)(this_label->pos)) { (*t->put_text)(map_x(xtemp),map_y(ytemp),this_label->text); } else { switch(this_label->pos) { case LEFT: (*t->put_text)(map_x(xtemp),map_y(ytemp), this_label->text); break; case CENTRE: (*t->put_text)(map_x(xtemp)- (t->h_char)*strlen(this_label->text)/2, map_y(ytemp), this_label->text); break; case RIGHT: (*t->put_text)(map_x(xtemp)- (t->h_char)*strlen(this_label->text), map_y(ytemp), this_label->text); break; } } } /* PLACE ARROWS */ (*t->linetype)(0); /* arrow line type */ for (this_arrow = first_arrow; this_arrow!=NULL; this_arrow = this_arrow->next ) { int sx = map_x(LogScale(this_arrow->sx, log_x, "arrow", "x")); int sy = map_y(LogScale(this_arrow->sy, log_y, "arrow", "y")); int ex = map_x(LogScale(this_arrow->ex, log_x, "arrow", "x")); int ey = map_y(LogScale(this_arrow->ey, log_y, "arrow", "y")); (*t->arrow)(sx, sy, ex, ey, this_arrow->head); } /* DRAW CURVES */ if (key == -1) { xl = xright - (t->h_tic) - (t->h_char)*5; yl = ytop - (t->v_tic) - (t->v_char); } if (key == 1) { xl = map_x( LogScale(key_x, log_x, "key", "x") ); yl = map_y( LogScale(key_y, log_y, "key", "y") ); } this_plot = plots; for (curve = 0; curve < pcount; this_plot = this_plot->next_cp, curve++) { (*t->linetype)(this_plot->line_type); if (key != 0) { if ((*t->justify_text)(RIGHT)) { (*t->put_text)(xl, yl,this_plot->title); } else { if (inrange(xl-(t->h_char)*strlen(this_plot->title), xleft, xright)) (*t->put_text)(xl-(t->h_char)*strlen(this_plot->title), yl,this_plot->title); } } switch(this_plot->plot_style) { case IMPULSES: { if (key != 0) { (*t->move)(xl+(t->h_char),yl); (*t->vector)(xl+4*(t->h_char),yl); } plot_impulses(this_plot, yaxis_x, xaxis_y); break; } case LINES: { if (key != 0) { (*t->move)(xl+(int)(t->h_char),yl); (*t->vector)(xl+(int)(4*(t->h_char)),yl); } plot_lines(this_plot); break; } case POINTS: { if (key != 0) { (*t->point)(xl+2*(t->h_char),yl, this_plot->point_type); } plot_points(this_plot); break; } case LINESPOINTS: { /* put lines */ if (key != 0) { (*t->move)(xl+(t->h_char),yl); (*t->vector)(xl+4*(t->h_char),yl); } plot_lines(this_plot); /* put points */ if (key != 0) { (*t->point)(xl+2*(t->h_char),yl, this_plot->point_type); } plot_points(this_plot); break; } case DOTS: { if (key != 0) { (*t->point)(xl+2*(t->h_char),yl, -1); } plot_dots(this_plot); break; } case ERRORBARS: { if (key != 0) { (*t->point)(xl+2*(t->h_char),yl, this_plot->point_type); } plot_points(this_plot); /* for functions, just like POINTS */ if (this_plot->plot_type == DATA) { if (key != 0) { (*t->move)(xl+(t->h_char),yl); (*t->vector)(xl+4*(t->h_char),yl); (*t->move)(xl+(t->h_char),yl+ERRORBARTIC); (*t->vector)(xl+(t->h_char),yl-ERRORBARTIC); (*t->move)(xl+4*(t->h_char),yl+ERRORBARTIC); (*t->vector)(xl+4*(t->h_char),yl-ERRORBARTIC); } plot_bars(this_plot); } break; } } yl = yl - (t->v_char); } (*t->text)(); (void) fflush(outfile); } /* plot_impulses: * Plot the curves in IMPULSES style */ void plot_impulses(plot, yaxis_x, xaxis_y) struct curve_points *plot; int yaxis_x, xaxis_y; { int i; int x,y; struct termentry *t = &term_tbl[term]; for (i = 0; i < plot->p_count; i++) { switch (plot->points[i].type) { case INRANGE: { x = map_x(plot->points[i].x); y = map_y(plot->points[i].y); break; } case OUTRANGE: { if (!inrange(plot->points[i].x, x_min,x_max)) continue; x = map_x(plot->points[i].x); if ((y_min < y_max && plot->points[i].y < y_min) || (y_max < y_min && plot->points[i].y > y_min)) y = map_y(y_min); if ((y_min < y_max && plot->points[i].y > y_max) || (y_max<y_min && plot->points[i].y < y_max)) y = map_y(y_max); break; } default: /* just a safety */ case UNDEFINED: { continue; } } if (polar) (*t->move)(yaxis_x,xaxis_y); else (*t->move)(x,xaxis_y); (*t->vector)(x,y); } } /* plot_lines: * Plot the curves in LINES style */ void plot_lines(plot) struct curve_points *plot; { int i; /* point index */ int x,y; /* point in terminal coordinates */ struct termentry *t = &term_tbl[term]; enum coord_type prev = UNDEFINED; /* type of previous point */ double ex, ey; /* an edge point */ double lx[2], ly[2]; /* two edge points */ for (i = 0; i < plot->p_count; i++) { switch (plot->points[i].type) { case INRANGE: { x = map_x(plot->points[i].x); y = map_y(plot->points[i].y); if (prev == INRANGE) { (*t->vector)(x,y); } else if (prev == OUTRANGE) { /* from outrange to inrange */ if (!clip_lines1) { (*t->move)(x,y); } else { edge_intersect(plot->points, i, &ex, &ey); (*t->move)(map_x(ex), map_y(ey)); (*t->vector)(x,y); } } else { /* prev == UNDEFINED */ (*t->move)(x,y); (*t->vector)(x,y); } break; } case OUTRANGE: { if (prev == INRANGE) { /* from inrange to outrange */ if (clip_lines1) { edge_intersect(plot->points, i, &ex, &ey); (*t->vector)(map_x(ex), map_y(ey)); } } else if (prev == OUTRANGE) { /* from outrange to outrange */ if (clip_lines2) { if (two_edge_intersect(plot->points, i, lx, ly)) { (*t->move)(map_x(lx[0]), map_y(ly[0])); (*t->vector)(map_x(lx[1]), map_y(ly[1])); } } } break; } default: /* just a safety */ case UNDEFINED: { break; } } prev = plot->points[i].type; } } /* plot_bars: * Plot the curves in ERRORBARS style * we just plot the bars; the points are plotted in plot_points */ void plot_bars(plot) struct curve_points *plot; { int i; /* point index */ struct termentry *t = &term_tbl[term]; double x; /* position of the bar */ double ylow, yhigh; /* the ends of the bars */ unsigned int xM, ylowM, yhighM; /* the mapped version of above */ BOOLEAN low_inrange, high_inrange; int tic = ERRORBARTIC; for (i = 0; i < plot->p_count; i++) { /* undefined points don't count */ if (plot->points[i].type == UNDEFINED) continue; /* check to see if in xrange */ x = plot->points[i].x; if (! inrange(x, x_min, x_max)) continue; xM = map_x(x); /* find low and high points of bar, and check yrange */ yhigh = plot->points[i].yhigh; ylow = plot->points[i].ylow; high_inrange = inrange(yhigh, y_min,y_max); low_inrange = inrange(ylow, y_min,y_max); /* compute the plot position of yhigh */ if (high_inrange) yhighM = map_y(yhigh); else if (samesign(yhigh-y_max, y_max-y_min)) yhighM = map_y(y_max); else yhighM = map_y(y_min); /* compute the plot position of ylow */ if (low_inrange) ylowM = map_y(ylow); else if (samesign(ylow-y_max, y_max-y_min)) ylowM = map_y(y_max); else ylowM = map_y(y_min); if (!high_inrange && !low_inrange && ylowM == yhighM) /* both out of range on the same side */ continue; /* by here everything has been mapped */ (*t->move)(xM, ylowM); (*t->vector)(xM, yhighM); /* draw the main bar */ (*t->move)(xM-tic, ylowM); /* draw the bottom tic */ (*t->vector)(xM+tic, ylowM); (*t->move)(xM-tic, yhighM); /* draw the top tic */ (*t->vector)(xM+tic, yhighM); } } /* plot_points: * Plot the curves in POINTS style */ void plot_points(plot) struct curve_points *plot; { int i; int x,y; struct termentry *t = &term_tbl[term]; for (i = 0; i < plot->p_count; i++) { if (plot->points[i].type == INRANGE) { x = map_x(plot->points[i].x); y = map_y(plot->points[i].y); /* do clipping if necessary */ if (!clip_points || ( x >= xleft + t->h_tic && y >= ybot + t->v_tic && x <= xright - t->h_tic && y <= ytop - t->v_tic)) (*t->point)(x,y, plot->point_type); } } } /* plot_dots: * Plot the curves in DOTS style */ void plot_dots(plot) struct curve_points *plot; { int i; int x,y; struct termentry *t = &term_tbl[term]; for (i = 0; i < plot->p_count; i++) { if (plot->points[i].type == INRANGE) { x = map_x(plot->points[i].x); y = map_y(plot->points[i].y); /* point type -1 is a dot */ (*t->point)(x,y, -1); } } } /* single edge intersection algorithm */ /* Given two points, one inside and one outside the plot, return * the point where an edge of the plot intersects the line segment defined * by the two points. */ void edge_intersect(points, i, ex, ey) struct coordinate *points; /* the points array */ int i; /* line segment from point i-1 to point i */ double *ex, *ey; /* the point where it crosses an edge */ { /* global x_min, x_max, y_min, x_max */ double ax = points[i-1].x; double ay = points[i-1].y; double bx = points[i].x; double by = points[i].y; double x, y; /* possible intersection point */ if (by == ay) { /* horizontal line */ /* assume inrange(by, y_min, y_max) */ *ey = by; /* == ay */ if (inrange(x_max, ax, bx)) *ex = x_max; else if (inrange(x_min, ax, bx)) *ex = x_min; else { (*term_tbl[term].text)(); (void) fflush(outfile); int_error("error in edge_intersect", NO_CARET); } return; } else if (bx == ax) { /* vertical line */ /* assume inrange(bx, x_min, x_max) */ *ex = bx; /* == ax */ if (inrange(y_max, ay, by)) *ey = y_max; else if (inrange(y_min, ay, by)) *ey = y_min; else { (*term_tbl[term].text)(); (void) fflush(outfile); int_error("error in edge_intersect", NO_CARET); } return; } /* slanted line of some kind */ /* does it intersect y_min edge */ if (inrange(y_min, ay, by) && y_min != ay && y_min != by) { x = ax + (y_min-ay) * ((bx-ax) / (by-ay)); if (inrange(x, x_min, x_max)) { *ex = x; *ey = y_min; return; /* yes */ } } /* does it intersect y_max edge */ if (inrange(y_max, ay, by) && y_max != ay && y_max != by) { x = ax + (y_max-ay) * ((bx-ax) / (by-ay)); if (inrange(x, x_min, x_max)) { *ex = x; *ey = y_max; return; /* yes */ } } /* does it intersect x_min edge */ if (inrange(x_min, ax, bx) && x_min != ax && x_min != bx) { y = ay + (x_min-ax) * ((by-ay) / (bx-ax)); if (inrange(y, y_min, y_max)) { *ex = x_min; *ey = y; return; } } /* does it intersect x_max edge */ if (inrange(x_max, ax, bx) && x_max != ax && x_max != bx) { y = ay + (x_max-ax) * ((by-ay) / (bx-ax)); if (inrange(y, y_min, y_max)) { *ex = x_max; *ey = y; return; } } /* It is possible for one or two of the [ab][xy] values to be -VERYLARGE. * If ax=bx=-VERYLARGE or ay=by=-VERYLARGE we have already returned * FALSE above. Otherwise we fall through all the tests above. * If two are -VERYLARGE, it is ax=ay=-VERYLARGE or bx=by=-VERYLARGE * since either a or b must be INRANGE. * Note that for ax=ay=-VERYLARGE or bx=by=-VERYLARGE we can do nothing. * Handle them carefully here. As yet we have no way for them to be * +VERYLARGE. */ if (ax == -VERYLARGE) { if (ay != -VERYLARGE) { *ex = min(x_min, x_max); *ey = by; return; } } else if (bx == -VERYLARGE) { if (by != -VERYLARGE) { *ex = min(x_min, x_max); *ey = ay; return; } } else if (ay == -VERYLARGE) { /* note we know ax != -VERYLARGE */ *ex = bx; *ey = min(y_min, y_max); return; } else if (by == -VERYLARGE) { /* note we know bx != -VERYLARGE */ *ex = ax; *ey = min(y_min, y_max); return; } /* If we reach here, then either one point is (-VERYLARGE,-VERYLARGE), * or the inrange point is on the edge, and * the line segment from the outrange point does not cross any * other edges to get there. In either case, we return the inrange * point as the 'edge' intersection point. This will basically draw * line. */ if (points[i].type == INRANGE) { *ex = bx; *ey = by; } else { *ex = ax; *ey = ay; } return; } /* double edge intersection algorithm */ /* Given two points, both outside the plot, return * the points where an edge of the plot intersects the line segment defined * by the two points. There may be zero, one, two, or an infinite number * of intersection points. (One means an intersection at a corner, infinite * means overlaying the edge itself). We return FALSE when there is nothing * to draw (zero intersections), and TRUE when there is something to * draw (the one-point case is a degenerate of the two-point case and we do * not distinguish it - we draw it anyway). */ BOOLEAN /* any intersection? */ two_edge_intersect(points, i, lx, ly) struct coordinate *points; /* the points array */ int i; /* line segment from point i-1 to point i */ double *lx, *ly; /* lx[2], ly[2]: points where it crosses edges */ { /* global x_min, x_max, y_min, x_max */ double ax = points[i-1].x; double ay = points[i-1].y; double bx = points[i].x; double by = points[i].y; double x, y; /* possible intersection point */ BOOLEAN intersect = FALSE; if (by == ay) { /* horizontal line */ /* y coord must be in range, and line must span both x_min and x_max */ /* note that spanning x_min implies spanning x_max */ if (inrange(by, y_min, y_max) && inrange(x_min, ax, bx)) { *lx++ = x_min; *ly++ = by; *lx++ = x_max; *ly++ = by; return(TRUE); } else return(FALSE); } else if (bx == ax) { /* vertical line */ /* x coord must be in range, and line must span both y_min and y_max */ /* note that spanning y_min implies spanning y_max */ if (inrange(bx, x_min, x_max) && inrange(y_min, ay, by)) { *lx++ = bx; *ly++ = y_min; *lx++ = bx; *ly++ = y_max; return(TRUE); } else return(FALSE); } /* slanted line of some kind */ /* there can be only zero or two intersections below */ /* does it intersect y_min edge */ if (inrange(y_min, ay, by)) { x = ax + (y_min-ay) * ((bx-ax) / (by-ay)); if (inrange(x, x_min, x_max)) { *lx++ = x; *ly++ = y_min; intersect = TRUE; } } /* does it intersect y_max edge */ if (inrange(y_max, ay, by)) { x = ax + (y_max-ay) * ((bx-ax) / (by-ay)); if (inrange(x, x_min, x_max)) { *lx++ = x; *ly++ = y_max; intersect = TRUE; } } /* does it intersect x_min edge */ if (inrange(x_min, ax, bx)) { y = ay + (x_min-ax) * ((by-ay) / (bx-ax)); if (inrange(y, y_min, y_max)) { *lx++ = x_min; *ly++ = y; intersect = TRUE; } } /* does it intersect x_max edge */ if (inrange(x_max, ax, bx)) { y = ay + (x_max-ax) * ((by-ay) / (bx-ax)); if (inrange(y, y_min, y_max)) { *lx++ = x_max; *ly++ = y; intersect = TRUE; } } if (intersect) return(TRUE); /* It is possible for one or more of the [ab][xy] values to be -VERYLARGE. * If ax=bx=-VERYLARGE or ay=by=-VERYLARGE we have already returned * FALSE above. * Note that for ax=ay=-VERYLARGE or bx=by=-VERYLARGE we can do nothing. * Otherwise we fall through all the tests above. * Handle them carefully here. As yet we have no way for them to be +VERYLARGE. */ if (ax == -VERYLARGE) { if (ay != -VERYLARGE && inrange(by, y_min, y_max) && inrange(x_max, ax, bx)) { *lx++ = x_min; *ly = by; *lx++ = x_max; *ly = by; intersect = TRUE; } } else if (bx == -VERYLARGE) { if (by != -VERYLARGE && inrange(ay, y_min, y_max) && inrange(x_max, ax, bx)) { *lx++ = x_min; *ly = ay; *lx++ = x_max; *ly = ay; intersect = TRUE; } } else if (ay == -VERYLARGE) { /* note we know ax != -VERYLARGE */ if (inrange(bx, x_min, x_max) && inrange(y_max, ay, by)) { *lx++ = bx; *ly = y_min; *lx++ = bx; *ly = y_max; intersect = TRUE; } } else if (by == -VERYLARGE) { /* note we know bx != -VERYLARGE */ if (inrange(ax, x_min, x_max) && inrange(y_max, ay, by)) { *lx++ = ax; *ly = y_min; *lx++ = ax; *ly = y_max; intersect = TRUE; } } return(intersect); } /* Polar transform of all curves */ /* Original code by John Campbell (CAMPBELL@NAUVAX.bitnet) */ polar_xform (plots, pcount) struct curve_points *plots; int pcount; /* count of curves in plots array */ { struct curve_points *this_plot; int curve; /* loop var, for curves */ register int i, p_cnt; /* loop/limit var, for points */ struct coordinate *pnts; /* abbrev. for points array */ double x, y; /* new cartesian value */ BOOLEAN anydefined = FALSE; double d2r; if(angles_format == ANGLES_DEGREES){ d2r = DEG2RAD; } else { d2r = 1.0; } /* Cycle through all the plots converting polar to rectangular. If autoscaling, adjust max and mins. Ignore previous values. If not autoscaling, use the yrange for both x and y ranges. */ if (autoscale_ly) { x_min = VERYLARGE; y_min = VERYLARGE; x_max = -VERYLARGE; y_max = -VERYLARGE; autoscale_lx = TRUE; } else { x_min = y_min; x_max = y_max; } this_plot = plots; for (curve = 0; curve < pcount; this_plot = this_plot->next_cp, curve++) { p_cnt = this_plot->p_count; pnts = &(this_plot->points[0]); /* Convert to cartesian all points in this curve. */ for (i = 0; i < p_cnt; i++) { if (pnts[i].type != UNDEFINED) { anydefined = TRUE; /* modify points to reset origin and from degrees */ pnts[i].y -= rmin; pnts[i].x *= d2r; /* convert to cartesian coordinates */ x = pnts[i].y*cos(pnts[i].x); y = pnts[i].y*sin(pnts[i].x); pnts[i].x = x; pnts[i].y = y; if (autoscale_ly) { if (x_min > x) x_min = x; if (x_max < x) x_max = x; if (y_min > y) y_min = y; if (y_max < y) y_max = y; pnts[i].type = INRANGE; } else if(inrange(x, x_min, x_max) && inrange(y, y_min, y_max)) pnts[i].type = INRANGE; else pnts[i].type = OUTRANGE; } } } if (autoscale_lx && anydefined && fabs(x_max - x_min) < zero) { /* This happens at least for the plot of 1/cos(x) (vertical line). */ fprintf(stderr, "Warning: empty x range [%g:%g], ", x_min,x_max); if (x_min == 0.0) { x_min = -1; x_max = 1; } else { x_min *= 0.9; x_max *= 1.1; } fprintf(stderr, "adjusting to [%g:%g]\n", x_min,x_max); } if (autoscale_ly && anydefined && fabs(y_max - y_min) < zero) { /* This happens at least for the plot of 1/sin(x) (horiz. line). */ fprintf(stderr, "Warning: empty y range [%g:%g], ", y_min, y_max); if (y_min == 0.0) { y_min = -1; y_max = 1; } else { y_min *= 0.9; y_max *= 1.1; } fprintf(stderr, "adjusting to [%g:%g]\n", y_min, y_max); } } /* DRAW_YTICS: draw a regular tic series, y axis */ draw_ytics(start, incr, end) double start, incr, end; /* tic series definition */ /* assume start < end, incr > 0 */ { double ticplace; int ltic; /* for mini log tics */ double lticplace; /* for mini log tics */ double ticmin, ticmax; /* for checking if tic is almost inrange */ if (end == VERYLARGE) /* for user-def series */ end = max(y_min,y_max); /* limit to right side of plot */ end = min(end, max(y_min,y_max)); /* to allow for rounding errors */ ticmin = min(y_min,y_max) - SIGNIF*incr; ticmax = max(y_min,y_max) + SIGNIF*incr; end = end + SIGNIF*incr; for (ticplace = start; ticplace <= end; ticplace +=incr) { if ( inrange(ticplace,ticmin,ticmax) ) ytick(ticplace, yformat, incr, 1.0); if (log_y && incr == 1.0) { /* add mini-ticks to log scale ticmarks */ int lstart, linc; if ((end - start) >= 10) { lstart = 10; /* No little ticks */ linc = 5; } else if((end - start) >= 5) { lstart = 2; /* 4 per decade */ linc = 3; } else { lstart = 2; /* 9 per decade */ linc = 1; } for (ltic = lstart; ltic <= 9; ltic += linc) { lticplace = ticplace+log10((double)ltic); if ( inrange(lticplace,ticmin,ticmax) ) ytick(lticplace, "\0", incr, 0.5); } } } } /* DRAW_XTICS: draw a regular tic series, x axis */ draw_xtics(start, incr, end) double start, incr, end; /* tic series definition */ /* assume start < end, incr > 0 */ { double ticplace; int ltic; /* for mini log tics */ double lticplace; /* for mini log tics */ double ticmin, ticmax; /* for checking if tic is almost inrange */ if (end == VERYLARGE) /* for user-def series */ end = max(x_min,x_max); /* limit to right side of plot */ end = min(end, max(x_min,x_max)); /* to allow for rounding errors */ ticmin = min(x_min,x_max) - SIGNIF*incr; ticmax = max(x_min,x_max) + SIGNIF*incr; end = end + SIGNIF*incr; for (ticplace = start; ticplace <= end; ticplace +=incr) { if ( inrange(ticplace,ticmin,ticmax) ) xtick(ticplace, xformat, incr, 1.0); if (log_x && incr == 1.0) { /* add mini-ticks to log scale ticmarks */ int lstart, linc; if ((end - start) >= 10) { lstart = 10; /* No little ticks */ linc = 5; } else if((end - start) >= 5) { lstart = 2; /* 4 per decade */ linc = 3; } else { lstart = 2; /* 9 per decade */ linc = 1; } for (ltic = lstart; ltic <= 9; ltic += linc) { lticplace = ticplace+log10((double)ltic); if ( inrange(lticplace,ticmin,ticmax) ) xtick(lticplace, "\0", incr, 0.5); } } } } /* DRAW_SERIES_YTICS: draw a user tic series, y axis */ draw_series_ytics(start, incr, end) double start, incr, end; /* tic series definition */ /* assume start < end, incr > 0 */ { double ticplace, place; double ticmin, ticmax; /* for checking if tic is almost inrange */ double spacing = log_y ? log10(incr) : incr; if (end == VERYLARGE) end = max(CheckLog(log_y, y_min), CheckLog(log_y, y_max)); else /* limit to right side of plot */ end = min(end, max(CheckLog(log_y, y_min), CheckLog(log_y, y_max))); /* to allow for rounding errors */ ticmin = min(y_min,y_max) - SIGNIF*incr; ticmax = max(y_min,y_max) + SIGNIF*incr; end = end + SIGNIF*incr; for (ticplace = start; ticplace <= end; ticplace +=incr) { place = (log_y ? log10(ticplace) : ticplace); if ( inrange(place,ticmin,ticmax) ) ytick(place, yformat, spacing, 1.0); } } /* DRAW_SERIES_XTICS: draw a user tic series, x axis */ draw_series_xtics(start, incr, end) double start, incr, end; /* tic series definition */ /* assume start < end, incr > 0 */ { double ticplace, place; double ticmin, ticmax; /* for checking if tic is almost inrange */ double spacing = log_x ? log10(incr) : incr; if (end == VERYLARGE) end = max(CheckLog(log_x, x_min), CheckLog(log_x, x_max)); else /* limit to right side of plot */ end = min(end, max(CheckLog(log_x, x_min), CheckLog(log_x, x_max))); /* to allow for rounding errors */ ticmin = min(x_min,x_max) - SIGNIF*incr; ticmax = max(x_min,x_max) + SIGNIF*incr; end = end + SIGNIF*incr; for (ticplace = start; ticplace <= end; ticplace +=incr) { place = (log_x ? log10(ticplace) : ticplace); if ( inrange(place,ticmin,ticmax) ) xtick(place, xformat, spacing, 1.0); } } /* DRAW_SET_YTICS: draw a user tic set, y axis */ draw_set_ytics(list) struct ticmark *list; /* list of tic marks */ { double ticplace; double incr = (y_max - y_min) / 10; /* global x_min, x_max, xscale, y_min, y_max, yscale */ while (list != NULL) { ticplace = (log_y ? log10(list->position) : list->position); if ( inrange(ticplace, y_min, y_max) /* in range */ || NearlyEqual(ticplace, y_min, incr) /* == y_min */ || NearlyEqual(ticplace, y_max, incr)) /* == y_max */ ytick(ticplace, list->label, incr, 1.0); list = list->next; } } /* DRAW_SET_XTICS: draw a user tic set, x axis */ draw_set_xtics(list) struct ticmark *list; /* list of tic marks */ { double ticplace; double incr = (x_max - x_min) / 10; /* global x_min, x_max, xscale, y_min, y_max, yscale */ while (list != NULL) { ticplace = (log_x ? log10(list->position) : list->position); if ( inrange(ticplace, x_min, x_max) /* in range */ || NearlyEqual(ticplace, x_min, incr) /* == x_min */ || NearlyEqual(ticplace, x_max, incr)) /* == x_max */ xtick(ticplace, list->label, incr, 1.0); list = list->next; } } /* draw and label a y-axis ticmark */ ytick(place, text, spacing, ticscale) double place; /* where on axis to put it */ char *text; /* optional text label */ double spacing; /* something to use with checkzero */ double ticscale; /* scale factor for tic mark (0..1] */ { register struct termentry *t = &term_tbl[term]; char ticlabel[101]; int ticsize = (int)((t->h_tic) * ticscale); place = CheckZero(place,spacing); /* to fix rounding error near zero */ if (grid) { (*t->linetype)(-1); /* axis line type */ /* do not put a rectangular grid on a polar plot */ if( !polar){ (*t->move)(xleft, map_y(place)); (*t->vector)(xright, map_y(place)); } (*t->linetype)(-2); /* border linetype */ } if (tic_in) { /* if polar plot, put the tics along the axes */ if( polar){ (*t->move)(map_x(ZERO),map_y(place)); (*t->vector)(map_x(ZERO) + ticsize, map_y(place)); (*t->move)(map_x(ZERO), map_y(place)); (*t->vector)(map_x(ZERO) - ticsize, map_y(place)); } else { (*t->move)(xleft, map_y(place)); (*t->vector)(xleft + ticsize, map_y(place)); (*t->move)(xright, map_y(place)); (*t->vector)(xright - ticsize, map_y(place)); } } else { if( polar){ (*t->move)(map_x(ZERO), map_y(place)); (*t->vector)(map_x(ZERO) - ticsize, map_y(place)); }else{ (*t->move)(xleft, map_y(place)); (*t->vector)(xleft - ticsize, map_y(place)); } } /* label the ticmark */ if (text == NULL) text = yformat; if( polar){ (void) sprintf(ticlabel, text, CheckLog(log_y,fabs( place)+rmin)); if ((*t->justify_text)(RIGHT)) { (*t->put_text)(map_x(ZERO)-(t->h_char), map_y(place), ticlabel); } else { (*t->put_text)(map_x(ZERO)-(t->h_char)*(strlen(ticlabel)+1), map_y(place), ticlabel); } } else { (void) sprintf(ticlabel, text, CheckLog(log_y, place)); if ((*t->justify_text)(RIGHT)) { (*t->put_text)(xleft-(t->h_char), map_y(place), ticlabel); } else { (*t->put_text)(xleft-(t->h_char)*(strlen(ticlabel)+1), map_y(place), ticlabel); } } } /* draw and label an x-axis ticmark */ xtick(place, text, spacing, ticscale) double place; /* where on axis to put it */ char *text; /* optional text label */ double spacing; /* something to use with checkzero */ double ticscale; /* scale factor for tic mark (0..1] */ { register struct termentry *t = &term_tbl[term]; char ticlabel[101]; int ticsize = (int)((t->v_tic) * ticscale); place = CheckZero(place,spacing); /* to fix rounding error near zero */ if (grid) { (*t->linetype)(-1); /* axis line type */ if( !polar){ (*t->move)(map_x(place), ybot); (*t->vector)(map_x(place), ytop); } (*t->linetype)(-2); /* border linetype */ } if (tic_in) { if( polar){ (*t->move)(map_x(place), map_y(ZERO)); (*t->vector)(map_x(place), map_y(ZERO) + ticsize); (*t->move)(map_x(place), map_y(ZERO)); (*t->vector)(map_x(place), map_y(ZERO) - ticsize); } else{ (*t->move)(map_x(place), ybot); (*t->vector)(map_x(place), ybot + ticsize); (*t->move)(map_x(place), ytop); (*t->vector)(map_x(place), ytop - ticsize); } } else { if( polar){ (*t->move)(map_x(place), map_y(ZERO)); (*t->vector)(map_x(place), map_y(ZERO) - ticsize); }else{ (*t->move)(map_x(place), ybot); (*t->vector)(map_x(place), ybot - ticsize); } } /* label the ticmark */ if (text == NULL) text = xformat; if(polar){ (void) sprintf(ticlabel, text, CheckLog(log_x, fabs(place)+rmin)); if ((*t->justify_text)(CENTRE)) { (*t->put_text)(map_x(place), map_y(ZERO)-(t->v_char), ticlabel); } else { (*t->put_text)(map_x(place)-(t->h_char)*strlen(ticlabel)/2, map_y(ZERO)-(t->v_char), ticlabel); } }else{ (void) sprintf(ticlabel, text, CheckLog(log_x, place)); if ((*t->justify_text)(CENTRE)) { (*t->put_text)(map_x(place), ybot-(t->v_char), ticlabel); } else { (*t->put_text)(map_x(place)-(t->h_char)*strlen(ticlabel)/2, ybot-(t->v_char), ticlabel); } } }