/* This file is part of the GNU plotutils package. Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2005, Free Software Foundation, Inc. The GNU plotutils package is free software. You may redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software foundation; either version 2, or (at your option) any later version. The GNU plotutils package is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with the GNU plotutils package; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin St., Fifth Floor, Boston, MA 02110-1301, USA. */ /* This file contains the internal paint_path() and paint_paths() methods, which the public method endpath() is a wrapper around. */ /* This file also contains the internal path_is_flushable() method, which is invoked after any path segment is added to the segment list, provided (0) the segment list has become greater than or equal to the `max_unfilled_path_length' Plotter parameter, (1) the path isn't to be filled. In most Plotters, this operation simply returns true. */ /* This file also contains the internal maybe_prepaint_segments() method. It is called immediately after any segment is added to a path. Some Plotters, at least under some circumstances, treat endpath() as a no-op. Instead, they plot the segments of a path in real time. */ /**********************************************************************/ /* This version of paint_path() is for XDrawablePlotters (and XPlotters). By construction, for such Plotters our path buffer always contains either a segment list, or an ellipse object. If it's a segment list, it contains either (1) a sequence of line segments, or (2) a single circular or elliptic arc segment. Those are all sorts of path that X11 can handle. (For an ellipse or circular/elliptic arc segment to have been added to the path buffer, the map from user to device coordinates must preserve axes.) */ /* If the line style is "solid" and the path has zero width, it's actually drawn in real time, before endpath() and paint_path() are called; see the maybe_prepaint_segments() method further below in this file. So if the path doesn't need to be filled, we don't do anything in paint_path(). If it does, we fill it, and then redraw it. */ /* Note that when filling a polyline, we look at _plotter->drawstate->path->primitive to determine which X11 rendering algorithm to use. Our default algorithm is "Complex" (i.e. generic), but when drawing polygonal approximations to ellipse and rectangle primitives, which we know must be convex, we specify "Convex" instead, to speed up rendering. */ #include "sys-defines.h" #include "extern.h" /* number of XPoint structs we can store on the stack, for speed, without invoking malloc */ #define MAX_NUM_POINTS_ON_STACK 128 #define DIST(p1, p2) sqrt( ((p1).x - (p2).x) * ((p1).x - (p2).x) \ + ((p1).y - (p2).y) * ((p1).y - (p2).y)) void _pl_x_paint_path (S___(Plotter *_plotter)) { if (_plotter->drawstate->pen_type == 0 && _plotter->drawstate->fill_type == 0) /* nothing to draw */ return; switch ((int)_plotter->drawstate->path->type) { case (int)PATH_SEGMENT_LIST: { bool closed; /* not currently used */ int is_a_rectangle; int i, polyline_len; plPoint p0, p1, pc; XPoint *xarray, local_xarray[MAX_NUM_POINTS_ON_STACK]; bool heap_storage; double xu_last, yu_last; bool identical_user_coordinates; /* sanity checks */ if (_plotter->drawstate->path->num_segments == 0)/* nothing to do */ break; if (_plotter->drawstate->path->num_segments == 1) /*shouldn't happen */ break; if (_plotter->drawstate->path->num_segments == 2 && _plotter->drawstate->path->segments[1].type == S_ARC) /* segment buffer contains a single circular arc, not a polyline */ { p0 = _plotter->drawstate->path->segments[0].p; p1 = _plotter->drawstate->path->segments[1].p; pc = _plotter->drawstate->path->segments[1].pc; /* use native X rendering to draw the (transformed) circular arc */ _pl_x_draw_elliptic_arc (R___(_plotter) p0, p1, pc); break; } if (_plotter->drawstate->path->num_segments == 2 && _plotter->drawstate->path->segments[1].type == S_ELLARC) /* segment buffer contains a single elliptic arc, not a polyline */ { p0 = _plotter->drawstate->path->segments[0].p; p1 = _plotter->drawstate->path->segments[1].p; pc = _plotter->drawstate->path->segments[1].pc; /* use native X rendering to draw the (transformed) elliptic arc */ _pl_x_draw_elliptic_arc_2 (R___(_plotter) p0, p1, pc); break; } /* neither of above applied, so segment buffer contains a polyline, not an arc */ if ((_plotter->drawstate->path->num_segments >= 3)/*check for closure*/ && (_plotter->drawstate->path->segments[_plotter->drawstate->path->num_segments - 1].p.x == _plotter->drawstate->path->segments[0].p.x) && (_plotter->drawstate->path->segments[_plotter->drawstate->path->num_segments - 1].p.y == _plotter->drawstate->path->segments[0].p.y)) closed = true; else closed = false; /* 2-point ones should be open */ /* Check whether we `pre-drew' the polyline, i.e., drew every line segment in real time. (See the maybe_prepaint_segments() method further below, which is invoked to do that.) Our convention: we pre-draw only if pen width is zero, and line style is "solid". Also, we don't do it if we're drawing a polygonalized built-in object (i.e. a rectangle or ellipse). If we pre-drew, we don't do anything here unless there's filling to be done. If so, we'll fill the polyline and re-edge it. */ if ((_plotter->drawstate->pen_type != 0 /* pen is present */ && _plotter->drawstate->line_type == PL_L_SOLID && !_plotter->drawstate->dash_array_in_effect /* really solid */ && _plotter->drawstate->points_are_connected /* really, really */ && _plotter->drawstate->quantized_device_line_width == 0 && !_plotter->drawstate->path->primitive) /* not builtin object */ /* we pre-drew */ && _plotter->drawstate->fill_type == 0) /* there's no filling to be done, so we're out of here */ break; /* At this point we know that we didn't pre-draw, or we did, but the polyline was drawn unfilled and it'll need to be re-drawn as filled. */ /* prepare an array of XPoint structures (X11 uses short ints for these) */ if (_plotter->drawstate->path->num_segments <= MAX_NUM_POINTS_ON_STACK) /* store XPoints on stack, for speed */ { xarray = local_xarray; heap_storage = false; } else /* store XPoints in heap */ { xarray = (XPoint *)_pl_xmalloc (_plotter->drawstate->path->num_segments * sizeof(XPoint)); heap_storage = true; } /* convert vertices to device coordinates, removing runs; also keep track of whether or not all points in user space are the same */ polyline_len = 0; xu_last = 0.0; yu_last = 0.0; identical_user_coordinates = true; for (i = 0; i < _plotter->drawstate->path->num_segments; i++) { plPathSegment datapoint; double xu, yu, xd, yd; int device_x, device_y; datapoint = _plotter->drawstate->path->segments[i]; xu = datapoint.p.x; yu = datapoint.p.y; xd = XD(xu, yu); yd = YD(xu, yu); device_x = IROUND(xd); device_y = IROUND(yd); if (X_OOB_INT(device_x) || X_OOB_INT(device_y)) /* point position can't be represented using X11's 2-byte ints, so truncate the polyline right here */ { _plotter->warning (R___(_plotter) "truncating a polyline that extends too far for X11"); break; } if (i > 0 && (xu != xu_last || yu != yu_last)) /* in user space, not all points are the same */ identical_user_coordinates = false; if ((polyline_len == 0) || (device_x != xarray[polyline_len-1].x) || (device_y != xarray[polyline_len-1].y)) /* add point, in integer X coordinates, to the array */ { xarray[polyline_len].x = device_x; xarray[polyline_len].y = device_y; polyline_len++; if (polyline_len >= _plotter->x_max_polyline_len) /* polyline is getting too long for the X server to handle (we determined the maximum X request size when openpl() was invoked), so truncate it right here */ { _plotter->warning (R___(_plotter) "truncating a polyline that's too long for the X display"); break; } } xu_last = xu; yu_last = yu; } /* Is this path a rectangle in device space? We check this because by calling XFillRectangle (and XDrawRectangle too, if the edging is solid), we can save a bit of time, or at least network bandwidth. */ /* N.B. This checks only for rectangles traced counterclockwise from the lower left corner. Should improve this. */ #define IS_A_RECTANGLE(len,q) \ ((len) == 5 && (q)[0].x == (q)[4].x && (q)[0].y == (q)[4].y && \ (q)[0].x == (q)[3].x && (q)[1].x == (q)[2].x && \ (q)[0].y == (q)[1].y && (q)[2].y == (q)[3].y && \ (q)[0].x < (q)[1].x && (q)[0].y > (q)[2].y) /* note flipped-y convention */ is_a_rectangle = IS_A_RECTANGLE(polyline_len, xarray); /* N.B. If a rectangle, upper left corner = q[3], and also, width = q[1].x - q[0].x and height = q[0].y - q[2].y (note flipped-y convention). */ /* compute the square size, and offset of upper left vertex from center of square, that we'll use when handling the notorious special case: all user-space points in the polyline get mapped to a single integer X pixel */ /* FIRST TASK: fill the polygon (if necessary). */ if (_plotter->drawstate->fill_type) /* not transparent, so fill the path */ { int x_polygon_type = (_plotter->drawstate->path->primitive ? Convex : Complex); /* update GC used for filling */ _pl_x_set_attributes (R___(_plotter) X_GC_FOR_FILLING); /* select fill color as foreground color in GC used for filling */ _pl_x_set_fill_color (S___(_plotter)); if (_plotter->x_double_buffering != X_DBL_BUF_NONE) { if (_plotter->drawstate->path->num_segments > 1 && polyline_len == 1) /* special case: all user-space points in the polyline were mapped to a single integer X pixel */ XDrawPoint (_plotter->x_dpy, _plotter->x_drawable3, _plotter->drawstate->x_gc_fill, (int)(xarray[0].x), (int)(xarray[0].y)); else /* general case */ { if (is_a_rectangle) /* call XFillRectangle, for speed */ XFillRectangle (_plotter->x_dpy, _plotter->x_drawable3, _plotter->drawstate->x_gc_fill, (int)(xarray[3].x), (int)(xarray[3].y), (unsigned int)(xarray[1].x - xarray[0].x), /* flipped y */ (unsigned int)(xarray[0].y - xarray[2].y)); else /* not a rectangle, call XFillPolygon */ XFillPolygon (_plotter->x_dpy, _plotter->x_drawable3, _plotter->drawstate->x_gc_fill, xarray, polyline_len, x_polygon_type, CoordModeOrigin); } } else /* not double buffering, no `x_drawable3' */ { if (_plotter->drawstate->path->num_segments > 1 && polyline_len == 1) /* special case: all user-space points in the polyline were mapped to a single integer X pixel. */ { if (_plotter->x_drawable1) XDrawPoint (_plotter->x_dpy, _plotter->x_drawable1, _plotter->drawstate->x_gc_fill, (int)(xarray[0].x), (int)(xarray[0].y)); if (_plotter->x_drawable2) XDrawPoint (_plotter->x_dpy, _plotter->x_drawable2, _plotter->drawstate->x_gc_fill, (int)(xarray[0].x), (int)(xarray[0].y)); } else /* general case */ { if (is_a_rectangle) /* call XFillRectangle, for speed */ { if (_plotter->x_drawable1) XFillRectangle (_plotter->x_dpy, _plotter->x_drawable1, _plotter->drawstate->x_gc_fill, (int)(xarray[3].x), (int)(xarray[3].y), (unsigned int)(xarray[1].x - xarray[0].x), /* flipped y */ (unsigned int)(xarray[0].y - xarray[2].y)); if (_plotter->x_drawable2) XFillRectangle (_plotter->x_dpy, _plotter->x_drawable2, _plotter->drawstate->x_gc_fill, (int)(xarray[3].x), (int)(xarray[3].y), (unsigned int)(xarray[1].x - xarray[0].x), /* flipped y */ (unsigned int)(xarray[0].y - xarray[2].y)); } else /* not a rectangle, call XFillPolygon */ { if (_plotter->x_drawable1) XFillPolygon (_plotter->x_dpy, _plotter->x_drawable1, _plotter->drawstate->x_gc_fill, xarray, polyline_len, x_polygon_type, CoordModeOrigin); if (_plotter->x_drawable2) XFillPolygon (_plotter->x_dpy, _plotter->x_drawable2, _plotter->drawstate->x_gc_fill, xarray, polyline_len, x_polygon_type, CoordModeOrigin); } } } } /* SECOND TASK: edge the polygon (if necessary). */ if (_plotter->drawstate->pen_type) /* pen is present, so edge the path */ { int xloc = 0, yloc = 0; unsigned int sp_size = 1; /* update GC used for drawing */ _pl_x_set_attributes (R___(_plotter) X_GC_FOR_DRAWING); /* select pen color as foreground color in GC used for drawing */ _pl_x_set_pen_color (S___(_plotter)); /* Check first for the special case: all points in the polyline were mapped to a single integer X pixel. If (1) they weren't all the same to begin with, or (2) they were all the same to begin with and the cap mode is "round", then draw as a filled circle of diameter equal to the line width; otherwise draw nothing. (If the circle would have diameter 1 or less, we draw a point instead.) */ if (_plotter->drawstate->path->num_segments > 1 && polyline_len == 1) /* this is the special case, so compute quantities needed for drawing the filled circle */ { int sp_offset; sp_size = (unsigned int)_plotter->drawstate->quantized_device_line_width; if (sp_size == 0) sp_size = 1; sp_offset = (_plotter->drawstate->quantized_device_line_width + 1) / 2; xloc = xarray[0].x - sp_offset; yloc = xarray[0].y - sp_offset; } if (_plotter->x_double_buffering != X_DBL_BUF_NONE) /* double buffering, have a `x_drawable3' to draw into */ { if (_plotter->drawstate->path->num_segments > 1 && polyline_len == 1) /* special case */ { if (identical_user_coordinates == false || _plotter->drawstate->cap_type == PL_CAP_ROUND) { if (sp_size == 1) /* subcase: just draw a point */ XDrawPoint (_plotter->x_dpy, _plotter->x_drawable3, _plotter->drawstate->x_gc_fg, (int)(xarray[0].x), (int)(xarray[0].y)); else /* draw filled circle */ XFillArc(_plotter->x_dpy, _plotter->x_drawable3, _plotter->drawstate->x_gc_fg, xloc, yloc, sp_size, sp_size, 0, 64 * 360); } } else /* general case */ /* NOTE: this code is what libplot uses to draw nearly all polylines, in the case when double buffering is used */ { if (is_a_rectangle && _plotter->drawstate->dash_array_in_effect == false && _plotter->drawstate->line_type == PL_L_SOLID) /* call XDrawRectangle, for speed */ XDrawRectangle (_plotter->x_dpy, _plotter->x_drawable3, _plotter->drawstate->x_gc_fg, (int)(xarray[3].x), (int)(xarray[3].y), (unsigned int)(xarray[1].x - xarray[0].x), /* flipped y */ (unsigned int)(xarray[0].y - xarray[2].y)); else /* can't call XDrawRectangle */ XDrawLines (_plotter->x_dpy, _plotter->x_drawable3, _plotter->drawstate->x_gc_fg, xarray, polyline_len, CoordModeOrigin); } } else /* not double buffering, have no `x_drawable3' */ { if (_plotter->drawstate->path->num_segments > 1 && polyline_len == 1) /* special case */ { if (identical_user_coordinates == false || _plotter->drawstate->cap_type == PL_CAP_ROUND) { if (sp_size == 1) /* subcase: just draw a point */ { if (_plotter->x_drawable1) XDrawPoint (_plotter->x_dpy, _plotter->x_drawable1, _plotter->drawstate->x_gc_fg, (int)(xarray[0].x), (int)(xarray[0].y)); if (_plotter->x_drawable2) XDrawPoint (_plotter->x_dpy, _plotter->x_drawable2, _plotter->drawstate->x_gc_fg, (int)(xarray[0].x), (int)(xarray[0].y)); } else /* draw filled circle */ { if (_plotter->x_drawable1) XFillArc(_plotter->x_dpy, _plotter->x_drawable1, _plotter->drawstate->x_gc_fg, xloc, yloc, sp_size, sp_size, 0, 64 * 360); if (_plotter->x_drawable2) XFillArc(_plotter->x_dpy, _plotter->x_drawable2, _plotter->drawstate->x_gc_fg, xloc, yloc, sp_size, sp_size, 0, 64 * 360); } } } else /* general case */ /* NOTE: this code is what libplot uses to draw nearly all polylines; at least, if double buffering is not used */ { if (is_a_rectangle && _plotter->drawstate->dash_array_in_effect == false && _plotter->drawstate->line_type == PL_L_SOLID) /* call XDrawRectangle, for speed */ { if (_plotter->x_drawable1) XDrawRectangle (_plotter->x_dpy, _plotter->x_drawable1, _plotter->drawstate->x_gc_fg, (int)(xarray[3].x), (int)(xarray[3].y), (unsigned int)(xarray[1].x - xarray[0].x), /* flipped y */ (unsigned int)(xarray[0].y - xarray[2].y)); if (_plotter->x_drawable2) XDrawRectangle (_plotter->x_dpy, _plotter->x_drawable2, _plotter->drawstate->x_gc_fg, (int)(xarray[3].x), (int)(xarray[3].y), (unsigned int)(xarray[1].x - xarray[0].x), /* flipped y */ (unsigned int)(xarray[0].y - xarray[2].y)); } else /* can't use XDrawRectangle() */ { if (_plotter->x_drawable1) XDrawLines (_plotter->x_dpy, _plotter->x_drawable1, _plotter->drawstate->x_gc_fg, xarray, polyline_len, CoordModeOrigin); if (_plotter->x_drawable2) XDrawLines (_plotter->x_dpy, _plotter->x_drawable2, _plotter->drawstate->x_gc_fg, xarray, polyline_len, CoordModeOrigin); } } } } /* reset buffer used for array of XPoint structs */ if (_plotter->drawstate->path->num_segments > 0) { if (heap_storage) free (xarray); /* free malloc'd array of XPoints */ } } break; case (int)PATH_ELLIPSE: { int ninetymult; int x_orientation, y_orientation; int xorigin, yorigin; unsigned int squaresize_x, squaresize_y; plPoint pc; double rx, ry, angle; pc = _plotter->drawstate->path->pc; rx = _plotter->drawstate->path->rx; ry = _plotter->drawstate->path->ry; angle = _plotter->drawstate->path->angle; /* if angle is multiple of 90 degrees, modify to permit use of X11 arc rendering */ ninetymult = IROUND(angle / 90.0); if (angle == (double) (90 * ninetymult)) { angle = 0.0; if (ninetymult % 2) { double temp; temp = rx; rx = ry; ry = temp; } } rx = (rx < 0.0 ? -rx : rx); /* avoid obscure libxmi problems */ ry = (ry < 0.0 ? -ry : ry); /* axes flipped? (by default y-axis is, due to libxmi's flipped-y convention) */ x_orientation = (_plotter->drawstate->transform.m[0] >= 0 ? 1 : -1); y_orientation = (_plotter->drawstate->transform.m[3] >= 0 ? 1 : -1); /* location of `origin' (upper left corner of bounding rect. for ellipse) and width and height; X11's flipped-y convention affects these values */ xorigin = IROUND(XD(pc.x - x_orientation * rx, pc.y - y_orientation * ry)); yorigin = IROUND(YD(pc.x - x_orientation * rx, pc.y - y_orientation * ry)); squaresize_x = (unsigned int)IROUND(XDV(2 * x_orientation * rx, 0.0)); squaresize_y = (unsigned int)IROUND(YDV(0.0, 2 * y_orientation * ry)); /* Because this ellipse object was added to the path buffer, we already know that (1) the user->device frame map preserves coordinate axes, (2) effectively, angle == 0. These are necessary for the libxmi scan-conversion module to do the drawing. */ /* draw ellipse (elliptic arc aligned with the coordinate axes, arc range = 64*360 64'ths of a degree) */ _pl_x_draw_elliptic_arc_internal (R___(_plotter) xorigin, yorigin, squaresize_x, squaresize_y, 0, 64 * 360); } break; default: /* shouldn't happen */ break; } /* maybe flush X output buffer and handle X events (a no-op for XDrawablePlotters, which is overridden for XPlotters) */ _maybe_handle_x_events (S___(_plotter)); } /* Use native X rendering to draw what would be a circular arc in the user frame on an X display. If this is called, the map from user to device coordinates is assumed to preserve coordinate axes (it may be anisotropic [x and y directions scaled differently], and it may include a reflection through either or both axes). So it will be a circular or elliptic arc in the device frame, of the sort that X11 supports. */ void _pl_x_draw_elliptic_arc (R___(Plotter *_plotter) plPoint p0, plPoint p1, plPoint pc) { double radius; double theta0, theta1; int startangle, anglerange; int x_orientation, y_orientation; int xorigin, yorigin; unsigned int squaresize_x, squaresize_y; /* axes flipped? (by default y-axis is, due to X's flipped-y convention) */ x_orientation = (_plotter->drawstate->transform.m[0] >= 0 ? 1 : -1); y_orientation = (_plotter->drawstate->transform.m[3] >= 0 ? 1 : -1); /* radius of circular arc in user frame is distance to p0, and also to p1 */ radius = DIST(pc, p0); /* location of `origin' (upper left corner of bounding rect. on display) and width and height; X's flipped-y convention affects these values */ xorigin = IROUND(XD(pc.x - x_orientation * radius, pc.y - y_orientation * radius)); yorigin = IROUND(YD(pc.x - x_orientation * radius, pc.y - y_orientation * radius)); squaresize_x = (unsigned int)IROUND(XDV(2 * x_orientation * radius, 0.0)); squaresize_y = (unsigned int)IROUND(YDV(0.0, 2 * y_orientation * radius)); theta0 = _xatan2 (-y_orientation * (p0.y - pc.y), x_orientation * (p0.x - pc.x)) / M_PI; theta1 = _xatan2 (-y_orientation * (p1.y - pc.y), x_orientation * (p1.x - pc.x)) / M_PI; if (theta1 < theta0) theta1 += 2.0; /* adjust so that difference > 0 */ if (theta0 < 0.0) { theta0 += 2.0; /* adjust so that startangle > 0 */ theta1 += 2.0; } if (theta1 - theta0 > 1.0) /* swap if angle appear to be > 180 degrees */ { double tmp; tmp = theta0; theta0 = theta1; theta1 = tmp; theta1 += 2.0; /* adjust so that difference > 0 */ } if (theta0 >= 2.0 && theta1 >= 2.0) /* avoid obscure X bug */ { theta0 -= 2.0; theta1 -= 2.0; } startangle = IROUND(64 * theta0 * 180.0); /* in 64'ths of a degree */ anglerange = IROUND(64 * (theta1 - theta0) * 180.0); /* likewise */ _pl_x_draw_elliptic_arc_internal (R___(_plotter) xorigin, yorigin, squaresize_x, squaresize_y, startangle, anglerange); } /* Use native X rendering to draw what would be a quarter-ellipse in the user frame on an X display. If this is called, the map from user to device coordinates is assumed to preserve coordinate axes (it may be anisotropic [x and y directions scaled differently], and it may include a reflection through either or both axes). So it will be a quarter-ellipse in the device frame, of the sort that the X11 drawing protocol supports. */ void _pl_x_draw_elliptic_arc_2 (R___(Plotter *_plotter) plPoint p0, plPoint p1, plPoint pc) { double rx, ry; double x0, y0, x1, y1, xc, yc; int startangle, endangle, anglerange; int x_orientation, y_orientation; int xorigin, yorigin; unsigned int squaresize_x, squaresize_y; /* axes flipped? (by default y-axis is, due to X's flipped-y convention) */ x_orientation = (_plotter->drawstate->transform.m[0] >= 0 ? 1 : -1); y_orientation = (_plotter->drawstate->transform.m[3] >= 0 ? 1 : -1); xc = pc.x, yc = pc.y; x0 = p0.x, y0 = p0.y; x1 = p1.x, y1 = p1.y; if (y0 == yc && x1 == xc) /* initial pt. on x-axis, final pt. on y-axis */ { /* semi-axes in user frame */ rx = (x0 > xc) ? x0 - xc : xc - x0; ry = (y1 > yc) ? y1 - yc : yc - y1; /* starting and ending angles; note flipped-y convention */ startangle = ((x0 > xc ? 1 : -1) * x_orientation == 1) ? 0 : 180; endangle = ((y1 > yc ? 1 : -1) * y_orientation == -1) ? 90 : 270; } else /* initial pt. on y-axis, final pt. on x-axis */ { /* semi-axes in user frame */ rx = (x1 > xc) ? x1 - xc : xc - x1; ry = (y0 > yc) ? y0 - yc : yc - y0; /* starting and ending angles; note flipped-y convention */ startangle = ((y0 > yc ? 1 : -1) * y_orientation == -1) ? 90 : 270; endangle = ((x1 > xc ? 1 : -1) * x_orientation == 1) ? 0 : 180; } if (endangle < startangle) endangle += 360; anglerange = endangle - startangle; /* always 90 or 270 */ /* our convention: a quarter-ellipse can only be 90 degrees of an X ellipse, not 270 degrees, so interchange points */ if (anglerange == 270) { int tmp; tmp = startangle; startangle = endangle; endangle = tmp; anglerange = 90; } if (startangle >= 360) /* avoid obscure X bug */ startangle -= 360; /* endangle no longer relevant */ /* location of `origin' (upper left corner of bounding rect. on display) and width and height; X's flipped-y convention affects these values */ xorigin = IROUND(XD(xc - x_orientation * rx, yc - y_orientation * ry)); yorigin = IROUND(YD(xc - x_orientation * rx, yc - y_orientation * ry)); squaresize_x = (unsigned int)IROUND(XDV(2 * x_orientation * rx, 0.0)); squaresize_y = (unsigned int)IROUND(YDV(0.0, 2 * y_orientation * ry)); /* reexpress in 64'ths of a degree (X11 convention) */ startangle *= 64; anglerange *= 64; _pl_x_draw_elliptic_arc_internal (R___(_plotter) xorigin, yorigin, squaresize_x, squaresize_y, startangle, anglerange); } /* Use native X rendering to draw an elliptic arc on an X display. Takes account of the possible presence of more than one drawable, and the possible need for filling. The cases squaresize_{x,y} <= 1 are handled specially, since XFillArc() and XDrawArc() don't support them in the way we wish. More accurately, they don't support squaresize_{x,y} = 0 (documented), and don't support squaresize_{x,y} = 1 in the way we'd like (undocumented). */ void _pl_x_draw_elliptic_arc_internal (R___(Plotter *_plotter) int xorigin, int yorigin, unsigned int squaresize_x, unsigned int squaresize_y, int startangle, int anglerange) { if (X_OOB_INT(xorigin) || X_OOB_INT(yorigin) || X_OOB_UNSIGNED(squaresize_x) || X_OOB_UNSIGNED(squaresize_y)) /* dimensions can't be represented using X11's 2-byte ints, so punt */ { _plotter->warning (R___(_plotter) "not drawing an arc that extends too far for X11"); return; } if (_plotter->drawstate->fill_type) /* not transparent, so fill the arc */ { /* update GC used for filling */ _pl_x_set_attributes (R___(_plotter) X_GC_FOR_FILLING); /* select fill color as foreground color in GC used for filling */ _pl_x_set_fill_color (S___(_plotter)); if (squaresize_x <= 1 || squaresize_y <= 1) /* a special case, which XFillArc() doesn't handle in the way we'd like; just paint a single pixel, irrespective of angle range */ { if (_plotter->x_double_buffering != X_DBL_BUF_NONE) XDrawPoint (_plotter->x_dpy, _plotter->x_drawable3, _plotter->drawstate->x_gc_fill, xorigin, yorigin); else { if (_plotter->x_drawable1) XDrawPoint (_plotter->x_dpy, _plotter->x_drawable1, _plotter->drawstate->x_gc_fill, xorigin, yorigin); if (_plotter->x_drawable2) XDrawPoint (_plotter->x_dpy, _plotter->x_drawable2, _plotter->drawstate->x_gc_fill, xorigin, yorigin); } } else /* default case, almost always used */ { if (_plotter->x_double_buffering != X_DBL_BUF_NONE) XFillArc(_plotter->x_dpy, _plotter->x_drawable3, _plotter->drawstate->x_gc_fill, xorigin, yorigin, squaresize_x, squaresize_y, startangle, anglerange); else { if (_plotter->x_drawable1) XFillArc(_plotter->x_dpy, _plotter->x_drawable1, _plotter->drawstate->x_gc_fill, xorigin, yorigin, squaresize_x, squaresize_y, startangle, anglerange); if (_plotter->x_drawable2) XFillArc(_plotter->x_dpy, _plotter->x_drawable2, _plotter->drawstate->x_gc_fill, xorigin, yorigin, squaresize_x, squaresize_y, startangle, anglerange); } } } if (_plotter->drawstate->pen_type) /* pen is present, so edge the arc */ { unsigned int sp_size = 0; /* keep compiler happy */ /* update GC used for drawing */ _pl_x_set_attributes (R___(_plotter) X_GC_FOR_DRAWING); /* select pen color as foreground color in GC used for drawing */ _pl_x_set_pen_color (S___(_plotter)); if (squaresize_x <= 1 || squaresize_y <= 1) /* Won't call XDrawArc in the usual way, because it performs poorly when one of these two is zero, at least. Irrespective of angle range, will fill a disk of diameter equal to line width */ { int sp_offset; sp_size = (unsigned int)_plotter->drawstate->quantized_device_line_width; sp_offset = (int)(_plotter->drawstate->quantized_device_line_width + 1) / 2; if (sp_size == 0) sp_size = 1; xorigin -= sp_offset; yorigin -= sp_offset; } if (squaresize_x <= 1 || squaresize_y <= 1) /* special case */ { if (sp_size == 1) /* special subcase: line width is small too, so just paint a single pixel rather than filling abovementioned disk */ { if (_plotter->x_double_buffering != X_DBL_BUF_NONE) XDrawPoint (_plotter->x_dpy, _plotter->x_drawable3, _plotter->drawstate->x_gc_fg, xorigin, yorigin); else { if (_plotter->x_drawable1) XDrawPoint (_plotter->x_dpy, _plotter->x_drawable1, _plotter->drawstate->x_gc_fg, xorigin, yorigin); if (_plotter->x_drawable2) XDrawPoint (_plotter->x_dpy, _plotter->x_drawable2, _plotter->drawstate->x_gc_fg, xorigin, yorigin); } } else /* normal version of special case: fill a disk of diameter equal to line width */ { if (_plotter->x_double_buffering != X_DBL_BUF_NONE) XFillArc(_plotter->x_dpy, _plotter->x_drawable3, _plotter->drawstate->x_gc_fg, xorigin, yorigin, sp_size, sp_size, 0, 64 * 360); else { if (_plotter->x_drawable1) XFillArc(_plotter->x_dpy, _plotter->x_drawable1, _plotter->drawstate->x_gc_fg, xorigin, yorigin, sp_size, sp_size, 0, 64 * 360); if (_plotter->x_drawable2) XFillArc(_plotter->x_dpy, _plotter->x_drawable2, _plotter->drawstate->x_gc_fg, xorigin, yorigin, sp_size, sp_size, 0, 64 * 360); } } } else /* default case, which is what is almost always used */ { if (_plotter->x_double_buffering != X_DBL_BUF_NONE) XDrawArc(_plotter->x_dpy, _plotter->x_drawable3, _plotter->drawstate->x_gc_fg, xorigin, yorigin, squaresize_x, squaresize_y, startangle, anglerange); else { if (_plotter->x_drawable1) XDrawArc(_plotter->x_dpy, _plotter->x_drawable1, _plotter->drawstate->x_gc_fg, xorigin, yorigin, squaresize_x, squaresize_y, startangle, anglerange); if (_plotter->x_drawable2) XDrawArc(_plotter->x_dpy, _plotter->x_drawable2, _plotter->drawstate->x_gc_fg, xorigin, yorigin, squaresize_x, squaresize_y, startangle, anglerange); } } } } /**********************************************************************/ /* This version of the internal method path_is_flushable() is for XDrawable and X Plotters, which will under some circumstances `pre-draw', i.e., draw line segments in real time. (This requires a zero line width and a "solid" line style.). In that case, this returns false; otherwise it will return true. */ bool _pl_x_path_is_flushable (S___(Plotter *_plotter)) { if (_plotter->drawstate->pen_type != 0 /* pen is present */ && _plotter->drawstate->line_type == PL_L_SOLID && !_plotter->drawstate->dash_array_in_effect /* really solid */ && _plotter->drawstate->points_are_connected /* really, really */ && _plotter->drawstate->quantized_device_line_width == 0 && !_plotter->drawstate->path->primitive) /* not a builtin */ /* we're pre-drawing rather than drawing when endpath() is finally invoked, so flushing out a partially drawn path by invoking endpath() early would be absurd */ return false; else /* endpath() will be invoked */ return true; } /**********************************************************************/ /* This version of the internal method maybe_prepaint_segments() is for XDrawable and X Plotters. It will draw line segments in real time if the line width is zero, the line style is "solid", and there's no filling to be done. Also, it requires that the polyline being drawn be unfilled, and not be one one of the polygonalized convex closed primitives (box/circle/ellipse). This hack makes it possible, after doing `graph -TX' (which has a default line width of zero), to type in points manually, and see the corresponding polyline drawn in real time. The `-x' and `-y' options must of course be specified too, to set the axis limits in advance. */ void _pl_x_maybe_prepaint_segments (R___(Plotter *_plotter) int prev_num_segments) { int i; bool something_drawn = false; /* sanity check */ if (_plotter->drawstate->path->num_segments < 2) return; if (_plotter->drawstate->path->num_segments == prev_num_segments) /* nothing to paint */ return; /* Our criteria for pre-drawing line segments: zero-width solid line, and we're not drawing this line segment as part of a polygonalized built-in object (i.e. a rectangles or ellipse). If the criteria aren't met, we wait until endpath() is invoked, or in general until the path is flushed out, before painting it. If we pre-draw, we don't also draw when endpath() is invoked. One exception: if the polyline is to be filled. In that case, at endpath time, we'll fill it and re-edge it. */ if (!(_plotter->drawstate->pen_type != 0 /* pen is present */ && _plotter->drawstate->line_type == PL_L_SOLID && !_plotter->drawstate->dash_array_in_effect /* really solid */ && _plotter->drawstate->points_are_connected /* really, really */ && _plotter->drawstate->quantized_device_line_width == 0 && !_plotter->drawstate->path->primitive)) /* not a built-in object */ /* we're not pre-drawing */ return; /* An X/XDrawable Plotter's segment list, at painting time, will only contain a polyline (i.e. a sequence of line segments) or a single circular or elliptic arc. That's because X/XDrawable Plotters can't handle `mixed paths'. Since they can't handle mixed paths, any single arc that's placed in a previously empty segment list will need to be replaced by a polygonal approximation, when and if additional segments need to be added. The maybe_replace_arc() function, which is invoked in the base Plotter code in several places, takes care of that. Because of this replacement procedure, maybe_prepaint_segments() may be invoked on a segment list that consists of a single moveto-arc or moveto-ellarc pair. We don't prepaint such things. Of course if the arc is subsequently replaced by a polygonal approximation, then we'll prepaint the polygonal approximation, at that time. */ if (prev_num_segments == 0 && _plotter->drawstate->path->num_segments == 2 && _plotter->drawstate->path->segments[0].type == S_MOVETO && (_plotter->drawstate->path->segments[1].type == S_ARC || _plotter->drawstate->path->segments[1].type == S_ELLARC)) return; if (prev_num_segments == 0) /* first segment of path; this must be a `moveto' */ { /* update GC used for drawing */ _pl_x_set_attributes (R___(_plotter) X_GC_FOR_DRAWING); /* select pen color as foreground color in GC used for drawing */ _pl_x_set_pen_color (S___(_plotter)); } /* Iterate over all segments to be painted. Because X/XDrawable Plotters can't handle `mixed paths', this function ends up being called only on sequences of line segments. */ for (i = IMAX(1, prev_num_segments); i < _plotter->drawstate->path->num_segments; i++) { /* use same variables for points #1 and #2, since reusing them works around an obscure bug in gcc 2.7.2.3 that rears its head if -O2 is used */ double xu, yu, xd, yd; double x, y; int x1, y1, x2, y2; /* starting and ending points for zero-width line segment: (xu,yu) and (x,y) respectively */ xu = _plotter->drawstate->path->segments[i-1].p.x; yu = _plotter->drawstate->path->segments[i-1].p.y; x = _plotter->drawstate->path->segments[i].p.x; y = _plotter->drawstate->path->segments[i].p.y; /* convert to integer X11 coordinates */ xd = XD(xu, yu); yd = YD(xu, yu); x1 = IROUND(xd); y1 = IROUND(yd); xd = XD(x,y); yd = YD(x,y); x2 = IROUND(xd); y2 = IROUND(yd); if (x1 != x2 || y1 != y2) /* line segment has nonzero length, so draw it */ { if (_plotter->x_double_buffering != X_DBL_BUF_NONE) /* double buffering, have a `x_drawable3' to draw into */ XDrawLine (_plotter->x_dpy, _plotter->x_drawable3, _plotter->drawstate->x_gc_fg, x1, y1, x2, y2); else { if (_plotter->x_drawable1) XDrawLine (_plotter->x_dpy, _plotter->x_drawable1, _plotter->drawstate->x_gc_fg, x1, y1, x2, y2); if (_plotter->x_drawable2) XDrawLine (_plotter->x_dpy, _plotter->x_drawable2, _plotter->drawstate->x_gc_fg, x1, y1, x2, y2); } something_drawn = true; } else /* line segment in terms of integer device coordinates has zero length; but if it has nonzero length in user coordinates, draw it as a single pixel unless cap type is "butt" */ if (!(_plotter->drawstate->cap_type == PL_CAP_BUTT && xu == x && yu == y)) { if (_plotter->x_double_buffering != X_DBL_BUF_NONE) /* double buffering, have a `x_drawable3' to draw into */ XDrawPoint (_plotter->x_dpy, _plotter->x_drawable3, _plotter->drawstate->x_gc_fg, x1, y1); else /* not double buffering */ { if (_plotter->x_drawable1) XDrawPoint (_plotter->x_dpy, _plotter->x_drawable1, _plotter->drawstate->x_gc_fg, x1, y1); if (_plotter->x_drawable2) XDrawPoint (_plotter->x_dpy, _plotter->x_drawable2, _plotter->drawstate->x_gc_fg, x1, y1); } something_drawn = true; } } if (something_drawn) /* maybe flush X output buffer and handle X events (a no-op for XDrawablePlotters, which is overridden for XPlotters) */ _maybe_handle_x_events (S___(_plotter)); } bool _pl_x_paint_paths (S___(Plotter *_plotter)) { return false; }