fltk/src/fl_line_style.cxx

187 lines
7.0 KiB
C++

//
// "$Id$"
//
// Line style code for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2009 by Bill Spitzak and others.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library 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
// Library General Public License for more details.
//
// You should have received a copy of the GNU Library General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
// USA.
//
// Please report all bugs and problems on the following page:
//
// http://www.fltk.org/str.php
//
/**
\file fl_line_style.cxx
\brief Line style drawing utility hiding different platforms.
*/
#include <FL/Fl.H>
#include <FL/fl_draw.H>
#include <FL/x.H>
#include "flstring.h"
#include <stdio.h>
#ifdef __APPLE_QUARTZ__
float fl_quartz_line_width_ = 1.0f;
static enum CGLineCap fl_quartz_line_cap_ = kCGLineCapButt;
static enum CGLineJoin fl_quartz_line_join_ = kCGLineJoinMiter;
static float *fl_quartz_line_pattern = 0;
static int fl_quartz_line_pattern_size = 0;
void fl_quartz_restore_line_style_() {
CGContextSetLineWidth(fl_gc, fl_quartz_line_width_);
CGContextSetLineCap(fl_gc, fl_quartz_line_cap_);
CGContextSetLineJoin(fl_gc, fl_quartz_line_join_);
CGContextSetLineDash(fl_gc, 0, fl_quartz_line_pattern, fl_quartz_line_pattern_size);
}
#endif
/**
Sets how to draw lines (the "pen").
If you change this it is your responsibility to set it back to the default
using \c fl_line_style(0).
\param[in] style A bitmask which is a bitwise-OR of a line style, a cap
style, and a join style. If you don't specify a dash type you
will get a solid line. If you don't specify a cap or join type
you will get a system-defined default of whatever value is
fastest.
\param[in] width The thickness of the lines in pixels. Zero results in the
system defined default, which on both X and Windows is somewhat
different and nicer than 1.
\param[in] dashes A pointer to an array of dash lengths, measured in pixels.
The first location is how long to draw a solid portion, the next
is how long to draw the gap, then the solid, etc. It is terminated
with a zero-length entry. A \c NULL pointer or a zero-length
array results in a solid line. Odd array sizes are not supported
and result in undefined behavior.
\note Because of how line styles are implemented on Win32 systems,
you \e must set the line style \e after setting the drawing
color. If you set the color after the line style you will lose
the line style settings.
\note The \p dashes array does not work under Windows 95, 98 or Me,
since those operating systems do not support complex line styles.
*/
void fl_line_style(int style, int width, char* dashes) {
#if defined(USE_X11)
int ndashes = dashes ? strlen(dashes) : 0;
// emulate the WIN32 dash patterns on X
char buf[7];
if (!ndashes && (style&0xff)) {
int w = width ? width : 1;
char dash, dot, gap;
// adjust lengths to account for cap:
if (style & 0x200) {
dash = char(2*w);
dot = 1; // unfortunately 0 does not work
gap = char(2*w-1);
} else {
dash = char(3*w);
dot = gap = char(w);
}
char* p = dashes = buf;
switch (style & 0xff) {
case FL_DASH: *p++ = dash; *p++ = gap; break;
case FL_DOT: *p++ = dot; *p++ = gap; break;
case FL_DASHDOT: *p++ = dash; *p++ = gap; *p++ = dot; *p++ = gap; break;
case FL_DASHDOTDOT: *p++ = dash; *p++ = gap; *p++ = dot; *p++ = gap; *p++ = dot; *p++ = gap; break;
}
ndashes = p-buf;
}
static int Cap[4] = {CapButt, CapButt, CapRound, CapProjecting};
static int Join[4] = {JoinMiter, JoinMiter, JoinRound, JoinBevel};
XSetLineAttributes(fl_display, fl_gc, width,
ndashes ? LineOnOffDash : LineSolid,
Cap[(style>>8)&3], Join[(style>>12)&3]);
if (ndashes) XSetDashes(fl_display, fl_gc, 0, dashes, ndashes);
#elif defined(WIN32)
// According to Bill, the "default" cap and join should be the
// "fastest" mode supported for the platform. I don't know why
// they should be different (same graphics cards, etc., right?) MRS
static DWORD Cap[4]= {PS_ENDCAP_FLAT, PS_ENDCAP_FLAT, PS_ENDCAP_ROUND, PS_ENDCAP_SQUARE};
static DWORD Join[4]={PS_JOIN_ROUND, PS_JOIN_MITER, PS_JOIN_ROUND, PS_JOIN_BEVEL};
int s1 = PS_GEOMETRIC | Cap[(style>>8)&3] | Join[(style>>12)&3];
DWORD a[16]; int n = 0;
if (dashes && dashes[0]) {
s1 |= PS_USERSTYLE;
for (n = 0; n < 16 && *dashes; n++) a[n] = *dashes++;
} else {
s1 |= style & 0xff; // allow them to pass any low 8 bits for style
}
if ((style || n) && !width) width = 1; // fix cards that do nothing for 0?
LOGBRUSH penbrush = {BS_SOLID,fl_RGB(),0}; // can this be fl_brush()?
HPEN newpen = ExtCreatePen(s1, width, &penbrush, n, n ? a : 0);
if (!newpen) {
Fl::error("fl_line_style(): Could not create GDI pen object.");
return;
}
HPEN oldpen = (HPEN)SelectObject(fl_gc, newpen);
DeleteObject(oldpen);
DeleteObject(fl_current_xmap->pen);
fl_current_xmap->pen = newpen;
#elif defined(__APPLE_QUARTZ__)
static enum CGLineCap Cap[4] = { kCGLineCapButt, kCGLineCapButt,
kCGLineCapRound, kCGLineCapSquare };
static enum CGLineJoin Join[4] = { kCGLineJoinMiter, kCGLineJoinMiter,
kCGLineJoinRound, kCGLineJoinBevel };
if (width<1) width = 1;
fl_quartz_line_width_ = (float)width;
fl_quartz_line_cap_ = Cap[(style>>8)&3];
fl_quartz_line_join_ = Join[(style>>12)&3];
char *d = dashes;
static float pattern[16];
if (d && *d) {
float *p = pattern;
while (*d) { *p++ = (float)*d++; }
fl_quartz_line_pattern = pattern;
fl_quartz_line_pattern_size = d-dashes;
} else if (style & 0xff) {
char dash, dot, gap;
// adjust lengths to account for cap:
if (style & 0x200) {
dash = char(2*width);
dot = 1;
gap = char(2*width-1);
} else {
dash = char(3*width);
dot = gap = char(width);
}
float *p = pattern;
switch (style & 0xff) {
case FL_DASH: *p++ = dash; *p++ = gap; break;
case FL_DOT: *p++ = dot; *p++ = gap; break;
case FL_DASHDOT: *p++ = dash; *p++ = gap; *p++ = dot; *p++ = gap; break;
case FL_DASHDOTDOT: *p++ = dash; *p++ = gap; *p++ = dot; *p++ = gap; *p++ = dot; *p++ = gap; break;
}
fl_quartz_line_pattern_size = p-pattern;
fl_quartz_line_pattern = pattern;
} else {
fl_quartz_line_pattern = 0; fl_quartz_line_pattern_size = 0;
}
fl_quartz_restore_line_style_();
#else
# error unsupported platform
#endif
}
//
// End of "$Id$".
//