ref: 7f75ad6ef8ca9c1a2b87f860e4287b32c14845f3
dir: /DoConfig/fltk/cairo/Fl_Cairo.cxx/
//
// "$Id$"
//
// Main header file for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2016 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file. If this
// file is missing or damaged, see the license at:
//
// http://www.fltk.org/COPYING.php
//
// Please report all bugs and problems on the following page:
//
// http://www.fltk.org/str.php
//
#include <config.h>
#ifdef FLTK_HAVE_CAIRO
#include <FL/Fl.H>
#include <FL/x.H>
#include <FL/Fl_Window.H>
#ifdef __APPLE__
#include <Carbon/Carbon.h>
#endif
// Cairo is currently supported for the following platforms:
// Win32, Apple Quartz, X11
# if defined(USE_X11) // X11
# include <cairo-xlib.h>
# elif defined(WIN32)
# include <cairo-win32.h>
# elif defined(__APPLE_QUARTZ__)
# include <cairo-quartz.h>
# else
# error Cairo is not supported on this platform.
# endif
// static Fl module initialization :
Fl_Cairo_State Fl::cairo_state_; ///< contains all necessary info for current cairo context mapping
// Fl cairo features implementation
// Fl_Cairo_State class impl
void Fl_Cairo_State::autolink(bool b) {
#ifdef FLTK_USE_CAIRO
autolink_ = b;
#else
Fl::fatal("In Fl::autolink(bool) : Cairo autolink() feature is only "
"available with the enable-cairoext configure option, now quitting.");
#endif
}
/**
Provides a corresponding cairo context for window \a wi.
This is needed in a draw() override if Fl::cairo_autolink_context()
returns false, which is the default.
The cairo_context() does not need to be freed as it is freed every time
a new cairo context is created. When the program terminates,
a call to Fl::cairo_make_current(0) will destroy any residual context.
\note A new cairo context is not always re-created when this method
is used. In particular, if the current graphical context and the current
window didn't change between two calls, the previous gc is internally kept,
thus optimizing the drawing performances.
Also, after this call, Fl::cairo_cc() is adequately updated with this
cairo context.
\note Only available when configure has the --enable-cairo option
\return the valid cairo_t* cairo context associated to this window.
*/
cairo_t * Fl::cairo_make_current(Fl_Window* wi) {
if (!wi) return NULL; // Precondition
if (fl_gc==0) { // means remove current cc
Fl::cairo_cc(0); // destroy any previous cc
cairo_state_.window(0);
return 0;
}
// don't re-create a context if it's the same gc/window couple
if (fl_gc==Fl::cairo_state_.gc() && fl_xid(wi) == (Window) Fl::cairo_state_.window())
return Fl::cairo_cc();
cairo_state_.window(wi);
#if defined(USE_X11)
return Fl::cairo_make_current(0, wi->w(), wi->h());
#else
return Fl::cairo_make_current(fl_gc, wi->w(), wi->h());
#endif
}
/*
Creates transparently a cairo_surface_t object.
gc is an HDC context in WIN32, a CGContext* in Quartz, and
a display on X11 (not used on this platform)
*/
static cairo_surface_t * cairo_create_surface(void * gc, int W, int H) {
# if defined(USE_X11)
return cairo_xlib_surface_create(fl_display, fl_window, fl_visual->visual, W, H);
# elif defined(WIN32)
return cairo_win32_surface_create((HDC) gc);
# elif defined(__APPLE_QUARTZ__)
return cairo_quartz_surface_create_for_cg_context((CGContext*) gc, W, H);
# else
# error Cairo is not supported under this platform.
# endif
}
/**
Creates a cairo context from a \a gc only, gets its window size or
offscreen size if fl_window is null.
\note Only available when configure has the --enable-cairo option
*/
cairo_t * Fl::cairo_make_current(void *gc) {
int W=0,H=0;
#if defined(USE_X11)
//FIXME X11 get W,H
// gc will be the window handle here
# warning FIXME get W,H for cairo_make_current(void*)
#elif defined(__APPLE_QUARTZ__)
if (fl_window) {
W = Fl_Window::current()->w();
H = Fl_Window::current()->h();
}
else {
W = CGBitmapContextGetHeight(fl_gc);
H = CGBitmapContextGetHeight(fl_gc);
}
#elif defined(WIN32)
// we don't need any W,H for WIN32
#else
# error Cairo is not supported on this platform.
#endif
if (!gc) {
Fl::cairo_cc(0);
cairo_state_.gc(0); // keep track for next time
return 0;
}
if (gc==Fl::cairo_state_.gc() &&
fl_window== (Window) Fl::cairo_state_.window() &&
cairo_state_.cc()!=0)
return Fl::cairo_cc();
cairo_state_.gc(fl_gc); // keep track for next time
cairo_surface_t * s = cairo_create_surface(gc, W, H);
cairo_t * c = cairo_create(s);
cairo_surface_destroy(s);
cairo_state_.cc(c);
return c;
}
/**
Creates a cairo context from a \a gc and its size
\note Only available when configure has the --enable-cairo option
*/
cairo_t * Fl::cairo_make_current(void *gc, int W, int H) {
if (gc==Fl::cairo_state_.gc() &&
fl_window== (Window) Fl::cairo_state_.window() &&
cairo_state_.cc()!=0) // no need to create a cc, just return that one
return cairo_state_.cc();
// we need to (re-)create a fresh cc ...
cairo_state_.gc(gc); // keep track for next time
cairo_surface_t * s = cairo_create_surface(gc, W, H);
cairo_t * c = cairo_create(s);
cairo_state_.cc(c); // and purge any previously owned context
cairo_surface_destroy(s);
return c;
}
#else
// just don't leave the libfltk_cairo lib empty to avoid warnings
#include <FL/Fl_Export.H>
FL_EXPORT int fltk_cairo_dummy() { return 1;}
#endif // FLTK_HAVE_CAIRO
//
// End of "$Id$" .
//