fltk/test/cairo_test.cxx

//
// "$Id$"
//
// Arc drawing test program for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2018 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_Cairo_Window.H>
#include <FL/Fl_Box.H>
#include <FL/platform.H>
#include <FL/fl_draw.H>
#include <FL/math.h>
#define DEF_WIDTH 0.03

// uncomment the following line to enable cairo context autolink feature:
// #define AUTOLINK

// put your drawing stuff here
float drawargs[7] = {90, 90, 100, 100, 0, 360, 0};
const char* name[7] = {"X", "Y", "W", "H", "start", "end", "rotate"};


static void centered_text(cairo_t* cr, double x0,double y0,double w0,double h0, const char * my_text) {
    cairo_select_font_face (cr, "Sans", CAIRO_FONT_SLANT_OBLIQUE,CAIRO_FONT_WEIGHT_BOLD);
    cairo_set_source_rgba (cr, 0.9, 0.9, 0.4, 0.6);
    cairo_text_extents_t extents;
    cairo_text_extents (cr, my_text, &extents);
    double x = (extents.width/2 + extents.x_bearing);
    double y = (extents.height/2 + extents.y_bearing);
    cairo_move_to  (cr, x0+w0/2-x, y0+h0/2 - y);
    cairo_text_path(cr,my_text);
    cairo_fill_preserve (cr);
    cairo_set_source_rgba (cr, 0, 0, 0,1);
    cairo_set_line_width (cr, 0.004);
    cairo_stroke (cr);
    cairo_set_line_width (cr, DEF_WIDTH);


}

static void round_button(cairo_t* cr, double x0, double y0, 
		  double rect_width, double rect_height, double radius,
		  double r, double g, double b) {
    
    double x1,y1;
    
    
    x1=x0+rect_width;
    y1=y0+rect_height;
    if (!rect_width || !rect_height)
	return;
    if (rect_width/2<radius) {
	if (rect_height/2<radius) {
	    cairo_move_to  (cr, x0, (y0 + y1)/2);
	    cairo_curve_to (cr, x0 ,y0, x0, y0, (x0 + x1)/2, y0);
	    cairo_curve_to (cr, x1, y0, x1, y0, x1, (y0 + y1)/2);
	    cairo_curve_to (cr, x1, y1, x1, y1, (x1 + x0)/2, y1);
	    cairo_curve_to (cr, x0, y1, x0, y1, x0, (y0 + y1)/2);
	} else {
	    cairo_move_to  (cr, x0, y0 + radius);
	    cairo_curve_to (cr, x0 ,y0, x0, y0, (x0 + x1)/2, y0);
	    cairo_curve_to (cr, x1, y0, x1, y0, x1, y0 + radius);
	    cairo_line_to (cr, x1 , y1 - radius);
	    cairo_curve_to (cr, x1, y1, x1, y1, (x1 + x0)/2, y1);
	    cairo_curve_to (cr, x0, y1, x0, y1, x0, y1- radius);
	}
    } else {
	if (rect_height/2<radius) {
	    cairo_move_to  (cr, x0, (y0 + y1)/2);
	    cairo_curve_to (cr, x0 , y0, x0 , y0, x0 + radius, y0);
	    cairo_line_to (cr, x1 - radius, y0);
	    cairo_curve_to (cr, x1, y0, x1, y0, x1, (y0 + y1)/2);
	    cairo_curve_to (cr, x1, y1, x1, y1, x1 - radius, y1);
	    cairo_line_to (cr, x0 + radius, y1);
	    cairo_curve_to (cr, x0, y1, x0, y1, x0, (y0 + y1)/2);
	} else {
	    cairo_move_to  (cr, x0, y0 + radius);
	    cairo_curve_to (cr, x0 , y0, x0 , y0, x0 + radius, y0);
	    cairo_line_to (cr, x1 - radius, y0);
	    cairo_curve_to (cr, x1, y0, x1, y0, x1, y0 + radius);
	    cairo_line_to (cr, x1 , y1 - radius);
	    cairo_curve_to (cr, x1, y1, x1, y1, x1 - radius, y1);
	    cairo_line_to (cr, x0 + radius, y1);
	    cairo_curve_to (cr, x0, y1, x0, y1, x0, y1- radius);
	}
    }
    cairo_close_path (cr);
    
    cairo_pattern_t *pat= 
	//cairo_pattern_create_linear (0.0, 0.0,  0.0, 1.0);
        cairo_pattern_create_radial (0.25, 0.24, 0.11, 0.24,  0.14, 0.35);
    cairo_pattern_set_extend (pat, CAIRO_EXTEND_REFLECT);
    
    cairo_pattern_add_color_stop_rgba (pat, 1.0, r, g, b, 1);
    cairo_pattern_add_color_stop_rgba (pat, 0.0, 1, 1, 1, 1);
    cairo_set_source (cr, pat);
    cairo_fill_preserve (cr);
    cairo_pattern_destroy (pat);

    //cairo_set_source_rgb (cr, 0.5,0.5,1);    cairo_fill_preserve (cr);
    cairo_set_source_rgba (cr, 0, 0, 0.5, 0.3);
    cairo_stroke (cr);

    cairo_set_font_size (cr, 0.08);
    centered_text(cr,x0,y0,rect_width, rect_height, "FLTK loves Cairo!");

}
// The cairo rendering cb called during Fl_Cairo_Window::draw() :
static void my_cairo_draw_cb(Fl_Cairo_Window* window, cairo_t* cr) {
	
  int w= window->w(), h = window->h(); 
  
    cairo_set_line_width (cr, DEF_WIDTH);
    cairo_scale (cr, w,h);

    round_button(cr,0.1,0.05,0.8,0.2,0.4,0,0,1);
    round_button(cr,0.1,0.35,0.8,0.2,0.4,1,0,0);
    round_button(cr,0.1,0.65,0.8,0.2,0.4,0,1,0);
    return;
}

int main(int argc, char** argv) {
#ifdef AUTOLINK
  Fl::cairo_autolink_context(true);
#endif
  Fl_Cairo_Window window(300, 300, "FLTK loves Cairo");

  window.resizable(&window);
  window.color(FL_WHITE);
  window.set_draw_cb(my_cairo_draw_cb);
  window.show(argc,argv);

  return Fl::run();
}
#else
#include <FL/fl_ask.H>

int main(int argc, char** argv) {
  fl_message("please configure fltk with CAIRO enabled (--enable-cairo or --enable-cairoext)"); 
  return 0;
}
#endif

//
// End of "$Id$".
//