{"id":2545,"date":"2010-08-16T20:49:15","date_gmt":"2010-08-16T15:19:15","guid":{"rendered":"http:\/\/www.jeffrin.in\/?p=2545"},"modified":"2010-08-16T20:49:15","modified_gmt":"2010-08-16T15:19:15","slug":"cairo-graphics-0-6-circle-animation","status":"publish","type":"post","link":"https:\/\/www.trueangle.org\/index.php\/2010\/08\/16\/cairo-graphics-0-6-circle-animation\/","title":{"rendered":"cairo graphics 0.6 Circle animation"},"content":{"rendered":"

\"\"<\/a>
\n
\n\/* Jeffrin Jose Licensed GPL v3 Copyright
\nAugust 2010 GPL --> http:\/\/www.gnu.org\/copyleft\/gpl.html *\/<\/p>\n

#include
\n#include
\n#include <\/p>\n

\/\/the global pixmap that will serve as our buffer
\nstatic GdkPixmap *pixmap = NULL;<\/p>\n

gboolean on_window_configure_event(GtkWidget * da, GdkEventConfigure * event, gpointer user_data){
\n static int oldw = 0;
\n static int oldh = 0;
\n \/\/make our selves a properly sized pixmap if our window has been resized
\n if (oldw != event->width || oldh != event->height){
\n \/\/create our new pixmap with the correct size.
\n GdkPixmap *tmppixmap = gdk_pixmap_new(da->window, event->width, event->height, -1);
\n \/\/copy the contents of the old pixmap to the new pixmap. This keeps ugly uninitialized
\n \/\/pixmaps from being painted upon resize
\n int minw = oldw, minh = oldh;
\n if( event->width width; }
\n if( event->height height; }
\n gdk_draw_drawable(tmppixmap, da->style->fg_gc[GTK_WIDGET_STATE(da)], pixmap, 0, 0, 0, 0, minw, minh);
\n \/\/we're done with our old pixmap, so we can get rid of it and replace it with our properly-sized one.
\n g_object_unref(pixmap);
\n pixmap = tmppixmap;
\n }
\n oldw = event->width;
\n oldh = event->height;
\n return TRUE;
\n}<\/p>\n

gboolean on_window_expose_event(GtkWidget * da, GdkEventExpose * event, gpointer user_data){
\n gdk_draw_drawable(da->window,
\n da->style->fg_gc[GTK_WIDGET_STATE(da)], pixmap,
\n \/\/ Only copy the area that was exposed.
\n event->area.x, event->area.y,
\n event->area.x, event->area.y,
\n event->area.width, event->area.height);
\n return TRUE;
\n}<\/p>\n

static int currently_drawing = 0;
\n\/\/do_draw will be executed in a separate thread whenever we would like to update
\n\/\/our animation
\nvoid *do_draw(void *ptr){<\/p>\n

currently_drawing = 1;<\/p>\n

int width, height;
\n gdk_threads_enter();
\n gdk_drawable_get_size(pixmap, &width, &height);
\n gdk_threads_leave();<\/p>\n

\/\/create a gtk-independant surface to draw on
\n cairo_surface_t *cst = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, width, height);
\n cairo_t *cr = cairo_create(cst);<\/p>\n

\/\/do some time-consuming drawing
\n static int i = 0;
\n ++i; i = i % 300; \/\/give a little movement to our animation
\n cairo_set_source_rgb (cr, .9, .9, .9);
\n cairo_paint(cr);
\n cairo_set_source_rgb (cr, 0.8, 0.5, 0.9);
\n cairo_move_to(cr, 50,50);<\/p>\n

int j,k;
\n\/* for(k=0; k<100; ++k){*\/ \/\/lets just redraw lots of times to use a lot of proc power
\n for(j=0; j window,700,700,-1);
\n \/\/because we will be painting our pixmap manually during expose events
\n \/\/we can turn off gtk's automatic painting and double buffering routines.
\n gtk_widget_set_app_paintable(window, TRUE);
\n gtk_widget_set_double_buffered(window, FALSE);<\/p>\n

(void)g_timeout_add(33, (GSourceFunc)timer_exe, window);<\/p>\n

gtk_main();
\n gdk_threads_leave();<\/p>\n

return 0;
\n}
\n<\/code><\/p>\n","protected":false},"excerpt":{"rendered":"

\/* Jeffrin Jose Licensed GPL v3 Copyright August 2010 GPL –> http:\/\/www.gnu.org\/copyleft\/gpl.html *\/ #include #include #include \/\/the global pixmap that will serve as our buffer static GdkPixmap *pixmap = NULL; gboolean on_window_configure_event(GtkWidget * da, GdkEventConfigure * event, gpointer user_data){ static int oldw = 0; static int oldh = 0; \/\/make our selves a properly sized … <\/p>\n

Continue reading “cairo graphics 0.6 Circle animation”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[395,540,908,1030,1132],"_links":{"self":[{"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/posts\/2545"}],"collection":[{"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/comments?post=2545"}],"version-history":[{"count":0,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/posts\/2545\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/media?parent=2545"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/categories?post=2545"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/tags?post=2545"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}