hello_wayland_EGL/SOURCES/graphics/os/WAYLAND/wl_context.c

#include "wl_context.h"

#include "registry_listeners/wl_output_listener.h"
#include "registry_listeners/xdg_wm_base_listener.h"

#include <wayland-client.h>

#include <stdlib.h>
#include <stdio.h>
#include <string.h>


static const struct wl_output_listener output_listener = {
    .geometry = output_geometry,
    .mode = output_mode,
    .done = output_done,
    .scale = output_scale,
};

static const struct xdg_wm_base_listener wm_base_listener = {
	wm_ping
};

/***************************************/
/***************************************/
/**********REGISTRY CALLBACKS***********/
/***************************************/
/***************************************/

/*
	listener on the registry object's add events
	used for picking the singletons to COMPOSITOR, SUBCOMPOSITOR and XDG_WM_BASE
*/
void global_registry(
	void *data, 
	struct wl_registry *wl_registry,
	uint32_t name, 
	const char *interface, 
	uint32_t version
) {
	surface_builders *builders = data;

	printf("REGISTRY EVENT\nname: %s\nversion: %d\n", interface, version);

	/*
	printf("%s\n%s\n%s\n\n", wl_compositor_interface.name,  wl_subcompositor_interface.name, xdg_wm_base_interface.name);
	*/

	if(!strcmp(interface, wl_compositor_interface.name)) {
		printf("FOUND COMP\n");
		builders->compositor = wl_registry_bind(
			wl_registry, 
			name,
			&wl_compositor_interface, 
			version
		);
	}
	else if(!strcmp(interface, wl_subcompositor_interface.name)){
		printf("FOUND SUBCOMP\n");
		builders->subcompositor = wl_registry_bind(
			wl_registry, 
			name,
			&wl_subcompositor_interface, 
			version
		);
	}
	else if(!strcmp(interface, xdg_wm_base_interface.name)) {
		printf("FOUND XDG\n");
		builders->xdg_wm_base = wl_registry_bind(
			wl_registry, 
			name,
			&xdg_wm_base_interface, 
			version
		);
	}

	if (strcmp(interface, "wl_output") == 0) {
		printf("FOUND OUTPUT\n");
        builders->output = wl_registry_bind(
        	wl_registry, 
        	name,
			&wl_output_interface, 
			1
		);
        wl_output_add_listener( builders->output, &output_listener, NULL);
    }
}

/*
	listener on the registry object's remove events
	it is an error the body being unimplemented ( when an interface becomes unavailable it could mean that the physical device has been disconnected )
*/
void global_remove(void *data, struct wl_registry *wl_registry,
			    uint32_t name) {
	(void) data;
	(void) wl_registry;
	(void) name;
}

static const struct wl_registry_listener registry_listener = {
	global_registry,
	global_remove
};

wl_context* wl_context_new() {
	wl_context *w = malloc( sizeof( wl_context));
	w->display = wl_display_connect(NULL);
	if(! w->display) {
		fprintf(stderr, "Couldn't connect to wayland display\n");
		exit(EXIT_FAILURE);
	}

	w->builders = malloc( sizeof( surface_builders));
	w->registry = wl_display_get_registry( w->display);
	wl_registry_add_listener( w->registry, &registry_listener, w->builders);
	wl_display_roundtrip( w->display);
	if( ! w->builders->compositor || ! w->builders->subcompositor || ! w->builders->xdg_wm_base) {
		fprintf(stderr, "Couldn't find compositor or xdg shell\n");
		exit(EXIT_FAILURE);
	}
	xdg_wm_base_add_listener(w->builders->xdg_wm_base, &wm_base_listener, NULL);

	return w;
}


/* ALLOWS FOR QUERYING OF SOME ENVIRONMENT VARIABLE */
int wl_context_get(int query){
	switch( query) {
		case GLUT_SCREEN_WIDTH :
			return 192;
		break;
		case GLUT_SCREEN_HEIGHT :
			return 108;	/* 1156 */
		break;
		default:
			exit(1);
	}
}