* Allow the driver initialisation to fail, for instance when $DISPLAY = "".

caca/caca.c

@@ -122,92 +122,56 @@ static int caca_init_driver(caca_t *kk)
     if(var && *var)
     {
 #if defined(USE_WIN32)
-        if(!strcasecmp(var, "win32"))
+        if(!strcasecmp(var, "win32")) return win32_install(kk);
-            win32_init_driver(kk);
-        else
 #endif
 #if defined(USE_CONIO)
-        if(!strcasecmp(var, "conio"))
+        if(!strcasecmp(var, "conio")) return conio_install(kk);
-            conio_init_driver(kk);
-        else
 #endif
 #if defined(USE_X11)
-        if(!strcasecmp(var, "x11"))
+        if(!strcasecmp(var, "x11")) return x11_install(kk);
-            x11_init_driver(kk);
-        else
 #endif
 #if defined(USE_GL)
-        if(!strcasecmp(var, "gl"))
+        if(!strcasecmp(var, "gl")) return gl_install(kk);
-            gl_init_driver(kk);
-        else
 #endif
 #if defined(USE_SLANG)
-        if(!strcasecmp(var, "slang"))
+        if(!strcasecmp(var, "slang")) return slang_install(kk);
-            slang_init_driver(kk);
-        else
 #endif
 #if defined(USE_NCURSES)
-        if(!strcasecmp(var, "ncurses"))
+        if(!strcasecmp(var, "ncurses")) return ncurses_install(kk);
-            ncurses_init_driver(kk);
-        else
 #endif
 #if defined(USE_NETWORK)
-        if(!strcasecmp(var, "network"))
+        if(!strcasecmp(var, "network")) return network_install(kk);
-            network_init_driver(kk);
-        else
 #endif
 #if defined(USE_VGA)
-        if(!strcasecmp(var, "vga"))
+        if(!strcasecmp(var, "vga")) return vga_install(kk);
-            vga_init_driver(kk);
-        else
 #endif
-            return -1;
+        return -1;
-
-        return 0;
     }
 #endif
 
 #if defined(USE_WIN32)
-    win32_init_driver(kk);
+    if(win32_install(kk) == 0) return 0;
-    return 0;
 #endif
 #if defined(USE_CONIO)
-    conio_init_driver(kk);
+    if(conio_install(kk) == 0) return 0;
-    return 0;
 #endif
 #if defined(USE_VGA)
-    vga_init_driver(kk);
+    if(vga_install(kk) == 0) return 0;
-    return 0;
 #endif
 #if defined(USE_X11)
-#if defined(HAVE_GETENV)
+    if(x11_install(kk) == 0) return 0;
-    if(getenv("DISPLAY") && *(getenv("DISPLAY")))
-#endif
-    {
-        x11_init_driver(kk);
-        return 0;
-    }
 #endif
 #if defined(USE_GL)
-#if defined(HAVE_GETENV) && defined(GLUT_XLIB_IMPLEMENTATION)
+    if(gl_install(kk) == 0) return 0;
-    if(getenv("DISPLAY") && *(getenv("DISPLAY")))
-#endif
-    {
-        gl_init_driver(kk);
-        return 0;
-    }
 #endif
 #if defined(USE_SLANG)
-    slang_init_driver(kk);
+    if(slang_install(kk) == 0) return 0;
-    return 0;
 #endif
 #if defined(USE_NCURSES)
-    ncurses_init_driver(kk);
+    if(ncurses_install(kk) == 0) return 0;
-    return 0;
 #endif
 #if defined(USE_NETWORK)
-    network_init_driver(kk);
+    if(network_install(kk) == 0) return 0;
-    return 0;
 #endif
 
     return -1;

caca/caca_internals.h

@@ -38,6 +38,7 @@ typedef long unsigned int uintptr_t;
 /* Graphics driver */
 enum caca_driver
 {
+    CACA_DRIVER_NONE = 0,
 #if defined(USE_CONIO)
     CACA_DRIVER_CONIO = 1,
 #endif
@@ -62,34 +63,34 @@ enum caca_driver
 #if defined(USE_VGA)
     CACA_DRIVER_VGA = 8,
 #endif
-    CACA_DRIVER_NONE = 0
 };
 
 /* Available drivers */
 #if defined(USE_CONIO)
-void conio_init_driver(caca_t *);
+int conio_install(caca_t *);
 #endif
 #if defined(USE_GL)
-void gl_init_driver(caca_t *);
+int gl_install(caca_t *);
 #endif
 #if defined(USE_NCURSES)
-void ncurses_init_driver(caca_t *);
+int ncurses_install(caca_t *);
 #endif
 #if defined(USE_SLANG)
-void slang_init_driver(caca_t *);
+int slang_install(caca_t *);
 #endif
 #if defined(USE_WIN32)
-void win32_init_driver(caca_t *);
+int win32_install(caca_t *);
 #endif
 #if defined(USE_X11)
-void x11_init_driver(caca_t *);
+int x11_install(caca_t *);
 #endif
 #if defined(USE_NETWORK)
-void network_init_driver(caca_t *);
+int network_install(caca_t *);
 #endif
 #if defined(USE_VGA)
-void vga_init_driver(caca_t *);
+int vga_install(caca_t *);
 #endif
+
 /* Timer structure */
 struct caca_timer
 {
@@ -128,7 +129,6 @@ struct caca_context
     struct resize
     {
         int resized;   /* A resize event was requested */
-        //int acked;     /* The event has been acknowledged by the user */
         unsigned w, h; /* Requested width and height */
     } resize;
 

caca/driver_conio.c

@@ -151,7 +151,7 @@ static int conio_get_event(caca_t *kk, struct caca_event *ev)
  * Driver initialisation
  */
 
-void conio_init_driver(caca_t *kk)
+int conio_install(caca_t *kk)
 {
     kk->drv.driver = CACA_DRIVER_CONIO;
 
@@ -163,6 +163,8 @@ void conio_init_driver(caca_t *kk)
     kk->drv.display = conio_display;
     kk->drv.handle_resize = conio_handle_resize;
     kk->drv.get_event = conio_get_event;
+
+    return 0;
 }
 
 #endif /* USE_CONIO */

caca/driver_gl.c

@@ -106,9 +106,11 @@ static int gl_init_graphics(caca_t *kk)
 
     gl_kk = kk;
 
+#if defined(HAVE_GETENV)
     geometry = getenv("CACA_GEOMETRY");
     if(geometry && *geometry)
         sscanf(geometry, "%ux%u", &width, &height);
+#endif
 
     if(width && height)
         _cucul_set_size(kk->qq, width, height);
@@ -445,8 +447,13 @@ static void gl_handle_mouse_motion(int x, int y)
  * Driver initialisation
  */
 
-void gl_init_driver(caca_t *kk)
+int gl_install(caca_t *kk)
 {
+#if defined(HAVE_GETENV) && defined(GLUT_XLIB_IMPLEMENTATION)
+    if(!getenv("DISPLAY") || !*(getenv("DISPLAY")))
+        return -1;
+#endif
+
     kk->drv.driver = CACA_DRIVER_GL;
 
     kk->drv.init_graphics = gl_init_graphics;
@@ -457,6 +464,8 @@ void gl_init_driver(caca_t *kk)
     kk->drv.display = gl_display;
     kk->drv.handle_resize = gl_handle_resize;
     kk->drv.get_event = gl_get_event;
+
+    return 0;
 }
 
 #endif /* USE_GL */

caca/driver_ncurses.c

@@ -530,7 +530,7 @@ static void ncurses_write_utf32(uint32_t c)
  * Driver initialisation
  */
 
-void ncurses_init_driver(caca_t *kk)
+int ncurses_install(caca_t *kk)
 {
     kk->drv.driver = CACA_DRIVER_NCURSES;
 
@@ -542,6 +542,8 @@ void ncurses_init_driver(caca_t *kk)
     kk->drv.display = ncurses_display;
     kk->drv.handle_resize = ncurses_handle_resize;
     kk->drv.get_event = ncurses_get_event;
+
+    return 0;
 }
 
 #endif /* USE_NCURSES */

caca/driver_network.c

@@ -550,7 +550,7 @@ ssize_t nonblock_write(int fd, void *buf, size_t len)
  * Driver initialisation
  */
 
-void network_init_driver(caca_t *kk)
+int network_install(caca_t *kk)
 {
     kk->drv.driver = CACA_DRIVER_NETWORK;
 
@@ -562,6 +562,8 @@ void network_init_driver(caca_t *kk)
     kk->drv.display = network_display;
     kk->drv.handle_resize = network_handle_resize;
     kk->drv.get_event = network_get_event;
+
+    return 0;
 }
 
 

caca/driver_slang.c

@@ -468,7 +468,7 @@ static void slang_check_terminal(void)
  * Driver initialisation
  */
 
-void slang_init_driver(caca_t *kk)
+int slang_install(caca_t *kk)
 {
     kk->drv.driver = CACA_DRIVER_SLANG;
 
@@ -480,6 +480,8 @@ void slang_init_driver(caca_t *kk)
     kk->drv.display = slang_display;
     kk->drv.handle_resize = slang_handle_resize;
     kk->drv.get_event = slang_get_event;
+
+    return 0;
 }
 
 #endif /* USE_SLANG */

caca/driver_vga.c

@@ -145,7 +145,7 @@ static int vga_get_event(caca_t *kk, struct caca_event *ev)
  * Driver initialisation
  */
 
-void vga_init_driver(caca_t *kk)
+int vga_install(caca_t *kk)
 {
     kk->drv.driver = CACA_DRIVER_VGA;
 
@@ -157,6 +157,8 @@ void vga_init_driver(caca_t *kk)
     kk->drv.display = vga_display;
     kk->drv.handle_resize = vga_handle_resize;
     kk->drv.get_event = vga_get_event;
+
+    return 0;
 }
 
 #endif /* USE_VGA */

caca/driver_win32.c

@@ -333,7 +333,7 @@ static int win32_get_event(caca_t *kk, struct caca_event *ev)
  * Driver initialisation
  */
 
-void win32_init_driver(caca_t *kk)
+int win32_install(caca_t *kk)
 {
     kk->drv.driver = CACA_DRIVER_WIN32;
 
@@ -345,6 +345,8 @@ void win32_init_driver(caca_t *kk)
     kk->drv.display = win32_display;
     kk->drv.handle_resize = win32_handle_resize;
     kk->drv.get_event = win32_get_event;
+
+    return 0;
 }
 
 #endif /* USE_WIN32 */

caca/driver_x11.c

@@ -92,9 +92,11 @@ static int x11_init_graphics(caca_t *kk)
 
     kk->drv.p = malloc(sizeof(struct driver_private));
 
+#if defined(HAVE_GETENV)
     geometry = getenv("CACA_GEOMETRY");
     if(geometry && *geometry)
         sscanf(geometry, "%ux%u", &width, &height);
+#endif
 
     if(width && height)
         _cucul_set_size(kk->qq, width, height);
@@ -103,10 +105,12 @@ static int x11_init_graphics(caca_t *kk)
     if(kk->drv.p->dpy == NULL)
         return -1;
 
+#if defined(HAVE_GETENV)
     fonts[0] = getenv("CACA_FONT");
     if(fonts[0] && *fonts[0])
         parser = fonts;
     else
+#endif
         parser = fonts + 1;
 
     /* Ignore font errors */
@@ -543,8 +547,13 @@ static int x11_error_handler(Display *dpy, XErrorEvent *xevent)
  * Driver initialisation
  */
 
-void x11_init_driver(caca_t *kk)
+int x11_install(caca_t *kk)
 {
+#if defined(HAVE_GETENV)
+    if(!getenv("DISPLAY") || !*(getenv("DISPLAY")))
+        return -1;
+#endif
+
     kk->drv.driver = CACA_DRIVER_X11;
 
     kk->drv.init_graphics = x11_init_graphics;
@@ -555,6 +564,8 @@ void x11_init_driver(caca_t *kk)
     kk->drv.display = x11_display;
     kk->drv.handle_resize = x11_handle_resize;
     kk->drv.get_event = x11_get_event;
+
+    return 0;
 }
 
 #endif /* USE_X11 */