[AD] examples

[Elias Pschernig <elias@xxxxxxxxxx>]

On Mon, 2004-07-12 at 18:26 +0200, Evert Glebbeek wrote: 
> > Maybe someone should comb through the examples, as well.
> 
> Wouldn't be such a bad idea...
> 

I took the next example, ex3buf. Having new users go through the
examples, just to see lots of "This doesn't work", is not a good idea.
ex3buf now works if there are 3 video buffers available, no matter if
triple buffering is actually supported. If it is - then it stays like
before. Otherwise, there's a message saying it is only simulated, and
the user isn't disappointed. I also enabled the palette fading in case
there's no retrace sync avable - I see no reason to disable it.

And as last, I increased the resolution to 640x480 if we are outside
DOS, since 320x240 is hardly supported anymore in newer X11 versions
(same goes for windows I think).

Going to apply if there aren't any objections.

-- 
Elias Pschernig

Index: ex3buf.c
===================================================================
RCS file: /cvsroot/alleg/allegro/examples/ex3buf.c,v
retrieving revision 1.9
diff -u -p -r1.9 ex3buf.c
--- ex3buf.c	14 Jun 2003 09:48:06 -0000	1.9
+++ ex3buf.c	15 Jul 2004 20:46:35 -0000
@@ -24,6 +24,8 @@ typedef struct SHAPE
 
 
 SHAPE shapes[NUM_SHAPES];
+int triplebuffer_not_available = 0;
+int retrace_sync_not_available = 0;
 
 
 
@@ -80,6 +82,7 @@ void move_shape(SHAPE *shape)
 void draw(BITMAP *b)
 {
    int c;
+   char message[1024];
 
    acquire_bitmap(b);
 
@@ -98,10 +101,17 @@ void draw(BITMAP *b)
       move_shape(shapes+c);
    } 
 
-   if (retrace_proc)
-      textout_ex(b, font, "Triple buffering with retrace sync", 0, 0, 255, -1);
+   if (triplebuffer_not_available)
+      ustrzcpy (message, sizeof message, "Simulated triple buffering");
    else
-      textout_ex(b, font, "Triple buffering", 0, 0, 255, -1);
+      ustrzcpy (message, sizeof message, "Real triple buffering");
+
+   if (retrace_sync_not_available)
+      ustrzcat(message,  sizeof message, " with simulated retrace sync");
+   else
+      ustrzcat(message,  sizeof message, " with real retrace sync");
+
+   textout_ex(b, font, message, 0, 0, 255, -1);
 
    release_bitmap(b);
 }
@@ -164,6 +174,15 @@ int main(void)
 {
    BITMAP *page1, *page2, *page3;
    int c;
+   int w, h;
+
+#ifdef ALLEGRO_DOS
+   w = 320;
+   h = 240;
+#else
+   w = 640;
+   h = 480;
+#endif
 
    if (allegro_init() != 0)
       return 1;
@@ -172,13 +191,15 @@ int main(void)
    install_mouse();
 
    /* see comments in exflip.c */
-   if (set_gfx_mode(GFX_AUTODETECT, 320, 240, 0, 720) != 0) {
-      if (set_gfx_mode(GFX_AUTODETECT, 320, 240, 0, 0) != 0) {
-	 if (set_gfx_mode(GFX_SAFE, 320, 240, 0, 0) != 0) {
-	    set_gfx_mode(GFX_TEXT, 0, 0, 0, 0);
-	    allegro_message("Unable to set any graphic mode\n%s\n", allegro_error);
-	    return 1;
-         }
+#ifdef ALLEGRO_VRAM_SINGLE_SURFACE
+   if (set_gfx_mode(GFX_AUTODETECT, w, h, 0, h * 3) != 0) {
+#else
+   if (set_gfx_mode(GFX_AUTODETECT, w, h, 0, 0) != 0) {
+#endif
+      if (set_gfx_mode(GFX_SAFE, w, h, 0, 0) != 0) {
+         set_gfx_mode(GFX_TEXT, 0, 0, 0, 0);
+         allegro_message("Unable to set any graphic mode\n%s\n", allegro_error);
+         return 1;
       }
    }
 
@@ -190,15 +211,7 @@ int main(void)
 
    /* if that didn't work, give up */
    if (!(gfx_capabilities & GFX_CAN_TRIPLE_BUFFER)) {
-      set_gfx_mode(GFX_TEXT, 0, 0, 0, 0);
-
-      #ifdef ALLEGRO_DOS
-	 allegro_message("Triple buffering not available, sorry\n\nTry again in clean DOS mode (not under Windows)\n");
-      #else
-	 allegro_message("Triple buffering not available, sorry\n");
-      #endif
-
-      return 1;
+      triplebuffer_not_available = TRUE;
    }
 
    /* allocate three sub bitmaps to access pages of the screen */
@@ -224,10 +237,11 @@ int main(void)
       retrace_proc = fade;
    }
    else {
-      alert("Retrace sync is not available in",
-	    "this environment, so you won't get",
-	    "the funky smooth palette fading", 
-	    "Damn, that's a shame", NULL, 13, 0);
+      /* Well, we don't have retrace simulation. But we still can
+       * do the palette fading.
+       */
+      retrace_sync_not_available = TRUE;
+      retrace_proc = fade;
    }
 
    triple_buffer(page1, page2, page3);