[Freeciv-Dev] Re: [PATCH] bugfix for wrapping problem

[Jason Dorje Short <jshort@xxxxxxxxxxxxx>]

Raimar Falke wrote:
> 

> So we need another type of positions in the client gui? Since I like
> "map pos(ition)" for the general (almost always normalized)
> position. What about "canvas position"? This is just so that nobody
> will get misunderstood.

Canvas position is no good because canvas_x and canvas_y are used for
drawing positions (pixels).

If any new nomenclature is needed, it should be "absolute".  In my
patch, I've used this as a naming convention, i.e. abs_x versus map_x.

The attached patch should be in a usable form.  It fixes the wrapping
problem for drawing cities as well - the error was identical.  It
doesn't touch isometric view code, and only fixes GTK.  I don't see any
reason not apply it :-)

There's still a small bug: when updating units received from the server
the client will only move them in one position, leaving the other tile
of the unit in place.  When the client next does a redraw (soon after)
they'll get updated.  This should only be a problem for people using a
super-wide window.

jason

Index: client/gui-gtk/mapview.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/client/gui-gtk/mapview.c,v
retrieving revision 1.90
diff -u -r1.90 mapview.c
--- client/gui-gtk/mapview.c    2001/08/24 07:12:45     1.90
+++ client/gui-gtk/mapview.c    2001/08/24 08:22:53
@@ -254,7 +254,7 @@
 Beside setting the results in canvas_x,canvas_y it returns whether the tile
 is inside the visible map.
 **************************************************************************/
-static int get_canvas_xy(int map_x, int map_y, int *canvas_x, int *canvas_y)
+static int get_canvas_xy(int abs_x, int abs_y, int *canvas_x, int *canvas_y)
 {
   if (is_isometric) {
     /* canvas_x,canvas_y is the top corner of the actual tile, not the pixmap.
@@ -265,6 +265,7 @@
     int diff_xy;
     int diff_x, diff_y;
     int width, height;
+    int map_x = abs_x, map_y = abs_y; /* FIXME: we should use abs coords */
     gdk_window_get_size(map_canvas->window, &width, &height);
 
     map_x %= map.xsize;
@@ -294,19 +295,10 @@
       && (*canvas_y > -NORMAL_TILE_HEIGHT)
       && (*canvas_y < height);
   } else { /* is_isometric */
-    if (map_view_x0+map_canvas_store_twidth <= map.xsize)
-      *canvas_x = map_x-map_view_x0;
-    else if(map_x >= map_view_x0)
-      *canvas_x = map_x-map_view_x0;
-    else if(map_x < map_adjust_x(map_view_x0+map_canvas_store_twidth))
-      *canvas_x = map_x+map.xsize-map_view_x0;
-    else *canvas_x = -1;
 
-    *canvas_y = map_y - map_view_y0;
+    *canvas_x = NORMAL_TILE_WIDTH * (abs_x - map_view_x0);
+    *canvas_y = NORMAL_TILE_HEIGHT * (abs_y - map_view_y0);
 
-    *canvas_x *= NORMAL_TILE_WIDTH;
-    *canvas_y *= NORMAL_TILE_HEIGHT;
-
     return *canvas_x >= 0
       && *canvas_x < map_canvas_store_twidth*NORMAL_TILE_WIDTH
       && *canvas_y >= 0
@@ -658,9 +650,7 @@
     return get_canvas_xy(x, y, &dummy_x, &dummy_y);
   } else {
     return (y>=map_view_y0 && y<map_view_y0+map_canvas_store_theight &&
-           ((x>=map_view_x0 && x<map_view_x0+map_canvas_store_twidth) ||
-            (x+map.xsize>=map_view_x0 && 
-             x+map.xsize<map_view_x0+map_canvas_store_twidth)));
+           x>=map_view_x0 && x<map_view_x0+map_canvas_store_twidth);
   }
 }
 
@@ -1397,13 +1387,10 @@
 
     for (y_itr=y; y_itr<y+height; y_itr++) {
       for (x_itr=x; x_itr<x+width; x_itr++) {
-       int map_x = map_adjust_x(x_itr);
-       int map_y = y_itr; /* not adjusted;, we want to draw black tiles */
-
-       get_canvas_xy(map_x, map_y, &canvas_x, &canvas_y);
-       if (tile_visible_mapcanvas(map_x, map_y)) {
+       get_canvas_xy(x_itr, y_itr, &canvas_x, &canvas_y);
+       if (tile_visible_mapcanvas(x_itr, y_itr)) {
          pixmap_put_tile(map_canvas_store,
-                         map_x, map_y,
+                         x_itr, y_itr,
                          canvas_x, canvas_y, 0);
        }
       }
@@ -1466,15 +1453,21 @@
 /**************************************************************************
 ...
 **************************************************************************/
-static void show_desc_at_tile(int x, int y)
+static void show_desc_at_tile(int abs_x, int abs_y)
 {
   static char buffer[512];
   struct city *pcity;
-  if ((pcity = map_get_city(x, y))) {
+  int map_x = abs_x, map_y = abs_y;
+
+  /* abs_x/abs_y are absolute coordinates used for drawing;
+   * map_x/map_y are map coordinates that should be normalized. */
+  if (!normalize_map_pos(&map_x, &map_y)) return;
+
+  if ((pcity = map_get_city(map_x, map_y))) {
     int canvas_x, canvas_y;
     int w;
 
-    get_canvas_xy(x, y, &canvas_x, &canvas_y);
+    get_canvas_xy(abs_x, abs_y, &canvas_x, &canvas_y);
     if (draw_city_names) {
       my_snprintf(buffer, sizeof(buffer), "%s", pcity->name);
       w = gdk_string_width(main_font, buffer);
@@ -1550,12 +1543,10 @@
     int x, y;
     int x1, y1;
     for (x1 = 0; x1 < map_canvas_store_twidth; x1++) {
-      x = (map_view_x0 + x1) % map.xsize;
+      x = map_view_x0 + x1;
       for (y1 = 0; y1 < map_canvas_store_twidth; y1++) {
        y = map_view_y0 + y1;
-       if (normalize_map_pos(&x, &y)) {
-         show_desc_at_tile(x, y);
-       }
+       show_desc_at_tile(x, y);
       }
     }
   }