[Freeciv-Dev] Re: (PR#13518) city dialog scaling

["Jason Short" <jdorje@xxxxxxxxxxxxxxxxxxxxx>]

<URL: http://bugs.freeciv.org/Ticket/Display.html?id=13518 >

Jason Short wrote:
> <URL: http://bugs.freeciv.org/Ticket/Display.html?id=13518 >
> 
> This patch does scaling of the city dialog citymap.  A maximum width of
> 300 pixels is imposed on the dialog - anything wider than this will be
> scaled down to fit.

In this patch the problem is fixed by using a pixmap for the drawing,
then rendering to a pixbuf, then compositing the pixbuf onto the
GtkImage's pixbuf.  This means an extra step is done in final drawing
but this is probably faster than using pixbufs for ALL drawing.  I
imagine it's still pretty slow but citydlgs aren't speed-crucial.  The
only thing that could be done to improve it is to use entirely pixmaps
for the case where no scaling is needed...but this probably isn't
necessary since those tilesets are really fast anyway.

I think we might as well apply this patch.  Maybe we (Vasco) can do
better at picking the widget size.  Ideally the whole dialog would have
a target size (like 600 pixels) and the citymap portion would not have
any fixed size but would take up all extra horizontal and vertical room.
 Then scaling is done to fit the graphics into the available room.  But
for the moment just capping the width at 300 pixels is probably a lot
better for 96x48 and 128x64 tilesets - although on my system this means
the citydlg is still about 750 pixels wide.

http://bugs.freeciv.org/Ticket/Attachment/100094/64560/dialog.png

This screenshot shows it in action for the amplio tileset.  For amplio
the scaling is hardly noticeable (300/384 = 78% of full size); with
civ3gfx or a larger citymap-radius it would be much more noticeable.

In summary I think this patch should be committed.  Gametesters, please
try it out.

-jason

Index: client/gui-gtk-2.0/citydlg.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/client/gui-gtk-2.0/citydlg.c,v
retrieving revision 1.133
diff -p -u -r1.133 citydlg.c
--- client/gui-gtk-2.0/citydlg.c        23 Jul 2005 00:59:33 -0000      1.133
+++ client/gui-gtk-2.0/citydlg.c        23 Jul 2005 08:00:39 -0000
@@ -59,6 +59,9 @@
 
 #include "citydlg.h"
 
+#define CITYMAP_WIDTH MIN(300, canvas_width)
+#define CITYMAP_HEIGHT (CITYMAP_WIDTH * canvas_height / canvas_width)
+
 struct city_dialog;
 
 /* get 'struct dialog_list' and related function */
@@ -104,7 +107,8 @@ struct city_dialog {
   GtkWidget *shell;
   GtkWidget *name_label;
   GtkWidget *citizen_pixmap;
-  GdkPixmap *map_canvas_store;
+  GdkPixbuf *map_canvas_store, *map_pixbuf_unscaled;
+  GdkPixmap *map_canvas_store_unscaled;
   GtkWidget *notebook;
 
   GtkTooltips *tips;
@@ -679,8 +683,8 @@ static void create_and_append_overview_p
   gtk_container_add(GTK_CONTAINER(align), pdialog->overview.map_canvas);
   gtk_widget_add_events(pdialog->overview.map_canvas, GDK_BUTTON_PRESS_MASK);
 
-  pdialog->overview.map_canvas_pixmap =
-       gtk_image_new_from_pixmap(pdialog->map_canvas_store, NULL);
+  pdialog->overview.map_canvas_pixmap
+    = gtk_image_new_from_pixbuf(pdialog->map_canvas_store);
   gtk_container_add(GTK_CONTAINER(pdialog->overview.map_canvas),
                    pdialog->overview.map_canvas_pixmap);
 
@@ -968,8 +972,8 @@ static void create_and_append_happiness_
   gtk_container_add(GTK_CONTAINER(align), pdialog->happiness.map_canvas);
   gtk_widget_add_events(pdialog->happiness.map_canvas, GDK_BUTTON_PRESS_MASK);
 
-  pdialog->happiness.map_canvas_pixmap =
-       gtk_image_new_from_pixmap(pdialog->map_canvas_store, NULL);
+  pdialog->happiness.map_canvas_pixmap
+    = gtk_image_new_from_pixbuf(pdialog->map_canvas_store);
   gtk_container_add(GTK_CONTAINER(pdialog->happiness.map_canvas),
                    pdialog->happiness.map_canvas_pixmap);
   g_signal_connect(pdialog->happiness.map_canvas,
@@ -1165,8 +1169,12 @@ static struct city_dialog *create_city_d
   pdialog->rename_shell = NULL;
   pdialog->happiness.map_canvas = NULL;         /* make sure NULL if spy */
   pdialog->happiness.map_canvas_pixmap = NULL;  /* ditto */
-  pdialog->map_canvas_store = gdk_pixmap_new(root_window, canvas_width,
-                                            canvas_height, -1);
+  pdialog->map_canvas_store = gdk_pixbuf_new(GDK_COLORSPACE_RGB, TRUE, 8,
+                                            CITYMAP_WIDTH, CITYMAP_HEIGHT);
+  pdialog->map_pixbuf_unscaled = NULL;
+  pdialog->map_canvas_store_unscaled
+    = gdk_pixmap_new(root_window, canvas_width, canvas_height, -1);
+
 
 
   pdialog->shell = gtk_dialog_new_with_buttons(pcity->name,
@@ -1444,12 +1452,32 @@ static void city_dialog_update_informati
 *****************************************************************/
 static void city_dialog_update_map(struct city_dialog *pdialog)
 {
-  struct canvas store;
+  struct canvas store = {
+    .type = CANVAS_PIXMAP,
+    .v = {.pixmap = pdialog->map_canvas_store_unscaled}
+  };
 
-  store.type = CANVAS_PIXMAP;
-  store.v.pixmap = pdialog->map_canvas_store;
+  /* The drawing is done in three steps.
+   *   1.  First we render to a pixmap with the appropriate canvas size.
+   *   2.  Then the pixmap is rendered into a pixbuf of equal size.
+   *   3.  Finally this pixbuf is composited and scaled onto the GtkImage's
+   *       target pixbuf.
+   */
 
   city_dialog_redraw_map(pdialog->pcity, &store);
+  pdialog->map_pixbuf_unscaled
+    = gdk_pixbuf_get_from_drawable(pdialog->map_pixbuf_unscaled,
+                                  pdialog->map_canvas_store_unscaled,
+                                  NULL,
+                                  0, 0, 0, 0,
+                                  canvas_width, canvas_height);
+  gdk_pixbuf_composite(pdialog->map_pixbuf_unscaled,
+                      pdialog->map_canvas_store,
+                      0, 0, CITYMAP_WIDTH, CITYMAP_HEIGHT,
+                      0.0, 0.0,
+                      (double)CITYMAP_WIDTH / (double)canvas_width,
+                      (double)CITYMAP_HEIGHT / (double)canvas_height,
+                      GDK_INTERP_BILINEAR, 255);
 
   /* draw to real window */
   draw_map_canvas(pdialog);
@@ -2328,14 +2356,17 @@ static gboolean button_down_citymap(GtkW
                                    gpointer data)
 {
   struct city_dialog *pdialog = data;
-  int xtile, ytile;
+  int canvas_x, canvas_y, city_x, city_y;
 
   if (!can_client_issue_orders()) {
     return FALSE;
   }
 
-  if (canvas_to_city_pos(&xtile, &ytile, ev->x, ev->y)) {
-    city_toggle_worker(pdialog->pcity, xtile, ytile);
+  canvas_x = ev->x * (double)canvas_width / (double)CITYMAP_WIDTH;
+  canvas_y = ev->y * (double)canvas_height / (double)CITYMAP_HEIGHT;
+
+  if (canvas_to_city_pos(&city_x, &city_y, canvas_x, canvas_y)) {
+    city_toggle_worker(pdialog->pcity, city_x, city_y);
   }
 
   return TRUE;