Add method for frontends to query the backend's cursor location.

The Rockbox frontend allows games to be displayed in a "zoomed-in"
state targets with small displays. Currently we use a modal interface
-- a "viewing" mode in which the cursor keys are used to pan around
the rendered bitmap; and an "interaction" mode that actually sends
keys to the game.

This commit adds a midend_get_cursor_location() function to allow the
frontend to retrieve the backend's cursor location or other "region of
interest" -- such as the player location in Cube or Inertia.

With this information, the Rockbox frontend can now intelligently
follow the cursor around in the zoomed-in state, eliminating the need
for a modal interface.

1 files changed, 32 insertions, 0 deletions

diff --git a/tracks.c b/tracks.c
index 4a7e9b0..9149c2a 100644
--- a/tracks.c
+++ b/tracks.c
@@ -2854,6 +2854,37 @@ static float game_flash_length(const game_state *oldstate, const game_state *new
         return 0.0F;
 }
 
+static void game_get_cursor_location(const game_ui *ui,
+                                     const game_drawstate *ds,
+                                     const game_state *state,
+                                     const game_params *params,
+                                     int *x, int *y, int *w, int *h)
+{
+    if(ui->cursor_active) {
+        int off = HALFSZ / 4;
+        int cx = COORD(ui->curx / 2) + off;
+        int cy = COORD(ui->cury / 2) + off;
+        int cw, ch;
+        cw = ch = TILE_SIZE - (2*off) + 1;
+
+        if(ui->curx % 2 == 0) {
+            /* left border */
+            cx -= off;
+            cw = 2 * off + 1;
+        }
+        if(ui->cury % 2 == 0) {
+            /* upper border */
+            cy -= off;
+            ch = 2 * off + 1;
+        }
+
+        *x = cx;
+        *y = cy;
+        *w = cw;
+        *h = ch;
+    }
+}
+
 static int game_status(const game_state *state)
 {
     return state->completed ? +1 : 0;
@@ -2948,6 +2979,7 @@ const struct game thegame = {
     game_redraw,
     game_anim_length,
     game_flash_length,
+    game_get_cursor_location,
     game_status,
     true, false, game_print_size, game_print,
     false,			       /* wants_statusbar */