Prepare cursor scaling by bbox calculation

3 files changed, 100 insertions, 3 deletions

diff --git a/navit/graphics.c b/navit/graphics.c
index 7a3c2800d..7580354df 100644
--- a/navit/graphics.c
+++ b/navit/graphics.c
@@ -2222,6 +2222,81 @@ static void xdisplay_draw_elements(struct graphics *gra, struct displaylist *dis
     }
 }
 
+/**
+ * @brief alter a box to contain a point
+ *
+ * @param pt new point
+ * @param tl top left of existing box
+ * @param br bottom right of existing box
+ * @param width line width to assume at the point
+ * @returns nothing
+ */
+static void graphics_itemgra_add_point_to_bbox (const struct coord *pt, struct coord *tl, struct coord *br, int width) {
+    if (pt->x-width < tl->x)
+        tl->x = pt->x-width;
+    if (pt->x+width > br->x)
+        br->x = pt->x+width;
+    if (pt->y-width < tl->y)
+        tl->y = pt->y-width;
+    if (pt->y+width > br->y)
+        br->y = pt->y+width;
+}
+
+/**
+ * @brief get bounding box of a raw and unscaled itemgra.
+ *
+ * @param itm the itemgra
+ * @param tl top left coordinate of the itemgra. Needs to be properly initialized.
+ * @param br bottom right coordinate of the itemgra. Needs to be properly initialized.
+ * returns notinhg
+ */
+void graphics_itmgra_bbox(struct itemgra * itm, struct coord *tl, struct coord *br) {
+    GList *es;
+    if(!itm || !tl || !br)
+        return;
+
+    es = itm->elements;
+    while(es) {
+        struct element *e=es->data;
+        switch (e->type) {
+        case element_point:
+            if(e->coord_count > 0)
+                graphics_itemgra_add_point_to_bbox (&(e->coord[0]), tl, br, 0);
+            break;
+        case element_polyline:
+        case element_polygon:
+            if(e->coord_count > 0) {
+                int a;
+                int width = 0;
+                if(e->type == element_polyline)
+                    width = e->u.polyline.width;
+                for(a=0; a < e->coord_count; a ++)
+                    graphics_itemgra_add_point_to_bbox (&(e->coord[a]), tl, br,width);
+            }
+            break;
+        case element_circle:
+            if(e->coord_count > 0) {
+                struct coord box;
+                box.x = e->coord[0].x - e->u.circle.radius;
+                box.y = e->coord[0].y - e->u.circle.radius;
+                graphics_itemgra_add_point_to_bbox (&box, tl, br, e->u.circle.width);
+                box.x = e->coord[0].x + e->u.circle.radius;
+                box.y = e->coord[0].y + e->u.circle.radius;
+                graphics_itemgra_add_point_to_bbox (&box, tl, br, e->u.circle.width);
+            }
+            break;
+        case element_text:
+        case element_icon:
+        case element_image:
+        case element_arrows:
+            /* ignore */
+            dbg(lvl_error,"getting bbox for \"text, icon, image, arows\" not yet supported.");
+            break;
+        }
+        es=g_list_next(es);
+    }
+}
+
 void graphics_draw_itemgra(struct graphics *gra, struct itemgra *itm, struct transformation *t, char *label) {
     GList *es;
     struct display_context dc;
diff --git a/navit/graphics.h b/navit/graphics.h
index 9271fd6ef..f92961354 100644
--- a/navit/graphics.h
+++ b/navit/graphics.h
@@ -271,6 +271,7 @@ int graphics_draw_drag(struct graphics *this_, struct point *p);
 void graphics_background_gc(struct graphics *this_, struct graphics_gc *gc);
 void graphics_draw_text_std(struct graphics *this_, int text_size, char *text, struct point *p);
 char *graphics_icon_path(const char *icon);
+void graphics_itmgra_bbox(struct itemgra * itm, struct coord *tl, struct coord *br);
 void graphics_draw_itemgra(struct graphics *gra, struct itemgra *itm, struct transformation *t, char *label);
 void graphics_displaylist_draw(struct graphics *gra, struct displaylist *displaylist, struct transformation *trans,
                                struct layout *l, int flags);
diff --git a/navit/vehicle.c b/navit/vehicle.c
index 67306c3d3..196051743 100644
--- a/navit/vehicle.c
+++ b/navit/vehicle.c
@@ -73,6 +73,8 @@ struct vehicle {
     int need_resize;
     int real_w;
     int real_h;
+    struct coord tl;
+    struct coord br;
     struct graphics *gra;
     struct graphics_gc *bg;
     struct transformation *trans;
@@ -331,6 +333,25 @@ void vehicle_set_cursor(struct vehicle *this_, struct cursor *cursor, int overwr
     this_->need_resize=1;
     this_->cursor=cursor;
 
+    /* calculate the raw bounding box of the cursor*/
+    if (this_->cursor) {
+        struct attr **attr;
+        this_->tl.x = 0;
+        this_->tl.y = 0;
+        this_->br.x = 0;
+        this_->br.y = 0;
+        attr=cursor->attrs;
+        while (*attr) {
+            if ((*attr)->type == attr_itemgra) {
+                struct itemgra *itm=(*attr)->u.itemgra;
+                /* use all elements for outline regardless if speed or angle ranged */
+                graphics_itmgra_bbox(itm, &(this_->tl), &(this_->br));
+            }
+            ++attr;
+        }
+        dbg(lvl_debug,"got cursor bbox %d,%d %d,%d", this_->tl.x, this_->tl.y,this_->br.x, this_->br.y);
+    }
+
     /* if the graphics was already created, but a NULL cursor was set, we need to disable
      * otherwise stale overlay
      */
@@ -383,10 +404,10 @@ void vehicle_draw(struct vehicle *this_, struct graphics *gra, struct point *pnt
         sc.x = this_->real_w/2;
         sc.y = this_->real_h/2;
         transform_set_screen_center(this_->trans, &sc);
+        /*TODO: use the transformation to scale the cursor to fit inside the scaled surrounding.
+         * We already have the bbox in br / tl. */
+
     }
-    /*TODO: use the transformation to scale the cursor to fit inside the scaled surrounding.
-     * to do this we need to scan all coordinates inside the cursor to get it's bounding box
-     * in raw pixels. then we can scale it to fit */
 
     /* move the cursor point from te center to the top left*/
     this_->cursor_pnt.x-=(this_->real_w/2);