diff options
| -rw-r--r-- | navit/graphics.c | 76 |
1 files changed, 74 insertions, 2 deletions
diff --git a/navit/graphics.c b/navit/graphics.c index b5c86bcad..784ca5540 100644 --- a/navit/graphics.c +++ b/navit/graphics.c @@ -2268,6 +2268,78 @@ void graphics_draw_polygon_clipped(struct graphics *gra, struct graphics_gc *gc, } } +/** + * @brief Draw a plain polygon with holes on the display + * + * @param gra The graphics instance on which to draw + * @param gc The graphics context + * @param[in] pin An array of points forming the polygon + * @param count_in The number of elements inside @p pin + * @param hole_count The number of hole polygons to cut out + * @param pcount array of [hole_count] integers giving the number of + * points per hole + * @param holes array of point arrays for the hole polygons + */ +static void graphics_draw_polygon_with_holes_clipped(struct graphics *gra, struct graphics_gc *gc, struct point *pin, + int count_in, int hole_count, int* ccount, struct point **holes) { + int i; + struct point_rect r=gra->r; + int limit=10000; + struct point *pa1; + struct point *clipped; + int total_count_in; + int count_out; + int count_used; + int found_hole_count; + int *found_ccount; + struct point ** found_holes; + /* get total node count for polygon plus all holes */ + total_count_in = count_in; + for(i = 0; i < hole_count; i ++) { + total_count_in += ccount[i]; + } + count_out = total_count_in*8+1+hole_count; + + /* prepare buffer */ + pa1=g_alloca(sizeof(struct point) * (total_count_in < limit ? total_count_in*8+1:0)); + if (count_in < limit) { + /* use on stack buffer */ + clipped=pa1; + } else { + /* too big. allocate buffer (slower) */ + clipped=g_new(struct point, count_in*8+1); + } + count_used=0; + + /* prepare arrays for new holes */ + found_ccount=g_alloca(sizeof(int)*hole_count); + found_holes=g_alloca(sizeof(struct point*)*hole_count); + found_hole_count=0; + + /* clip outer polygon */ + graphics_clip_polygon(&r, pin, count_in, clipped, &count_out); + count_used += count_out; + /* clip the holes */ + for (i=0; i < hole_count; i ++) { + struct point* buffer = clipped + count_used; + int count = total_count_in*8+1+hole_count - count_used; + graphics_clip_polygon(&r, holes[i], ccount[i], buffer, &count); + count_used +=count; + if(count > 0) { + /* only if there are points left after clipping */ + found_ccount[found_hole_count]=count; + found_holes[found_hole_count]=buffer; + found_hole_count ++; + } + } + /* call drawing function */ + graphics_draw_polygon_with_holes(gra, gc, clipped, count_out, found_hole_count, found_ccount, found_holes); + + /* if we had to allocate buffer, free it */ + if (total_count_in >= limit) { + g_free(clipped); + } +} static void display_context_free(struct display_context *dc) { if (dc->gc) @@ -2458,9 +2530,9 @@ static void displayitem_free_holes(struct displayitem_poly_holes * holes) { static inline void displayitem_draw_polygon (struct display_context * dc, struct graphics * gra, struct point * pa, int count, struct displayitem_poly_holes * holes) { - /*TODO: implement a "clipped" version of graphics_draw_polygon_with_holes*/ if((holes != NULL) && (holes->count > 0)) - graphics_draw_polygon_with_holes(gra, dc->gc, pa, count, holes->count, holes->ccount, (struct point **)holes->coords); + graphics_draw_polygon_with_holes_clipped(gra, dc->gc, pa, count, holes->count, holes->ccount, + (struct point **)holes->coords); else graphics_draw_polygon_clipped(gra, dc->gc, pa, count); } |