diff options
Diffstat (limited to 'libstorycode/narrative_render_cairo.c')
| -rw-r--r-- | libstorycode/narrative_render_cairo.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/libstorycode/narrative_render_cairo.c b/libstorycode/narrative_render_cairo.c index e00ea78..f23f18c 100644 --- a/libstorycode/narrative_render_cairo.c +++ b/libstorycode/narrative_render_cairo.c @@ -505,6 +505,38 @@ int narrative_render_item_cairo(Narrative*n, cairo_t *cr, int i) } +/* Given a y-coordinate range, works out which range of items (inclusive) + * are at least partially within the range */ +void narrative_get_item_range(Narrative *n, double min_y, double max_y, + int *start_item, int *end_item) +{ + int i; + double hpos = 0.0; + + *start_item = n->n_items; + for ( i=0; i<n->n_items; i++ ) { + + double cur_h = narrative_item_get_height(n, i); + + if ( hpos + cur_h < min_y ) goto next; + + if ( *start_item == n->n_items ) { + *start_item = i; + } + + if ( hpos > max_y ) { + *end_item = i -1; + return; + } +next: + hpos += cur_h; + + } + + *end_item = n->n_items - 1; +} + + /* NB You must first call narrative_wrap() */ int narrative_render_cairo(Narrative *n, cairo_t *cr, Stylesheet *stylesheet, ImageStore *is, double min_y, double max_y) |