diff options
| -rw-r--r-- | libdocument/ev-document-misc.c | 38 | ||||
| -rw-r--r-- | libdocument/ev-document-misc.h | 1 |
2 files changed, 39 insertions, 0 deletions
diff --git a/libdocument/ev-document-misc.c b/libdocument/ev-document-misc.c index ced1ca1..14bc3a3 100644 --- a/libdocument/ev-document-misc.c +++ b/libdocument/ev-document-misc.c @@ -297,6 +297,44 @@ ev_document_misc_surface_rotate_and_scale (cairo_surface_t *surface, } void +ev_document_misc_invert_surface (cairo_surface_t *surface) { +#if CAIRO_VERSION > CAIRO_VERSION_ENCODE(1, 9, 2) + cairo_t *cr; + + cr = cairo_create (surface); + + /* white + DIFFERENCE -> invert */ + cairo_set_operator (cr, CAIRO_OPERATOR_DIFFERENCE); + cairo_set_source_rgb (cr, 1., 1., 1.); + cairo_paint(cr); + cairo_destroy (cr); +#else + guchar *data; + gint rowstride; + gint width, height; + gint x, y; + + data = cairo_image_surface_get_data (surface); + rowstride = cairo_image_surface_get_stride (surface); + width = cairo_image_surface_get_width (surface); + height = cairo_image_surface_get_height (surface); + + for (y = 0; y < height; y++) { + guchar *p = data + y * rowstride; + + for (x = 0; x < width; x++) { + p[0] = 255 - p[0]; + p[1] = 255 - p[1]; + p[2] = 255 - p[2]; + p += 4; + } + } + + cairo_surface_mark_dirty (surface); +#endif +} + +void ev_document_misc_invert_pixbuf (GdkPixbuf *pixbuf) { guchar *data, *p; diff --git a/libdocument/ev-document-misc.h b/libdocument/ev-document-misc.h index 47e3c41..8e92983 100644 --- a/libdocument/ev-document-misc.h +++ b/libdocument/ev-document-misc.h @@ -51,6 +51,7 @@ cairo_surface_t *ev_document_misc_surface_rotate_and_scale (cairo_surface_t *sur gint dest_width, gint dest_height, gint dest_rotation); +void ev_document_misc_invert_surface (cairo_surface_t *surface); void ev_document_misc_invert_pixbuf (GdkPixbuf *pixbuf); G_END_DECLS |