X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?a=blobdiff_plain;f=libdocument%2Fev-document-misc.c;h=14bc3a354a3d86cd122293499fecf7e1e91020b9;hb=f9c2880d31bb2f5d4411849b9207c5d26a5c616a;hp=7898a8cd8324cf9915e0489ae2396ef2b140ab8d;hpb=7119bcd8d46f21d20e55deeba2e0f9b7fa4737ef;p=evince.git

diff --git a/libdocument/ev-document-misc.c b/libdocument/ev-document-misc.c
index 7898a8cd..14bc3a35 100644
--- a/libdocument/ev-document-misc.c
+++ b/libdocument/ev-document-misc.c
@@ -1,4 +1,5 @@
 /*
+ *  Copyright (C) 2009 Juanjo Marín <juanj.marin@juntadeandalucia.es>
  *  Copyright (c) 2007 Carlos Garcia Campos <carlosgc@gnome.org>
  *  Copyright (C) 2000-2003 Marco Pesenti Gritti
  *
@@ -18,10 +19,13 @@
  */
 
 #include <config.h>
-#include "ev-document-misc.h"
+
 #include <string.h>
+
 #include <gtk/gtk.h>
 
+#include "ev-document-misc.h"
+
 /* Returns a new GdkPixbuf that is suitable for placing in the thumbnail view.
  * It is four pixels wider and taller than the source.  If source_pixbuf is not
  * NULL, then it will fill the return pixbuf with the contents of
@@ -291,4 +295,71 @@ ev_document_misc_surface_rotate_and_scale (cairo_surface_t *surface,
 
 	return new_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;
+	guint   width, height, x, y, rowstride, n_channels;
+
+	n_channels = gdk_pixbuf_get_n_channels (pixbuf);
+	g_assert (gdk_pixbuf_get_colorspace (pixbuf) == GDK_COLORSPACE_RGB);
+	g_assert (gdk_pixbuf_get_bits_per_sample (pixbuf) == 8);
+
+	/* First grab a pointer to the raw pixel data. */
+	data = gdk_pixbuf_get_pixels (pixbuf);
+
+	/* Find the number of bytes per row (could be padded). */
+	rowstride = gdk_pixbuf_get_rowstride (pixbuf);
+
+	width = gdk_pixbuf_get_width (pixbuf);
+	height = gdk_pixbuf_get_height (pixbuf);
+	for (x = 0; x < width; x++) {
+		for (y = 0; y < height; y++) {
+			/* Calculate pixel's offset into the data array. */
+			p = data + x * n_channels + y * rowstride;
+			/* Change the RGB values*/
+			p[0] = 255 - p[0];
+			p[1] = 255 - p[1];
+			p[2] = 255 - p[2];
+		}
+	}
+}