Document BMP saving support.

2005-02-23  Matthias Clasen  <mclasen@redhat.com>

	* gdk-pixbuf-io.c: Document BMP saving support.

	* io-bmp.c: Support saving as BMP. (168173, Ivan Wong)

3 files changed, 128 insertions, 7 deletions

diff --git a/gdk-pixbuf/ChangeLog b/gdk-pixbuf/ChangeLog
index 4bde8bd49..35ad83df4 100644
--- a/gdk-pixbuf/ChangeLog
+++ b/gdk-pixbuf/ChangeLog
@@ -1,5 +1,9 @@
 2005-02-23  Matthias Clasen  <mclasen@redhat.com>
 
+	* gdk-pixbuf-io.c: Document BMP saving support.
+
+	* io-bmp.c: Support saving as BMP. (168173, Ivan Wong)
+
 	* io-ico.c: Fix a typo.  (#168173, Ivan Wong)
 
 2005-02-15  Matthias Clasen  <mclasen@redhat.com>
diff --git a/gdk-pixbuf/gdk-pixbuf-io.c b/gdk-pixbuf/gdk-pixbuf-io.c
index 3afb09f19..28ccaec7b 100644
--- a/gdk-pixbuf/gdk-pixbuf-io.c
+++ b/gdk-pixbuf/gdk-pixbuf-io.c
@@ -1528,8 +1528,8 @@ gdk_pixbuf_real_save_to_callback (GdkPixbuf         *pixbuf,
  * @error: return location for error, or %NULL
  * @Varargs: list of key-value save options
  *
- * Saves pixbuf to a file in format @type. By default, "jpeg", "png" and 
- * "ico" are possible file formats to save in, but more formats may be
+ * Saves pixbuf to a file in format @type. By default, "jpeg", "png", "ico" 
+ * and "bmp" are possible file formats to save in, but more formats may be
  * installed. The list of all writable formats can be determined in the 
  * following way:
  *
@@ -1608,7 +1608,7 @@ gdk_pixbuf_save (GdkPixbuf  *pixbuf,
  * @option_values: values for named options
  * @error: return location for error, or %NULL
  *
- * Saves pixbuf to a file in @type, which is currently "jpeg", "png" or "ico".
+ * Saves pixbuf to a file in @type, which is currently "jpeg", "png", "ico" or "bmp".
  * If @error is set, %FALSE will be returned. 
  * See gdk_pixbuf_save () for more details.
  *
@@ -1738,7 +1738,7 @@ gdk_pixbuf_save_to_callback    (GdkPixbuf  *pixbuf,
  * @error: return location for error, or %NULL
  *
  * Saves pixbuf to a callback in format @type, which is currently "jpeg",
- * "png" or "ico".  If @error is set, %FALSE will be returned. See
+ * "png", "ico" or "bmp".  If @error is set, %FALSE will be returned. See
  * gdk_pixbuf_save_to_callback () for more details.
  *
  * Return value: whether an error was set
@@ -1784,7 +1784,7 @@ gdk_pixbuf_save_to_callbackv   (GdkPixbuf  *pixbuf,
  * @Varargs: list of key-value save options
  *
  * Saves pixbuf to a new buffer in format @type, which is currently "jpeg",
- * "png" or "ico".  This is a convenience function that uses
+ * "png", "ico" or "bmp".  This is a convenience function that uses
  * gdk_pixbuf_save_to_callback() to do the real work. Note that the buffer 
  * is not nul-terminated and may contain embedded  nuls.
  * If @error is set, %FALSE will be returned and @string will be set to
@@ -1872,7 +1872,7 @@ save_to_buffer_callback (const gchar *data,
  * @error: return location for error, or %NULL
  *
  * Saves pixbuf to a new buffer in format @type, which is currently "jpeg",
- * "png" or "ico".  See gdk_pixbuf_save_to_buffer() for more details.
+ * "png", "ico" or "bmp".  See gdk_pixbuf_save_to_buffer() for more details.
  *
  * Return value: whether an error was set
  *
diff --git a/gdk-pixbuf/io-bmp.c b/gdk-pixbuf/io-bmp.c
index 2724914ab..82882048d 100644
--- a/gdk-pixbuf/io-bmp.c
+++ b/gdk-pixbuf/io-bmp.c
@@ -1123,12 +1123,129 @@ gdk_pixbuf__bmp_image_load_increment(gpointer data,
 	return TRUE;
 }
 
+/* for our convenience when filling file header */
+#define put16u(buf,data)	{ *(guint16*)(buf) = GUINT16_TO_LE (data); buf += 2; }
+#define put32u(buf,data)	{ *(guint32*)(buf) = GUINT32_TO_LE (data); buf += 4; }
+#define put16(buf,data)		{ *(gint16*)(buf) = GINT16_TO_LE (data); buf += 2; }
+#define put32(buf,data)		{ *(gint32*)(buf) = GINT32_TO_LE (data); buf += 4; }
+
+static gboolean
+gdk_pixbuf__bmp_image_save_to_callback (GdkPixbufSaveFunc   save_func,
+					gpointer            user_data,
+					GdkPixbuf          *pixbuf, 
+					gchar             **keys,
+					gchar             **values,
+					GError            **error)
+{
+	guint width, height, channel, size, stride, src_stride, x, y;
+	guchar BFH_BIH[40], *pixels, *buf, *src, *dst, *dst_line;
+	gboolean ret;
+
+	width = gdk_pixbuf_get_width (pixbuf);
+	height = gdk_pixbuf_get_height (pixbuf);
+	channel = gdk_pixbuf_get_n_channels (pixbuf);
+	pixels = gdk_pixbuf_get_pixels (pixbuf);
+	src_stride = gdk_pixbuf_get_rowstride (pixbuf);
+	stride = (width * 3 + 3) & ~3;
+	size = stride * height;
+
+	/* filling BFH */
+	dst = BFH_BIH;
+	*dst++ = 'B';			/* bfType */
+	*dst++ = 'M';
+	put32u (dst, size + 14 + 40);	/* bfSize */
+	put32u (dst, 0);		/* bfReserved1 + bfReserved2 */
+	put32u (dst, 14 + 40);		/* bfOffBits */
+
+	/* filling BIH */
+	put32u (dst, 40);		/* biSize */
+	put32 (dst, width);		/* biWidth */
+	put32 (dst, height);		/* biHeight */
+	put16 (dst, 1);			/* biPlanes */
+	put16 (dst, 24);		/* biBitCount */
+	put32u (dst, BI_RGB);		/* biCompression */
+	put32u (dst, size);		/* biSizeImage */
+	put32 (dst, 0);			/* biXPelsPerMeter */
+	put32 (dst, 0);			/* biYPelsPerMeter */
+	put32u (dst, 0);		/* biClrUsed */
+	put32u (dst, 0);		/* biClrImportant */
+
+	if (!save_func (BFH_BIH, 14 + 40, error, user_data))
+		return FALSE;
+
+	dst_line = buf = g_try_malloc (size);
+	if (!buf) {
+		g_set_error (error,
+			     GDK_PIXBUF_ERROR,
+			     GDK_PIXBUF_ERROR_INSUFFICIENT_MEMORY,
+			     _("Couldn't allocate memory for saving BMP file"));
+		return FALSE;
+	}
+
+	/* saving as a bottom-up bmp */
+	pixels += (height - 1) * src_stride;
+	for (y = 0; y < height; ++y, pixels -= src_stride, dst_line += stride) {
+		dst = dst_line;
+		src = pixels;
+		for (x = 0; x < width; ++x, dst += 3, src += channel) {
+			dst[0] = src[2];
+			dst[1] = src[1];
+			dst[2] = src[0];
+		}
+	}
+	ret = save_func (buf, size, error, user_data);
+	g_free (buf);
+
+	return ret;
+}
+
+static gboolean
+save_to_file_cb (const gchar *buf,
+		 gsize count,
+		 GError **error,
+		 gpointer data)
+{
+	gint bytes;
+	
+	while (count > 0) {
+		bytes = fwrite (buf, sizeof (gchar), count, (FILE *) data);
+		if (bytes <= 0)
+			break;
+		count -= bytes;
+		buf += bytes;
+	}
+
+	if (count) {
+		g_set_error (error,
+			     GDK_PIXBUF_ERROR,
+			     GDK_PIXBUF_ERROR_FAILED,
+			     _("Couldn't write to BMP file"));
+		return FALSE;
+	}
+	
+	return TRUE;
+}
+
+static gboolean
+gdk_pixbuf__bmp_image_save (FILE          *f, 
+                            GdkPixbuf     *pixbuf, 
+                            gchar        **keys,
+                            gchar        **values,
+                            GError       **error)
+{
+	return gdk_pixbuf__bmp_image_save_to_callback (save_to_file_cb,
+						       f, pixbuf, keys,
+						       values, error);
+}
+
 void
 MODULE_ENTRY (bmp, fill_vtable) (GdkPixbufModule *module)
 {
 	module->begin_load = gdk_pixbuf__bmp_image_begin_load;
 	module->stop_load = gdk_pixbuf__bmp_image_stop_load;
 	module->load_increment = gdk_pixbuf__bmp_image_load_increment;
+	module->save = gdk_pixbuf__bmp_image_save;
+	module->save_to_callback = gdk_pixbuf__bmp_image_save_to_callback;
 }
 
 void
@@ -1154,7 +1271,7 @@ MODULE_ENTRY (bmp, fill_info) (GdkPixbufFormat *info)
 	info->description = N_("The BMP image format");
 	info->mime_types = mime_types;
 	info->extensions = extensions;
-	info->flags = GDK_PIXBUF_FORMAT_THREADSAFE;
+	info->flags = GDK_PIXBUF_FORMAT_WRITABLE | GDK_PIXBUF_FORMAT_THREADSAFE;
 	info->license = "LGPL";
 }