From a0b1a437cc85c638100517aa6037786d3c0e65e7 Mon Sep 17 00:00:00 2001
From: Michael Zucci <zucchi@src.gnome.org>
Date: Tue, 29 Jun 1999 11:13:31 +0000
Subject: [PATCH] 	Added loader for jpeg->RGB. 	Based really loosely
 on imlib's io-jpeg.c

---
 gdk-pixbuf/Makefile.am |  12 +++-
 gdk-pixbuf/io-jpeg.c   | 129 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 139 insertions(+), 2 deletions(-)
 create mode 100644 gdk-pixbuf/io-jpeg.c

diff --git a/gdk-pixbuf/Makefile.am b/gdk-pixbuf/Makefile.am
index acb7979975..d299b1a420 100644
--- a/gdk-pixbuf/Makefile.am
+++ b/gdk-pixbuf/Makefile.am
@@ -1,7 +1,8 @@
 
 lib_LTLIBRARIES = 		\
 	libgdk-pixbuf.la	\
-	libpixbuf-png.la
+	libpixbuf-png.la	\
+	libpixbuf-jpeg.la
 
 #
 # The GdkPixBuf library
@@ -19,4 +20,11 @@ libgdk_pixbufinclude_HEADERS =	\
 # The PNG plugin.
 #
 libpixbuf_png_la_SOURCES = 	\
-	io-png.c
\ No newline at end of file
+	io-png.c
+
+#
+# The JPEG loader
+#
+libpixbuf_jpeg_la_SOURCES =	\
+	io-jpeg.c
+
diff --git a/gdk-pixbuf/io-jpeg.c b/gdk-pixbuf/io-jpeg.c
new file mode 100644
index 0000000000..3ba9c36a0e
--- /dev/null
+++ b/gdk-pixbuf/io-jpeg.c
@@ -0,0 +1,129 @@
+/*
+  io-jpeg.c: GdkPixBuf loader for jpeg files.
+
+  Based on io-jpeg from gdk_imlib, but not much.
+
+  This code is licensed under the Lesser GNU
+  General Public License, version 2.1.
+
+  Author:
+    Michael Zucchi <zucchi@zedzone.mmc.com.au>
+*/
+
+#include <config.h>
+#include <stdio.h>
+#include <glib.h>
+#include <setjmp.h>
+#include "gdk-pixbuf.h"
+/*#include "gdk-pixbuf-io.h"*/
+#include <jpeglib.h>
+
+/* error handler data */
+struct iojpeg_JPEG_error_mgr
+{
+	struct jpeg_error_mgr pub;
+	sigjmp_buf          setjmp_buffer;
+};
+
+static void
+g_JPEGFatalErrorHandler(j_common_ptr cinfo)
+{
+	/* FIXME:
+	 * We should somehow signal what error occurred to the caller so the
+	 * caller can handle the error message */
+	struct iojpeg_JPEG_error_mgr *errmgr;
+
+	errmgr = (struct iojpeg_JPEG_error_mgr *) cinfo->err;
+	cinfo->err->output_message(cinfo);
+	siglongjmp(errmgr->setjmp_buffer, 1);
+	return;
+}
+
+GdkPixBuf *image_load(FILE *f)
+{
+	int w,h,i,j;
+	art_u8 *pixels=NULL, *dptr, *fptr, *pptr;
+	unsigned char *lines[4], /* Used to expand rows, via rec_outbuf_height, from
+				  the header file:
+				  "* Usually rec_outbuf_height will be 1 or 2, at most 4." */
+		**lptr;
+	struct jpeg_decompress_struct cinfo;
+	struct iojpeg_JPEG_error_mgr jerr;
+	GdkPixBuf *pixbuf;
+
+	/* setup error handler */
+	cinfo.err = jpeg_std_error(&(jerr.pub));
+	jerr.pub.error_exit = g_JPEGFatalErrorHandler;
+
+	if (sigsetjmp(jerr.setjmp_buffer, 1)) {
+		/* Whoops there was a jpeg error */
+		if (pixels != NULL)
+			art_free(pixels);
+		jpeg_destroy_decompress(&cinfo);
+		return NULL;
+	}
+
+	/* load header, setup */
+	jpeg_create_decompress(&cinfo);
+	jpeg_stdio_src(&cinfo, f);
+	jpeg_read_header(&cinfo, TRUE);
+	cinfo.do_fancy_upsampling = FALSE;
+	cinfo.do_block_smoothing = FALSE;
+	w = cinfo.output_width;
+	h = cinfo.output_height;
+
+	pixels = art_alloc(h * w * 3);
+	if (pixels == NULL) {
+		jpeg_destroy_decompress(&cinfo);
+		return NULL;
+	}
+	dptr = pixels;
+
+	/* decompress all the lines, a few at a time */
+	jpeg_start_decompress(&cinfo);
+
+	while (cinfo.output_scanline < cinfo.output_height) {
+		lptr = lines;
+		for (i=0;i<cinfo.rec_outbuf_height;i++) {
+			*lptr++=dptr;
+			dptr+=w*3;
+		}
+		jpeg_read_scanlines(&cinfo, lines, cinfo.rec_outbuf_height);
+		if (cinfo.output_components==1) {
+			/* expand grey->colour */
+			/* expand from the end of the memory down, so we can use
+			   the same buffer */
+			for (i=cinfo.rec_outbuf_height-1;i>=0;i--) {
+				unsigned char *from, *to;
+				from = lines[i]+w-1;
+				to = lines[i]+w*3-3;
+				for (j=w-1;j>=0;j++) {
+					to[0] = from[0];
+					to[1] = from[0];
+					to[2] = from[0];
+					to-=3;
+					from--;
+				}
+			}
+		}
+	}
+
+	jpeg_finish_decompress(&cinfo);
+	jpeg_destroy_decompress(&cinfo);
+
+	/* finish off, create the pixbuf */
+	pixbuf = g_new(GdkPixBuf, 1);
+	pixbuf->art_pixbuf = art_pixbuf_new_rgb(pixels, w, h, (w * 3));
+	if (!(pixbuf->art_pixbuf))
+		return NULL;
+	pixbuf->ref_count = 0;
+	pixbuf->unref_func = NULL;
+
+	return pixbuf;
+}
+
+/*
+ * Local variables:
+ * c-basic-offset: 8
+ * End:
+ */
-- 
2.30.2