1 files changed, 89 insertions, 0 deletions
diff --git a/lib/png.c b/lib/png.c
new file mode 100644
index 0000000000..f71fc6abc8
--- /dev/null
+++ b/lib/png.c
@@ -0,0 +1,89 @@
+#include <common.h>
+#include <errno.h>
+#include <malloc.h>
+#include <fb.h>
+#include <asm/byteorder.h>
+#include <init.h>
+#include <image_renderer.h>
+#include <graphic_utils.h>
+#include <linux/zlib.h>
+
+#include "png.h"
+
+z_stream png_stream;
+static int initialized;
+
+int png_uncompress_init(void)
+{
+	if (!initialized++) {
+		png_stream.workspace = malloc(zlib_inflate_workspacesize());
+		if (!png_stream.workspace) {
+			initialized = 0;
+			return -ENOMEM;
+		}
+		png_stream.next_in = NULL;
+		png_stream.avail_in = 0;
+		zlib_inflateInit(&png_stream);
+	}
+	return 0;
+}
+
+void png_uncompress_exit(void)
+{
+	if (!--initialized) {
+		zlib_inflateEnd(&png_stream);
+		vfree(png_stream.workspace);
+	}
+}
+
+static int png_renderer(struct fb_info *info, struct image *img, void* fb,
+		int startx, int starty, void* offscreenbuf)
+{
+	int width, height;
+	void *buf;
+	int xres, yres;
+
+	xres = info->xres;
+	yres = info->yres;
+
+	if (startx < 0) {
+		startx = (xres - img->width) / 2;
+		if (startx < 0)
+			startx = 0;
+	}
+
+	if (starty < 0) {
+		starty = (yres - img->height) / 2;
+		if (starty < 0)
+			starty = 0;
+	}
+
+	width = min(img->width, xres - startx);
+	height = min(img->height, yres - starty);
+
+	buf = offscreenbuf ? offscreenbuf : fb;
+
+	rgba_blend(info, img->data, buf, height, width, startx, starty, true);
+
+	if (offscreenbuf) {
+		int fbsize;
+
+		fbsize = xres * yres * (info->bits_per_pixel >> 3);
+		memcpy(fb, offscreenbuf, fbsize);
+	}
+
+	return img->height;
+}
+
+static struct image_renderer png = {
+	.type = filetype_png,
+	.open = png_open,
+	.close = png_close,
+	.renderer = png_renderer,
+};
+
+static int png_init(void)
+{
+	return image_renderer_register(&png);
+}
+fs_initcall(png_init);