1 files changed, 75 insertions, 0 deletions
diff --git a/common/lz.h b/common/lz.h
new file mode 100644
index 00000000..074f633b
--- /dev/null
+++ b/common/lz.h
@@ -0,0 +1,75 @@
+/*
+        dictionary compression for images based on fastlz (http://www.fastlz.org/)
+        (Distributed under MIT license).
+*/
+#ifndef __LZ_H
+#define __LZ_H
+
+#include "lz_common.h"
+#include "lz_config.h"
+#include "draw.h"
+
+typedef void *LzContext;
+
+typedef struct LzUsrContext LzUsrContext;
+struct LzUsrContext {
+    void (*error)(LzUsrContext *usr, const char *fmt, ...);
+    void (*warn)(LzUsrContext *usr, const char *fmt, ...);
+    void (*info)(LzUsrContext *usr, const char *fmt, ...);
+    void    *(*malloc)(LzUsrContext *usr, int size);
+    void (*free)(LzUsrContext *usr, void *ptr);
+    int (*more_space)(LzUsrContext *usr, uint8_t **io_ptr);     // get the next chunk of the
+                                                                // compressed buffer. return
+                                                                // number of bytes in the chunk.
+    int (*more_lines)(LzUsrContext *usr, uint8_t **lines);      // get the next chunk of the
+                                                                // original image. If the image
+                                                                // is down to top, return it from
+                                                                // the last line to the first one
+                                                                // (stride should always be
+                                                                // positive)
+};
+
+/*
+        assumes width is in pixels and stride is in bytes
+        return: the number of bytes in the compressed data
+
+        TODO :	determine size limit for the first segment and each chunk. check validity
+                        of the segment or go to literal copy.
+        TODO :	currently support only rgb images in which width*bytes_per_pixel = stride OR
+                        paletter images in which stride eqauls the min number of bytes to
+                        hold a line. stride is not necessary for now. just for sanity check.
+                        stride should be > 0
+*/
+int lz_encode(LzContext *lz, LzImageType type, int width, int height, int top_down,
+              uint8_t *lines, unsigned int num_lines, int stride,
+              uint8_t *io_ptr, unsigned int num_io_bytes);
+
+/*
+        prepare encoder and read lz magic.
+        out_n_pixels number of compressed pixels. May differ from Width*height in plt1/4.
+        Use it for allocation the decompressed buffer.
+
+*/
+void lz_decode_begin(LzContext *lz, uint8_t *io_ptr, unsigned int num_io_bytes,
+                     LzImageType *out_type, int *out_width, int *out_height,
+                     int *out_n_pixels, int *out_top_down, const Palette *palette);
+
+/*
+        to_type = the image output type.
+        We assume the buffer is consecutive. i.e. width = stride
+
+        Improtant: if the image is plt1/4 and to_type is rgb32, the image
+        will decompressed including the last bits in each line. This means buffer should be
+        larger than width*height if neede and you shoud use stride to fix it.
+        Note: If the image is down to top, set the stride in the cairo surface to negative.
+        use cairo_image_surface_create_for_data to create the surface and
+        cairo_surface_set_user_data in order to free the data in the destroy callback.
+*/
+void lz_decode(LzContext *lz, LzImageType to_type, uint8_t *buf);
+
+LzContext *lz_create(LzUsrContext *usr);
+
+void lz_destroy(LzContext *lz);
+
+
+#endif  // __LZ_H