From ec652af924ec9c667505c2811d57de0917f7ee7d Mon Sep 17 00:00:00 2001
From: Michael Jumper <zhangmaike@users.sourceforge.net>
Date: Sun, 1 Apr 2012 22:36:55 -0700
Subject: [PATCH] Store palette in libpng format, add PLTE section.

---
 libguac/include/palette.h |  3 ++-
 libguac/src/palette.c     | 12 ++++++++++--
 libguac/src/protocol.c    |  3 +++
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/libguac/include/palette.h b/libguac/include/palette.h
index d2263e95..ce6256f0 100644
--- a/libguac/include/palette.h
+++ b/libguac/include/palette.h
@@ -38,6 +38,7 @@
 #ifndef __GUAC_PALETTE_H
 #define __GUAC_PALETTE_H
 
+#include <png.h>
 #include <cairo/cairo.h>
 
 typedef struct guac_palette_entry {
@@ -51,7 +52,7 @@ typedef struct guac_palette_entry {
 typedef struct guac_palette {
 
     guac_palette_entry entries[0xFFF];
-    int colors[256];
+    png_color colors[256];
     int size;
 
 } guac_palette;
diff --git a/libguac/src/palette.c b/libguac/src/palette.c
index 8d38c771..be1a6518 100644
--- a/libguac/src/palette.c
+++ b/libguac/src/palette.c
@@ -79,16 +79,24 @@ guac_palette* guac_palette_alloc(cairo_surface_t* surface) {
                 /* If we've found a free space, use it */
                 if (entry->index == 0) {
 
+                    png_color* c;
+
                     /* Stop if already at capacity */
                     if (palette->size == 256) {
                         guac_palette_free(palette);
                         return NULL;
                     }
 
-                    /* Add color to map, done */
-                    palette->colors[palette->size] = color;
+                    /* Store in palette */
+                    c = &(palette->colors[palette->size]);
+                    c->blue  = (color & 0x0000FF);
+                    c->green = (color & 0x00FF00) >> 8;
+                    c->red   = (color & 0xFF0000) >> 16;
+
+                    /* Add color to map */
                     entry->index = ++palette->size;
                     entry->color = color;
+
                     break;
 
                 }
diff --git a/libguac/src/protocol.c b/libguac/src/protocol.c
index 160b91d6..3e93f3b5 100644
--- a/libguac/src/protocol.c
+++ b/libguac/src/protocol.c
@@ -263,6 +263,9 @@ int __guac_socket_write_length_png(guac_socket* socket, cairo_surface_t* surface
         PNG_FILTER_TYPE_DEFAULT
     );
 
+    /* Write palette */
+    png_set_PLTE(png, png_info, palette->colors, palette->size);
+
     /* Write image */
     png_set_rows(png, png_info, png_rows);
     png_write_png(png, png_info, PNG_TRANSFORM_IDENTITY, NULL);