From 314e8c9222f64b1520e384ca7a0e03a2c51d44c5 Mon Sep 17 00:00:00 2001
From: Michael Jumper <zhangmaike@users.sourceforge.net>
Date: Sun, 1 Apr 2012 21:57:19 -0700
Subject: [PATCH] Add palette find function.

---
 libguac/include/palette.h |  1 +
 libguac/src/palette.c     | 27 +++++++++++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/libguac/include/palette.h b/libguac/include/palette.h
index fc3cc3dd..fb30066e 100644
--- a/libguac/include/palette.h
+++ b/libguac/include/palette.h
@@ -56,6 +56,7 @@ typedef struct guac_palette {
 } guac_palette;
 
 guac_palette* guac_palette_alloc(cairo_surface_t* surface);
+int guac_palette_find(guac_palette* palette, int color);
 void guac_palette_free(guac_palette* palette);
 
 #endif
diff --git a/libguac/src/palette.c b/libguac/src/palette.c
index 2add6b1a..dc18ebb8 100644
--- a/libguac/src/palette.c
+++ b/libguac/src/palette.c
@@ -111,6 +111,33 @@ guac_palette* guac_palette_alloc(cairo_surface_t* surface) {
 
 }
 
+int guac_palette_find(guac_palette* palette, int color) {
+
+    /* Calculate hash code */
+    int hash = ((color & 0xFFF000) >> 12) ^ (color & 0xFFF);
+
+    guac_palette_entry* entry;
+
+    /* Search for palette entry */
+    for (;;) {
+        
+        entry = &(palette->entries[hash]);
+
+        /* If we've found a free space, color not stored. */
+        if (entry->index == 0)
+            return -1;
+
+        /* Otherwise, if color indeed stored here, done */
+        if (entry->color == color)
+            return entry->index;
+
+        /* Otherwise, collision. Move on to another bucket */
+        hash = (hash+1) & 0xFFF;
+
+    }
+
+}
+
 void guac_palette_free(guac_palette* palette) {
     free(palette);
 }