maride/guacamole-spice-protocol
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Fix signedness, fix hash size.

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This commit is contained in:
Michael Jumper 2012-08-19 21:10:19 -07:00
parent 97ac78c1e5
commit b35947daea
2 changed files with 8 additions and 8 deletions
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2
libguac/include/hash.h
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@ -51,7 +51,7 @@
* @return An arbitrary 24-bit unsigned integer value intended to be well * @return An arbitrary 24-bit unsigned integer value intended to be well
* distributed across different images. * distributed across different images.
*/ */
int guac_hash_surface(cairo_surface_t* surface); unsigned int guac_hash_surface(cairo_surface_t* surface);
#endif #endif

14
libguac/src/hash.c
View File

@ -44,10 +44,10 @@
* evenly, while guaranteeing that all 24-bit numbers are mapped onto * evenly, while guaranteeing that all 24-bit numbers are mapped onto
* themselves. * themselves.
*/ */
int _guac_hash_32to24(int value) { unsigned int _guac_hash_32to24(unsigned int value) {
/* Grab highest-order byte */ /* Grab highest-order byte */
int upper = value & 0xFF000000; unsigned int upper = value & 0xFF000000;
/* XOR upper with lower three bytes, truncate to 24-bit */ /* XOR upper with lower three bytes, truncate to 24-bit */
return return
@ -73,10 +73,10 @@ unsigned int _guac_rotate(unsigned int value, int amount) {
} }
int guac_hash_surface(cairo_surface_t* surface) { unsigned int guac_hash_surface(cairo_surface_t* surface) {
/* Init to zero */ /* Init to zero */
int hash_value = 0; unsigned int hash_value = 0;
int x, y; int x, y;
@ -95,19 +95,19 @@ int guac_hash_surface(cairo_surface_t* surface) {
for (x=0; x<width; x++) { for (x=0; x<width; x++) {
/* Get color at current pixel */ /* Get color at current pixel */
int color = *row; unsigned int color = *row;
row++; row++;
/* Compute next hash */ /* Compute next hash */
hash_value = hash_value =
_guac_rotate(hash_value, 1) ^ _guac_hash_32to24(color); _guac_rotate(hash_value, 1) ^ color;
} }
} /* end for each row */ } /* end for each row */
/* Done */ /* Done */
return hash_value; return _guac_hash_32to24(hash_value);
} }