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Clean up utility functions that are also used in other projects

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This commit is contained in:
Eric Fischer
2017-03-16 15:06:58 -07:00
parent 8c6f6250b1
commit fa56adc530
9 changed files with 110 additions and 77 deletions
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projection.cpp
+23 -4
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@@ -83,13 +83,32 @@ unsigned long long encode(unsigned int wx, unsigned int wy) {
return out;
}
static unsigned char decodex[256];
static unsigned char decodey[256];
void decode(unsigned long long index, unsigned *wx, unsigned *wy) {
static int initialized = 0;
if (!initialized) {
for (size_t ix = 0; ix < 256; ix++) {
size_t xx = 0, yy = 0;
for (size_t i = 0; i < 32; i++) {
xx |= ((ix >> (64 - 2 * (i + 1) + 1)) & 1) << (32 - (i + 1));
yy |= ((ix >> (64 - 2 * (i + 1) + 0)) & 1) << (32 - (i + 1));
}
decodex[ix] = xx;
decodey[ix] = yy;
}
initialized = 1;
}
*wx = *wy = 0;
int i;
for (i = 0; i < 32; i++) {
*wx |= ((index >> (64 - 2 * (i + 1) + 1)) & 1) << (32 - (i + 1));
*wy |= ((index >> (64 - 2 * (i + 1) + 0)) & 1) << (32 - (i + 1));
for (size_t i = 0; i < 8; i++) {
*wx |= ((unsigned) decodex[(index >> (8 * i)) & 0xFF]) << (4 * i);
*wy |= ((unsigned) decodey[(index >> (8 * i)) & 0xFF]) << (4 * i);
}
}