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stb_image: Extract zhuffman_decode slow path into own function.

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This commit is contained in:
Fabian Giesen 2014-12-13 18:18:36 -08:00
parent cdc230598e
commit 007de5eb6e
1 changed files with 15 additions and 10 deletions
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25
stb_image.h
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@ -2119,18 +2119,9 @@ stbi_inline static unsigned int stbi__zreceive(stbi__zbuf *z, int n)
return k; return k;
} }
stbi_inline static int stbi__zhuffman_decode(stbi__zbuf *a, stbi__zhuffman *z) static int stbi__zhuffman_decode_slowpath(stbi__zbuf *a, stbi__zhuffman *z)
{ {
int b,s,k; int b,s,k;
if (a->num_bits < 16) stbi__fill_bits(a);
b = z->fast[a->code_buffer & STBI__ZFAST_MASK];
if (b < 0xffff) {
s = z->size[b];
a->code_buffer >>= s;
a->num_bits -= s;
return z->value[b];
}
// not resolved by fast table, so compute it the slow way // not resolved by fast table, so compute it the slow way
// use jpeg approach, which requires MSbits at top // use jpeg approach, which requires MSbits at top
k = stbi__bit_reverse(a->code_buffer, 16); k = stbi__bit_reverse(a->code_buffer, 16);
@ -2146,6 +2137,20 @@ stbi_inline static int stbi__zhuffman_decode(stbi__zbuf *a, stbi__zhuffman *z)
return z->value[b]; return z->value[b];
} }
stbi_inline static int stbi__zhuffman_decode(stbi__zbuf *a, stbi__zhuffman *z)
{
int b,s;
if (a->num_bits < 16) stbi__fill_bits(a);
b = z->fast[a->code_buffer & STBI__ZFAST_MASK];
if (b < 0xffff) {
s = z->size[b];
a->code_buffer >>= s;
a->num_bits -= s;
return z->value[b];
}
return stbi__zhuffman_decode_slowpath(a, z);
}
static int stbi__zexpand(stbi__zbuf *z, char *zout, int n) // need to make room for n bytes static int stbi__zexpand(stbi__zbuf *z, char *zout, int n) // need to make room for n bytes
{ {
char *q; char *q;