static unsigned int refhash(naRef key)
{
if(IS_STR(key)) {
struct naStr* s = PTR(key).str;
if(s->hashcode) return s->hashcode;
return s->hashcode = hash32((void*)naStr_data(key), naStr_len(key));
} else { /* must be a number */
union { double d; unsigned int u[2]; } n;
n.d = key.num == -0.0 ? 0.0 : key.num; /* remember negative zero! */
return mix32(mix32(n.u[0]) ^ n.u[1]);
}
}
static unsigned int hash32(const unsigned char* in, int len)
{
unsigned int h = len, val = 0;
int i, count = 0;
for(i=0; i<len; i++) {
val = (val<<8) ^ in[i];
if(++count == 4) {
h = mix32(h ^ val);
val = count = 0;
}
}
return mix32(h ^ val);
}
Color4f TextureSource::get_texel(
TextureCache& texture_cache,
const size_t ix,
const size_t iy) const
{
assert(ix >= 0);
assert(iy >= 0);
assert(ix < m_texture_props.m_canvas_width);
assert(iy < m_texture_props.m_canvas_height);
// Compute the coordinates of the tile containing the texel (x, y).
const size_t tile_x = truncate<size_t>(ix * m_texture_props.m_rcp_tile_width);
const size_t tile_y = truncate<size_t>(iy * m_texture_props.m_rcp_tile_height);
assert(tile_x < m_texture_props.m_tile_count_x);
assert(tile_y < m_texture_props.m_tile_count_y);
#ifdef DEBUG_DISPLAY_TEXTURE_TILES
return
integer_to_color(
mix32(
static_cast<uint32>(m_assembly_uid),
static_cast<uint32>(m_texture_index),
static_cast<uint32>(tile_x),
static_cast<uint32>(tile_y)));
#endif
// Compute the tile space coordinates of the texel (x, y).
const size_t pixel_x = ix - tile_x * m_texture_props.m_tile_width;
const size_t pixel_y = iy - tile_y * m_texture_props.m_tile_height;
assert(pixel_x < m_texture_props.m_tile_width);
assert(pixel_y < m_texture_props.m_tile_height);
// Sample the tile.
Color4f sample;
sample_tile(
texture_cache,
m_assembly_uid,
m_texture_index,
tile_x,
tile_y,
pixel_x,
pixel_y,
sample);
return sample;
}
static inline uint64_t final64(uint64_t h)
{
h += (h << 3);
h ^= (h >> 23);
h += (h << 34);
return h;
}
//
// public
//
uint32_t strhash32(uint32_t h, const char * restrict s)
{
while(*s)
h = mix32(h, *s);
return final32(h);
}
uint32_t hash32(uint32_t h, const void * const restrict v, size_t l)
{
const char * s = v;
size_t x;
for(x = 0; x < l; x++)
h = mix32(h, s[x]);
return final32(h);
}
