int
threshold(VMPM *vmpm)
{
unsigned int i;
if (vmpm->buffer_high)
free(vmpm->buffer_high);
if ((vmpm->buffer_high = malloc(vmpm->bufferused)) == NULL)
return 0;
if (vmpm->buffer_low)
free(vmpm->buffer_low);
if ((vmpm->buffer_low = malloc(vmpm->bufferused)) == NULL)
return 0;
vmpm->bits_per_symbol = 8 - vmpm->nlowbits;
vmpm->alphabetsize = 1 << vmpm->bits_per_symbol;
vmpm->buffer_low_size = vmpm->bufferused;
for (i = 0; i < vmpm->bufferused; i++) {
vmpm->buffer_low[i] = vmpm->buffer[i] & LOW_MASK(vmpm->nlowbits);
vmpm->buffer[i] >>= vmpm->nlowbits;
vmpm->buffer_high[i] = vmpm->buffer[i];
}
return 1;
}
REGPARM_ATTR (1) static void
cfdiv_r_2exp (mpz_ptr w, mpz_srcptr u, unsigned long cnt, int dir)
{
mp_size_t usize, abs_usize, limb_cnt, i;
mp_srcptr up;
mp_ptr wp;
mp_limb_t high;
usize = SIZ(u);
if (usize == 0)
{
SIZ(w) = 0;
return;
}
limb_cnt = cnt / GMP_NUMB_BITS;
cnt %= GMP_NUMB_BITS;
abs_usize = ABS (usize);
/* MPZ_REALLOC(w) below is only when w!=u, so we can fetch PTR(u) here
nice and early */
up = PTR(u);
if ((usize ^ dir) < 0)
{
/* Round towards zero, means just truncate */
if (w == u)
{
/* if already smaller than limb_cnt then do nothing */
if (abs_usize <= limb_cnt)
return;
wp = PTR(w);
}
else
{
i = MIN (abs_usize, limb_cnt+1);
MPZ_REALLOC (w, i);
wp = PTR(w);
MPN_COPY (wp, up, i);
/* if smaller than limb_cnt then only the copy is needed */
if (abs_usize <= limb_cnt)
{
SIZ(w) = usize;
return;
}
}
}
else
{
/* Round away from zero, means twos complement if non-zero */
/* if u!=0 and smaller than divisor, then must negate */
if (abs_usize <= limb_cnt)
goto negate;
/* if non-zero low limb, then must negate */
for (i = 0; i < limb_cnt; i++)
if (up[i] != 0)
goto negate;
/* if non-zero partial limb, then must negate */
if ((up[limb_cnt] & LOW_MASK (cnt)) != 0)
goto negate;
/* otherwise low bits of u are zero, so that's the result */
SIZ(w) = 0;
return;
negate:
/* twos complement negation to get 2**cnt-u */
MPZ_REALLOC (w, limb_cnt+1);
up = PTR(u);
wp = PTR(w);
/* Ones complement */
i = MIN (abs_usize, limb_cnt+1);
mpn_com_n (wp, up, i);
for ( ; i <= limb_cnt; i++)
wp[i] = GMP_NUMB_MAX;
/* Twos complement. Since u!=0 in the relevant part, the twos
complement never gives 0 and a carry, so can use MPN_INCR_U. */
MPN_INCR_U (wp, limb_cnt+1, CNST_LIMB(1));
usize = -usize;
}
/* Mask the high limb */
high = wp[limb_cnt];
high &= LOW_MASK (cnt);
wp[limb_cnt] = high;
/* Strip any consequent high zeros */
while (high == 0)
{
limb_cnt--;
if (limb_cnt < 0)
{
SIZ(w) = 0;
return;
}
high = wp[limb_cnt];
}
limb_cnt++;
SIZ(w) = (usize >= 0 ? limb_cnt : -limb_cnt);
}
uint16_t
tile_mask_calculate(uint8_t tl,
uint8_t tr,
uint8_t bl,
uint8_t br)
{
/* Helpers */
#define TILE_HAS(type) _tile_has_type(tl, tr, bl, br, type)
#define LOW_MASK(first) _tile_boundry_low_mask_get(tl, tr, bl, br, first)
uint16_t tile = 0x0000;
if (tile_solid_is(tl, tr, bl, br))
{
switch (tl & 0x0f) /* tl == tr == bl == br */
{
case TILE_WATER_LIGHT: tile = 0x0010; break;
case TILE_WATER_DARK: tile = 0x0020; break;
case TILE_GROUND_LIGHT: tile = 0x0030; break;
case TILE_GROUND_DARK: tile = 0x0040; break;
case TILE_GRASS_LIGHT: tile = 0x0050; break;
case TILE_GRASS_DARK: tile = 0x0060; break;
case TILE_TREES: tile = 0x0070; break;
case TILE_ROCKS: tile = 0x0080; break;
case TILE_HUMAN_WALL:
tile = (tl & TILE_WALL_OPEN) ? 0x00b0 : 0x0090;
break;
case TILE_ORC_WALL:
tile = (tl & TILE_WALL_OPEN) ? 0x00c0 : 0x00a0;
break;
default:
CRI("Unhandled solid tile %x", tl);
goto fail;
}
}
else
{
if (TILE_HAS(TILE_GRASS_LIGHT))
{
if (TILE_HAS(TILE_TREES))
{
tile = 0x0700 | LOW_MASK(TILE_TREES);
}
else if (TILE_HAS(TILE_GRASS_DARK))
{
tile = 0x0600 | LOW_MASK(TILE_GRASS_DARK);
}
else if (TILE_HAS(TILE_GROUND_LIGHT))
{
tile = 0x0500 | LOW_MASK(TILE_GROUND_LIGHT);
}
else
{
CRI("Invalid disposition of tiles (with grass light)");
goto fail;
}
}
else if (TILE_HAS(TILE_GROUND_LIGHT))
{
if (TILE_HAS(TILE_GROUND_DARK))
{
tile = 0x0300 | LOW_MASK(TILE_GROUND_DARK);
}
else if (TILE_HAS(TILE_ROCKS))
{
tile = 0x0400 | LOW_MASK(TILE_ROCKS);
}
else if (TILE_HAS(TILE_WATER_LIGHT))
{
tile = 0x0200 | LOW_MASK(TILE_WATER_LIGHT);
}
else
{
CRI("Invalid disposition of tiles (with ground light)");
goto fail;
}
}
else if (TILE_HAS(TILE_WATER_LIGHT))
{
if (TILE_HAS(TILE_WATER_DARK))
{
tile = 0x0100 | LOW_MASK(TILE_WATER_DARK);
}
else
{
CRI("Invalid disposition of tiles (with water light)");
goto fail;
}
}
else if (TILE_HAS(TILE_ORC_WALL))
{
tile = 0x0900 | _tile_wall_mask_get(tl, tr, bl, br);
}
else if (TILE_HAS(TILE_HUMAN_WALL))
{
tile = 0x0800 | _tile_wall_mask_get(tl, tr, bl, br);
}
else
{
CRI("Uncovered tile disposition");
goto fail;
}
}
return tile;
fail:
CRI("Analysis of tile (tl, tr, bl, br) = (0x%02x, 0x%02x, 0x%02x, 0x%02x) failed",
tl, tr, bl, br);
return 0x0000;
#undef LOW_MASK
#undef TILE_HAS
}
