OpenTTD-patches/sprite.c

99 lines
2.0 KiB
C

#include "stdafx.h"
#include <stdarg.h>
#include "ttd.h"
#include "sprite.h"
SpriteGroup *EvalDeterministicSpriteGroup(DeterministicSpriteGroup *dsg, int value)
{
int i;
value >>= dsg->shift_num; // This should bring us to the byte range.
value &= dsg->and_mask;
if (dsg->operation != DSG_OP_NONE)
value += (signed char) dsg->add_val;
switch (dsg->operation) {
case DSG_OP_DIV:
value /= (signed char) dsg->divmod_val;
break;
case DSG_OP_MOD:
value %= (signed char) dsg->divmod_val;
break;
case DSG_OP_NONE:
break;
}
for (i = 0; i < dsg->num_ranges; i++) {
DeterministicSpriteGroupRange *range = &dsg->ranges[i];
if (range->low <= value && value <= range->high)
return &range->group;
}
return dsg->default_group;
}
int GetDeterministicSpriteValue(byte var)
{
switch (var) {
case 0x00:
return _date;
case 0x01:
return _cur_year;
case 0x02:
return _cur_month;
case 0x03:
return _opt.landscape;
case 0x09:
return _date_fract;
case 0x0A:
return _tick_counter;
case 0x0C:
/* If we got here, it means there was no callback or
* callbacks aren't supported on our callpath. */
return 0;
default:
return -1;
}
}
SpriteGroup *EvalRandomizedSpriteGroup(RandomizedSpriteGroup *rsg, byte random_bits)
{
byte mask;
byte index;
/* Noone likes mangling with bits, but you don't get around it here.
* Sorry. --pasky */
// rsg->num_groups is always power of 2
mask = (rsg->num_groups - 1) << rsg->lowest_randbit;
index = (random_bits & mask) >> rsg->lowest_randbit;
assert(index < rsg->num_groups);
return &rsg->groups[index];
}
byte RandomizedSpriteGroupTriggeredBits(RandomizedSpriteGroup *rsg,
byte triggers, byte *waiting_triggers)
{
byte match = rsg->triggers & (*waiting_triggers | triggers);
bool res;
if (rsg->cmp_mode == RSG_CMP_ANY) {
res = (match != 0);
} else { /* RSG_CMP_ALL */
res = (match == rsg->triggers);
}
if (!res) {
*waiting_triggers |= triggers;
return 0;
}
*waiting_triggers &= ~match;
return (rsg->num_groups - 1) << rsg->lowest_randbit;
}