darkvater@414: #include "stdafx.h"
darkvater@414: 
darkvater@414: #include <stdarg.h>
darkvater@414: 
Darkvater@1891: #include "openttd.h"
darkvater@414: #include "sprite.h"
darkvater@414: 
darkvater@414: 
tron@1477: SpriteGroup *EvalDeterministicSpriteGroup(DeterministicSpriteGroup *dsg, int value)
darkvater@414: {
darkvater@414: 	int i;
darkvater@414: 
darkvater@414: 	value >>= dsg->shift_num; // This should bring us to the byte range.
darkvater@414: 	value &= dsg->and_mask;
darkvater@414: 
darkvater@414: 	if (dsg->operation != DSG_OP_NONE)
darkvater@414: 		value += (signed char) dsg->add_val;
darkvater@414: 
darkvater@414: 	switch (dsg->operation) {
darkvater@414: 		case DSG_OP_DIV:
darkvater@414: 			value /= (signed char) dsg->divmod_val;
darkvater@414: 			break;
darkvater@414: 		case DSG_OP_MOD:
darkvater@414: 			value %= (signed char) dsg->divmod_val;
darkvater@414: 			break;
darkvater@414: 		case DSG_OP_NONE:
darkvater@414: 			break;
darkvater@414: 	}
darkvater@414: 
darkvater@414: 	for (i = 0; i < dsg->num_ranges; i++) {
tron@1477: 		DeterministicSpriteGroupRange *range = &dsg->ranges[i];
darkvater@414: 
darkvater@414: 		if (range->low <= value && value <= range->high)
darkvater@414: 			return &range->group;
darkvater@414: 	}
darkvater@414: 
darkvater@414: 	return dsg->default_group;
darkvater@414: }
darkvater@414: 
darkvater@414: int GetDeterministicSpriteValue(byte var)
darkvater@414: {
darkvater@414: 	switch (var) {
darkvater@414: 		case 0x00:
darkvater@414: 			return _date;
darkvater@414: 		case 0x01:
darkvater@414: 			return _cur_year;
darkvater@414: 		case 0x02:
darkvater@414: 			return _cur_month;
darkvater@414: 		case 0x03:
darkvater@414: 			return _opt.landscape;
darkvater@414: 		case 0x09:
darkvater@414: 			return _date_fract;
darkvater@414: 		case 0x0A:
darkvater@414: 			return _tick_counter;
darkvater@414: 		case 0x0C:
darkvater@414: 			/* If we got here, it means there was no callback or
darkvater@414: 			 * callbacks aren't supported on our callpath. */
darkvater@414: 			return 0;
darkvater@414: 		default:
darkvater@414: 			return -1;
darkvater@414: 	}
darkvater@414: }
tron@445: 
tron@1477: SpriteGroup *EvalRandomizedSpriteGroup(RandomizedSpriteGroup *rsg, byte random_bits)
tron@445: {
tron@445: 	byte mask;
tron@445: 	byte index;
tron@445: 
tron@445: 	/* Noone likes mangling with bits, but you don't get around it here.
tron@445: 	 * Sorry. --pasky */
tron@445: 	// rsg->num_groups is always power of 2
tron@445: 	mask = (rsg->num_groups - 1) << rsg->lowest_randbit;
tron@445: 	index = (random_bits & mask) >> rsg->lowest_randbit;
tron@445: 	assert(index < rsg->num_groups);
tron@445: 	return &rsg->groups[index];
tron@445: }
tron@445: 
tron@1477: byte RandomizedSpriteGroupTriggeredBits(RandomizedSpriteGroup *rsg,
tron@1477: 	byte triggers, byte *waiting_triggers)
tron@445: {
tron@445: 	byte match = rsg->triggers & (*waiting_triggers | triggers);
tron@445: 	bool res;
tron@445: 
tron@445: 	if (rsg->cmp_mode == RSG_CMP_ANY) {
tron@445: 		res = (match != 0);
tron@445: 	} else { /* RSG_CMP_ALL */
tron@445: 		res = (match == rsg->triggers);
tron@445: 	}
tron@445: 
tron@445: 	if (!res) {
tron@445: 		*waiting_triggers |= triggers;
tron@445: 		return 0;
tron@445: 	}
tron@445: 
tron@445: 	*waiting_triggers &= ~match;
tron@445: 
tron@445: 	return (rsg->num_groups - 1) << rsg->lowest_randbit;
tron@445: }