darkvater@414: #include "stdafx.h"
darkvater@414: 
darkvater@414: #include <stdarg.h>
darkvater@414: 
darkvater@414: #include "ttd.h"
darkvater@414: #include "sprite.h"
darkvater@414: 
darkvater@414: 
darkvater@414: struct SpriteGroup *EvalDeterministicSpriteGroup(struct 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++) {
darkvater@414: 		struct 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: }