Fix MML argument validation looping for non-po2 limits

Silly of me not to consider that pretty much every
existing top limit for voice arguments was po2. So
I was reusing the same trick in a couple of other
places, when I should've been more careful.

Luckily, only two places were wrong because of this,
and while fixing it I also decided to robustify algo
validation. Original code was kind of all over the
place when suggesting which value ranges are
good. Comments would say one thing, code
another, and the actual table of algo mappings
would say the secret third thing.

Maybe this was needed for compatibility with
something, but we are still talking about invalid
values here. At best we'd loop them, at worse —
reject them. At this point, it's better to clearly
tell the user what the valid range is. None of the
MML songs that we can use for tests seem to mind
the change.

src/utils/translator_util.cpp

@@ -72,6 +72,7 @@ int TranslatorUtil::_sanitize_param_loop(int p_value, int p_min, int p_max, cons
 		return p_value;
 	}
 
+	// WARN: Max value must be a bitmask, e.g. 0xFF. In other words, it's power-of-2 minus 1 (1, 3, 7, 15, 31, 63, 127, 255, 511).
 	return p_value & p_max;
 }
 
@@ -85,13 +86,14 @@ int TranslatorUtil::_sanitize_param_clamp(int p_value, int p_min, int p_max, con
 
 int TranslatorUtil::_get_params_algorithm(int (&p_algorithms)[4][16], int p_operator_count, int p_data_value, int p_max_value, const String &p_command) {
 	int alg_index = p_operator_count - 1;
-	ERR_FAIL_INDEX_V_MSG(alg_index, 4, -1, vformat("Translator: Invalid algorithm parameter %d in '%s'.", p_data_value, p_command));
+	ERR_FAIL_INDEX_V_MSG(alg_index, 4, -1, vformat("Translator: Invalid operator count (%d) for the algorithm in '%s'.", p_operator_count, p_command));
 
+	// WARN: Max value must be a bitmask, e.g. 0xFF. In other words, it's power-of-2 minus 1 (1, 3, 7, 15, 31, 63, 127, 255, 511).
 	int alg_data = _sanitize_param_loop(p_data_value, 0, p_max_value, "AL");
 	ERR_FAIL_INDEX_V_MSG(alg_data, 16, -1, vformat("Translator: Invalid algorithm parameter %d in '%s'.", p_data_value, p_command));
 
 	int algorithm = p_algorithms[alg_index][alg_data];
-	ERR_FAIL_COND_V_MSG(algorithm == -1, -1, vformat("Translator: Invalid algorithm parameter %d in '%s'.", p_data_value, p_command));
+	ERR_FAIL_COND_V_MSG(algorithm == -1, -1, vformat("Translator: Unsupported algorithm parameter %d in '%s'.", p_data_value, p_command));
 
 	return algorithm;
 }
@@ -137,10 +139,10 @@ void TranslatorUtil::_set_opl_params_by_array(const Ref<SiOPMChannelParams> &p_p
 	}
 
 	// #OPL@ signature:
-	// AL[0-5], FB[0-7],
+	// AL[0-3], FB[0-7],
 	// (WS[0-31], AR[0-15], DR[0-15], RR[0-15], EG[0,1], SL[0-15], TL[0-63], KR[0,1], KL[0-3], ML[0-15], AM[0-3]) x operator_count
 
-	int algorithm = _get_params_algorithm(SiMMLRefTable::get_instance()->algorithm_opl, p_params->operator_count, p_data[0], 5, "#OPL@");
+	int algorithm = _get_params_algorithm(SiMMLRefTable::get_instance()->algorithm_opl, p_params->operator_count, p_data[0], 3, "#OPL@");
 	if (algorithm == -1) {
 		return;
 	}
@@ -299,10 +301,10 @@ void TranslatorUtil::_set_ma3_params_by_array(const Ref<SiOPMChannelParams> &p_p
 	}
 
 	// #MA@ signature:
-	// AL[0-15], FB[0-7],
+	// AL[0-7], FB[0-7],
 	// (WS[0-31], AR[0-15], DR[0-15], SR[0-15], RR[0-15], SL[0-15], TL[0-63], KR[0,1], KL[0-3], ML[0-15], D1[0-7], AM[0-3]) x operator_count
 
-	int algorithm = _get_params_algorithm(SiMMLRefTable::get_instance()->algorithm_ma3, p_params->operator_count, p_data[0], 15, "#MA@");
+	int algorithm = _get_params_algorithm(SiMMLRefTable::get_instance()->algorithm_ma3, p_params->operator_count, p_data[0], 7, "#MA@");
 	if (algorithm == -1) {
 		return;
 	}
@@ -339,10 +341,16 @@ void TranslatorUtil::_set_al_params_by_array(const Ref<SiOPMChannelParams> &p_pa
 	p_params->set_analog_like(true);
 
 	// #AL@ signature:
-	// AL[0-2], W1[0-511], W2[0-511], BL[-64-+64], DT[]
+	// CN[0-2], W1[0-511], W2[0-511], BL[-64-+64], DT[]
 	// AR[0-63], DR[0-63], SL[0-15], RR[0-63]
 
-	p_params->algorithm = _sanitize_param_loop(p_data[0], 0, 2, "AL");
+	// Can't use _sanitize_param_loop here because 2 is not a valid number for the max value. So hack something ad-hoc together instead.
+	if (unlikely(p_data[0] < 0 || p_data[0] > 2)) {
+		ERR_PRINT(vformat("Translator: Parameter '%s' value (%d) is outside of valid range (%d : %d).", "CN", p_data[0], 0, 2));
+		p_params->algorithm = 0;
+	} else {
+		p_params->algorithm = p_data[0];
+	}
 
 	SiOPMOperatorParams *op_params0 = p_params->operator_params[0];
 	SiOPMOperatorParams *op_params1 = p_params->operator_params[1];