From 7912a69246ff09e6544e1bde2dd85f55e34cc9ed Mon Sep 17 00:00:00 2001
From: Peter Nelson <peter1138@openttd.org>
Date: Sat, 15 Feb 2025 15:44:04 +0000
Subject: [PATCH] Add: [NewGRF] More basic bitwise operators for varact2.

Adds ANDN, NAND, NOR and XNOR operators for whoever might find them useful.
---
 src/newgrf_spritegroup.cpp | 4 ++++
 src/newgrf_spritegroup.h   | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/src/newgrf_spritegroup.cpp b/src/newgrf_spritegroup.cpp
index a8a081c0c2..b0ccef5859 100644
--- a/src/newgrf_spritegroup.cpp
+++ b/src/newgrf_spritegroup.cpp
@@ -175,6 +175,10 @@ static U EvalAdjustT(const DeterministicSpriteGroupAdjust &adjust, ScopeResolver
 		case DSGA_OP_SHL:  return (uint32_t)(U)last_value << ((U)value & 0x1F); // Same behaviour as in ParamSet, mask 'value' to 5 bits, which should behave the same on all architectures.
 		case DSGA_OP_SHR:  return (uint32_t)(U)last_value >> ((U)value & 0x1F);
 		case DSGA_OP_SAR:  return (int32_t)(S)last_value >> ((U)value & 0x1F);
+		case DSGA_OP_ANDN: return last_value & ~value;
+		case DSGA_OP_NAND: return ~(last_value & value);
+		case DSGA_OP_NOR:  return ~(last_value | value);
+		case DSGA_OP_XNOR: return ~(last_value ^ value);
 		default:           return value;
 	}
 }
diff --git a/src/newgrf_spritegroup.h b/src/newgrf_spritegroup.h
index 6b49d17040..3e69329734 100644
--- a/src/newgrf_spritegroup.h
+++ b/src/newgrf_spritegroup.h
@@ -141,6 +141,10 @@ enum DeterministicSpriteGroupAdjustOperation : uint8_t {
 	DSGA_OP_SHL,  ///< a << b
 	DSGA_OP_SHR,  ///< (unsigned) a >> b
 	DSGA_OP_SAR,  ///< (signed) a >> b
+	DSGA_OP_ANDN, ///< x & ~y
+	DSGA_OP_NAND, ///< ~(x & y)
+	DSGA_OP_NOR,  ///< ~(x | y)
+	DSGA_OP_XNOR, ///< ~(x ^ y)
 };