Method ProcessRegisters

src/newgrf_commons.cpp:665–729

* Evaluates the register modifiers and integrates them into the preprocessed sprite layout. * @param object ResolverObject owning the temporary storage. * @param resolved_var10 The value of var10 the action-1-2-3 chain was evaluated for. * @param resolved_sprite Result sprite of the action-1-2-3 chain. */

 * @param resolved_sprite Result sprite of the action-1-2-3 chain.
 */
void SpriteLayoutProcessor::ProcessRegisters(const ResolverObject &object, uint8_t resolved_var10, uint32_t resolved_sprite)
{
	assert(this->raw_layout != nullptr);
	const TileLayoutRegisters *regs = this->raw_layout->registers.empty() ? nullptr : this->raw_layout->registers.data();
	bool ground = true;
	for (DrawTileSeqStruct &result : this->result_seq) {
		TileLayoutFlags flags = TLF_NOTHING;
		if (regs != nullptr) flags = regs->flags;

		/* Is the sprite or bounding box affected by an action-1-2-3 chain? */
		if (HasBit(result.image.sprite, SPRITE_MODIFIER_CUSTOM_SPRITE) || (flags & TLF_SPRITE_REG_FLAGS)) {
			/* Does the var10 value apply to this sprite? */
			uint8_t var10 = (flags & TLF_SPRITE_VAR10) ? regs->sprite_var10 : (ground && this->separate_ground ? 1 : 0);
			if (var10 == resolved_var10) {
				/* Apply registers */
				if ((flags & TLF_DODRAW) && object.GetRegister(regs->dodraw) == 0) {
					result.image.sprite = 0;
				} else {
					if (HasBit(result.image.sprite, SPRITE_MODIFIER_CUSTOM_SPRITE)) result.image.sprite += resolved_sprite;
					if (flags & TLF_SPRITE) {
						int16_t offset = static_cast<int16_t>(object.GetRegister(regs->sprite)); // mask to 16 bits to avoid trouble
						if (!HasBit(result.image.sprite, SPRITE_MODIFIER_CUSTOM_SPRITE) || (offset >= 0 && offset < regs->max_sprite_offset)) {
							result.image.sprite += offset;
						} else {
							result.image.sprite = SPR_IMG_QUERY;
						}
					}

					if (result.IsParentSprite()) {
						if (flags & TLF_BB_XY_OFFSET) {
							result.origin.x += object.GetRegister(regs->delta.parent[0]);
							result.origin.y += object.GetRegister(regs->delta.parent[1]);
						}
						if (flags & TLF_BB_Z_OFFSET) result.origin.z += object.GetRegister(regs->delta.parent[2]);
					} else {
						if (flags & TLF_CHILD_X_OFFSET) result.origin.x += object.GetRegister(regs->delta.child[0]);
						if (flags & TLF_CHILD_Y_OFFSET) result.origin.y += object.GetRegister(regs->delta.child[1]);
					}
				}
			}
		}

		/* Is the palette affected by an action-1-2-3 chain? */
		if (result.image.sprite != 0 && (HasBit(result.image.pal, SPRITE_MODIFIER_CUSTOM_SPRITE) || (flags & TLF_PALETTE_REG_FLAGS))) {
			/* Does the var10 value apply to this sprite? */
			uint8_t var10 = (flags & TLF_PALETTE_VAR10) ? regs->palette_var10 : (ground && this->separate_ground ? 1 : 0);
			if (var10 == resolved_var10) {
				/* Apply registers */
				if (HasBit(result.image.pal, SPRITE_MODIFIER_CUSTOM_SPRITE)) result.image.pal += resolved_sprite;
				if (flags & TLF_PALETTE) {
					int16_t offset = static_cast<int16_t>(object.GetRegister(regs->palette)); // mask to 16 bits to avoid trouble
					if (!HasBit(result.image.pal, SPRITE_MODIFIER_CUSTOM_SPRITE) || (offset >= 0 && offset < regs->max_palette_offset)) {
						result.image.pal += offset;
					} else {
						result.image.sprite = SPR_IMG_QUERY;
						result.image.pal = PAL_NONE;
					}
				}