X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=nageru%2Fscene.cpp;h=70bccbe1a73f11d31424654a630ef2d1600e21db;hb=c0763f1f26189bdc2ee487e38ccb7e8fe77fac25;hp=2612de639961e8336d3eb4a6a8d8f8fb1f5f842a;hpb=e4ebe67b6523038484df30d1d5fafc6055398acc;p=nageru

diff --git a/nageru/scene.cpp b/nageru/scene.cpp
index 2612de6..70bccbe 100644
--- a/nageru/scene.cpp
+++ b/nageru/scene.cpp
@@ -59,9 +59,9 @@ size_t Scene::compute_chain_number_for_block(size_t block_idx, const bitset<256>
 
 	size_t currently_chosen_alternative;
 	if (disabled.test(block_idx)) {
-		// It doesn't matter, so pick 0 as the canonical choice
+		// It doesn't matter, so pick the canonical choice
 		// (this is the only one that is actually instantiated).
-		currently_chosen_alternative = 0;
+		currently_chosen_alternative = block->canonical_alternative;
 	} else {
 		currently_chosen_alternative = block->currently_chosen_alternative;
 	}
@@ -80,8 +80,27 @@ bitset<256> Scene::find_disabled_blocks(size_t chain_idx) const
 {
 	assert(blocks.size() < 256);
 
-	bitset<256> ret;
-	find_disabled_blocks(chain_idx, blocks.size() - 1, /*currently_disabled=*/false, &ret);
+	// The find_disabled_blocks() recursion logic needs only one pass by itself,
+	// but the disabler logic is not so smart, so we just run multiple times
+	// until it converges.
+	bitset<256> prev, ret;
+	do {
+		find_disabled_blocks(chain_idx, blocks.size() - 1, /*currently_disabled=*/false, &ret);
+		prev = ret;
+		for (Block *block : blocks) {
+			EffectType chosen_type = block->alternatives[block->chosen_alternative(chain_idx)]->effect_type;
+			if (ret.test(block->idx) || chosen_type == IDENTITY_EFFECT) continue;  // Already disabled.
+
+			for (Block::Index disabler_idx : block->disablers) {
+				Block *disabler = blocks[disabler_idx];
+				EffectType chosen_type = disabler->alternatives[disabler->chosen_alternative(chain_idx)]->effect_type;
+				if (ret.test(disabler->idx) || chosen_type == IDENTITY_EFFECT) {
+					ret.set(block->idx);
+					break;
+				}
+			}
+		}
+	} while (prev != ret);
 	return ret;
 }
 
@@ -113,7 +132,8 @@ bool Scene::is_noncanonical_chain(size_t chain_idx) const
 	}
 	assert(blocks.size() < 256);
 	for (size_t block_idx = 0; block_idx < blocks.size(); ++block_idx) {
-		if (disabled.test(block_idx) && blocks[block_idx]->chosen_alternative(chain_idx) != 0) {
+		Block *block = blocks[block_idx];
+		if (disabled.test(block_idx) && block->chosen_alternative(chain_idx) != block->canonical_alternative) {
 			return true;
 		}
 	}
@@ -217,6 +237,15 @@ int Scene::add_effect(lua_State* L)
 		block->alternatives.push_back(blueprint);
 	}
 
+	int identity_index = find_index_of(block, IDENTITY_EFFECT);
+	if (identity_index == -1) {
+		block->canonical_alternative = 0;
+	} else {
+		// Pick the IdentityEffect as the canonical alternative, in case it
+		// helps us disable more stuff.
+		block->canonical_alternative = identity_index;
+	}
+
 	find_inputs_for_block(L, scene, block);
 	scene->blocks.push_back(block);
 
@@ -237,6 +266,8 @@ int Scene::add_optional_effect(lua_State* L)
 	// An IdentityEffect will be the alternative for when the effect is disabled.
 	block->alternatives.push_back(new EffectBlueprint(IDENTITY_EFFECT));
 
+	block->canonical_alternative = 1;
+
 	find_inputs_for_block(L, scene, block);
 	scene->blocks.push_back(block);
 
@@ -633,6 +664,27 @@ int Block_disable(lua_State *L)
 	return 0;
 }
 
+int Block_always_disable_if_disabled(lua_State *L)
+{
+	assert(lua_gettop(L) == 2);
+	Block *block = *(Block **)luaL_checkudata(L, 1, "Block");
+	Block *disabler_block = *(Block **)luaL_checkudata(L, 2, "Block");
+
+	int my_alternative = find_index_of(block, IDENTITY_EFFECT);
+	int their_alternative = find_index_of(disabler_block, IDENTITY_EFFECT);
+	if (my_alternative == -1) {
+		luaL_error(L, "always_disable_if_disabled() called on something that didn't have an IdentityEffect fallback (try add_optional_effect())");
+	}
+	if (their_alternative == -1) {
+		luaL_error(L, "always_disable_if_disabled() with an argument that didn't have an IdentityEffect fallback (try add_optional_effect())");
+	}
+
+	block->disablers.push_back(disabler_block->idx);
+
+	lua_pop(L, 2);
+	return 0;
+}
+
 int Block_set_int(lua_State *L)
 {
 	assert(lua_gettop(L) == 3);