From d8fadf26db4a259ce24b958e8c254d77dd7ea80a Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
Date: Wed, 17 Jul 2019 15:46:40 +0200
Subject: [PATCH] Deal better with the user forgetting to set width/height on
 effects that require them.

---
 nageru/scene.cpp | 38 ++++++++++++++++++++++++++++++++++++++
 nageru/scene.h   |  2 ++
 2 files changed, 40 insertions(+)

diff --git a/nageru/scene.cpp b/nageru/scene.cpp
index 70bccbe..1694882 100644
--- a/nageru/scene.cpp
+++ b/nageru/scene.cpp
@@ -35,6 +35,16 @@ int find_index_of(const Block *block, EffectType val)
 	return -1;
 }
 
+string get_declaration_point(lua_State *L)
+{
+	lua_Debug ar;
+	lua_getstack(L, 1, &ar);
+	lua_getinfo(L, "nSl", &ar);
+	char buf[256];
+	snprintf(buf, sizeof(buf), "%s:%d", ar.source, ar.currentline);
+	return buf;
+}
+
 Scene::Scene(Theme *theme, float aspect_nom, float aspect_denom)
 	: theme(theme), aspect_nom(aspect_nom), aspect_denom(aspect_denom), resource_pool(theme->get_resource_pool()) {}
 
@@ -146,6 +156,7 @@ int Scene::add_input(lua_State* L)
 	Scene *scene = (Scene *)luaL_checkudata(L, 1, "Scene");
 
 	Block *block = new Block;
+	block->declaration_point = get_declaration_point(L);
 	block->idx = scene->blocks.size();
 	if (lua_gettop(L) == 1) {
 		// No parameter given, so a flexible input.
@@ -222,6 +233,7 @@ int Scene::add_effect(lua_State* L)
 	Scene *scene = (Scene *)luaL_checkudata(L, 1, "Scene");
 
 	Block *block = new Block;
+	block->declaration_point = get_declaration_point(L);
 	block->idx = scene->blocks.size();
 
 	if (lua_istable(L, 2)) {
@@ -258,6 +270,7 @@ int Scene::add_optional_effect(lua_State* L)
 	Scene *scene = (Scene *)luaL_checkudata(L, 1, "Scene");
 
 	Block *block = new Block;
+	block->declaration_point = get_declaration_point(L);
 	block->idx = scene->blocks.size();
 
 	EffectBlueprint *blueprint = *(EffectBlueprint **)luaL_checkudata(L, 2, "EffectBlueprint");
@@ -450,8 +463,19 @@ Scene::get_chain(Theme *theme, lua_State *L, unsigned num, const InputState &inp
 		Block *block = blocks[index_and_effect.first];
 		Effect *effect = index_and_effect.second;
 
+		bool missing_width = (current_type(block) == RESIZE_EFFECT ||
+			current_type(block) == RESAMPLE_EFFECT ||
+			current_type(block) == PADDING_EFFECT);
+		bool missing_height = missing_width;
+
 		// Get the effects currently set on the block.
 		if (current_type(block) != IDENTITY_EFFECT) {  // Ignore settings on optional effects.
+			if (block->int_parameters.count("width") && block->int_parameters["width"] > 0) {
+				missing_width = false;
+			}
+			if (block->int_parameters.count("height") && block->int_parameters["height"] > 0) {
+				missing_height = false;
+			}
 			for (const auto &key_and_tuple : block->int_parameters) {
 				int_to_set.emplace(make_pair(effect, key_and_tuple.first), key_and_tuple.second);
 			}
@@ -470,6 +494,12 @@ Scene::get_chain(Theme *theme, lua_State *L, unsigned num, const InputState &inp
 		// so they are set afterwards.
 		if (!block->alternatives.empty()) {
 			EffectBlueprint *blueprint = block->alternatives[block->currently_chosen_alternative];
+			if (blueprint->int_parameters.count("width") && blueprint->int_parameters["width"] > 0) {
+				missing_width = false;
+			}
+			if (blueprint->int_parameters.count("height") && blueprint->int_parameters["height"] > 0) {
+				missing_height = false;
+			}
 			for (const auto &key_and_tuple : blueprint->int_parameters) {
 				int_to_set[make_pair(effect, key_and_tuple.first)] = key_and_tuple.second;
 			}
@@ -483,6 +513,14 @@ Scene::get_chain(Theme *theme, lua_State *L, unsigned num, const InputState &inp
 				vec4_to_set[make_pair(effect, key_and_tuple.first)] = key_and_tuple.second;
 			}
 		}
+
+		if (missing_width || missing_height) {
+			fprintf(stderr, "WARNING: Unset or nonpositive width/height for effect declared at %s "
+				"when getting scene for signal %u; setting to 1x1 to avoid crash.\n",
+				block->declaration_point.c_str(), num);
+			int_to_set[make_pair(effect, "width")] = 1;
+			int_to_set[make_pair(effect, "height")] = 1;
+		}
 	}
 
 	lua_pop(L, 1);
diff --git a/nageru/scene.h b/nageru/scene.h
index 32b3203..7715547 100644
--- a/nageru/scene.h
+++ b/nageru/scene.h
@@ -115,6 +115,8 @@ struct Block {
 	std::map<std::string, float> float_parameters;
 	std::map<std::string, std::array<float, 3>> vec3_parameters;
 	std::map<std::string, std::array<float, 4>> vec4_parameters;
+
+	std::string declaration_point;  // For error messages.
 };
 
 int Block_display(lua_State* L);
-- 
2.39.2