Fix #4415: Make sure that changing team colors only happens when there are team colors to change and only dump the envmap to disk if there actually is an envmap to dump

Author: Fabian Woltermann

code/lab/manager/lab_manager.cpp

@@ -224,7 +224,9 @@ void LabManager::onFrame(float frametime) {
 				break;
 
 			case KEY_M:
-				gr_dump_envmap(Renderer->currentMissionBackground.c_str());
+				// Dumping the environment map only makes sense if we actually have a background set
+				if (Renderer->currentMissionBackground != LAB_MISSION_NONE_STRING)
+					gr_dump_envmap(Renderer->currentMissionBackground.c_str());
 				break;
 
 				// bail...

code/lab/renderer/lab_renderer.cpp

@@ -63,7 +63,8 @@ void LabRenderer::renderModel(float frametime) {
 		Ships[obj->instance].flags.set(Ship::Ship_Flags::Subsystem_movement_locked, !renderFlags[LabRenderFlag::RotateSubsystems]);
 		Ships[obj->instance].flags.set(Ship::Ship_Flags::Draw_as_wireframe, renderFlags[LabRenderFlag::ShowWireframe]);
 		Ships[obj->instance].flags.set(Ship::Ship_Flags::Render_full_detail, renderFlags[LabRenderFlag::ShowFullDetail]);
-		Ships[obj->instance].flags.set(Ship::Ship_Flags::Render_without_light, renderFlags[LabRenderFlag::NoLighting] || currentMissionBackground == "None");
+		Ships[obj->instance].flags.set(Ship::Ship_Flags::Render_without_light,
+			renderFlags[LabRenderFlag::NoLighting] || currentMissionBackground == LAB_MISSION_NONE_STRING);
 		Ships[obj->instance].flags.set(Ship::Ship_Flags::Render_without_diffuse, renderFlags[LabRenderFlag::NoDiffuseMap]);
 		Ships[obj->instance].flags.set(Ship::Ship_Flags::Render_without_glowmap, renderFlags[LabRenderFlag::NoGlowMap]);
 		Ships[obj->instance].flags.set(Ship::Ship_Flags::Render_without_normalmap, renderFlags[LabRenderFlag::NoNormalMap]);
@@ -218,7 +219,7 @@ void LabRenderer::renderHud(float) {
 	}
 
 	//Print current Team Color setting, if any
-	if (currentTeamColor != "<none>") {
+	if (currentTeamColor != LAB_TEAM_COLOR_NONE) {
 		gr_printf_no_resize(gr_screen.center_offset_x + 2,
 			gr_screen.center_offset_y + gr_screen.center_h - (gr_get_font_height() * 3) - 3,
 			"Use T and Y to cycle through available Team Color settings. Current: %s",

code/lab/renderer/lab_renderer.h

@@ -67,6 +67,9 @@ enum class TextureOverride {
 	Specular
 };
 
+constexpr auto LAB_MISSION_NONE_STRING = "None";
+constexpr auto LAB_TEAM_COLOR_NONE = "<none>";
+
 class LabRenderer {
 public:
 	LabRenderer() {
@@ -75,8 +78,8 @@ class LabRenderer {
 		directionalFactor = static_light_factor;
 		textureQuality = TextureQuality::Maximum;
 		cameraDistance = 100.0f;
-		currentTeamColor = "<none>";
-		useBackground("None");
+		currentTeamColor = LAB_TEAM_COLOR_NONE;
+		useBackground(LAB_MISSION_NONE_STRING);
 
 		labCamera.reset(new OrbitCamera());
 
@@ -110,25 +113,28 @@ class LabRenderer {
 	}
 
 	void useNextTeamColorPreset() {
-		auto color_itr = Team_Colors.find(currentTeamColor);
-
-		if (color_itr == Team_Colors.begin()) {
-			color_itr = --Team_Colors.end();
-			currentTeamColor = color_itr->first;
-		}
-		else {
-			--color_itr;
-			currentTeamColor = color_itr->first;
+		if (!Team_Colors.empty()) {
+			auto color_itr = Team_Colors.find(currentTeamColor);
+
+			if (color_itr == Team_Colors.begin()) {
+				color_itr = --Team_Colors.end();
+				currentTeamColor = color_itr->first;
+			} else {
+				--color_itr;
+				currentTeamColor = color_itr->first;
+			}
 		}
 	}
 
 	void usePreviousTeamColorPreset() {
-		auto color_itr = Team_Colors.find(currentTeamColor);
+		if (!Team_Colors.empty()) {
+			auto color_itr = Team_Colors.find(currentTeamColor);
 
-		++color_itr;
-		if (color_itr == Team_Colors.end())
-			color_itr = Team_Colors.begin();
-		currentTeamColor = color_itr->first;
+			++color_itr;
+			if (color_itr == Team_Colors.end())
+				color_itr = Team_Colors.begin();
+			currentTeamColor = color_itr->first;
+		}
 	}
 
 	void setTeamColor(SCP_string teamColor) {