feat(ui): "Fancy" cloaked ship outlines (endless-sky#9642)

data/_ui/interfaces.txt

@@ -75,6 +75,8 @@ color "escort split fuel" .35 .31 .215 0.
 
 color "flagship highlight" .5 .8 .2 0.
 
+color "cloak highlight" .45 0. 0. .65
+
 color "drag select" .2 1. 0. 0.
 
 # Colors used for drawing mission or job pointers on the map,

data/_ui/tooltips.txt

@@ -1350,6 +1350,9 @@ tip "Ship outlines in shops"
 tip "Ship outlines in HUD"
 	`Controls the display of your flagship and target ship icons in the HUD. When fancy, applies a sobel filter to the sprites. (This can result in high GPU load for some ships on very old or low performance computers.) When fast, just uses the ship's sprite.`
 
+tip "Cloaked ship outlines"
+	`Controls the display of cloaked escorts. When fancy, causes the ship to become transparent and applies a red outline. When fast, simply shifts the ship to being red.`
+
 tip "Show status overlays"
 	`Display status overlays over top of all ships when in flight. Status overlays display a ship's shields and hull. If the damaged option is chosen, overlays only appear on ships that have taken damage.`
 

source/DrawList.cpp

@@ -80,14 +80,14 @@ bool DrawList::AddUnblurred(const Body &body)
 
 
 
-bool DrawList::AddSwizzled(const Body &body, int swizzle)
+bool DrawList::AddSwizzled(const Body &body, int swizzle, double cloak)
 {
 	Point position = body.Position() - center;
 	Point blur = body.Velocity() - centerVelocity;
 	if(Cull(body, position, blur))
 		return false;
 
-	Push(body, position, blur, 0., swizzle);
+	Push(body, position, blur, cloak, swizzle);
 	return true;
 }
 

source/DrawList.h

@@ -46,7 +46,7 @@ class DrawList {
 	// Add an object that should not be drawn with motion blur.
 	bool AddUnblurred(const Body &body);
 	// Add an object using a specific swizzle (rather than its own).
-	bool AddSwizzled(const Body &body, int swizzle);
+	bool AddSwizzled(const Body &body, int swizzle, double cloak = 0.);
 
 	// Draw all the items in this list.
 	void Draw() const;

source/Engine.cpp

@@ -582,15 +582,24 @@ void Engine::Step(bool isActive)
 		}
 	}
 
-	// Draw a highlight to distinguish the flagship from other ships.
+	outlines.clear();
+	const Color &cloakColor = *GameData::Colors().Get("cloak highlight");
+	if(Preferences::Has("Cloaked ship outlines"))
+		for(const auto &ship : player.Ships())
+		{
+			if(ship->IsParked() || ship->GetSystem() != player.GetSystem() || ship->Cloaking() == 0.)
+				continue;
+
+			outlines.emplace_back(ship->GetSprite(), (ship->Position() - center) * zoom, ship->Unit() * zoom,
+				ship->GetFrame(), Color::Multiply(ship->Cloaking(), cloakColor));
+		}
+
+	// Add the flagship outline last to distinguish the flagship from other ships.
 	if(flagship && !flagship->IsDestroyed() && Preferences::Has("Highlight player's flagship"))
 	{
-		highlightSprite = flagship->GetSprite();
-		highlightUnit = flagship->Unit() * zoom;
-		highlightFrame = flagship->GetFrame();
+		outlines.emplace_back(flagship->GetSprite(), (flagship->Position() - center) * zoom, flagship->Unit() * zoom,
+			flagship->GetFrame(), *GameData::Colors().Get("flagship highlight"));
 	}
-	else
-		highlightSprite = nullptr;
 
 	// Any of the player's ships that are in system are assumed to have
 	// landed along with the player.
@@ -1061,13 +1070,10 @@ void Engine::Draw() const
 	for(const AlertLabel &label : missileLabels)
 		label.Draw();
 
-	// Draw the flagship highlight, if any.
-	if(highlightSprite)
+	for(const auto &outline : outlines)
 	{
-		Point size(highlightSprite->Width(), highlightSprite->Height());
-		const Color &color = *colors.Get("flagship highlight");
-		// The flagship is always in the dead center of the screen.
-		OutlineShader::Draw(highlightSprite, Point(), size, color, highlightUnit, highlightFrame);
+		Point size(outline.sprite->Width(), outline.sprite->Height());
+		OutlineShader::Draw(outline.sprite, outline.position, size, outline.color, outline.unit, outline.frame);
 	}
 
 	if(flash)
@@ -2508,13 +2514,14 @@ void Engine::DrawShipSprites(const Ship &ship)
 	bool hasFighters = ship.PositionFighters();
 	double cloak = ship.Cloaking();
 	bool drawCloaked = (cloak && ship.IsYours());
+	bool fancyCloak = Preferences::Has("Cloaked ship outlines");
 	auto &itemsToDraw = draw[currentCalcBuffer];
-	auto drawObject = [&itemsToDraw, cloak, drawCloaked](const Body &body) -> void
+	auto drawObject = [&itemsToDraw, cloak, drawCloaked, fancyCloak](const Body &body) -> void
 	{
-		// Draw cloaked/cloaking sprites swizzled red, and overlay this solid
-		// sprite with an increasingly transparent "regular" sprite.
+		// Draw cloaked/cloaking sprites swizzled red or transparent (depending on whether we are using fancy
+		// cloaking effects), and overlay this solid sprite with an increasingly transparent "regular" sprite.
 		if(drawCloaked)
-			itemsToDraw.AddSwizzled(body, 27);
+			itemsToDraw.AddSwizzled(body, fancyCloak ? 9 : 27, fancyCloak ? 0.5 : 0.25);
 		itemsToDraw.Add(body, cloak);
 	};
 
@@ -2681,27 +2688,27 @@ void Engine::CreateStatusOverlays()
 
 	for(const auto &it : ships)
 	{
-		if(!it->GetGovernment() || it->GetSystem() != currentSystem ||
-				it->IsCloaked())
+		if(!it->GetGovernment() || it->GetSystem() != currentSystem || (!it->IsYours() && it->Cloaking() == 1.))
 			continue;
 		// Don't show status for dead ships.
 		if(it->IsDestroyed())
 			continue;
 
 		if(it == flagship)
-			EmplaceStatusOverlay(it, overlaySettings[Preferences::OverlayType::FLAGSHIP], 0);
+			EmplaceStatusOverlay(it, overlaySettings[Preferences::OverlayType::FLAGSHIP], 0, it->Cloaking());
 		else if(it->GetGovernment()->IsEnemy())
-			EmplaceStatusOverlay(it, overlaySettings[Preferences::OverlayType::ENEMY], 2);
+			EmplaceStatusOverlay(it, overlaySettings[Preferences::OverlayType::ENEMY], 2, it->Cloaking());
 		else if(it->IsYours() || it->GetPersonality().IsEscort())
-			EmplaceStatusOverlay(it, overlaySettings[Preferences::OverlayType::ESCORT], 1);
+			EmplaceStatusOverlay(it, overlaySettings[Preferences::OverlayType::ESCORT], 1, it->Cloaking());
 		else
-			EmplaceStatusOverlay(it, overlaySettings[Preferences::OverlayType::NEUTRAL], 3);
+			EmplaceStatusOverlay(it, overlaySettings[Preferences::OverlayType::NEUTRAL], 3, it->Cloaking());
 	}
 }
 
 
 
-void Engine::EmplaceStatusOverlay(const shared_ptr<Ship> &it, Preferences::OverlayState overlaySetting, int type)
+void Engine::EmplaceStatusOverlay(const shared_ptr<Ship> &it, Preferences::OverlayState overlaySetting,
+	int type, double cloak)
 {
 	if(overlaySetting == Preferences::OverlayState::OFF)
 		return;
@@ -2724,6 +2731,10 @@ void Engine::EmplaceStatusOverlay(const shared_ptr<Ship> &it, Preferences::Overl
 		else
 			alpha = 0.f;
 	}
+
+	if(it->IsYours())
+		cloak *= 0.6;
+
 	statuses.emplace_back(it->Position() - center, it->Shields(), it->Hull(),
-		min(it->Hull(), it->DisabledHull()), max(20., width * .5), type, alpha);
+		min(it->Hull(), it->DisabledHull()), max(20., width * .5), type, alpha * (1. - cloak));
 }

source/Engine.h

@@ -22,6 +22,7 @@ this program. If not, see <https://www.gnu.org/licenses/>.
 #include "AsteroidField.h"
 #include "BatchDrawList.h"
 #include "CollisionSet.h"
+#include "Color.h"
 #include "Command.h"
 #include "DrawList.h"
 #include "EscortDisplay.h"
@@ -100,6 +101,21 @@ class Engine {
 
 
 private:
+	class Outline {
+	public:
+		constexpr Outline(const Sprite *sprite, const Point &position, const Point &unit,
+			const float frame, const Color &color)
+			: sprite(sprite), position(position), unit(unit), frame(frame), color(color)
+		{
+		}
+
+		const Sprite *sprite;
+		const Point position;
+		const Point unit;
+		const float frame;
+		const Color color;
+	};
+
 	class Target {
 	public:
 		Point center;
@@ -167,7 +183,8 @@ class Engine {
 	void DoGrudge(const std::shared_ptr<Ship> &target, const Government *attacker);
 
 	void CreateStatusOverlays();
-	void EmplaceStatusOverlay(const std::shared_ptr<Ship> &ship, Preferences::OverlayState overlaySetting, int value);
+	void EmplaceStatusOverlay(const std::shared_ptr<Ship> &ship, Preferences::OverlayState overlaySetting,
+		int value, double cloak);
 
 
 private:
@@ -220,15 +237,13 @@ class Engine {
 	int targetSwizzle = -1;
 	EscortDisplay escorts;
 	AmmoDisplay ammoDisplay;
+	std::vector<Outline> outlines;
 	std::vector<Status> statuses;
 	std::vector<PlanetLabel> labels;
 	std::vector<AlertLabel> missileLabels;
 	std::vector<std::pair<const Outfit *, int>> ammo;
 	int jumpCount = 0;
 	const System *jumpInProgress[2] = {nullptr, nullptr};
-	const Sprite *highlightSprite = nullptr;
-	Point highlightUnit;
-	float highlightFrame = 0.f;
 
 	int step = 0;
 

source/Preferences.cpp

@@ -151,6 +151,7 @@ void Preferences::Load()
 	// values for settings that are off by default.
 	settings["Landing zoom"] = true;
 	settings["Render motion blur"] = true;
+	settings["Cloaked ship outlines"] = true;
 	settings[FRUGAL_ESCORTS] = true;
 	settings[EXPEND_AMMO] = true;
 	settings["Damaged fighters retreat"] = true;

source/PreferencesPanel.cpp

@@ -57,6 +57,7 @@ namespace {
 	const string AUTO_FIRE_SETTING = "Automatic firing";
 	const string SCREEN_MODE_SETTING = "Screen mode";
 	const string VSYNC_SETTING = "VSync";
+	const string CLOAK_OUTLINE = "Cloaked ship outlines";
 	const string STATUS_OVERLAYS_ALL = "Show status overlays";
 	const string STATUS_OVERLAYS_FLAGSHIP = "   Show flagship overlay";
 	const string STATUS_OVERLAYS_ESCORT = "   Show escort overlays";
@@ -645,6 +646,7 @@ void PreferencesPanel::DrawSettings()
 		EXTENDED_JUMP_EFFECTS,
 		SHIP_OUTLINES,
 		HUD_SHIP_OUTLINES,
+		CLOAK_OUTLINE,
 		"\t",
 		"HUD",
 		STATUS_OVERLAYS_ALL,
@@ -784,6 +786,11 @@ void PreferencesPanel::DrawSettings()
 			text = Preferences::StatusOverlaysSetting(Preferences::OverlayType::NEUTRAL);
 			isOn = text != "off" && text != "--";
 		}
+		else if(setting == CLOAK_OUTLINE)
+		{
+			text = Preferences::Has(CLOAK_OUTLINE) ? "fancy" : "fast";
+			isOn = true;
+		}
 		else if(setting == AUTO_AIM_SETTING)
 		{
 			text = Preferences::AutoAimSetting();