begin work on maneuver nodes

src/game.cpp

@@ -105,6 +105,47 @@ selectOrbit(GameState* gs, GameOrbit* orbit)
 	gs->last_selected_orbit = orbit;
 }
 
+bool
+addManeuver(GameOrbit* orbit,
+			double anomaly,
+			vec3 impulse_vector,
+			double impulse_delta_v)
+{
+	assert(orbit);
+
+	if (anomaly < -M_PI || anomaly > M_PI) {
+		LOGF(Error, "invalid true anomaly: %f\n", anomaly);
+		return false;
+	}
+
+	if (orbit->maneuver.active) {
+		LOGF(Warning, "cannot add multiple maneuvers (yet)\n");
+		return false;
+	}
+
+	if (impulse_delta_v == 0.f) {
+		LOGF(Warning, "refusing to add maneuver with 0 dv\n");
+		return false;
+	}
+
+	orbit->maneuver.true_anomaly = anomaly;
+	//orbit->maneuver.impulse_vector = ...
+	orbit->maneuver.impulse_delta_v = impulse_delta_v;
+	orbit->maneuver.active = true;
+
+	return true;
+}
+
+void
+removeManeuver(GameOrbit* orbit)
+{
+	assert(orbit);
+
+	if (orbit->maneuver.active) {
+		orbit->maneuver = {0};
+	}
+}
+
 
 // internal
 

src/game.h

@@ -19,10 +19,22 @@ struct Ellipse3D
 	uint vert_count;
 };
 
+struct ManeuverNode
+{
+	double true_anomaly;
+	vec3 impulse_vector;
+	double impulse_delta_v;
+	// TODO: thrust calculations
+
+	bool active;
+};
+
 struct GameOrbit
 {
 	TwoBodySystem system;
 	Ellipse3D e3d;
+	// TODO: multiple maneuvers
+	ManeuverNode maneuver;
 
 	Entity* grav_body;
 	Entity* ellipse_entity;
@@ -60,3 +72,8 @@ Ellipse3D ellipse3DInit(EllipseParameters ep, uint vert_count);
 void ellipse3DUpdate(EllipseParameters ep, Ellipse3D& e3d);
 
 void selectOrbit(GameState* gs, GameOrbit* orbit);
+
+bool addManeuver(GameOrbit* orbit, double anomaly, vec3 impulse_vector,
+		double impulse_delta_v);
+
+void removeManeuver(GameOrbit* orbit);

src/gooey.cpp

@@ -10,7 +10,7 @@ using namespace ImGui;
 #include "orbits.h"
 
 
-const static int G_WIDTH = 350;
+const static int G_WIDTH = 400;
 const static ImVec2 V_SPACER(0, 10);
 const int H_FLAGS = ImGuiTreeNodeFlags_DefaultOpen;
 
@@ -23,6 +23,7 @@ void drawGravitationalBody(GravBody& body);
 void drawOrbitalElements(OrbitalElements& el);
 void drawSatelliteWindow(Satellite& sat);
 void drawSystemWindow(TwoBodySystem& sys);
+void drawManeuverWindow(GameState* gs);
 
 
 // interface
@@ -75,9 +76,12 @@ gooDraw(SDL_Window* window, GameState* gs)
 	drawSimulationWindow(gs->running, gs->sim_time_ms, gs->sim_speed);
 	Separator();
 
+	// FIXME: slit up orbit window into function calls here
 	drawOrbitWindow(gs);
-	Separator();
-	drawManeuverWinow(gs);
+
+	BeginChild("impulsive maneuver", ImVec2(G_WIDTH - 20, 300), true);
+	drawManeuverWindow(gs);
+	EndChild();
 #if 0
 	assert(gs->orbits[0].in_use);
 	TwoBodySystem& sys = gs->orbits[0].system;
@@ -111,11 +115,6 @@ void drawSimulationWindow(bool& running, u64 sim_time_ms, float& sim_speed)
 
 void drawOrbitWindow(GameState* gs)
 {
-	Text("WIP: Show a list of orbits, with grav\n"
-				"body and satellite properties.\n"
-				"Select a satellite to perform an inertial\n"
-				"maneuver\n");
-
 	Text("Orbit Selection");
 
 	BeginChild("orbit selection", ImVec2(G_WIDTH - 20, 100), true);
@@ -220,3 +219,53 @@ void drawSystemWindow(TwoBodySystem& sys)
 		Text("time to periapsis:    %.2f s", tof_periapse);
 	Unindent();
 }
+
+void
+drawManeuverWindow(GameState* gs)
+{
+	GameOrbit* orbit = getSelectedOrbit(gs);
+	static int item_current_idx = 0;
+	static double anom = 0.f;
+	static float dv = 0.f;
+
+	if (orbit) {
+		if (orbit->maneuver.active) {
+			Text("Orbital Maneuver");
+			Indent();
+			Text("true anomaly: %f", orbit->maneuver.true_anomaly);
+			Text("impulse dv: %f km/s", orbit->maneuver.impulse_delta_v);
+			Unindent();
+
+			if (Button("remove")) {
+				removeManeuver(orbit);
+				item_current_idx = 0;
+				anom = 0.f;
+				dv = 0.f;
+			}
+		} else {
+			Text("Add orbital maneuver");
+
+			const double min_anom = -M_PI, max_anom = M_PI;
+			SliderScalar("maneuver anomaly", ImGuiDataType_Double, &anom,
+					&min_anom, &max_anom, "%.19f");
+
+			// select maneuver vector
+			const char* items[] = {
+				"prograde",
+				"retrograde",
+				"some other vector"
+			};
+
+			Combo("thrust vector", &item_current_idx, items,
+					IM_ARRAYSIZE(items));
+
+			InputFloat("impulse dv, km/s", &dv, 0.1, 4.0, "%.1f");
+
+			if (Button("apply")) {
+				if (!addManeuver(orbit, anom, vec3(), dv)) {
+					// flash a color or something?
+				}
+			}
+		}
+	}
+}