Improved zooming movement in views (See details).

- Added smooth zoom animation upon mouse wheel movement for System and Galactic views, as for SectorView.
- Made zooming commands be affected by shift keys, for faster movement, as for paning in SectorView.
- Moved the "shift key factors" into "Pi::GetMoveSpeedShiftModifier()" for maintenability.
- Coded value animation in a separate header (still for maintenability).

src/Animation.h

@@ -0,0 +1,40 @@
+#ifndef ANIMATION_H
+#define ANIMATION_H
+
+/// Namespace contains simple functions for value animation.
+/// This is very simple implementation, which could be improved in the future.
+///\todo Many interesting things could be added, such as play/pause/reset animations, loop/mirror animation, interpolations, etc. But implementations exist, and if we need something tougher, we should have a look at them instead of reinventing the wheel.
+namespace Animation {
+
+	/// Animates linearily a value over time, given a speed.
+	/// The speed must be "towards" the target value. Function will not go further than target.
+	template<class T>
+	inline void Linear(T & cur, const T target, const T speed, const float frameTime) {
+		//static_assert(static_cast<T>(-1) <0);		// Assert type is signed
+		const T delta(target - cur);
+		assert(delta * speed >=0);
+		cur += pow(speed, frameTime);
+		// Check for arrival
+		const T newDelta(target - cur);
+		if (newDelta*delta <0) cur = target;
+	}
+
+	/// Animates a value with "approach style" over time (zooming).
+	/// The speeds must be positive. Function will not go further than target.
+	template<class T>
+	inline void Approach(T & cur, const T target, float frameTime, const T deltaFactor=10, T targetFactor=1) {
+		//static_assert(static_cast<T>(-1) <0);		// Assert type is signed
+		if (frameTime>1) frameTime = 1;		// Clamp in case game hangs for a second
+		assert(deltaFactor>0 && targetFactor >=0);
+		const T delta(target - cur);
+		if (delta == 0) return;
+		if (delta<0) targetFactor=-targetFactor;
+		cur += (delta*deltaFactor + target*targetFactor)*frameTime;
+		// Check for arrival
+		const T newDelta(target - cur);
+		if (newDelta*delta <0) cur = target;
+	}
+
+} // namespace Animation
+
+#endif		// ANIMATION_H

src/GalacticView.cpp

@@ -10,11 +10,15 @@
 #include "Galaxy.h"
 #include "Lang.h"
 #include "StringF.h"
+#include "Animation.h"
 #include "graphics/Material.h"
 #include "graphics/Renderer.h"
 #include "graphics/TextureBuilder.h"
 
 using namespace Graphics;
+static const float ZOOM_IN_SPEED = 2;
+static const float ZOOM_OUT_SPEED = 1.f/ZOOM_IN_SPEED;
+static const float WHEEL_SENSITIVITY = .2f;		// Should be a variable in user settings.
 
 GalacticView::GalacticView() :
 	m_quad(Graphics::TextureBuilder::UI("galaxy.bmp").CreateTexture(Gui::Screen::GetRenderer()))
@@ -22,6 +26,7 @@ GalacticView::GalacticView() :
 
 	SetTransparency(true);
 	m_zoom = 1.0f;
+	m_zoomTo = m_zoom;
 
 	m_zoomInButton = new Gui::ImageButton("icons/zoom_in.png");
 	m_zoomInButton->SetToolTip(Lang::ZOOM_IN);
@@ -132,16 +137,18 @@ void GalacticView::Draw3D()
 	
 void GalacticView::Update()
 {
-	const float frameTime = Pi::GetFrameTime();
-	
-	if (m_zoomInButton->IsPressed()) m_zoom *= pow(4.0f, frameTime);
-	if (m_zoomOutButton->IsPressed()) m_zoom *= pow(0.25f, frameTime);
+	const float ft = Pi::GetFrameTime();
+
+	if (m_zoomInButton->IsPressed()) m_zoomTo *= pow(ZOOM_IN_SPEED * Pi::GetMoveSpeedShiftModifier(), ft);
+	if (m_zoomOutButton->IsPressed()) m_zoomTo *= pow(ZOOM_OUT_SPEED / Pi::GetMoveSpeedShiftModifier(), ft);
 	// XXX ugly hack checking for console here
 	if (!Pi::IsConsoleActive()) {
-		if (Pi::KeyState(SDLK_EQUALS)) m_zoom *= pow(4.0f, frameTime);
-		if (Pi::KeyState(SDLK_MINUS)) m_zoom *= pow(0.25f, frameTime);
+		if (Pi::KeyState(SDLK_EQUALS)) m_zoomTo *= pow(ZOOM_IN_SPEED * Pi::GetMoveSpeedShiftModifier(), ft);
+		if (Pi::KeyState(SDLK_MINUS)) m_zoomTo *= pow(ZOOM_OUT_SPEED / Pi::GetMoveSpeedShiftModifier(), ft);
 	}
+	m_zoomTo = Clamp(m_zoomTo, 0.5f, 100.0f);
 	m_zoom = Clamp(m_zoom, 0.5f, 100.0f);
+	Animation::Approach(m_zoom, m_zoomTo, ft);
 
 	m_scaleReadout->SetText(stringf(Lang::INT_LY, formatarg("scale", int(0.5*Galaxy::GALAXY_RADIUS/m_zoom))));
 }
@@ -149,11 +156,10 @@ void GalacticView::Update()
 void GalacticView::MouseButtonDown(int button, int x, int y)
 {
 	if (this == Pi::GetView()) {
-		const float ft = Pi::GetFrameTime();
-		if (Pi::MouseButtonState(SDL_BUTTON_WHEELDOWN)) 
-				m_zoom *= pow(0.25f, ft);
-		if (Pi::MouseButtonState(SDL_BUTTON_WHEELUP)) 
-				m_zoom *= pow(4.0f, ft);
+		if (Pi::MouseButtonState(SDL_BUTTON_WHEELDOWN))
+			m_zoomTo *= ((ZOOM_OUT_SPEED-1) * WHEEL_SENSITIVITY+1) / Pi::GetMoveSpeedShiftModifier();
+		else if (Pi::MouseButtonState(SDL_BUTTON_WHEELUP))
+			m_zoomTo *= ((ZOOM_IN_SPEED-1) * WHEEL_SENSITIVITY+1) * Pi::GetMoveSpeedShiftModifier();
 	}
 }
 

src/GalacticView.h

@@ -25,7 +25,7 @@ private:
 	Gui::ImageButton *m_zoomOutButton;
 	Gui::Label *m_scaleReadout;
 	Gui::LabelSet *m_labels;
-	float m_zoom;
+	float m_zoom, m_zoomTo;
 	Gui::TexturedQuad m_quad;
 	sigc::connection m_onMouseButtonDown;
 };

src/Makefile.am

@@ -11,6 +11,7 @@ bin_PROGRAMS = pioneer modelviewer
 noinst_HEADERS = \
 	Aabb.h \
 	AmbientSounds.h \
+	Animation.h \
 	Background.h \
 	BezierCurve.h \
 	Body.h \

src/Pi.cpp

@@ -1488,3 +1488,10 @@ void Pi::SetMouseGrab(bool on)
 		doingMouseGrab = false;
 	}
 }
+
+float Pi::GetMoveSpeedShiftModifier() {
+	// Suggestion: make x1000 speed on pressing both keys?
+	if (Pi::KeyState(SDLK_LSHIFT)) return 100.f;
+	if (Pi::KeyState(SDLK_RSHIFT)) return 10.f;
+	return 1;
+}

src/Pi.h

@@ -85,6 +85,9 @@ public:
     static void SetMouseYInvert(bool state) { mouseYInvert = state; }
     static bool IsMouseYInvert() { return mouseYInvert; }
 	static int MouseButtonState(int button) { return mouseButton[button]; }
+	/// Get the default speed modifier to apply to movement (scrolling, zooming...), depending on the "shift" keys.
+	/// This is a default value only, centralized here to promote uniform user expericience.
+	static float GetMoveSpeedShiftModifier();
 	static void GetMouseMotion(int motion[2]) {
 		memcpy(motion, mouseMotion, sizeof(int)*2);
 	}

src/SectorView.cpp

@@ -19,6 +19,8 @@ using namespace Graphics;
 
 #define INNER_RADIUS (Sector::SIZE*1.5f)
 #define OUTER_RADIUS (Sector::SIZE*3.0f)
+static const float ZOOM_SPEED = 10;
+static const float WHEEL_SENSITIVITY = .2f;		// Should be a variable in user settings.
 
 SectorView::SectorView()
 {
@@ -756,9 +758,7 @@ void SectorView::Update()
 	// don't check raw keypresses if the search box is active
 	// XXX ugly hack checking for Lua console here
 	if (!m_searchBox->IsFocused() && !Pi::IsConsoleActive()) {
-		float moveSpeed = 1.0;
-		if (Pi::KeyState(SDLK_LSHIFT)) moveSpeed = 100.0;
-		if (Pi::KeyState(SDLK_RSHIFT)) moveSpeed = 10.0;
+		const float moveSpeed = Pi::GetMoveSpeedShiftModifier();
 	
 		float move = moveSpeed*frameTime;
 		if (Pi::KeyState(SDLK_LEFT) || Pi::KeyState(SDLK_RIGHT))
@@ -807,7 +807,7 @@ void SectorView::Update()
 		else m_rotZ = m_rotZ + travelZ;
 
 		float diffZoom = m_zoomMovingTo - m_zoom;
-		float travelZoom = diffZoom * 10.0f*frameTime;
+		float travelZoom = diffZoom * ZOOM_SPEED*frameTime;
 		if (fabs(travelZoom) > fabs(diffZoom)) m_zoom = m_zoomMovingTo;
 		else m_zoom = m_zoom + travelZoom;
 	}
@@ -854,11 +854,15 @@ void SectorView::ShowAll()
 void SectorView::MouseButtonDown(int button, int x, int y)
 {
 	if (this == Pi::GetView()) {
-		const float ft = Pi::GetFrameTime();
-		if (Pi::MouseButtonState(SDL_BUTTON_WHEELDOWN)) 
-				m_zoomMovingTo += 10.0*ft;
-		if (Pi::MouseButtonState(SDL_BUTTON_WHEELUP)) 
-				m_zoomMovingTo -= 10.0*ft;
+		if (Pi::MouseButtonState(SDL_BUTTON_WHEELDOWN))
+			m_zoomMovingTo += ZOOM_SPEED * WHEEL_SENSITIVITY * Pi::GetMoveSpeedShiftModifier();
+		else if (Pi::MouseButtonState(SDL_BUTTON_WHEELUP))
+			m_zoomMovingTo -= ZOOM_SPEED * WHEEL_SENSITIVITY * Pi::GetMoveSpeedShiftModifier();
+		//const float ft = Pi::GetFrameTime() * Pi::GetMoveSpeedShiftModifier();
+		//if (Pi::MouseButtonState(SDL_BUTTON_WHEELDOWN)) 
+		//		m_zoomMovingTo += 10.0*ft;
+		//if (Pi::MouseButtonState(SDL_BUTTON_WHEELUP)) 
+		//		m_zoomMovingTo -= 10.0*ft;
 	}
 }
 

src/SystemView.cpp

@@ -8,12 +8,18 @@
 #include "Player.h"
 #include "FloatComparison.h"
 #include "Game.h"
+#include "Animation.h"
 #include "graphics/Material.h"
 #include "graphics/Renderer.h"
 
 using namespace Graphics;
 
 const double SystemView::PICK_OBJECT_RECT_SIZE = 12.0;
+static const float MIN_ZOOM = 1e-30f;		// Just to avoid having 0
+static const float MAX_ZOOM = 1e30f;
+static const float ZOOM_IN_SPEED = 2;
+static const float ZOOM_OUT_SPEED = 1.f/ZOOM_IN_SPEED;
+static const float WHEEL_SENSITIVITY = .2f;		// Should be a variable in user settings.
 
 SystemView::SystemView()
 {
@@ -93,6 +99,7 @@ void SystemView::ResetViewpoint()
 	m_rot_z = 0;
 	m_rot_x = 50;
 	m_zoom = 1.0f/float(AU);
+	m_zoomTo = m_zoom;
 	m_timeStep = 1.0f;
 	m_time = Pi::game->GetTime();
 }
@@ -327,11 +334,16 @@ void SystemView::Update()
 	if (!Pi::IsConsoleActive()) {
 		if (Pi::KeyState(SDLK_EQUALS) ||
 			m_zoomInButton->IsPressed()) 
-				m_zoom *= pow(4.0f, ft);
+				m_zoomTo *= pow(ZOOM_IN_SPEED * Pi::GetMoveSpeedShiftModifier(), ft);
 		if (Pi::KeyState(SDLK_MINUS) ||
 			m_zoomOutButton->IsPressed()) 
-				m_zoom *= pow(0.25f, ft);
+				m_zoomTo *= pow(ZOOM_OUT_SPEED / Pi::GetMoveSpeedShiftModifier(), ft);
 	}
+	// TODO: add "true" lower/upper bounds to m_zoomTo / m_zoom
+	m_zoomTo = Clamp(m_zoomTo, MIN_ZOOM, MAX_ZOOM);
+	m_zoom = Clamp(m_zoom, MIN_ZOOM, MAX_ZOOM);
+	Animation::Approach(m_zoom, m_zoomTo, ft);
+
 	if (Pi::MouseButtonState(SDL_BUTTON_RIGHT)) {
 		int motion[2];
 		Pi::GetMouseMotion(motion);
@@ -343,10 +355,9 @@ void SystemView::Update()
 void SystemView::MouseButtonDown(int button, int x, int y)
 {
 	if (this == Pi::GetView()) {
-		const float ft = Pi::GetFrameTime();
-		if (Pi::MouseButtonState(SDL_BUTTON_WHEELDOWN)) 
-				m_zoom *= pow(0.25f, ft);
-		if (Pi::MouseButtonState(SDL_BUTTON_WHEELUP)) 
-				m_zoom *= pow(4.0f, ft);
+		if (Pi::MouseButtonState(SDL_BUTTON_WHEELDOWN))
+			m_zoomTo *= ((ZOOM_OUT_SPEED-1) * WHEEL_SENSITIVITY+1) / Pi::GetMoveSpeedShiftModifier();
+		else if (Pi::MouseButtonState(SDL_BUTTON_WHEELUP))
+			m_zoomTo *= ((ZOOM_IN_SPEED-1) * WHEEL_SENSITIVITY+1) * Pi::GetMoveSpeedShiftModifier();
 	}
 }

src/SystemView.h

@@ -31,7 +31,7 @@ private:
 	RefCountedPtr<StarSystem> m_system;
 	SBody *m_selectedObject;
 	float m_rot_x, m_rot_z;
-	float m_zoom;
+	float m_zoom, m_zoomTo;
 	double m_time;
 	double m_timeStep;
 	Gui::ImageButton *m_zoomInButton;