Gravity: Live update settings and cleanup

Now that this screensaver shows a preview, update the settings live
so that the display updates immediately.

Since this didn't work before this screensaver took a shortcut and only
updated the settings when the saver started.

Some other changes include:
* Update copyright header, add myself to the authors list.
* Convert Particle from using a BList to a BObjectList and remove casts.
* Use switch statement to set particle color that has a default case for blue.
* Initialize member variables to a default value in the constructor.
* Remove Constants.h, the remaining constants are in ConfigView.cpp
* Convert deprecated GroupLayoutBuilder to a LayoutBuilder template instance
* Convert GravitySource from a class to a struct since all members are public.
* Simplify realCount calculation to just a single left shift.
* A bunch of style fixes
  - lots of whitespace fixes
  - rename rect to frame in GravityView and ConfigView
  - reorder the frame parameter first in GravityView and ConfigView
  - curly brace goes on same line as class or struct declaration

This turned out to be a bigger change than I originally intended to make.

src/add-ons/screen_savers/gravity/ConfigView.cpp

@@ -1,47 +1,48 @@
 /*
  * Copyright 2012-2013 Tri-Edge AI <[email protected]>
- * All rights reserved. Distributed under the terms of the MIT license.
+ * Copyright 2014 Haiku, Inc. All rights reserved.
+ *
+ * Distributed under the terms of the MIT license.
+ *
+ * Authors:
+ *		Tri-Edge AI
+ *		John Scipione, [email protected]
  */
 
 
 #include "ConfigView.h"
 
-#include "Constants.h"
+#include <LayoutBuilder.h>
-#include "Gravity.h"
-
-#include <GroupLayoutBuilder.h>
 #include <ListView.h>
 #include <ScrollView.h>
 #include <Slider.h>
 #include <StringView.h>
 #include <View.h>
 
+#include "Gravity.h"
 
-ConfigView::ConfigView(Gravity* parent, BRect rect)
+
+static const int32 kMsgSize = 'size';
+static const int32 kMsgShade = 'shad';
+
+
+ConfigView::ConfigView(BRect frame, Gravity* parent)
 	:
-	BView(rect, B_EMPTY_STRING, B_FOLLOW_ALL_SIDES, B_WILL_DRAW)
+	BView(frame, B_EMPTY_STRING, B_FOLLOW_ALL_SIDES, B_WILL_DRAW),
+	fParent(parent),
+	fTitleString(new BStringView(B_EMPTY_STRING, "OpenGL Gravity Effect")),
+	fAuthorString(new BStringView(B_EMPTY_STRING, "by Tri-Edge AI")),
+	fCountSlider(new BSlider(B_EMPTY_STRING, "Particle Count: ",
+		new BMessage(kMsgSize), 0, 4, B_HORIZONTAL, B_BLOCK_THUMB,
+		B_NAVIGABLE | B_WILL_DRAW)),
+	fShadeString(new BStringView(B_EMPTY_STRING, "Shade: ")),
+	fShadeList(new BListView(B_EMPTY_STRING, B_SINGLE_SELECTION_LIST,
+		B_WILL_DRAW | B_NAVIGABLE))
 {
-	fParent = parent;
-
 	SetLayout(new BGroupLayout(B_HORIZONTAL));
 	SetViewColor(ui_color(B_PANEL_BACKGROUND_COLOR));
 
-	fTitleString = new BStringView(RECT_0, B_EMPTY_STRING,
+	fShadeList->SetSelectionMessage(new BMessage(kMsgShade));
-		"OpenGL Gravity Effect", B_FOLLOW_LEFT);
-
-	fAuthorString = new BStringView(RECT_0, B_EMPTY_STRING,
-		"by Tri-Edge AI", B_FOLLOW_LEFT);
-
-	fCountSlider = new BSlider(RECT_0, B_EMPTY_STRING, "Particle Count: ",
-		new BMessage(MSG_COUNT), 0, 4, B_BLOCK_THUMB);
-
-	fShadeString = new BStringView(RECT_0, B_EMPTY_STRING, "Shade: ",
-		B_FOLLOW_LEFT);
-
-	fShadeList = new BListView(RECT_0, B_EMPTY_STRING, B_SINGLE_SELECTION_LIST,
-		B_FOLLOW_ALL);
-
-	fShadeList->SetSelectionMessage(new BMessage(MSG_SHADE));
 
 	fShadeList->AddItem(new BStringItem("Red"));
 	fShadeList->AddItem(new BStringItem("Green"));
@@ -59,22 +60,18 @@ ConfigView::ConfigView(Gravity* parent, BRect rect)
 	fCountSlider->SetHashMarks(B_HASH_MARKS_BOTTOM);
 	fCountSlider->SetHashMarkCount(5);
 	fCountSlider->SetLimitLabels("128", "2048");
-
+	fCountSlider->SetModificationMessage(new BMessage(kMsgSize));
 	fCountSlider->SetValue(parent->Config.ParticleCount);
 
-	AddChild(BGroupLayoutBuilder(B_VERTICAL, B_USE_DEFAULT_SPACING)
+	AddChild(BLayoutBuilder::Group<>(B_VERTICAL, B_USE_DEFAULT_SPACING)
-			.Add(BGroupLayoutBuilder(B_VERTICAL, 0)
+		.AddGroup(B_VERTICAL, 0)
-				.Add(fTitleString)
+			.Add(fTitleString)
-				.Add(fAuthorString)
+			.Add(fAuthorString)
-			)
+			.End()
-			.Add(fShadeString)
+		.Add(fShadeString)
-			.Add(fShadeScroll)
+		.Add(fShadeScroll)
-			.Add(fCountSlider)
+		.Add(fCountSlider)
-			.SetInsets(B_USE_DEFAULT_SPACING,
+		.SetInsets(B_USE_DEFAULT_SPACING));
-				B_USE_DEFAULT_SPACING,
-				B_USE_DEFAULT_SPACING,
-				B_USE_DEFAULT_SPACING)
-	);
 }
 
 
@@ -90,11 +87,11 @@ void
 ConfigView::MessageReceived(BMessage* message)
 {
 	switch (message->what) {
-		case MSG_COUNT:
+		case kMsgSize:
 			fParent->Config.ParticleCount = fCountSlider->Value();
 			break;
 
-		case MSG_SHADE:
+		case kMsgShade:
 			fParent->Config.ShadeID = fShadeList->CurrentSelection();
 			break;
 

src/add-ons/screen_savers/gravity/ConfigView.h

@@ -1,6 +1,12 @@
 /*
  * Copyright 2012-2013 Tri-Edge AI <[email protected]>
- * All rights reserved. Distributed under the terms of the MIT license.
+ * Copyright 2014 Haiku, Inc. All rights reserved.
+ *
+ * Distributed under the terms of the MIT license.
+ *
+ * Authors:
+ *		Tri-Edge AI
+ *		John Scipione, [email protected]
  */
 #ifndef GRAVITY_CONFIG_VIEW_H
 #define GRAVITY_CONFIG_VIEW_H
@@ -8,6 +14,7 @@
 
 #include <View.h>
 
+
 class Gravity;
 
 class BListView;
@@ -15,27 +22,26 @@ class BScrollView;
 class BSlider;
 class BStringView;
 
-class ConfigView : public BView
-{
-public:
-					ConfigView(Gravity* parent, BRect rect);
 
-	void 			AttachedToWindow();
+class ConfigView : public BView {
-	void 			MessageReceived(BMessage* message);
+public:
+								ConfigView(BRect frame, Gravity* parent);
+
+			void	 			AttachedToWindow();
+			void	 			MessageReceived(BMessage* message);
 
 private:
-	Gravity*		fParent;
+			Gravity*			fParent;
 
-	BStringView* 	fTitleString;
+			BStringView*		fTitleString;
-	BStringView*	fAuthorString;
+			BStringView*		fAuthorString;
 
-	BListView*		fShadeList;
+			BSlider*			fCountSlider;
-	BStringView*	fShadeString;
-	BScrollView*	fShadeScroll;
-
-	BSlider* 		fCountSlider;
 
+			BStringView*		fShadeString;
+			BListView*			fShadeList;
+			BScrollView*		fShadeScroll;
 };
 
 
-#endif
+#endif	// GRAVITY_CONFIG_VIEW_H

src/add-ons/screen_savers/gravity/Constants.h

@@ -1,15 +0,0 @@
-/*
- * Copyright 2012-2013 Tri-Edge AI <[email protected]>
- * All rights reserved. Distributed under the terms of the MIT license.
- */
-#ifndef CONSTANTS_H
-#define CONSTANTS_H
-
-
-#define MSG_SHADE 	'm000'
-#define MSG_COUNT 	'm001'
-
-#define RECT_0 		BRect(0, 0, 0, 0)
-
-
-#endif

src/add-ons/screen_savers/gravity/Gravity.cpp

@@ -1,6 +1,12 @@
 /*
  * Copyright 2012-2013 Tri-Edge AI <[email protected]>
- * All rights reserved. Distributed under the terms of the MIT license.
+ * Copyright 2014 Haiku, Inc. All rights reserved.
+ *
+ * Distributed under the terms of the MIT license.
+ *
+ * Authors:
+ *		Tri-Edge AI
+ *		John Scipione, [email protected]
  */
 
 
@@ -14,9 +20,12 @@
 
 #include <stdlib.h>
 
+
 Gravity::Gravity(BMessage* prefs, image_id imageID)
 	:
-	BScreenSaver(prefs, imageID)
+	BScreenSaver(prefs, imageID),
+	fGravityView(NULL),
+	fConfigView(NULL)
 {
 	srand(time(NULL));
 
@@ -45,7 +54,8 @@ Gravity::SaveState(BMessage* prefs) const
 void
 Gravity::StartConfig(BView* view)
 {
-	view->AddChild(new ConfigView(this, view->Bounds()));
+	fConfigView = new ConfigView(view->Bounds(), this);
+	view->AddChild(fConfigView);
 }
 
 
@@ -54,8 +64,8 @@ Gravity::StartSaver(BView* view, bool preview)
 {
 	SetTickSize((1000 / 20) * 1000);
 		// ~20 FPS
-	fView = new GravityView(this, view->Bounds());
+	fGravityView = new GravityView(view->Bounds(), this);
-	view->AddChild(fView);
+	view->AddChild(fGravityView);
 
 	return B_OK;
 }
@@ -64,17 +74,17 @@ Gravity::StartSaver(BView* view, bool preview)
 void
 Gravity::StopSaver()
 {
-	if (fView != NULL)
+	if (fGravityView != NULL)
-		fView->EnableDirectMode(false);
+		fGravityView->EnableDirectMode(false);
 }
 
 
 void
 Gravity::DirectConnected(direct_buffer_info* info)
 {
-	if (fView != NULL) {
+	if (fGravityView != NULL) {
-		fView->DirectConnected(info);
+		fGravityView->DirectConnected(info);
-		fView->EnableDirectMode(true);
+		fGravityView->EnableDirectMode(true);
 	}
 }
 
@@ -82,5 +92,5 @@ Gravity::DirectConnected(direct_buffer_info* info)
 void
 Gravity::DirectDraw(int32 frame)
 {
-	fView->DirectDraw();
+	fGravityView->DirectDraw();
 }

src/add-ons/screen_savers/gravity/Gravity.h

@@ -1,6 +1,12 @@
 /*
  * Copyright 2012-2013 Tri-Edge AI <[email protected]>
- * All rights reserved. Distributed under the terms of the MIT license.
+ * Copyright 2014 Haiku, Inc. All rights reserved.
+ *
+ * Distributed under the terms of the MIT license.
+ *
+ * Authors:
+ *		Tri-Edge AI
+ *		John Scipione, [email protected]
  */
 #ifndef GRAVITY_SCREEN_SAVER_H
 #define GRAVITY_SCREEN_SAVER_H
@@ -8,36 +14,37 @@
 
 #include <ScreenSaver.h>
 
-class GravityView;
 
 class BMessage;
 class BView;
 
+class ConfigView;
+class GravityView;
 
-class Gravity : public BScreenSaver
+
-{
+class Gravity : public BScreenSaver {
 public:
-	struct
+	struct {
-	{
 		int32 ShadeID;
 		int32 ParticleCount;
 	} Config;
 
-					Gravity(BMessage* prefs, image_id imageID);
+							Gravity(BMessage* prefs, image_id imageID);
 
-	status_t 		SaveState(BMessage* prefs) const;
+			status_t		SaveState(BMessage* prefs) const;
 
-	void 			StartConfig(BView* view);
+			void			StartConfig(BView* view);
 
-	status_t 		StartSaver(BView* view, bool preview);
+			status_t		StartSaver(BView* view, bool preview);
-	void 			StopSaver();
+			void			StopSaver();
 
-	void 			DirectConnected(direct_buffer_info* info);
+			void			DirectConnected(direct_buffer_info* info);
-	void 			DirectDraw(int32 frame);
+			void			DirectDraw(int32 frame);
 
 private:
-	GravityView* 	fView;
+			GravityView*	fGravityView;
+			ConfigView*		fConfigView;
 };
 
 
-#endif
+#endif	// GRAVITY_SCREEN_SAVER_H

src/add-ons/screen_savers/gravity/GravitySource.cpp

@@ -1,9 +1,16 @@
 /*
  * Copyright 2012-2013 Tri-Edge AI <[email protected]>
- * All rights reserved. Distributed under the terms of the MIT license.
+ * Copyright 2014 Haiku, Inc. All rights reserved.
+ *
+ * Distributed under the terms of the MIT license.
+ *
+ * Authors:
+ *		Tri-Edge AI
+ *		John Scipione, [email protected]
  */
 
 
+
 #include "GravitySource.h"
 
 #include "Particle.h"
@@ -59,7 +66,7 @@ GravitySource::Tick()
 	}
 
 	for (int32 i = 0; i < Particle::list->CountItems(); i++) {
-		Particle* p = (Particle*)Particle::list->ItemAt(i);
+		Particle* p = Particle::list->ItemAt(i);
 		dx = x - p->x;
 		dy = y - p->y;
 		dz = z - p->z;

src/add-ons/screen_savers/gravity/GravitySource.h

@@ -1,34 +1,36 @@
 /*
  * Copyright 2012-2013 Tri-Edge AI <[email protected]>
- * All rights reserved. Distributed under the terms of the MIT license.
+ * Copyright 2014 Haiku, Inc. All rights reserved.
+ *
+ * Distributed under the terms of the MIT license.
+ *
+ * Authors:
+ *		Tri-Edge AI
+ *		John Scipione, [email protected]
  */
+
 #ifndef GRAVITY_SOURCE_H
 #define GRAVITY_SOURCE_H
 
 
-class GravitySource
+struct GravitySource {
-{
+	float	x;
-public:
+	float	y;
-	float 	x;
+	float	z;
-	float 	y;
-	float 	z;
 	float	r;
 
-	float 	vx;
+	float	vx;
-	float 	vy;
+	float	vy;
-	float 	vz;
+	float	vz;
 
-	float 	tx;
+	float	tx;
-	float 	ty;
+	float	ty;
-	float 	tz;
+	float	tz;
 
 			GravitySource();
 
-	void 	Tick();
+	void	Tick();
-
-private:
-
 };
 
 
-#endif
+#endif	// GRAVITY_SOURCE_H

src/add-ons/screen_savers/gravity/GravityView.cpp

@@ -1,6 +1,12 @@
 /*
  * Copyright 2012-2013 Tri-Edge AI <[email protected]>
- * All rights reserved. Distributed under the terms of the MIT license.
+ * Copyright 2014 Haiku, Inc. All rights reserved.
+ *
+ * Distributed under the terms of the MIT license.
+ *
+ * Authors:
+ *		Tri-Edge AI
+ *		John Scipione, [email protected]
  */
 
 
@@ -13,29 +19,16 @@
 #include <GL/glu.h>
 
 
-GravityView::GravityView(Gravity* parent, BRect rect)
+GravityView::GravityView(BRect frame, Gravity* parent)
 	:
-	BGLView(rect, B_EMPTY_STRING, B_FOLLOW_NONE, 0,
+	BGLView(frame, B_EMPTY_STRING, B_FOLLOW_NONE, 0,
-		BGL_RGB | BGL_DEPTH | BGL_DOUBLE)
+		BGL_RGB | BGL_DEPTH | BGL_DOUBLE),
+	fParent(parent),
+	fGravitySource(new GravitySource()),
+	fSize(128 << parent->Config.ParticleCount),
+	fShade(parent->Config.ShadeID)
 {
-	fParent = parent;
+	Particle::Initialize(fSize, fShade);
-
-	int realCount;
-
-	if (parent->Config.ParticleCount == 0)
-		realCount = 128;
-	else if (parent->Config.ParticleCount == 1)
-		realCount = 256;
-	else if (parent->Config.ParticleCount == 2)
-		realCount = 512;
-	else if (parent->Config.ParticleCount == 3)
-		realCount = 1024;
-	else if (parent->Config.ParticleCount == 4)
-		realCount = 2048;
-	else
-		realCount = 128;
-
-	Particle::Initialize(realCount, parent->Config.ShadeID);
 
 	LockGL();
 
@@ -46,7 +39,7 @@ GravityView::GravityView(Gravity* parent, BRect rect)
 
 	glMatrixMode(GL_PROJECTION);
 	glLoadIdentity();
-	gluPerspective(45.0f, rect.Width() / rect.Height(), 2.0f, 20000.0f);
+	gluPerspective(45.0f, frame.Width() / frame.Height(), 2.0f, 20000.0f);
 	glMatrixMode(GL_MODELVIEW);
 	glLoadIdentity();
 
@@ -55,15 +48,13 @@ GravityView::GravityView(Gravity* parent, BRect rect)
 	glDepthMask(GL_FALSE);
 
 	UnlockGL();
-
-	fGravSource = new GravitySource();
 }
 
 
 GravityView::~GravityView()
 {
 	Particle::Terminate();
-	delete fGravSource;
+	delete fGravitySource;
 }
 
 
@@ -79,13 +70,29 @@ GravityView::AttachedToWindow()
 void
 GravityView::DirectDraw()
 {
+	int32 size = 128 << fParent->Config.ParticleCount;
+	int32 shade = fParent->Config.ShadeID;
+
+	// resize particle list if needed
+	if (size > fSize)
+		Particle::AddParticles(size, shade);
+	else if (size < fSize)
+		Particle::RemoveParticles(size, shade);
+
+	// recolor particles if needed
+	if (shade != fShade)
+		Particle::ColorParticles(size, shade);
+
+	fSize = size;
+	fShade = shade;
+
 	LockGL();
 
 	glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
 	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
 	Particle::Tick();
-	fGravSource->Tick();
+	fGravitySource->Tick();
 
 	SwapBuffers();
 

src/add-ons/screen_savers/gravity/GravityView.h

@@ -1,6 +1,12 @@
 /*
  * Copyright 2012-2013 Tri-Edge AI <[email protected]>
- * All rights reserved. Distributed under the terms of the MIT license.
+ * Copyright 2014 Haiku, Inc. All rights reserved.
+ *
+ * Distributed under the terms of the MIT license.
+ *
+ * Authors:
+ *		Tri-Edge AI
+ *		John Scipione, [email protected]
  */
 #ifndef GRAVITY_VIEW_H
 #define GRAVITY_VIEW_H
@@ -12,21 +18,23 @@
 class Gravity;
 class GravitySource;
 
-class GravityView : public BGLView
+
-{
+class GravityView : public BGLView {
 public:
-					GravityView(Gravity* parent, BRect rect);
+							GravityView(BRect frame, Gravity* parent);
-					~GravityView();
+							~GravityView();
 
-	void			AttachedToWindow();
+			void			AttachedToWindow();
 
-	void			DirectDraw();
+			void			DirectDraw();
 
 private:
-	Gravity*		fParent;
+			Gravity*		fParent;
-	GravitySource*	fGravSource;
+			GravitySource*	fGravitySource;
 
+			int32			fSize;
+			int32			fShade;
 };
 
 
-#endif
+#endif	// GRAVITY_VIEW_H

src/add-ons/screen_savers/gravity/Particle.cpp

@@ -1,101 +1,81 @@
 /*
  * Copyright 2012-2013 Tri-Edge AI <[email protected]>
- * All rights reserved. Distributed under the terms of the MIT license.
+ * Copyright 2014 Haiku, Inc. All rights reserved.
+ *
+ * Distributed under the terms of the MIT license.
+ *
+ * Authors:
+ *		Tri-Edge AI
+ *		John Scipione, [email protected]
  */
 
 
 #include "Particle.h"
 
-#include <List.h>
-
 #include <stdlib.h>
 
 
 #define frand() ((float)rand() / (float)RAND_MAX)
 
 
-BList* Particle::list;
+BObjectList<Particle>* Particle::list;
 
 
-void
+/*static*/ void
 Particle::Initialize(int32 size, int32 shade)
 {
-	list = new BList();
+	list = new BObjectList<Particle>(2048);
 
 	for (int32 i = 0; i < size; i++) {
 		Particle* p = new Particle();
-
+		Particle::_FillParticle(p, size, shade);
-		p->x = frand() * 30.0f - 15.0f;
-		p->y = frand() * 30.0f - 15.0f;
-		p->z = frand() * 5.0f;
-		p->r = frand() * 360.0f;
-
-		p->vx = frand() - 0.5f;
-		p->vy = frand() - 0.5f;
-		p->vz = frand() - 0.5f;
-		p->vr = (frand() - 0.5f) * 180.0f;
-
-		if (shade == 0) {
-			// Red
-			p->red = 0.1f + frand() * 0.2f;
-			p->green = 0.0f;
-			p->blue = frand() * 0.05f;
-		} else if (shade == 1) {
-			// Green
-			p->red = 0;
-			p->green =  0.1f + frand() * 0.2f;
-			p->blue = frand() * 0.05f;
-		} else if (shade == 2) {
-			// Blue
-			p->red = 0;
-			p->green = frand() * 0.05f;
-			p->blue = 0.1f + frand() * 0.2f;
-		} else if (shade == 3) {
-			// Orange
-			p->red = 0.1f + frand() * 0.1f;
-			p->green =  0.05f + frand() * 0.1f;
-			p->blue = 0.0f;
-		} else if (shade == 4) {
-			// Purple
-			p->red = 0.1f + frand() * 0.2f;
-			p->green = 0.0f;
-			p->blue = 0.1f + frand() * 0.2f;
-		} else if (shade == 5) {
-			// White
-			p->red = p->green = p->blue = 0.1f + frand() * 0.2f;
-		} else if (shade == 6) {
-			// Rainbow
-			p->red = 0.1f + frand() * 0.2f;
-			p->green = 0.1f + frand() * 0.2f;
-			p->blue = 0.1f + frand() * 0.2f;
-		} else {
-			// Man, this shouldn't even happen.. Blue.
-			p->red = 0;
-			p->green = frand() * 0.05f;
-			p->blue = 0.1f + frand() * 0.2f;
-		}
-
 		list->AddItem(p);
 	}
 }
 
 
-void
+/*static*/ void
+Particle::AddParticles(int32 size, int32 shade)
+{
+	for (int32 i = list->CountItems(); i < size; i++) {
+		Particle* p = new Particle();
+		Particle::_FillParticle(p, size, shade);
+		list->AddItem(p);
+	}
+}
+
+
+/*static*/ void
+Particle::RemoveParticles(int32 size, int32 shade)
+{
+	while (list->CountItems() > size)
+		delete list->RemoveItemAt(list->CountItems() - 1);
+}
+
+
+/*static*/ void
+Particle::ColorParticles(int32 size, int32 shade)
+{
+	for (int32 i = 0; i < size; i++) {
+		Particle* p = list->ItemAt(i);
+		Particle::_ColorParticle(p, size, shade);
+	}
+}
+
+
+/*static*/ void
 Particle::Terminate()
 {
-	for (int32 i = 0; i < list->CountItems(); i++)
-		delete (Particle*)list->ItemAt(i);
-
 	list->MakeEmpty();
 	delete list;
 }
 
 
-void
+/*static*/ void
 Particle::Tick()
 {
 	for (int32 i = 0; i < list->CountItems(); i++) {
-		Particle* p = (Particle*)list->ItemAt(i);
+		Particle* p = list->ItemAt(i);
 		p->_Logic();
 		p->_Render();
 	}
@@ -134,3 +114,74 @@ Particle::_Render() const
 	glEnd();
 	glPopMatrix();
 }
+
+
+/*static*/ void
+Particle::_FillParticle(Particle* p, int32 size, int32 shade)
+{
+	p->x = frand() * 30.0f - 15.0f;
+	p->y = frand() * 30.0f - 15.0f;
+	p->z = frand() * 5.0f;
+	p->r = frand() * 360.0f;
+
+	p->vx = frand() - 0.5f;
+	p->vy = frand() - 0.5f;
+	p->vz = frand() - 0.5f;
+	p->vr = (frand() - 0.5f) * 180.0f;
+
+	Particle::_ColorParticle(p, size, shade);
+}
+
+
+/*static*/ void
+Particle::_ColorParticle(Particle* p, int32 size, int32 shade)
+{
+	switch(shade) {
+		case 0:
+			// Red
+			p->red   = 0.1f + frand() * 0.2f;
+			p->green = 0.0f;
+			p->blue  = frand() * 0.05f;
+			break;
+
+		case 1:
+			// Green
+			p->red   = 0;
+			p->green = 0.1f + frand() * 0.2f;
+			p->blue  = frand() * 0.05f;
+			break;
+
+		case 2:
+		default:
+			// Blue
+			p->red   = 0;
+			p->green = frand() * 0.05f;
+			p->blue  = 0.1f + frand() * 0.2f;
+			break;
+
+		case 3:
+			// Orange
+			p->red   = 0.1f + frand() * 0.1f;
+			p->green = 0.05f + frand() * 0.1f;
+			p->blue  = 0.0f;
+			break;
+
+		case 4:
+			// Purple
+			p->red   = 0.1f + frand() * 0.2f;
+			p->green = 0.0f;
+			p->blue  = 0.1f + frand() * 0.2f;
+			break;
+
+		case 5:
+			// White
+			p->red = p->green = p->blue = 0.1f + frand() * 0.2f;
+
+		case 6:
+			// Rainbow
+			p->red   = 0.1f + frand() * 0.2f;
+			p->green = 0.1f + frand() * 0.2f;
+			p->blue  = 0.1f + frand() * 0.2f;
+			break;
+	}
+}

src/add-ons/screen_savers/gravity/Particle.h

@@ -1,44 +1,55 @@
 /*
  * Copyright 2012-2013 Tri-Edge AI <[email protected]>
- * All rights reserved. Distributed under the terms of the MIT license.
+ * Copyright 2014 Haiku, Inc. All rights reserved.
+ *
+ * Distributed under the terms of the MIT license.
+ *
+ * Authors:
+ *		Tri-Edge AI
+ *		John Scipione, [email protected]
  */
 #ifndef PARTICLE_H
 #define PARTICLE_H
 
 
+#include <ObjectList.h>
 #include <GLView.h>
 
-class BList;
 
-
+class Particle {
-class Particle
-{
 public:
-	static	BList* 	list;
+	static	BObjectList<Particle>*	list;
 
-	static	void 	Initialize(int32 size, int32 shade);
+	static	void					Initialize(int32 size, int32 shade);
-	static	void 	Terminate();
+	static	void					AddParticles(int32 size, int32 shade);
-	static	void 	Tick();
+	static	void					RemoveParticles(int32 size, int32 shade);
+	static	void					ColorParticles(int32 size, int32 shade);
+	static	void					Terminate();
+	static	void					Tick();
 
-			float 	x;
+			float					x;
-			float 	y;
+			float					y;
-			float 	z;
+			float					z;
-			float 	r;
+			float					r;
 
-			float 	vx;
+			float					vx;
-			float 	vy;
+			float					vy;
-			float 	vz;
+			float					vz;
-			float 	vr;
+			float					vr;
 
-			float 	red;
+			float					red;
-			float 	green;
+			float					green;
-			float 	blue;
+			float					blue;
 
 private:
-			void 	_Logic();
+			void					_Logic();
-			void 	_Render() const;
+			void					_Render() const;
 
+	static	void					_FillParticle(Particle* p, int32 size,
+										int32 shade);
+	static	void					_ColorParticle(Particle* p, int32 size,
+										int32 shade);
 };
 
 
-#endif
+#endif	// PARTICLE_H