screensaver: Add gravity based on GCI 2012 work

* A modified version of TriEdgeAI's original work.
* Cleaned up style problems
* Some virtual functions didn't mesh properly with
  ones defined in the OpenGL kit (Draw for example)
* Wrote Jamfile
* Add missing include cstdlib for rand
* Not in image yet as it still needs gcc2 testing

src/add-ons/screen_savers/Jamfile

@@ -4,6 +4,7 @@ SubInclude HAIKU_TOP src add-ons screen_savers butterfly ;
 SubInclude HAIKU_TOP src add-ons screen_savers debugnow ;
 SubInclude HAIKU_TOP src add-ons screen_savers flurry ;
 SubInclude HAIKU_TOP src add-ons screen_savers glife ;
+SubInclude HAIKU_TOP src add-ons screen_savers gravity ;
 SubInclude HAIKU_TOP src add-ons screen_savers haiku ;
 SubInclude HAIKU_TOP src add-ons screen_savers icons ;
 SubInclude HAIKU_TOP src add-ons screen_savers ifs ;

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

@@ -0,0 +1,17 @@
+/* 
+ * Copyright 2012, Haiku, Inc.
+ * Distributed under the terms of the MIT License.
+ *
+ * Authors:
+ * 		Tri-Edge AI <triedgeai@gmail.com>
+ */ 
+
+
+#include "GravityScreenSaver.hpp"
+
+
+extern "C" _EXPORT BScreenSaver* 
+instantiate_screen_saver(BMessage* pbmPrefs, image_id iidImage)
+{
+	return new GravityScreenSaver(pbmPrefs, iidImage);
+}

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

@@ -0,0 +1,14 @@
+resource app_signature "application/x-vnd.Haiku-GravityScreenSaver";
+
+resource app_name_catalog_entry "x-vnd.Haiku-GravityScreenSaver:System name:Gravity";
+
+resource app_version 
+{
+    major  = 1,
+    middle = 0,
+    minor  = 0,
+    variety = 0,
+    internal = 0,
+    short_info = "1.0",
+    long_info = "The screensaver simulates a gravity hole effect with particles, utilizing the OpenGL interface for Haiku."
+};

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

@@ -0,0 +1,94 @@
+/* 
+ * Copyright 2012, Haiku, Inc.
+ * Distributed under the terms of the MIT License.
+ * 
+ * Authors:
+ * 		Tri-Edge AI <triedgeai@gmail.com>
+ */ 
+
+
+#include "GravityConfigView.hpp"
+
+
+class GravityScreenSaver;
+
+GravityConfigView::GravityConfigView(GravityScreenSaver* parent, BRect frame)
+	:
+	BView(frame, "", B_FOLLOW_ALL_SIDES, B_WILL_DRAW)
+{
+	this->parent = parent;
+
+	SetLayout(new BGroupLayout(B_HORIZONTAL));
+	SetViewColor(ui_color(B_PANEL_BACKGROUND_COLOR));
+
+	BStringView* pbsvTitle = new BStringView(frame, B_EMPTY_STRING, 
+		"OpenGL Gravity Effect", B_FOLLOW_LEFT);
+
+	BStringView* pbsvAuthor = new BStringView(frame, B_EMPTY_STRING, 
+		"by Tri-Edge AI", B_FOLLOW_LEFT);
+
+	pbsParticleCount = new BSlider(frame, B_EMPTY_STRING, "Particle Count: ",
+		new BMessage('pcnt'), 0, 4, B_BLOCK_THUMB);
+
+	pbsvShadeText = new BStringView(frame, B_EMPTY_STRING, "Shade: ", 
+		B_FOLLOW_LEFT);
+
+	pblvShade = new BListView(frame, B_EMPTY_STRING, B_SINGLE_SELECTION_LIST,
+		B_FOLLOW_ALL);
+
+	pblvShade->SetSelectionMessage(new BMessage('shds'));
+
+	pblvShade->AddItem(new BStringItem("Red"));
+	pblvShade->AddItem(new BStringItem("Green"));
+	pblvShade->AddItem(new BStringItem("Blue"));
+	pblvShade->AddItem(new BStringItem("Orange"));
+	pblvShade->AddItem(new BStringItem("Purple"));
+	pblvShade->AddItem(new BStringItem("White"));
+	pblvShade->AddItem(new BStringItem("Rainbow"));
+
+	pblvShade->Select(parent->Config.ShadeID);
+
+	BScrollView* scroll = new BScrollView(B_EMPTY_STRING, pblvShade, 
+		B_WILL_DRAW | B_FRAME_EVENTS, false, true);
+
+	pbsParticleCount->SetHashMarks(B_HASH_MARKS_BOTTOM);
+	pbsParticleCount->SetHashMarkCount(5);
+	pbsParticleCount->SetLimitLabels("128", "2048");
+
+	pbsParticleCount->SetValue(parent->Config.ParticleCount);
+
+	AddChild(BGroupLayoutBuilder(B_VERTICAL, B_USE_DEFAULT_SPACING)
+			.Add(BGroupLayoutBuilder(B_VERTICAL, 0)
+				.Add(pbsvTitle)
+				.Add(pbsvAuthor)
+			)
+			.Add(pbsvShadeText)
+			.Add(scroll)
+			.Add(pbsParticleCount)
+			.SetInsets(B_USE_DEFAULT_SPACING, 
+				B_USE_DEFAULT_SPACING, 
+				B_USE_DEFAULT_SPACING, 
+				B_USE_DEFAULT_SPACING)
+	);
+}
+
+
+void
+GravityConfigView::AttachedToWindow()
+{
+	pblvShade->SetTarget(this);
+	pbsParticleCount->SetTarget(this);	
+}
+
+
+void
+GravityConfigView::MessageReceived(BMessage* pbmMessage)
+{
+	if (pbmMessage->what == 'pcnt') {
+		parent->Config.ParticleCount = pbsParticleCount->Value();
+	} else if (pbmMessage->what == 'shds') {
+		parent->Config.ShadeID = pblvShade->CurrentSelection();	
+	} else {
+		BView::MessageReceived(pbmMessage);	
+	}
+}

src/add-ons/screen_savers/gravity/GravityConfigView.hpp

@@ -0,0 +1,42 @@
+/* 
+ * Copyright 2012, Haiku, Inc.
+ * Distributed under the terms of the MIT License.
+ * 
+ * Authors:
+ * 		Tri-Edge AI <triedgeai@gmail.com>
+ */ 
+#ifndef _GRAVITY_CONFIG_VIEW_HPP_
+#define _GRAVITY_CONFIG_VIEW_HPP_
+
+
+#include "GravityScreenSaver.hpp"
+
+#include <GroupLayout.h>
+#include <GroupLayoutBuilder.h>
+#include <ListView.h>
+#include <ScrollView.h>
+#include <Slider.h>
+#include <StringItem.h>
+#include <StringView.h>
+#include <View.h>
+
+
+class GravityScreenSaver;
+
+class GravityConfigView : public BView
+{
+public:
+	GravityConfigView(GravityScreenSaver* parent, BRect frame);
+
+	void AttachedToWindow();
+	void MessageReceived(BMessage* pbmMessage);
+
+private:	
+	GravityScreenSaver* parent;
+	BListView* pblvShade;
+	BStringView* pbsvShadeText;
+	BSlider* pbsParticleCount;
+};
+
+
+#endif /* _GRAVITY_CONFIG_VIEW_HPP_ */

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

@@ -0,0 +1,79 @@
+/* 
+ * Copyright 2012, Haiku, Inc.
+ * Distributed under the terms of the MIT License.
+ * 
+ * Authors:
+ * 		Tri-Edge AI <triedgeai@gmail.com>
+ */ 
+
+#include "Particle.hpp"
+#include "GravityHole.hpp"
+
+#include <math.h>
+#include <stdlib.h>
+
+#define frand() ((float)rand() / (float)RAND_MAX)
+
+GravityHole::GravityHole()
+{
+	x = 0.0f;
+	y = 0.0f;
+	z = 0.0f;
+
+	vx = 0.0f;
+	vy = 0.0f;
+	vz = 0.0f;
+
+	ax = frand() * 30.0f - 15.0f;
+	ay = frand() * 30.0f - 15.0f;
+	az = frand() * 10.0f - 5.0f;
+}
+
+
+void
+GravityHole::Run()
+{
+	float dx = ax - x;
+	float dy = ay - y;
+	float dz = az - z;
+
+	float d = dx * dx + dy * dy + dz * dz;
+
+	vx += dx * 0.005f;
+	vy += dy * 0.005f;
+	vz += dz * 0.005f;
+
+	x += vx;
+	y += vy;
+	z += vz;
+
+	vx *= 0.95f;
+	vy *= 0.95f;
+	vz *= 0.95f;
+
+	if (dx * dx + dy * dy + dz * dz < 10.0f) {
+		ax = frand() * 30.0f - 15.0f;
+		ay = frand() * 30.0f - 15.0f;
+		az = frand() * 10.0f - 5.0f;
+	}
+
+	for (uint32 i = 0; i < Particle::list.size(); i++) {
+		dx = x - Particle::list[i]->x;
+		dy = y - Particle::list[i]->y;
+		dz = z - Particle::list[i]->z;
+
+		d = dx * dx + dy * dy + dz * dz;
+
+		Particle::list[i]->vx += dx / d * 0.5f;
+		Particle::list[i]->vy += dy / d * 0.5f;
+		Particle::list[i]->vz += dz / d * 0.5f;
+		Particle::list[i]->vr += 1.0f / d;
+	}
+}
+
+
+void
+GravityHole::Draw()
+{
+	//...
+}

src/add-ons/screen_savers/gravity/GravityHole.hpp

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2012, Haiku, Inc.
+ * Distributed under the terms of the MIT License.
+ *
+ * Authors:
+ * 		Tri-Edge AI <triedgeai@gmail.com>
+ */
+
+#ifndef _GRAVITY_HOLE_HPP_
+#define _GRAVITY_HOLE_HPP_
+
+#include <GLView.h>
+
+class GravityHole
+{
+public:
+	float x;
+	float y;
+	float z;
+
+	float vx;
+	float vy;
+	float vz;
+
+	float ax;
+	float ay;
+	float az;
+
+	GravityHole();
+
+	void Run();
+	void Draw();
+};
+
+#endif /* _GRAVITY_HOLE_HPP */

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

@@ -0,0 +1,95 @@
+/* 
+ * Copyright 2012, Haiku, Inc.
+ * Distributed under the terms of the MIT License.
+ * 
+ * Authors:
+ * 		Tri-Edge AI <triedgeai@gmail.com>
+ */ 
+
+
+#include <View.h>
+#include <StringView.h>
+
+#include "GravityScreenSaver.hpp"
+
+
+GravityScreenSaver::GravityScreenSaver(BMessage* pbmPrefs, image_id iidImage) 
+	:
+	BScreenSaver(pbmPrefs, iidImage)
+{
+	srand(time(NULL));
+
+	if (pbmPrefs->IsEmpty()) {
+		Config.ParticleCount = 1;
+		Config.ShadeID = 2;
+	} else {
+		if (pbmPrefs->FindInt32("ParticleCount", &Config.ParticleCount) != B_OK)
+			Config.ParticleCount = 1;	
+
+		if (pbmPrefs->FindInt32("ShadeID", &Config.ShadeID) != B_OK)
+			Config.ShadeID = 2;	
+	}
+}
+
+
+status_t
+GravityScreenSaver::SaveState(BMessage* pbmPrefs) const
+{
+	pbmPrefs->AddInt32("ParticleCount", Config.ParticleCount);
+	pbmPrefs->AddInt32("ShadeID", Config.ShadeID);
+	return B_OK;	
+}
+
+
+void
+GravityScreenSaver::StartConfig(BView* pbvView)
+{
+	pbvView->AddChild(new GravityConfigView(this, pbvView->Bounds()));
+}
+
+
+status_t
+GravityScreenSaver::StartSaver(BView* pbvView, bool bPreview)
+{
+	if (bPreview) {
+		view = NULL;
+		return B_ERROR;
+	} else {
+		SetTickSize((1000 / 30) * 1000); // ~30 FPS
+
+		view = new GravityView(this, pbvView->Bounds());
+		pbvView->AddChild(view);
+
+		return B_OK;
+	}
+}
+
+
+void
+GravityScreenSaver::StopSaver()
+{
+	if (view != NULL) {
+		view->EnableDirectMode(false);
+	}
+}
+
+
+void
+GravityScreenSaver::DirectConnected(direct_buffer_info* pdbiInfo)
+{
+	if (view != NULL) {
+		// TODO: Find out why I had to uncomment this.
+		// view->DirectConnected(pdbiInfo);
+		// view->EnableDirectMode(true);
+	}
+}
+
+
+void
+GravityScreenSaver::DirectDraw(int32 iFrame)
+{
+	view->Run();
+	// Dummy rect
+	BRect rect;
+	view->Draw(rect);
+}