/*	Public domain	*/
/*
 * This program uses FreeSG to plot the Lorenz attractor.
 */

#include <agar/core.h>
#include <agar/gui.h>
#include <freesg/sg.h>

M_Real r = 28.0;
M_Real sigma = 10.0;
M_Real b = 8.0/3.0;
M_Real h = 0.01;
M_Real spinI = 0.0, spinJ = 0.0005, spinK = 0.0;
SG_Node *node;
int iter = 1, iteriter = 10;

SG_NodeClass LorenzAttractorClass;

static void
LorenzDraw(void *pNode, SG_View *sgv)
{
	SG_Node *node = pNode;
	M_Vector3 p = M_VecGet3(0.0, 1.0, -1.0);
	M_Color color;
	int i;
	
	GL_Begin(GL_LINE_STRIP);
	for (i = 0; i < iter; i++) {
		color.b = color.g = 0.2 + 0.8*(M_Real)i/(M_Real)iter;
		color.r = 1.0;
		GL_Color3v(&color);
		p.x += h*(sigma*(p.y - p.x));
		p.y += h*(p.x*(r - p.z) - p.y);
		p.z += h*(p.x*p.y - b*p.z);
		GL_Vertex3v(&p);
	}
	GL_End();
	
	SG_RotateI(node, spinI);
	SG_RotateJ(node, spinJ);
	SG_RotateK(node, spinK);
	iter += iteriter;
}

/* Create the user dialog for editing parameters. */
AG_Window *
CreateParametersWindow(void)
{
	AG_Window *win;
	AG_Numerical *num;
	
	win = AG_WindowNew(0);
	AG_WindowSetCaptionS(win, "Parameters");
	AG_WindowSetPosition(win, AG_WINDOW_MIDDLE_LEFT, 0);
	
	AG_NumericalNewInt(win, 0, NULL, "Iterations:", &iter);
	AG_NumericalNewInt(win, 0, NULL, "Iterations':", &iteriter);
	
	num = M_NumericalNewReal(win, 0, NULL, "r:", &r);
	AG_NumericalSetIncrement(num, 0.001);
	num = M_NumericalNewReal(win, 0, NULL, "sigma:", &sigma);
	AG_NumericalSetIncrement(num, 0.001);
	num = M_NumericalNewReal(win, 0, NULL, "h:", &h);
	AG_NumericalSetIncrement(num, 0.001);
	num = M_NumericalNewReal(win, 0, NULL, "b:", &b);
	AG_NumericalSetIncrement(num, 0.01);
	
	num = M_NumericalNewReal(win, 0, "deg", "Pitch:", &spinI);
	AG_NumericalSetIncrement(num, 0.0001);
	num = M_NumericalNewReal(win, 0, "deg", "Yaw:", &spinJ);
	AG_NumericalSetIncrement(num, 0.0001);
	num = M_NumericalNewReal(win, 0, "deg", "Roll:", &spinK);
	AG_NumericalSetIncrement(num, 0.0001);
	
	AG_WindowShow(win);
}

int
main(int argc, char *argv[])
{
	AG_Window *win;
	SG_View *sv;
	SG_Node *plot;
	SG *sg;

	if (AG_InitCore("lorenz-demo", 0) == -1) {
		fprintf(stderr, "%s\n", AG_GetError());
		return (1);
	}
	if (AG_InitGraphics("<OpenGL>") == -1) {
		fprintf(stderr, "%s\n", AG_GetError());
		return (-1);
	}
	SG_InitSubsystem();
	AG_BindGlobalKey(AG_KEY_ESCAPE, AG_KEYMOD_ANY, AG_Quit);
	AG_BindGlobalKey(AG_KEY_F8, AG_KEYMOD_ANY, AG_ViewCapture);
	agColors[WINDOW_BG_COLOR] = AG_ColorRGB(0,0,0);
	CreateParametersWindow();

	/* Create the scene. */
	sg = SG_New(NULL, "scene", 0);

	/* Create an instance of our plot object. */
	AG_RegisterClass(&LorenzAttractorClass);
	plot = AG_Malloc(sizeof(SG_Node));
	AG_ObjectInit(plot, &LorenzAttractorClass);
	AG_ObjectSetName(plot, "MyLorenzAttractor");
	AG_ObjectAttach(sg->root, plot);

	/* Create a window with a SG_View. Disable lighting. */
	win = AG_WindowNew(0);
	AG_WindowSetCaptionS(win, "Lorenz Attractor");
	sv = SG_ViewNew(win, sg, SG_VIEW_EXPAND|SG_VIEW_NO_LIGHTING);
	AG_WindowSetGeometryAlignedPct(win, AG_WINDOW_MC, 60, 40);
	AG_WindowShow(win);

	/* Reposition the default camera. */
	SG_Translate(sv->cam, 10.0, 0.0, -20.0);
	SG_Rotatevd(sv->cam, 180.0, M_VecI3());

	AG_EventLoop();
	AG_Destroy();
	return (0);
}

/* Define a new node class for our plot. */
SG_NodeClass LorenzAttractorClass = {
	{
		"SG_Node:LorenzAttractor",
		sizeof(SG_Node),
		{ 0,0 },
		NULL,		/* init */
		NULL,		/* destroy */
		NULL,		/* load */
		NULL,		/* save */
		NULL,		/* edit */
	},
	NULL,			/* menuInstance */
	NULL,			/* menuClass */
	LorenzDraw,
	NULL			/* edit */
};