/*	Public domain	*/
/*
 * This program uses FreeSG to display a 3D plot of (a subset of) all
 * linear combinations of 3 arbitrary vectors.
 */

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

#include <string.h>
#include <math.h>
#include <stdlib.h>

static M_Real step = 0.25;
static M_Real c1 = -5.0, c2 = 5.0;
static M_Real d1 = -5.0, d2 = 5.0;
static M_Real e1 = -5.0, e2 = 5.0;
static M_Vector3 u = { 1.0, 0.0, 0.0 };
static M_Vector3 v = { 0.0, 1.0, 0.0 };
static M_Vector3 w = { 0.0, 0.0, 1.0 };

SG_NodeClass LinearPlotClass;

static void
LinearDraw(void *p, SG_View *view)
{
	SG *sg = view->sg;
	SG_Node *node = p;
	M_Real c, d, e;
	M_Vector3 up, vp, wp;

	GL_Begin(GL_POINTS);
	for (c = c1; c < c2; c += step) {
		up = M_VecScale3(u, c);
		GL_Vertex3v(&up);
		GL_Color3(M_ColorRGB(c/c2, d/d2, e/e2));
		for (d = d1; d < d2; d += step) {
			vp = M_VecScale3(v, d);
			vp = M_VecAdd3(vp, up);
			GL_Color3(M_ColorRGB(c/c2, d/d2, e/e2));
			GL_Vertex3v(&vp);
			for (e = e1; e < e2; e += step) {
				wp = M_VecScale3(w, e);
				wp = M_VecAdd3(wp, up);
				wp = M_VecAdd3(wp, vp);
				GL_Color3(M_ColorRGB(c/c2, d/d2, e/e2));
				GL_Vertex3v(&wp);
			}
		}
	}
	GL_End();
}

AG_Window *
CreateParameterWindow(void)
{
	AG_Window *win;
	AG_Numerical *num;
	AG_HBox *hb;
	
	win = AG_WindowNew(0);
	AG_WindowSetCaptionS(win, "Parameters");
	AG_WindowSetPosition(win, AG_WINDOW_MIDDLE_LEFT, 0);

	hb = AG_HBoxNew(win, AG_HBOX_HOMOGENOUS);

	M_NumericalNewReal(hb, 0, NULL, "c1: ", &c1);
	M_NumericalNewReal(hb, 0, NULL, "c2: ", &c2);
	
	hb = AG_HBoxNew(win, AG_HBOX_HOMOGENOUS);
	M_NumericalNewReal(hb, 0, NULL, "d1: ", &d1);
	M_NumericalNewReal(hb, 0, NULL, "d2: ", &d2);
	
	hb = AG_HBoxNew(win, AG_HBOX_HOMOGENOUS);
	M_NumericalNewReal(hb, 0, NULL, "e1: ", &e1);
	M_NumericalNewReal(hb, 0, NULL, "e2: ", &e2);

	hb = AG_HBoxNew(win, AG_HBOX_HOMOGENOUS);
	M_NumericalNewReal(hb, 0, NULL, "u1: ", &u.x);
	M_NumericalNewReal(hb, 0, NULL, "u2: ", &u.y);
	M_NumericalNewReal(hb, 0, NULL, "u3: ", &u.z);
	
	hb = AG_HBoxNew(win, AG_HBOX_HOMOGENOUS);
	M_NumericalNewReal(hb, 0, NULL, "v1: ", &v.x);
	M_NumericalNewReal(hb, 0, NULL, "v2: ", &v.y);
	M_NumericalNewReal(hb, 0, NULL, "v3: ", &v.z);
	
	hb = AG_HBoxNew(win, AG_HBOX_HOMOGENOUS);
	M_NumericalNewReal(hb, 0, NULL, "w1: ", &w.x);
	M_NumericalNewReal(hb, 0, NULL, "w2: ", &w.y);
	M_NumericalNewReal(hb, 0, NULL, "w3: ", &w.z);
	
	num = M_NumericalNewReal(hb, 0, NULL, "step: ", &step);
	AG_NumericalSetIncrement(num, 0.01);

	AG_WindowShow(win);
}

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

	if (AG_InitCore("linear-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);
	CreateParameterWindow();

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

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

	/* Create a window with a SG_View. Disable lighting. */
	win = AG_WindowNew(0);
	AG_WindowSetCaptionS(win, "Linear combinations");
	sv = SG_ViewNew(win, sg, SG_VIEW_EXPAND|SG_VIEW_NO_LIGHTING);
	AG_WindowSetGeometryAlignedPct(win, AG_WINDOW_MC, 50, 50);
	AG_WindowShow(win);
	
	/* Reposition the default camera. */
	SG_Translate(sv->cam, 0.0, 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 LinearPlotClass = {
	{
		"SG_Node:LinearPlot",
		sizeof(SG_Node),
		{ 0,0 },
		NULL,		/* init */
		NULL,		/* destroy */
		NULL,		/* load */
		NULL,		/* save */
		NULL,		/* edit */
	},
	NULL,			/* menuInstance */
	NULL,			/* menuClass */
	LinearDraw,
	NULL			/* edit */
};