# HG changeset patch
# User John Tsiombikas <nuclear@member.fsf.org>
# Date 1334463541 -10800
# Node ID 70b9370081343efc059a6ffdc36829785d621067
# Parent  6ca076bf50847958daaa7697c5aa2ae8eb6fb105
demo :)

diff -r 6ca076bf5084 -r 70b937008134 qvolray.pro
--- a/qvolray.pro	Sun Apr 15 02:22:13 2012 +0300
+++ b/qvolray.pro	Sun Apr 15 07:19:01 2012 +0300
@@ -26,7 +26,8 @@
 HEADERS = src/ui.h \
 	src/ui_maingl.h \
 	src/ui_sliceview.h \
-	src/ui_xferview.h
+	src/ui_xferview.h \
+	src/demo.h
 
 SOURCES = src/main.cc \
 	src/sdr.c \
diff -r 6ca076bf5084 -r 70b937008134 sdr/demo.p.glsl
--- a/sdr/demo.p.glsl	Sun Apr 15 02:22:13 2012 +0300
+++ b/sdr/demo.p.glsl	Sun Apr 15 07:19:01 2012 +0300
@@ -1,9 +1,32 @@
+#define NBALLS	3
+
+uniform float energy[NBALLS];
+uniform vec3 pos[NBALLS];
+
+float eval(vec3 p)
+{
+	float val = 0.0;
+
+	for(int i=0; i<NBALLS; i++) {
+		vec3 dif = p - pos[i];
+		float len_sq = dot(dif, dif);
+		val += 0.1 * energy[i] / len_sq;
+	}
+	return val;
+}
+
+#define OFFS	0.01
+
 void main()
 {
 	vec3 pos = gl_TexCoord[0].xyz * 2.0 - 1.0;
 
-	float len = length(pos);
-	float val = 0.1 / (len * len);
+	float val = eval(pos);
 
-	gl_FragColor = vec4(-pos / len, val);
+	vec3 grad;
+	grad.x = eval(pos + vec3(OFFS, 0.0, 0.0)) - eval(pos - vec3(OFFS, 0.0, 0.0));
+	grad.y = eval(pos + vec3(0.0, OFFS, 0.0)) - eval(pos - vec3(0.0, OFFS, 0.0));
+	grad.z = eval(pos + vec3(0.0, 0.0, OFFS)) - eval(pos - vec3(0.0, 0.0, OFFS));
+
+	gl_FragColor = vec4(grad, val);
 }
diff -r 6ca076bf5084 -r 70b937008134 src/demo.cc
--- a/src/demo.cc	Sun Apr 15 02:22:13 2012 +0300
+++ b/src/demo.cc	Sun Apr 15 07:19:01 2012 +0300
@@ -1,16 +1,66 @@
+#include <random>
+#include <functional>
+#include <QTimer>
 #include <assert.h>
 #include <GL/glew.h>
 #include "demo.h"
 #include "sdr.h"
 #include "volray.h"
+#include "ui.h"
 
-#define SZ	128
+#define SZ 128
+#define TIMER_INTERVAL 33
 
-static Volume *vol;
-static unsigned int sdr_mballs;
-static unsigned int fbo;
 
-bool init_demo()
+Demo::Demo()
+{
+	vol = 0;
+	sdr_mballs = 0;
+	fbo = 0;
+	timer = 0;
+	balls = 0;
+	tmsec = 0;
+}
+
+Demo::~Demo()
+{
+	glDeleteFramebuffersEXT(1, &fbo);
+	free_program(sdr_mballs);
+	delete vol;
+	delete timer;
+
+	delete [] balls;
+}
+
+void Demo::timer_func()
+{
+	float tsec = tmsec / 1000.0;
+	const float speed = 1.0;
+
+	for(int i=0; i<num_balls; i++) {
+		float t = tsec * speed;
+		int idx = (int)t % MB_PATH_SZ;
+		t -= floor(t);
+
+		Vector3 a = balls[i].path[idx];
+		Vector3 b = balls[i].path[(idx + 1) % MB_PATH_SZ];
+		balls[i].pos = lerp(a, b, t);
+
+		char name[32];
+
+		sprintf(name, "pos[%d]", i);
+		set_uniform_float3(sdr_mballs, name, balls[i].pos.x, balls[i].pos.y, balls[i].pos.z);
+
+		sprintf(name, "energy[%d]", i);
+		set_uniform_float(sdr_mballs, name, balls[i].energy);
+	}
+
+	post_redisplay();
+
+	tmsec += TIMER_INTERVAL;
+}
+
+bool Demo::init()
 {
 	if(!(sdr_mballs = create_program_load("sdr/demo.v.glsl", "sdr/demo.p.glsl"))) {
 		return false;
@@ -38,13 +88,43 @@
 	}
 	glBindFramebufferEXT(GL_FRAMEBUFFER, 0);
 
+	// initialize metaballs
+	auto rnd_energy = std::bind(std::uniform_real_distribution<float>(0.7, 1.6), std::mt19937());
+	auto rnd_path = std::bind(std::uniform_real_distribution<float>(-0.5, 0.5), std::mt19937());
+
+	num_balls = 4;
+	balls = new MetaBall[4];
+
+	for(int i=0; i<4; i++) {
+		balls[i].energy = rnd_energy();
+
+		for(int j=0; j<MB_PATH_SZ; j++) {
+			balls[i].path[j].x = rnd_path();
+			balls[i].path[j].y = rnd_path();
+			balls[i].path[j].z = rnd_path();
+		}
+	}
+
+	// update timer
+	timer = new QTimer(this);
+	timer->setSingleShot(false);
+	connect(timer, SIGNAL(timeout()), this, SLOT(timer_func()));
+	timer->start(TIMER_INTERVAL);
+
 	return true;
 }
 
-void draw_demo()
+void Demo::draw() const
 {
 	if(volray_getvolume() != vol) {
+		if(timer->isActive()) {
+			timer->stop();
+		}
 		return;
+	} else {
+		if(!timer->isActive()) {
+			timer->start(TIMER_INTERVAL);
+		}
 	}
 
 	glPushAttrib(GL_VIEWPORT_BIT);
diff -r 6ca076bf5084 -r 70b937008134 src/demo.h
--- a/src/demo.h	Sun Apr 15 02:22:13 2012 +0300
+++ b/src/demo.h	Sun Apr 15 07:19:01 2012 +0300
@@ -1,8 +1,45 @@
 #ifndef DEMO_H_
 #define DEMO_H_
 
-bool init_demo();
-void draw_demo();
+#include <QObject>
+#include <QTimer>
+#include <vmath/vmath.h>
+
+class Volume;
+
+#define MB_PATH_SZ	5
+
+struct MetaBall {
+	float energy;
+	Vector3 pos;
+
+	Vector3 path[MB_PATH_SZ];
+};
+
+class Demo : public QObject {
+private:
+	Q_OBJECT
+
+	Volume *vol;
+	unsigned int sdr_mballs;
+	unsigned int fbo;
+
+	QTimer *timer;
+	MetaBall *balls;
+	int num_balls;
+
+	unsigned long tmsec;
+
+private slots:
+	void timer_func();
+
+public:
+	Demo();
+	~Demo();
+
+	bool init();
+	void draw() const;
+};
 
 
 #endif	// DEMO_H_
diff -r 6ca076bf5084 -r 70b937008134 src/volray.cc
--- a/src/volray.cc	Sun Apr 15 02:22:13 2012 +0300
+++ b/src/volray.cc	Sun Apr 15 07:19:01 2012 +0300
@@ -48,6 +48,7 @@
 static bool clip_z;
 static float ray_step = 0.01;
 
+static Demo *demo;
 static Volume *volume;
 
 static bool dbg_noray;
@@ -72,7 +73,10 @@
 	set_uniform_int(slice_sdr, "volume", 0);
 	set_uniform_int(slice_sdr, "xfer_tex", 1);
 
-	init_demo();
+	demo = new Demo;
+	if(!demo->init()) {
+		return false;
+	}
 
 	return true;
 }
@@ -141,7 +145,7 @@
 	if(dbg_noray)
 		return;
 
-	draw_demo();
+	demo->draw();
 
 	if(volume) {
 		render_volume();