# HG changeset patch
# User John Tsiombikas <nuclear@member.fsf.org>
# Date 1400804027 -10800
# Node ID 68db0e456733ef8514bb73a0d73f0fb9a42bed1e

initial commit

diff -r 000000000000 -r 68db0e456733 Makefile
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Makefile	Fri May 23 03:13:47 2014 +0300
@@ -0,0 +1,13 @@
+src = $(wildcard src/*.cc)
+obj = $(src:.cc=.o)
+bin = grav
+
+CXXFLAGS = -pedantic -Wall -g
+LDFLAGS = -lGL -lGLU -lglut -lm -lvmath
+
+$(bin): $(obj)
+	$(CXX) -o $@ $(obj) $(LDFLAGS)
+
+.PHONY: clean
+clean:
+	rm -f $(obj) $(bin)
diff -r 000000000000 -r 68db0e456733 src/main.cc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/main.cc	Fri May 23 03:13:47 2014 +0300
@@ -0,0 +1,39 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <GL/glut.h>
+#include "sim.h"
+
+static bool init();
+static void cleanup();
+static void update(long tmsec);
+static void display();
+static void idle();
+static void reshape(int x, int y);
+static void keyb(unsigned char key, int x, int y);
+
+static SimWorld sim;
+
+int main(int argc, char **argv)
+{
+	glutInitWindowSize(1024, 768);
+	glutInit(&argc, argv);
+	glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
+	glutCreateWindow("gravity");
+
+	glutDisplayFunc(display);
+	glutIdleFunc(idle);
+	glutReshapeFunc(reshape);
+	glutKeyboardFunc(keyb);
+}
+
+
+static bool init()
+{
+}
+
+static void cleanup();
+static void update(long tmsec);
+static void display();
+static void idle();
+static void reshape(int x, int y);
+static void keyb(unsigned char key, int x, int y);
diff -r 000000000000 -r 68db0e456733 src/sim.cc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/sim.cc	Fri May 23 03:13:47 2014 +0300
@@ -0,0 +1,73 @@
+#include <GL/gl.h>
+#include "sim.h"
+
+Particle::Particle()
+{
+	mass = 1.0;
+}
+
+void Particle::impulse(const Vector3 &imp)
+{
+	accel += imp;
+}
+
+void Particle::step(float dt)
+{
+	Vector3 npos = pos + vel * dt;
+
+	vel += accel * dt;
+	accel.x = accel.y = accel.z = 0.0;
+
+	pos = npos;
+}
+
+
+// ---- SimWorld ----
+SimWorld::SimWorld()
+{
+	set_world_bounds(1000.0f);
+}
+
+void SimWorld::set_world_bounds(float rad)
+{
+	radius_sq = rad * rad;
+}
+
+void SimWorld::add_particle(const Particle &p)
+{
+	particles.push_back(p);
+}
+
+void SimWorld::step(float dt)
+{
+	std::list<Particle>::iterator it = particles.begin();
+	while(it != particles.end()) {
+		Particle *p = &*it;
+		p->step(dt);
+
+		if(p->pos.length_sq() > radius_sq) {
+			it = particles.erase(it);
+		} else {
+			++it;
+		}
+	}
+}
+
+void SimWorld::draw() const
+{
+	glBlendFunc(GL_ONE, GL_ONE);
+	glEnable(GL_BLEND);
+
+	glBegin(GL_POINTS);
+	glColor3f(0.5, 0.6, 0.7);
+
+	std::list<Particle>::const_iterator it = particles.begin();
+	while(it != particles.end()) {
+		const Particle *p = &*it++;
+		glVertex3f(p->pos.x, p->pos.y, p->pos.z);
+	}
+
+	glEnd();
+
+	glDisable(GL_BLEND);
+}
diff -r 000000000000 -r 68db0e456733 src/sim.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/sim.h	Fri May 23 03:13:47 2014 +0300
@@ -0,0 +1,34 @@
+#ifndef SIM_H_
+#define SIM_H_
+
+#include <list>
+#include <vmath/vmath.h>
+
+class Particle {
+public:
+	float mass;
+	Vector3 pos, vel;
+	Vector3 accel;
+
+	Particle();
+
+	void impulse(const Vector3 &imp);
+	void step(float dt);
+};
+
+class SimWorld {
+private:
+	std::list<Particle> particles;
+	float radius_sq;
+
+public:
+	SimWorld();
+
+	void set_world_bounds(float rad);
+
+	void add_particle(const Particle &p);
+	void step(float dt);
+	void draw() const;
+};
+
+#endif	// SIM_H_