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Merge branch 'main' of http://git.hexaquo.at/mgs/quickhull into main

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karl 2020-11-28 20:48:43 +01:00
commit 3cfa15a33c
6 changed files with 415 additions and 25 deletions
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274
Display.cpp
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@ -1,16 +1,71 @@
// make sure sfml is installed:
// linux - sudo apt-get install libsfml-dev
// windows - manual dl from https://www.sfml-dev.org/download.php
#include <SFML/Graphics.hpp>
#include <iostream>
#include <chrono>
#include <thread>
#include "Display.h"
#include "Point.h"
#include "Utility.h"
Display::Display (const std::vector<Point> &pts)
{
if (!m_font.loadFromFile("arial.ttf"))
{
std::cerr << "font arial.ttf could not be loaded!" << std::endl;
}
m_textStatus.setPosition(OFFSET, HEIGHT - 2*OFFSET);
m_textStatus.setFont(m_font);
m_textStatus.setString("initializing...");
m_textStatus.setCharacterSize(12);
m_textStatus.setFillColor(sf::Color::Black);
size_t points = pts.size();
for (size_t i = 0; i < points; ++i)
{
const Point& pt = pts[i];
sf::CircleShape shape(OFFSET);
//shape.setPosition(pt.x() - OFFSET, pt.y() - OFFSET); // handle with origin or manually calc position
shape.setOrigin(OFFSET, OFFSET);
shape.setPosition(pt.x(), pt.y());
shape.setFillColor(sf::Color::Green);
shape.setOutlineThickness(1.f);
shape.setOutlineColor(sf::Color::Black);
m_points.push_back(shape);
//m_points.append(shape);
sf::Text label;
//label.setPosition(pt.x() - OFFSET / 2, pt.y() - OFFSET / 2 - 3);
label.setOrigin(OFFSET / 2 - 1, OFFSET / 2 + 3);
label.setPosition(pt.x(), pt.y());
label.setFont(m_font);
label.setString(std::to_string(i));
label.setCharacterSize(12);
label.setFillColor(sf::Color::Black);
m_labels.push_back(label);
//m_points.append(label);
}
}
// multiple options possible:
// a) draw every frame, using elapsed time for updates
// --> not really needed because we have no animations... also uses a lot of performance
// b) checking every frame if elapsed time since last tick is larger than a specified offset, then draw the field
// --> mostly doing nothing but still uses a lot of performance O_o
// c) just start a simple (c++11 <3) non-busy sleep
// --> may delay user input / events but don't care atm :p
void Display::show()
{
sf::RenderWindow window(sf::VideoMode(WIDTH, HEIGHT), "SFML works!");
sf::ContextSettings settings;
settings.antialiasingLevel = 8;
sf::RenderWindow window(sf::VideoMode(WIDTH, HEIGHT), "ALGO Prog2: Quickhull - visualization", sf::Style::Default, settings);
/* b)
window.setFramerateLimit(0.2);
sf::Clock clock;
sf::Time frameTime = sf::seconds(2); //sf::seconds(1.f / 60.f)
sf::Time timeSinceLastUpdate = frameTime; //sf::Time::Zero;*/
while (window.isOpen())
{
sf::Event event;
@ -20,19 +75,208 @@ void Display::show()
window.close();
}
window.clear();
for (auto &pt : m_points)
// a)
//update(elapsed);
//render(window);
/* b)
timeSinceLastUpdate += clock.restart();
// only handle every few seconds because we need no animations
if (timeSinceLastUpdate >= frameTime)
{
sf::CircleShape shape(10.f);
shape.setPosition(pt.x(), pt.y());
shape.setFillColor(sf::Color::Green);
window.draw(shape);
}
window.display();
std::cout << "entering update and render" << std::endl;
// start by getting the most left and right point
timeSinceLastUpdate -= frameTime;
update();
render(window);
}*/
// c)
// choose a simple sleep
update();
render(window);
std::this_thread::sleep_for(std::chrono::milliseconds(2000));
}
}
void Display::setData(std::vector<Point> pts)
void Display::update ()
{
m_points = pts;
// TODO: maybe include Akl–Toussaint heuristic first?
// https://en.wikipedia.org/wiki/Convex_hull_algorithms#Akl%E2%80%93Toussaint_heuristic
unsigned int curStep = (m_step > 5) ? ((m_step - 2) % 4 + 2) : (m_step % 6); // skip init and first step after first run
std::string text = "(" + std::to_string(m_step) + ") step " + std::to_string(curStep) + ": ";
if (curStep == 1)
{
// first step: select min - max x coordinates
m_textStatus.setString(text + "select min - max x coordinates...");
/* EDIT: manual iteration for combining x and x minmax; also need not previous sorting
std::pair<Point, Point> minmax = getMinMaxX(m_points);
std::cout << "min: " << minmax.first.x() << ", " << minmax.first.y() <<
", max: " << minmax.second.x() << ", " << minmax.second.y() << std::endl;
m_hull.setPrimitiveType(sf::Lines);
m_hull.append(sf::Vertex(sf::Vector2f(minmax.first.x(), minmax.first.y()), sf::Color::Blue));
m_hull.append(sf::Vertex(sf::Vector2f(minmax.second.x(), minmax.second.y()), sf::Color::Blue));*/
// if use Akl–Toussaint heuristic
bool useAkl = false;
if (useAkl)
{
sf::Vector2f topLeft(WIDTH, HEIGHT);
sf::Vector2f topRight(0, HEIGHT);
sf::Vector2f botLeft(WIDTH, 0);
sf::Vector2f botRight(0, 0);
for (auto& pt : m_points)
{
sf::Vector2f pos = pt.getPosition();
float x = pos.x;
float y = pos.y;
// TODO: only check explicit x and y seperate!
if (x < topLeft.x && y < topLeft.y) topLeft = pos;
if (x > topRight.x && y < topLeft.y) topRight = pos;
if (x < botLeft.x && y > botLeft.y) botLeft = pos;
if (x > botRight.x && y > botRight.y) botRight = pos;
}
/* TODO: use a convex shape? Or build from vertices in render?
sf::ConvexShape convex;
convex.setPointCount(5);
convex.setPoint(0, topLeft);
convex.setPoint(0, topRight);
convex.setPoint(0, botRight);
convex.setPoint(0, botLeft);*/
//m_hull.setPrimitiveType(sf::Lines);
m_hull.setPrimitiveType(sf::LineStrip);
m_hull.append(sf::Vertex(topLeft, sf::Color::Blue));
m_hull.append(sf::Vertex(topRight, sf::Color::Blue));
m_hull.append(sf::Vertex(botRight, sf::Color::Blue));
m_hull.append(sf::Vertex(botLeft, sf::Color::Blue));
m_hull.append(sf::Vertex(topLeft, sf::Color::Blue));
}
else
{
sf::Vector2f left(WIDTH, HEIGHT);
sf::Vector2f right(0, 0);
for (auto& pt : m_points)
{
sf::Vector2f pos = pt.getPosition();
float x = pos.x;
float y = pos.y;
if (x < left.x) left = pos;
if (x > right.x) right = pos;
}
//m_hull.setPrimitiveType(sf::Lines);
m_hull.setPrimitiveType(sf::LineStrip);
m_hull.append(sf::Vertex(left, sf::Color::Blue));
m_hull.append(sf::Vertex(right, sf::Color::Blue));
}
}
else if (curStep == 2)
{
// second step: split board and find furthest point
m_textStatus.setString(text + "split board and find furthest point...");
for (auto& pt : m_points)
{
pt.setFillColor(sign(
pt.getPosition().x, pt.getPosition().y,
m_hull[0].position.x, m_hull[0].position.y,
m_hull[1].position.x, m_hull[1].position.y) > 0 ? sf::Color::Red : sf::Color::Green);
}
}
else if (curStep == 3)
{
// third step: draw triangle, remove inner points
m_textStatus.setString(text + "find furthest point and draw triangle...");
sf::Vector2f pos = m_points[0].getPosition();
float maxDistance = 0;
for (auto& pt : m_points)
{
float distance = pDistance(
pt.getPosition().x, pt.getPosition().y,
m_hull[0].position.x, m_hull[0].position.y,
m_hull[1].position.x, m_hull[1].position.y);
if (pt.getFillColor() == sf::Color::Green)
{
std::cout << "distance to green point " << pt.getPosition().x << ", " << pt.getPosition().y << ": " << distance << std::endl;
}
else if (pt.getFillColor() == sf::Color::Red)
{
std::cout << "distance to red point " << pt.getPosition().x << ", " << pt.getPosition().y << ": " << distance << std::endl;
}
if (distance > maxDistance)
{
pos = pt.getPosition();
maxDistance = distance;
}
}
if (maxDistance > 0)
{
// TODO: not append but insert between last line points
m_hull.append(sf::Vertex(pos, sf::Color::Blue));
}
}
else if (curStep == 4)
{
// fourth step: remove inner points
m_textStatus.setString(text + "remove inner points...");
}
else if (curStep == 5)
{
// fifth step: adding new hull point
// TEMP: TEST check if ends
//if (m_step >= 10) m_points.clear();
if (m_points.size() == 0) m_textStatus.setString(text + "finished calculating convex hull");
else m_textStatus.setString(text + "adding new hull point...");
}
else m_textStatus.setString(text + "invalid status!");
if (curStep != 5 || m_points.size() > 0) m_step++;
}
void Display::render (sf::RenderWindow &window)
{
window.clear(sf::Color::White);
// always print remaining points
/*size_t points = m_points.size();
for (size_t i = 0; i < points; ++i)
{
drawPoint(window, i);
}*/
//for (auto& pt : m_points) // points and labels should have the same size -> combine in one loop
size_t points = m_points.size();
for (size_t i = 0; i < points; ++i)
{
window.draw(m_points[i]);
window.draw(m_labels[i]);
}
// draw already calculated hull
//if (step >= 1)
{
//window.draw(&m_hull[0], m_hull.size(), sf::Lines);
window.draw(&m_hull[0], m_hull.getVertexCount(), m_hull.getPrimitiveType());
}
window.draw(m_textStatus);
window.display();
}

30
Display.h
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@ -1,17 +1,39 @@
#pragma once
#ifndef DISPLAY_H
// make sure sfml is installed:
// linux - sudo apt-get install libsfml-dev
// windows - manual dl from https://www.sfml-dev.org/download.php
#include <SFML/Graphics.hpp>
class Point;
#define OFFSET 10.f
#define WIDTH 800
#define HEIGHT 600
class Display
{
private:
std::vector<Point> m_points;
sf::Font m_font;
sf::Text m_textStatus;
//std::vector<Point> m_points;
std::vector<sf::CircleShape> m_points;
std::vector<sf::Text> m_labels;
//sf::VertexArray m_points;
//sf::VertexArray m_labels;
//std::vector<sf::Vertex> m_hull;
sf::VertexArray m_hull;
unsigned int m_step = 0;
void update();
void render(sf::RenderWindow &);
public:
void show();
Display(const std::vector<Point> &);
void setData (std::vector<Point>);
};
void show();
};
#endif // DISPLAY_H

8
README.md
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@ -1,2 +1,10 @@
# quickhull
## TODO:
- Point class
- adding "features" such as "IsInTriangle", ... ?
- direct member access instead of getters?

91
Utility.h Normal file
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@ -0,0 +1,91 @@
#pragma once
#ifndef UTILITY_H
static float sign(float x, float y, float x1, float y1, float x2, float y2)
{
return (x - x2) * (y1 - y2) - (x1 - x2) * (y - y2);
}
static float sign (Point &p1, Point &p2, Point &p3)
{
return (p1.x() - p3.x()) * (p2.y() - p3.y()) - (p2.x() - p3.x()) * (p1.y() - p3.y());
}
static bool IsPointInTriangle(Point &pt, Point &p1, Point &p2, Point &p3)
{
float d1 = sign(pt, p1, p2);
float d2 = sign(pt, p2, p3);
float d3 = sign(pt, p3, p1);
bool has_neg = (d1 < 0) || (d2 < 0) || (d3 < 0);
bool has_pos = (d1 > 0) || (d2 > 0) || (d3 > 0);
return !(has_neg && has_pos);
}
static float pDistance(float x, float y, float x1, float y1, float x2, float y2) {
float A = x - x1;
float B = y - y1;
float C = x2 - x1;
float D = y2 - y1;
float dot = A * C + B * D;
float len_sq = C * C + D * D;
float param = -1;
if (len_sq != 0) // in case of 0 length line
param = dot / len_sq;
float xx, yy;
if (param < 0) {
xx = x1;
yy = y1;
}
else if (param > 1) {
xx = x2;
yy = y2;
}
else {
xx = x1 + param * C;
yy = y1 + param * D;
}
float dx = x - xx;
float dy = y - yy;
return dx * dx + dy * dy;
//return sqrt(dx * dx + dy * dy);
}
static bool SortForMinXMaxY (const Point& a, const Point& b)
{
if (a.x() != b.x())
{
return (a.x() < b.x());
}
return (a.y() > b.y());
}
static bool SortForMinYMaxX(const Point& a, const Point& b)
{
if (a.y() != b.y())
{
return (a.x() < b.x());
}
return (a.y() > b.y());
}
static void sortPoints (std::vector<Point>& pts)
{
std::sort(pts.begin(), pts.end(), SortForMinXMaxY);
}
// TODO: what happens if all/more points are on hor/vert line? -> sort for x, than y should handle this
static std::pair<Point, Point> getMinMaxX(std::vector<Point>& pts)
{
// TODO: check if already sorted? assume array is sorted? call sort utility function???
//sortPoints(pts);
std::sort(pts.begin(), pts.end(), SortForMinXMaxY);
return std::make_pair(pts[0], pts[pts.size() - 1]);
}
#endif // UTILITY_H

BIN
arial.ttf Normal file
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37
main.cpp
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@ -8,6 +8,7 @@
#include "Display.h"
#include "Point.h" // TODO: check if there is a usable SFML or c++ class
#include "Timing.h"
#include "Utility.h"
// TODOs:
// - use SFML vec2 instead of Point class
@ -41,10 +42,32 @@ int main (int argc, char **argv)
std::cout << "generating random numbers..." << std::endl;
//srand(static_cast <unsigned> (time(0)));
srand(static_cast <unsigned> (0)); // fixed seed for testing
// 2) rectangle
//float diff = (2.f * HEIGHT / valCount);
// 3) circle
//float rad = HEIGHT / 2; //8.0f;
//float deg = (float)(2 * 3.14159 / valCount);
float x = 0;
float y = 0;
for (int i = 0; i < valCount; ++i)
{
float x = static_cast <float> (rand()) / (static_cast <float> (RAND_MAX / WIDTH));
float y = static_cast <float> (rand()) / (static_cast <float> (RAND_MAX / HEIGHT));
// 1) random generation
//x = OFFSET + static_cast <float> (rand()) / (static_cast <float> (RAND_MAX / (WIDTH - OFFSET)));
//y = OFFSET + static_cast <float> (rand()) / (static_cast <float> (RAND_MAX / (HEIGHT - OFFSET)));
x = OFFSET + static_cast <float> (rand()) / (static_cast <float> (RAND_MAX / (WIDTH - 2*OFFSET)));
y = OFFSET + static_cast <float> (rand()) / (static_cast <float> (RAND_MAX / (HEIGHT - 2*OFFSET)));
// 2) rectangle
//x = (i%2 == 0) ? OFFSET : WIDTH - OFFSET;
//y = diff/2 + (i/2) * diff;
// 3) position in circle around center, x/y plane
//x = WIDTH/2 + rad * cosf(i * deg);
//y = HEIGHT/2 + rad * sinf(i * deg);
points.push_back(Point(x, y));
}
}
@ -76,7 +99,8 @@ int main (int argc, char **argv)
}
}
// TODO: need sort here?
// TODO: sort here, once and for all? xD
//sortPoints(points);
for (Point& pt : points)
{
std::cout << "pt: " << pt.x() << ", " << pt.y() << std::endl;
@ -84,9 +108,10 @@ int main (int argc, char **argv)
if (vis)
{
// TODO: use data as ctor argument? pointer?
Display display;
display.setData(points);
// TEST to check SFML coordinate system
//points.push_back(Point(0, 0));
Display display(points);
display.show();
}