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// Osman Zakir
// 6 / 26 / 2017
// Bjarne Stroustrup: Programming: Principles and Practice Using C++ 2nd Edition
// Chapter 15 Exercise 2
// chapter15ex2.cpp
// Exercise Specifications:
/**
* Define a class Fct that is just like Function except that it stores its
* constructor arguments. Provide Fct with “reset” operations, so that you can
* use it repeatedly for different ranges, different functions, etc.
*/
#include "../../Graph.h"
#include "../../Window.h"
double one(double);
double slope(double x);
double square(double x);
namespace Graph_lib
{
struct Fct2 : Shape
{
typedef double Funct(double);
Fct2(Funct f, double r1, double r2, Point orig, int count = 100, double xscale = 25, double yscale = 25);
Point orig() const { return m_orig; };
double r1() const { return m_r1; }
double r2() const { return m_r2; }
int count() const { return m_count; }
double xscale() const { return m_xscale; }
double yscale() const { return m_yscale; }
void set_orig(const Point &orig) { m_orig = orig; }
void set_r1(const double r1) { m_r1 = r1; }
void set_r2(const double r2) { m_r2 = r2; }
void set_count(const int count) { m_count = count; }
void set_xscale(const double xscale) { m_xscale = xscale; }
void set_yscale(const double yscale) { m_yscale = yscale; }
private:
Funct m_f;
Point m_orig;
double m_r1;
double m_r2;
int m_count;
double m_xscale;
double m_yscale;
};
}
int main()
{
using namespace Graph_lib;
constexpr int xmax = 600; // window size
constexpr int ymax = 400;
Graph_lib::Window win{ Point{ 100, 100 }, xmax, ymax, "Function graphing" };
constexpr int x_orig = xmax / 2; // position of (0,0) is center of window
constexpr int y_orig = ymax / 2;
const Point orig{ x_orig, y_orig };
constexpr int r_min = -10; // range [-10:11]
constexpr int r_max = 11;
constexpr int n_points = 400; // number of points in usage
constexpr int x_scale = 30; // scaling factors
constexpr int y_scale = 30;
Fct2 s{ one, r_min, r_max, orig, n_points, x_scale, y_scale };
Fct2 s2{ slope, r_min, r_max, orig, n_points, x_scale, y_scale };
Fct2 s3{ square, r_min, r_max, orig, n_points, x_scale, y_scale };
s.set_color(Color::black);
s2.set_color(Color::black);
s3.set_color(Color::black);
Text ts{ Point{ 100, y_orig - 40 }, "one" };
Text ts2{ Point{ 100, y_orig + y_orig / 2 - 20 }, "x/2" };
Text ts3{ Point{ x_orig - 100, 20 }, "x*x" };
ts.set_color(Color::black);
ts2.set_color(Color::black);
ts3.set_color(Color::black);
constexpr int xlength = xmax - 40; // make the axis a bit smaller than the window
constexpr int ylength = ymax - 40;
Axis x{ Axis::x, Point{ 20, y_orig }, xlength,
xlength / static_cast<int>(x_scale), "one notch == 1" };
Axis y{ Axis::y, Point{ x_orig, ylength + 20 }, ylength,
ylength / static_cast<int>(y_scale), "one notch == 1" };
x.set_color(Color::red);
y.set_color(Color::red);
win.attach(ts);
win.attach(ts2);
win.attach(ts3);
win.attach(s);
win.attach(s2);
win.attach(s3);
win.attach(x);
win.attach(y);
gui_main();
}
Graph_lib::Fct2::Fct2(Funct f, double r1, double r2, Point orig, int count, double xscale, double yscale)
:m_r1{r1}, m_r2{r2}, m_orig{orig}, m_count{count}, m_xscale{xscale}, m_yscale{yscale}
// graph f(x) for x in [r1:r2) using count line segments with (0,0) displayed at xy
// x coordinates are scaled by xscale and y coordinates scaled by yscale
{
if (r2 - r1 <= 0)
{
error("bad graphing range");
}
if (count <= 0)
{
error("non-positive graphing count");
}
double dist = (r2 - r1) / count;
double r = r1;
for (int i = 0; i < count; ++i)
{
add(Point(orig.x + int(r * xscale), orig.y - int(f(r) * yscale)));
r += dist;
}
}
double one(double)
{
return 1;
}
double slope(double x)
{
return x / 2;
}
double square(double x)
{
return x * x;
}
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