lab 3 / FUNC

#include <graphics.h>
#include <stdio.h>
#include <math.h>
#include <conio.h>

const int xStart = 10;
const float start = 3.14 / 2;
const float end = 3.14 * 8;
const int numberOfSteps = 200;

struct point {
    int X;
    int Y;
};

point getCoords(float x, float y, float xValue, float yValue){
    int maxY = getmaxy();
    int avrgY = maxY / 2;

    point result;
    int currX = xStart;
    float realValue = 0;
    if (x < 0)
        for (; realValue > x; realValue -= xValue, --currX);
    else
        for (; realValue < x; realValue += xValue, ++currX);
    result.X = currX;

    realValue = 0;
    int currY = avrgY;
    if (y < 0)
        for (; realValue > y; realValue -= yValue, ++currY);
    else
        for (; realValue < y; realValue += yValue, --currY);
    result.Y = currY;

    return result;
}

float max(float* arr, int size) {
    float result = arr[0];
    for (int i = 1; i < size; ++i) {
        if (arr[i] > result)
            result = arr[i];
    }
    return result;
}

float min(float* arr, int size) {
    float result = arr[0];
    for (int i = 0; i < size; ++i)
        if (arr[i] < result)
            result = arr[i];
    return result;
}

float myFunction(float x) {
    return pow(sin(x), 3) - pow(cos(x), 2);
}

void putAxis(float xValue, float yValue) {
    int maxX = getmaxx();
    int maxY = getmaxy();
    int avrgY = maxY / 2;

    line(0, avrgY, maxX, avrgY);
    line(xStart, 0, xStart, maxY);

    for (int i = 1; i < 9; ++i)
    {
        point p1 = getCoords(3.14 * i, 0, xValue, yValue);
        line(p1.X, p1.Y - 5, p1.X, p1.Y + 5);
        char c[] = { i + '0', 'p', 'i', '\0' };
        outtextxy(p1.X - 10, p1.Y + 20, c);
    }

    for (int j = 1; j <= 15; j += 2)
    {
        point p = getCoords(3.15 * j / 2, 0, xValue, yValue);
        line(p.X, p.Y - 5, p.X, p.Y + 5);
        char c[] = "  pi/2";
        c[1] = j % 10 + '0';
        if (j >= 10)
            c[0] = j / 10 + '0';
        outtextxy(p.X - 15, p.Y + 15, c);
    }

    for (int k = 1; k < 10; ++k)
    {
        point p1 = getCoords(0, float(k) / 10, xValue, yValue);
        point p2 = getCoords(0, -float(k) / 10, xValue, yValue);
        line(p1.X - 5, p1.Y, p1.X + 5, p1.Y);
        line(p2.X - 5, p2.Y, p2.X + 5, p2.Y);
        char c1[] = "0. ";
        char c2[] = "-0. ";
        c1[2] = c2[3] = k + '0';
        outtextxy(p1.X + 10, p1.Y, c1);
        outtextxy(p2.X + 10, p2.Y, c2);
    }
}

void drawGraph(float* X, float* Y, float xValue, float yValue) {
    for (int i = 0; i < numberOfSteps - 1; ++i)
    {
        point p1 = getCoords(X[i], Y[i], xValue, yValue);
        point p2 = getCoords(X[i + 1], Y[i + 1], xValue, yValue);
        line(p1.X, p1.Y, p2.X, p2.Y);
    }
    point p = getCoords(3.14 / 2, 0.5, xValue, yValue);
}

int main(){
    clrscr();
    int grMode, grDriver;
    grDriver = DETECT;
    grMode = 0;
    initgraph(&grDriver, &grMode, "C:\\TurboC3\\BGI");

    float* X = new float[numberOfSteps];
    float step = (end - start) / numberOfSteps;
    float* Y = new float[numberOfSteps];
    X[0] = 3.14 / 2;
    Y[0] = myFunction(3.14 / 2);
    for (int i = 1; i < numberOfSteps; ++i) {
        X[i] = X[i - 1] + step;
        Y[i] = myFunction(X[i]);
    }

    float xValue = end / getmaxx();
    float yValue = (max(Y, numberOfSteps) - min(Y, numberOfSteps)) / getmaxy();
    putAxis(xValue, yValue);
    drawGraph(X, Y, xValue, yValue);
    getch();
    delete[] X;
    delete[] Y;
    closegraph();
    return 0;
}