Source.cpp

#include <iostream>
#include <fstream>
#include <math.h>

using namespace std;

struct Point
{
	float x;
	float y;
};


void writeImage(const char *filename, char *img, int width, int height)
{
	FILE *file = fopen(filename, "wb");
	fprintf(file, "P5\n%i %i\n255\n", width, height);
	fwrite(img, sizeof(char), width * height, file);
}

int main()
{
	int width = 400;
	int height = 400;
	//cin >> width >> height;
	char *img = new char[width*height];
	memset(img, 255, width*height);

	Point p1, p2;
	p1.x = 50;
	p1.y = 90;
	p2.x = 130;
	p2.y = 60;
	float thickness = 5.0;
	/*cin >> start.x;
	cin >> start.y;
	cin >> end.x;
	cin >> end.y;*/
	int length_x = abs(p2.x - p1.x);
	int length_y = abs(p2.y - p1.y);

	int back = 255;
	int line = 0;

	float gback = pow(back / 255.0f, 2.2f);
	float gline = pow(line / 255.0f, 2.2f);

	if (length_x >= length_y) {
		Point start = p1.x < p2.x ? p1 : p2;
		Point end = p1.x < p2.x ? p2 : p1;
		int direction = 1;
		if (start.y > end.y) {
			direction *= -1;
		}
		
		float h = (thickness / 2.0) / cos(atan2(length_y, length_x));

		for (int i = 1; i <= length_x - 1; i++)
		{
			float realIndex = i + 0.5;
			float y_f = (float)((realIndex-1)*length_y) / length_x + start.y;
			float y_s = (float)(realIndex*length_y) / length_x + start.y;

			float maxLine = y_f > y_s ? y_f : y_s;
			float minLine = y_f < y_s ? y_f : y_s;

			float maxUp = maxLine + h;
			float minUp = minLine + h;
			float maxDown = maxLine - h;
			float minDown = minLine - h;

			int iMaxUp = maxUp;
			int iMinUp = minUp;
			int iMaxDown = maxDown;
			int iMinDown = minDown;

			if (iMaxUp == iMinUp) {
				cout << "Òðàïåöèÿ" << endl;
			}
			else {
				cout << "Òðåóãîëüíèêè" << endl;
			}

			if (iMaxDown == iMinDown) {
				cout << "Òðàïåöèÿ" << endl;
			}
			else {
				cout << "Òðåóãîëüíèêè" << endl;
			}

			if (iMaxDown == iMinUp) {

			}

			int y = ceil(start.y);
			int x = ceil(start.x);
			int realX = i + 0.5;

			for (int y_filling = maxDown+1; y_filling < minUp; y_filling++) {
				img[y_filling * width + realX + x] = 0;
			}


		}

		/*
		for (int i = 0; i <= length_x; i++)
		{
			float y_f = (float)(i*length_y) / length_x;
			int y = y_f;
			float f = (y_f - y);
			y *= direction;
			if (f == 0)
				img[(y + start.y)*width + i + start.x] = line;
			else {
				img[(y + start.y)*width + i + start.x] = pow(((1 - f)*gline + f*gback), 1 / 2.2f) * 255 + 0.5;
				img[(y + 1 * direction + start.y)*width + i + start.x] = pow(((1 - f)*gback + f*gline), 1 / 2.2f) * 255 + 0.5;
			}
		}
	}
	else {
		Point start = p1.y < p2.y ? p1 : p2;
		Point end = p1.y < p2.y ? p2 : p1;
		int direction = 1;
		if (end.x < start.x) {
			direction *= -1;
		}
		for (int i = 0; i <= length_y; i++)
		{
			float x_f = (float)(i*length_x) / length_y;
			int x = x_f;
			float f = (x_f - x);
			x *= direction;
			if (f == 0)
			{
				img[(i + start.y)*width + x + start.x] = line;
			}
			else {
				img[(i + start.y)*width + x + start.x] = pow(((1 - f)*gline + f*gback), 1 / 2.2f) * 255 + 0.5;
				img[(i + start.y)*width + x + 1 * direction + start.x] = pow(((1 - f)*gback + f*gline), 1 / 2.2f) * 255 + 0.5;
			}
		}*/
	}

	writeImage("myImage.pgm", img, width, height);

}