#include #include #include #include

using namespace std; //

struct point { int x, y;

// constructor point(int _x = 0, int _y = 0) : x(_x), y(_y) {}

};

// struct for rgb-pixel, holds red, green and blue values struct rgb { int r, g, b;

// constructor rgb(int _r = 0, int _g = 0, int _b = 0) : r(_r), g(_g), b(_b) {} };

class PPMImage { public: PPMImage(int width, int height) : w(width), h(height) { pixmap = new rgb*[h]; for (int i = 0; i < h; i++) pixmap[i] = new rgb[w]; } // destructor, clears data ~PPMImage() { w = 0; h = 0; for (int i = 0; i < h; ++i){ delete[] pixmap[i];

delete[] pixmap; }

}

void fill(rgb); void draw_Polygon(point, point, rgb); void draw_line(point, point, rgb); bool print_to_file(const string&) const; private: // image width and height int w, h; // image pixels. I know you said not to use double pointers, but it works because when I use one pointer the program crashes or gives me errors. rgb **pixmap;

}; void PPMImage::fill(rgb col) { // loop and assign put col in each pixel for (int i = 0; i < h; ++i) { for (int j = 0; j < w; ++j) { pixmap[i][j] = col; } } }

void PPMImage::draw_Polygon(point c, point a, rgb col) {

int k, b; int dx = abs(c.x - a.x); int dy = abs(c.y - a.y);

// if the x length is longer if (dx > dy) { // iterate through all x values for (int x = std::min(c.x, a.x); x <= std::max(c.x, a.x); x++) {

int y = (c.y - a.y)*(x - c.x)/(a.x - c.x) + c.y; // got from (y - y1)/(y2 - y1) = (x - x1)(x2 - x1) pixmap[y][x] = col; } } else { for (int y = std::min(c.y, a.y); y <= std::max(c.x, a.x); y++) { int x = (a.x - c.x)*(y - c.y)/(a.y - c.y) + c.x; // got from (y - y1)/(y2 - y1) = (x - x1)(x2 - x1) pixmap[y][x] = col;

} }

}

void PPMImage::draw_line(point p1, point p2, rgb col) { // swap points so p1.x if lesser than p2.x if (p1.x > p2.x) { point temp = p1; p1 = p2; p2 = temp; }

// loop increment value int dy = p1.y < p2.y ? 1 : -1,

// length of the each subline len = (p2.x - p1.x + 1) / (abs(p1.y - p2.y) + 1);

// draw each subline while (p1.y != p2.y) { for (int i = 0; i < len; ++i) { pixmap[p1.y][p1.x] = col; }

p1.y += dy; }

// fill remaining pixels while (p1.x < p2.x) { pixmap[p2.y][p1.x++] = col; } }

// prints image to file bool PPMImage::print_to_file(const string &filename) const { ofstream out(filename.c_str()); // couldn't open file if (!out){ return false; }

out << "P3" << endl; out << w << " " << h << endl; out << 255 << endl;

// fill each pixel for (int i = 0; i < h; ++i) { for (int j = 0; j < w; ++j) { rgb &col = pixmap[i][j]; out << col.r << " " << col.g << " " << col.b << endl; } }

return true; }

// constants const int WIDTH = 320, HEIGHT = 240,

point line1 = point(60, 120); point line2 = point(110, 200); point line3 = point(110, 150); point line4 = point(200, 220); point line5 = point(160, 120); // colors for background and line rgb LIGHT_GRAY = rgb(245, 245, 245), Magenta = rgb(255, 0, 255);

int main() { // create image PPMImage img(WIDTH, HEIGHT); // fill background img.fill(LIGHT_GRAY); img.draw_Polygon(line1, line1, Magenta); img.draw_Polygon(line2, line2, Magenta); img.draw_Polygon(line3, line3, Magenta); img.draw_Polygon(line4, line4, Magenta); img.draw_Polygon(line5, line5, Magenta); // print image img.print_to_file("Image.ppm");

return 0; }

****************program keeps crashing - c++ ppm image file -trying to draw a polygon with 5 vertex points - 60 120 110 200 110 150 200 220 160 120 ---

******PLEASE NOTE RUNNING CODEBLOCKS - PLEASE CORRECT WITHOUT HAVING TO USE GRAPHICS.H