PPP2 Chapter 13 Drill

[DragonOsman]

What about why it's skipping squares? Where should I call it move() and how much should I increment current_row and current_col by at every point?

Edit: It's still going past the right edge. And how do I make sure it only moves to the next square each time?

Here's the code now:

// Osman Zakir
// 5 / 3 / 2017
// Bjarne Stroustrup: Programming: Principles and Practice Using C++ 2nd Edition
// Chapter 13 Drill
// Drill Specifications:
/**
 * 1. Make an 800-by-1000 Simple_window.
 * 2. Put an 8-by-8 grid on the leftmost 800-by-800 part of that window (so that each square is 100 by
 *    100).
 * 3. Make the eight squares on the diagonal starting from the top left corner red (use Rectangle).
 * 4. Find a 200-by-200-pixel image (JPEG or GIF) and place three copies of it on the grid (each
 *    image covering four squares). If you can’t find an image that is exactly 200 by 200, use
 *    set_mask() to pick a 200-by-200 section of a larger image. Don’t obscure the red squares.
 * 5. Add a 100-by-100 image. Have it move around from square to square when you click the “Next”
 *    button. Just put wait_for_button() in a loop with some code that picks a new square for your
 *    image.
 */

#include "../../cust_std_lib_facilities.h"
#include "../../Simple_window.h"
#include "../../Graph.h"

int main()
{
	using namespace Graph_lib;

	constexpr int win_x = 100, win_y = 100;
	const Point top_left{ win_x, win_y };
	constexpr int win_width = 800, win_height = 1000;
	Simple_window win{ top_left, win_width, win_height, "grid-image drill" };

	Lines grid;
	constexpr int col_count = 8;
	constexpr int row_count = 8;
	constexpr int row_height = 100;
	constexpr int col_width = 100;
	constexpr int grid_width = col_count * col_width;
	constexpr int grid_height = row_height * row_count;
	for (int x = 0; x < grid_width; x += col_width)
	{
		for (int y = 0; y < grid_height; y += row_height)
		{
			grid.add(Point{ x, 0 }, Point{ x, grid_height });
			grid.add(Point{ 0, y }, Point{ grid_width, y });
		}
	}
	grid.set_color(Color::black);
	win.attach(grid);

	constexpr int rect_width = 100;
	constexpr int rect_height = 100;
	constexpr int num_rects = 8;
	Vector_ref<Graph_lib::Rectangle> rect_vr;
	for (int i = 0, x = 0, y = 0; i < num_rects; ++i, x += rect_width, y += rect_height)
	{
		rect_vr.push_back(new Graph_lib::Rectangle{ Point{ x, y }, rect_width, rect_height });
		rect_vr[i].set_color(Color::black);
		rect_vr[i].set_fill_color(Color::red);
		win.attach(rect_vr[i]);
	}

	Image rock1{ Point{500, 0}, "20051121_Peace_rock_th200.jpg" };
	win.attach(rock1);

	Image rock2{ Point{200, 0}, "20051121_Peace_rock_th200.jpg" };
	win.attach(rock2);

	Image rock3{ Point{200, 500}, "20051121_Peace_rock_th200.jpg" };
	win.attach(rock3);

	Image ichigo_flying{ Point{0, 0}, "ichigo-flying.gif" };
	win.attach(ichigo_flying);

	int current_row = 0, current_col = 0;
	while (current_row != win.y_max() && current_col != win.x_max())
	{
		if (win.wait_for_button())
		{
			if (current_row != win.y_max() - 1)
			{
				current_row++;
				ichigo_flying.move(current_row, current_col);
				if (current_row == win.x_max())
				{
					current_row = 0;
					ichigo_flying.move(current_row, current_col);
				}
			}
			else if (current_col != win.x_max() - 1)
			{
				current_col++;
				ichigo_flying.move(current_row, current_col);
				if (current_col == win.x_max())
				{
					current_col = 0;
					ichigo_flying.move(current_row, current_col);
				}
			}
			ichigo_flying.move(current_row, current_col);
		}
	}

	win.wait_for_button();
}

[Thomas1965]

What about why it's skipping squares?

What squares is it skipping? Did you ran it in VS ?

[DragonOsman]

First it skips from square 1 to square 3, then from 3 to 5, etc. And yes, of course I ran it in VS. I wouldn't know this otherwise.

[Thomas1965]

Just to clarify. Are you talking about my demo or your code ?

Somehow I don't understand your approach with the while loop. Normally you don't need it.
You move the image only when the button is clicked.
Also you should not use current_row != win.y_max() - 1 In this type of code you need to check for row_count

[DragonOsman]

Why would I talking about your demo? I'm talking about my own code, of course. So I don't need a loop?

Edit: Taking out the loop only makes the image move once, and then on the next click of the button the window closes. That's not what I want. It seems I do need a loop.

Edit2:
The code now (still have the same problem of the increment being wrong somehow and the image going off the edge):

int current_row = 0, current_col = 0;
while (current_row < win.y_max() && current_col < win.x_max())
{
	if (win.wait_for_button())
	{
		if (current_row != win.y_max() - 1)
		{
			current_row++;
			ichigo_flying.move(current_row, current_col);
			if (current_row == win.y_max())
			{
				current_row = 0;
				ichigo_flying.move(current_row, current_col);
			}
		}
		else if (current_col != win.x_max() - 1)
		{
			current_col++;
			ichigo_flying.move(current_row, current_col);
		        if (current_col == win.x_max())
			{
				current_col = 0;
				ichigo_flying.move(current_row, current_col);
			}
		}
		ichigo_flying.move(current_row, current_col);
	}
}

Edit: Why don't I just take the easy way and just have the image move to each of the red squares, and exit the program when it reaches the last one? Or would that not fulfill the spec?