draw.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   draw.c                                             :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: taehkwon <taehkwon@student.42.fr>          +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2023/07/06 19:26:11 by taehkwon          #+#    #+#             */
/*   Updated: 2023/07/27 20:29:12 by taehkwon         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "fdf.h"

void	draw_row(t_image *image, t_map *map)
{
	int		i;
	int		j;
	t_coord	first_coord;
	t_coord	second_coord;

	i = 0;
	while (i < map->height)
	{
		j = 0;
		while (j < map->width - 1)
		{
			first_coord = map->p_map[i * map->width + j];
			second_coord = map->p_map[i * map->width + (j + 1)];
			dda(image, first_coord, second_coord);
			j++;
		}
		i++;
	}
}

void	draw_col(t_image *image, t_map *map)
{
	int		i;
	int		j;
	t_coord	first_coord;
	t_coord	second_coord;

	i = 0;
	while (i < map->width)
	{
		j = 0;
		while (j < map->height - 1)
		{
			first_coord = map->p_map[j * map->width + i];
			second_coord = map->p_map[(j + 1) * map->width + i];
			dda(image, first_coord, second_coord);
			j++;
		}
		i++;
	}
}

void	dda(t_image *image, t_coord first, t_coord second)
{
	t_dda	dda_utils;
	t_dda	*p_dda;
	t_coord	*p;

	dda_utils.dx = second.x - first.x;
	dda_utils.dy = second.y - first.y;
	if (fabs(dda_utils.dx) > fabs(dda_utils.dy))
		dda_utils.step = fabs(dda_utils.dx);
	else
		dda_utils.step = fabs(dda_utils.dy);
	dda_utils.x_inc = dda_utils.dx / dda_utils.step;
	dda_utils.y_inc = dda_utils.dy / dda_utils.step;
	p = &first;
	p_dda = &dda_utils;
	dda_inc(image, p_dda, p);
}

void	dda_inc(t_image *image, t_dda *dda, t_coord *p)
{
	double	x_diff;
	double	y_diff;
	int		i;

	x_diff = WIDTH / 2;
	y_diff = HEIGHT / 2;
	i = 0;
	while (i <= dda->step)
	{
		if ((p->x + x_diff > 0 && p->y + y_diff > 0) \
		|| (p->x + x_diff < WIDTH && p->y + y_diff < HEIGHT))
		{
			pixel_color(image, (p->x + x_diff), (p->y + y_diff), p->color);
		}
		p->x = p->x + dda->x_inc;
		p->y = p->y + dda->y_inc;
		i++;
	}
}

void	pixel_color(t_image *image, int x, int y, int color)
{
	char	*dst;

	dst = image->ptr + (y * image->line_length + x * \
		(image->bits_per_pixel / 8));
	*(unsigned int *)dst = color;
}