draw_vertical_line.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   draw_vertical_line.c                               :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: kamitsui <kamitsui@student.42tokyo.jp>     +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2024/08/26 22:47:33 by kamitsui          #+#    #+#             */
/*   Updated: 2024/12/21 12:08:33 by kamitsui         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */
 
#include "cub3d.h"
 
static void draw_ceiling(t_frame *frame, int x, int ceiling_end)
{
    int y;
 
    y = 0;
    while (y < ceiling_end)
    {
        my_mlx_pixel_put(frame->img_3d, x, y, *frame->ceiling_color);
        y++;
    }
}
 
static void draw_floor(t_frame *frame, int x, int floor_start)
{
    int y;
 
    y = floor_start + 1;
    while (y < IMG_3D_HEIGHT)
    {
        my_mlx_pixel_put(frame->img_3d, x, y, *frame->floor_color);
        y++;
    }
}
 
static int  get_color_texture_pixel(t_frame *frame, int tex_x, int tex_y)
{
    int     offset;
    int     color;
    t_img   img_tex;
 
    img_tex = frame->dda.texture.img_tex;
    offset = (tex_y * img_tex.line_length) + (tex_x * (img_tex.bpp / 8));
    color = *(int *)(img_tex.addr + offset);
    return (color);
}
//  color = *(int *)(img_tex.addr + offset);// compatibility ??
 
int get_texture_y_coordinate(t_frame *frame, int y)
{
    int64_t d;
    int64_t line_height;
    int64_t tex_height;
    int64_t tex_y;
 
    line_height = frame->wall_slice.line_height;
    tex_height = frame->dda.texture.height;
    if (line_height == 0)
        line_height = 1;
    d = (y * 256) - (IMG_3D_HEIGHT * 128) + (line_height * 128);
    if (d < 0)
        d = 0;
    tex_y = ((d * tex_height) / line_height) / 256;
    if (tex_y < 0)
        tex_y = 0;
    if (tex_y > tex_height)
        tex_y = tex_height;
    return (tex_y);
}
 
void    draw_vertical_line(t_frame *frame, int x)
{
    int             y;
    int             tex_x;
    int             tex_y;
    int             color;
 
    tex_x = frame->dda.tex_x;
    if (x < 0 || x >= IMG_3D_WIDTH)
        return ;
    if (frame->wall_slice.draw_start < 0)
        frame->wall_slice.draw_start = 0;
    if (frame->wall_slice.draw_end >= IMG_3D_HEIGHT)
        frame->wall_slice.draw_end = IMG_3D_HEIGHT;
    y = frame->wall_slice.draw_start;
    draw_ceiling(frame, x, y);
    while (y <= frame->wall_slice.draw_end)
    {
        tex_y = get_texture_y_coordinate(frame, y);
        color = get_color_texture_pixel(frame, tex_x, tex_y);
        my_mlx_pixel_put(frame->img_3d, x, y, color);
        y++;
    }
    draw_floor(frame, x, frame->wall_slice.draw_end);
}
    //debug_texture_y_coordinate_overflow(frame, y);