cub3d/src/render/render_sprite.c
2025-05-08 23:19:35 +02:00

148 lines
4.1 KiB
C

/* ************************************************************************** */
/* */
/* :::::::: */
/* render_sprite.c :+: :+: */
/* +:+ */
/* By: whaffman <whaffman@student.codam.nl> +#+ */
/* +#+ */
/* Created: 2025/05/08 12:23:17 by qmennen #+# #+# */
/* Updated: 2025/05/08 23:18:06 by whaffman ######## odam.nl */
/* */
/* ************************************************************************** */
#include "render.h"
static void sort_sprites(t_game *game)
{
t_sprite sprite_temp;
int n;
int i;
int new_n;
n = game->map->n_sprites;
while (n > 1)
{
i = 1;
new_n = 0;
while (i <= n - 1)
{
if (game->map->sprites[i - 1].dist < game->map->sprites[i].dist)
{
sprite_temp = game->map->sprites[i - 1];
game->map->sprites[i - 1] = game->map->sprites[i];
game->map->sprites[i] = sprite_temp;
new_n = i;
}
i++;
}
n = new_n;
}
}
static void calculate_sprite_dist(t_game *game)
{
int i;
t_vec2 player_pos;
i = 0;
player_pos = game->player->pos;
while (i < game->map->n_sprites)
{
game->map->sprites[i].dist = dist_point_line(game->map->sprites[i].pos,
(t_vec2_line){player_pos, game->player->camera});
i++;
}
}
static void cam_fraction(t_game *game, t_sprite *sprite)
{
t_vec2 ps;
double frac_cam;
double frac_sprite;
double denominator;
ps = sub(sprite->pos, game->player->pos);
frac_cam = (ps.y * game->player->dir.x - ps.x * game->player->dir.y);
denominator = (ps.x * game->player->camera.y - ps.y * game->player->camera.x);
frac_sprite = (game->player->camera.y * game->player->dir.x - game->player->camera.x * game->player->dir.y);
if (denominator == 0 || (frac_sprite / denominator) < 0)
{
sprite->cam_frac = NAN;
return;
}
sprite->cam_frac = frac_cam / denominator;
if (sprite->cam_frac < -1 || sprite->cam_frac > 1)
{
sprite->cam_frac = NAN;
return;
}
return;
}
unsigned int sample_texture_color(mlx_texture_t *texture, int x, int y, double dist)
{
int index;
int alpha;
index = (x + y * texture->width) * texture->bytes_per_pixel;
dist = (dist > 1) * dist + (dist <= 1) * 1;
alpha = (texture->pixels[index + 3] != 0) * (255.0 / dist);
return texture->pixels[index] << 24 | texture->pixels[index + 1] << 16 | texture->pixels[index + 2] << 8 | alpha;
}
void draw_sprite(t_game *game, t_sprite *sprite, t_render *render)
{
double sprite_scale;
int x_start;
int y_start;
int x_end;
int y_end;
int x;
int y;
double tex_x;
double tex_y;
unsigned int color;
if (isnan(sprite->cam_frac) || sprite->dist <= 0)
return;
sprite_scale = 16.0 / sprite->dist;
x_start = game->screen->width * 0.5 * (1.0 + sprite->cam_frac) - (sprite->texture->width * sprite_scale * 0.5);
y_start = (game->screen->height - sprite->texture->height * sprite_scale )* 0.5;
x_end = x_start + (sprite->texture->width * sprite_scale);
y_end = y_start + (sprite->texture->height * sprite_scale);
x = x_start;
while (x < x_end)
{
if (x > 0 && x < game->screen->width && sprite->dist <= render[x].perp_dist)
{
y = y_start;
tex_x = ((double)((x - x_start) / (double)(x_end - x_start))) * sprite->texture->width;
while (y < y_end)
{
tex_y = ((double)((y- y_start) / (double)(y_end - y_start))) * sprite->texture->height;
color = sample_texture_color(sprite->texture, (int)(tex_x), (int)(tex_y), sprite->dist);
if (y > 0 && y < game->screen->height && (color & 0xFF) != 0)
{
mlx_put_pixel(game->screen->img, x, y, color);
}
y++;
}
}
x++;
}
}
void render_sprites(t_render *render, t_game *game)
{
int i;
calculate_sprite_dist(game);
sort_sprites(game);
i = 0;
while (i < game->map->n_sprites)
{
cam_fraction(game, &game->map->sprites[i]);
draw_sprite(game, &game->map->sprites[i], render);
i++;
}
}