42_cub3d/render.c
mcolonna fc2b243daa s
2024-10-15 12:56:03 +02:00

142 lines
3.9 KiB
C

/* ************************************************************************** */
/* */
/* ::: :::::::: */
/* render.c :+: :+: :+: */
/* +:+ +:+ +:+ */
/* By: mcolonna <mcolonna@student.42.fr> +#+ +:+ +#+ */
/* +#+#+#+#+#+ +#+ */
/* Created: 2024/10/15 12:40:52 by mcolonna #+# #+# */
/* Updated: 2024/10/15 12:51:25 by mcolonna ### ########.fr */
/* */
/* ************************************************************************** */
#include "algo.h"
int render(u_int32_t *img_data)
{
int x; // px
// clear image data
ft_bzero(img_data, SCREEN_WIDTH * SCREEN_HEIGHT * sizeof(int)); // TODO why
// 1
double dirX, dirY, planeX, planeY;
vector_from_rotation(&dirX, &dirY, g_ray.rot, 1);
vector_from_rotation(&planeX, &planeY, g_ray.rot + PI/2, FOV);
x = 0;
while (x < SCREEN_WIDTH)
{
// case player on map (cases)
int mapX = (int)g_ray.posX;
// case player on map (cases)
int mapY = (int)g_ray.posY;
// vector ray direction (1)
double raydirX, raydirY;
{
// ray direction in [-1;+1]. the highter the more to the right (1)
double ray_direction = 2 * x / (double)SCREEN_WIDTH - 1;
raydirX = dirX + planeX * ray_direction;
raydirY = dirY + planeY * ray_direction;
}
// longueur du rayon dans une même colonne de cases (cases)
double deltadistX = (raydirX == 0) ? 1e30 : fabs(1 / raydirX);
// longueur du rayon dans une même ligne de cases (cases)
double deltadistY = (raydirY == 0) ? 1e30 : fabs(1 / raydirY);
// longueur du rayon entre pos actuelle et pos du prochain coté ouest ou est d'une box
double sidedistX;
// longueur du rayon entre pos actuelle et pos du prochain coté nord ou sub d'une box
double sidedistY;
// direction du rayon sur x (+1 or -1)
int stepX;
// direction du rayon sur y (+1 or -1)
int stepY;
if (raydirX < 0)
{
stepX = -1;
sidedistX = (g_ray.posX - mapX) * deltadistX;
}
else
{
stepX = 1;
sidedistX = (mapX + 1.0 - g_ray.posX) * deltadistX;
}
if (raydirY < 0)
{
stepY = -1;
sidedistY = (g_ray.posY - mapY) * deltadistY;
}
else
{
stepY = 1;
sidedistY = (mapY + 1.0 - g_ray.posY) * deltadistY;
}
bool hit = false;
bool side;
while(!hit)
{
// jump to next map square, either in x-direction, or in y-direction
if(sidedistX < sidedistY)
{
sidedistX += deltadistX;
mapX += stepX;
side = false;
}
else
{
sidedistY += deltadistY;
mapY += stepY;
side = true;
}
// check if ray has hit a wall
if(worldMap[mapX][mapY] == 1)
hit = true;
}
// calcul lenght of ray (shortest perpendicular distance between wall and camera plane) (1)
double perpwalldist;
if(!side)
perpwalldist = (sidedistX - deltadistX);
else
perpwalldist = (sidedistY - deltadistY);
// calculate height of line to draw on screen (px)
int lineHeight = (int)(SCREEN_HEIGHT / perpwalldist);
// calculate lowest and highest pixel to fill in current stripe
int drawStart = -lineHeight / 2 + SCREEN_HEIGHT / 2;
if(drawStart < 0)
drawStart = 0;
int drawEnd = lineHeight / 2 + SCREEN_HEIGHT / 2;
if(drawEnd >= SCREEN_HEIGHT)
drawEnd = SCREEN_HEIGHT - 1;
// draw vertical line
int y = 0;
while (y < drawStart)
{
img_data[y * SCREEN_WIDTH + x] = COLOR_CEILING;
y++;
}
while (y < drawEnd)
{
img_data[y * SCREEN_WIDTH + x] = COLOR_WALL;
y++;
}
while (y < SCREEN_HEIGHT)
{
img_data[y * SCREEN_WIDTH + x] = COLOR_FLOOR;
y++;
}
x++;
}
return (0);
}