physic.c

#include "physic.h"
#include "constans.h"

int map[15][20] = {
    {1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1},
    {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
    {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
    {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
    {0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0},
    {0,0,0,0,0,0,0,1,1,1,1,1,1,0,0,0,0,0,0,0},
    {0,1,1,0,0,0,0,0,0,1,1,0,0,0,0,0,0,1,1,0},
    {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
    {0,0,0,1,1,1,0,0,0,0,0,0,0,0,1,1,1,0,0,0},
    {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
    {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
    {1,1,0,0,0,1,1,1,0,0,0,0,1,1,1,0,0,0,1,1},
    {1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1},
    {1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1},
    {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1}};

int sign(int a) {
    if (a < 0) {
        return -1;
    } else if (a > 0) {
        return 1;
    } else {
        return 0;
    }
}

void decrement_abs(int *a) {
    *a -= sign(*a);
}

int check_collisions(SDL_Rect *rect) {
    if (map[rect->y/TILE_SIZE][rect->x/TILE_SIZE] ||
            map[(rect->y + rect->h)/TILE_SIZE][rect->x/TILE_SIZE] ||
            map[(rect->y)/TILE_SIZE][(rect->x + rect->w)/TILE_SIZE] ||
            map[(rect->y + rect->h)/TILE_SIZE][(rect->x + rect->w)/TILE_SIZE] ||
            rect->x <= 0 || (rect->x + rect->w >= SCREEN_WIDTH)) {
        return true;
    } else {
        return false;
    }
}


int move_and_check_collisions(SDL_Rect *position, int axis, int mov) {
    SDL_Rect temp = *position;

    if (axis == X_AXIS) {
        temp.x += sign(mov);
    }

    if (axis == Y_AXIS) {
        temp.y += sign(mov);
    }

    if (check_collisions(&temp)) {
        return 0;
    } else {
        *position = temp;
        return 1;
    }
}
 
void move_bullets(struct node **bullets) {
    struct node *next = *bullets;
    struct Bullet *b = NULL;
    int i = 0;
    while (next != NULL) {
        b = (struct Bullet*) next->data;
        b->position.x += PLAYER_SPEED * b->face * 1;
        next = next->next;
        if (check_collisions(&b->position)) {
            erase_element(bullets, i);
        } else {
            i++;
        }
    }
}

int check_if_player_dies(struct Player *player, struct node **bullets, int *killer) {
    struct node *next = *bullets;
    struct SDL_Rect b; 
    struct SDL_Rect p = player->position;
    int i = 0;
    while (next != NULL) {
        b = ((struct Bullet*) next->data)->position;
        if (p.x < (b.x + b.w) &&
                (p.x + p.w) > b.x &&
                p.y < (b.y + b.h) &&
                (p.y + p.h) > b.y) {
            *killer = ((struct Bullet*) next->data)->player_id;
            erase_element(bullets, i);
            return true;
        }
        next = next->next;
        i++;
    }
    return false;
}



void move_player(struct Player *player) {
    int x_movement = 0;
    int y_movement = 0;
    if (player->left) {
        x_movement -= PLAYER_SPEED;
        player->face = -1;
    }
    if (player->right) {
        x_movement += PLAYER_SPEED;
        player->face = 1;
    }
    if (player->up) {
        if (player->can_jump) {
            player->can_jump = false;
            player->y_speed = -PLAYER_JUMP_POWER;
        }
    }
    
    y_movement = player->y_speed / 3;
    if (player->y_speed < MAX_VERTICAL_SPEED) {
        player->y_speed += GRAVITY;
    }

    while (x_movement != 0 || y_movement != 0) {
        if (x_movement != 0 && move_and_check_collisions(&player->position, X_AXIS, x_movement)) {
            decrement_abs(&x_movement);
        } else {
            x_movement = 0;
        }

        if (y_movement != 0 && move_and_check_collisions(&player->position, Y_AXIS, y_movement)) {
            decrement_abs(&y_movement);
            player->can_jump = false;
        } else {
            if(y_movement > 0) {
                player->can_jump = true;
                player->y_speed = 0;
            }
            if(y_movement < 0) {
                player->y_speed = 0;
            }
            y_movement = 0;
        }
    }
}

SDL_Texture* get_map_texture(SDL_Renderer *renderer) {
    SDL_Surface *bitmap = NULL;
    SDL_Texture *map_texture;
    SDL_Rect rect;
    rect.w = TILE_SIZE;
    rect.h = TILE_SIZE;
    bitmap = SDL_LoadBMP("resources/tile.bmp");
    SDL_Texture *tex = NULL;
    tex = SDL_CreateTextureFromSurface(renderer, bitmap);
    map_texture = SDL_CreateTexture(renderer,SDL_PIXELFORMAT_RGBA8888, SDL_TEXTUREACCESS_TARGET, SCREEN_WIDTH, SCREEN_HEIGHT);
    SDL_SetRenderTarget(renderer, map_texture);
    int i, j;
    for (i = 0; i < SCREEN_HEIGHT / TILE_SIZE; i++) {
        for (j = 0; j < SCREEN_WIDTH / TILE_SIZE; j++) {
            if (map[i][j]) {
                rect.x = TILE_SIZE * j;
                rect.y = TILE_SIZE * i;
                SDL_RenderCopy(renderer, tex, NULL, &rect);
            }
        }
    }
    SDL_SetRenderTarget(renderer, NULL);
    return map_texture;
}