starship/level.c

#include <string.h>
#include <stdio.h>

#include "level.h"

void init_level(Game *g, Level *l, char *filepath) {
  char *file_text = LoadFileText(filepath);
  l->data = malloc(strlen(file_text));
  char *line = NULL, *other_guy = NULL;
  char *first_line = strtok_r(file_text, "\n", &line);
  char* datum = strtok_r(first_line, ",", &other_guy);

  l->data_size = 0;
  do {
    l->data[l->data_size++] = atoi(datum);
  } while ((datum = strtok_r(NULL, ",", &other_guy)));
  l->width = l->data_size;

  while ((first_line = strtok_r(NULL, "\n", &line))) {
    datum = strtok_r(first_line, ",", &other_guy);
    do {
      l->data[l->data_size++] = (char)atoi(datum);
    } while ((datum = strtok_r(NULL, ",", &other_guy)));
  }
  l->length = l->data_size / l->width;

  printf(
	 "Loaded level from '%s': %dx%d = %zd total bytes\n",
	 filepath,
	 l->length,
	 l->width,
	 l->data_size);
  UnloadFileText(file_text);

  l->game = g;
}

size_t level_tile_index_from_position(Level *l, Vector2 p) {
  size_t x_tile = p.x / 32;
  size_t y_tile = p.y / 32;
  return ((y_tile * l->width) + x_tile) % l->data_size;
}

FourIndices rect_corners(Level *l, Rectangle r) {
  return (FourIndices) {
    level_tile_index_from_position(l, (Vector2) { r.x, r.y }),
    level_tile_index_from_position(l, (Vector2) { r.x + r.width, r.y }),
    level_tile_index_from_position(l, (Vector2) { r.x, r.y + r.height }),
    level_tile_index_from_position(l, (Vector2) { r.x + r.width, r.y + r.height}),
  };
}

Color COLORS[4] = {BLACK, DARKGRAY, GRAY, LIGHTGRAY};
void draw_tile(Level *l, float x, float y) {
  size_t index = (size_t)(x + (y * l->width)) % l->data_size;
  size_t data = l->data[index];
  Color c = COLORS[data];
  FourIndices fi = rect_corners(l, l->game->player->bbox);
  if (fi.index[0] == index) c = RED;
  if (fi.index[1] == index) c = RED;
  if (fi.index[2] == index) c = RED;
  if (fi.index[3] == index) c = RED;
  DrawRectangle(x * 32, y * 32, 32, 32, c);
}

void draw_level(Level *l) {
  float y = l->game->player->position.y;
  y /= 32;

  for (int i = 0; i < l->width; i++) {
    for (int j = y - 15; j < y + 15; j++) {
      draw_tile(l, i, j);
    }
  }
}