#include <gint/display.h>

#include "conf.h"
#include "level.h"
#include "camera.h"
#include "tiles.h"

#define VEC_PRECISE_HALF_DISP (Vec){DWIDTH * VEC_PRECISION / (2 * SCALE), DHEIGHT * VEC_PRECISION / (2 * SCALE)}

void level_step(const Level *level) {
}

void level_draw(const Level *level, Camera *camera) {
	for (int i = 0; i < level->layers_count; ++i) {
		layer_draw(level, camera, i);
	}
}

void layer_draw(const Level *level, Camera *camera, uint layer_id) {
	/* Include tileset. */
	extern bopti_image_t img_tileset;
	const Tile *layer = level->layers[layer_id];
	#ifdef FX9860G
	const int color = C_LIGHT;
	#endif /* FX9860G */
	#ifdef FXCG50
	const int color = C_GREEN;
	#endif /* FXCG50 */
	Vec display_tl, display_br;
	vec_cpy(&display_tl, camera->pos);
	vec_cpy(&display_br, display_tl);
	vec_sub(&display_tl, VEC_PRECISE_HALF_DISP);
	vec_add(&display_br, VEC_PRECISE_HALF_DISP);
	vec_div(&display_tl, TILE_SIZE);
	vec_div(&display_br, TILE_SIZE);
	int start_x = (display_tl.x > 0) ? (display_tl.x) : (0);
	int start_y = (display_tl.y > 0) ? (display_tl.y) : (0);
	int end_x = (display_br.x < level->width) ? (display_br.x + 1) : (level->width);
	int end_y = (display_br.y < level->height) ? (display_br.y + 1) : (level->height);
	for (int y = start_y; y < end_y; ++y) {
		for (int x = start_x; x < end_x; ++x) {
			const Tile tile = layer[x + y * level->width];
			if (tile) {
				const Vec tl = {
					(x * TILE_SIZE / VEC_PRECISION - camera->offset.x) * SCALE,
					(y * TILE_SIZE / VEC_PRECISION - camera->offset.y) * SCALE };
				dsubimage(tl.x, tl.y, &img_tileset,
					tile % TILESET_WIDTH * TILE_PX_SIZE,
					tile / TILESET_WIDTH * TILE_PX_SIZE,
					TILE_PX_SIZE, TILE_PX_SIZE, 0);
			}
		}
	}
}