#include <allegro.h>
#include <stdlib.h>
#include <stdio.h>

#include "lighting.h"

/* Load bitmap in given color depth, scale to screen size, and compensate
 * for desired lighting effects */
static BITMAP* load_funky_bitmap(char* filename)
{
	int x, y;
	BITMAP* ret;
	BITMAP* tmp;

	set_color_depth(32);
	ret = load_bitmap(filename, NULL);
	tmp = create_bitmap(ret->w, ret->h);
	
	if (use_overbright && !use_shadow)
		for (y = 0; y < ret->h; y++)
			for (x = 0; x < ret->w * 4; x += 4) {
				tmp->line[y][x] =
					ret->line[y][x] / 4 + 191;
				tmp->line[y][x + 1] =
					ret->line[y][x + 1] / 4 + 191;
				tmp->line[y][x + 2] =
					ret->line[y][x + 2] / 4 + 191;
			}
	else if (use_overbright && use_shadow)
		for (y = 0; y < ret->h; y++)
			for (x = 0; x < ret->w * 4; x += 4) {
				tmp->line[y][x] = ret->line[y][x];
				tmp->line[y][x + 1] = ret->line[y][x + 1];
				tmp->line[y][x + 2] = ret->line[y][x + 2];
			}
	else if (!use_overbright && use_shadow)
		for (y = 0; y < ret->h; y++)
			for (x = 0; x < ret->w * 4; x += 4) {
				tmp->line[y][x] =
					ret->line[y][x] * 191 / 255;
				tmp->line[y][x + 1] =
					ret->line[y][x + 1] * 191 / 255;
				tmp->line[y][x + 2] =
					ret->line[y][x + 2] * 191 / 255;
			}
	destroy_bitmap(ret);
	ret = create_bitmap(SCREEN_W, SCREEN_H);
	stretch_blit(tmp, ret, 0, 0, tmp->w, tmp->h, 0, 0, ret->w, ret->h);
	destroy_bitmap(tmp);

	return ret;
}

/* Load all the funky lighting maps */
BITMAP** load_lighting_maps(void)
{
	BITMAP** light;
	int i, y, x, ri, gi, bi;
	char filename[64];
	BITMAP* tmp;

	light = malloc(sizeof(BITMAP*) * 29);

	/* Allocate bitmaps */
	for (i = 0; i < 29; i++)
		light[i] = create_bitmap_ex(32, SCREEN_W, SCREEN_H);

	/* See if no special lighting effects are desired */
	if (!use_overbright && !use_shadow) {
		for (i = 0; i < 29; i++)
			clear_to_color(light[i], makecol32(191, 191, 191));
		return light;
	}

	/* Create the bitmaps from files on disk */
	for (i = 0; i < 29; i++) {
		ri = i % 29;
		gi = (i + 9) % 29;
		bi = (i + 18) % 29;

		sprintf(filename, "resource/light.%02i.bmp", i + 1);
		tmp = load_funky_bitmap(filename);

		/* Bring the colors out of phase */
		for (y = 0; y < SCREEN_H; y++)
			for (x = 0; x < SCREEN_W * 4; x += 4) {
				light[ri]->line[y][x] = tmp->line[y][x];
				light[gi]->line[y][x + 1] = tmp->line[y][x + 1];
				light[bi]->line[y][x + 2] = tmp->line[y][x + 2];
			}
	}
	return light;
}