/*
 * This file is part of the Minecraft Overviewer.
 *
 * Minecraft Overviewer is free software: you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or (at
 * your option) any later version.
 *
 * Minecraft Overviewer is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
 * Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with the Overviewer.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "overlay.h"
#include <math.h>

typedef struct {
    /* inherits from overlay */
    RenderPrimitiveOverlay parent;
} RenderPrimitiveSpawn;

static OverlayColor default_color[] = { 229, 36, 38, 0 };

static void get_color(void *data, RenderState *state,
                      unsigned char *r, unsigned char *g, unsigned char *b, unsigned char *a) {
    RenderPrimitiveSpawn* self = (RenderPrimitiveSpawn *)data;
    int x = state->x, y = state->y, z = state->z;
    int y_light = y + 1;
    unsigned char blocklight, skylight;
    
    /* set a nice, pretty red color */
    *r = self->parent.color->r;
    *g = self->parent.color->g;
    *b = self->parent.color->b;
    
    /* default to no overlay, until told otherwise */
    *a = 0;
    
    if (block_has_property(state->block, NOSPAWN)) {
        /* nothing can spawn on this */
        return;
    }
    
    blocklight = get_data(state, BLOCKLIGHT, x, y_light, z);
    skylight = get_data(state, SKYLIGHT, x, y_light, z);
    
    if (MAX(blocklight, skylight) <= 7) {
        /* hostile mobs spawn in daylight */
        *a = 240;
    } else if (MAX(blocklight, skylight - 11) <= 7) {
        /* hostile mobs spawn at night */
        *a = 150;
    }
}

static int
overlay_spawn_start(void *data, RenderState *state, PyObject *support) {
    RenderPrimitiveSpawn* self;

    /* first, chain up */
    int ret = primitive_overlay.start(data, state, support);
    if (ret != 0)
        return ret;
    
    /* now do custom initializations */
    self = (RenderPrimitiveSpawn *)data;
    self->parent.get_color = get_color;
    
    return 0;
}

static void
overlay_spawn_finish(void *data, RenderState *state) {
    /* chain up */
    primitive_overlay.finish(data, state);
}

RenderPrimitiveInterface primitive_overlay_spawn = {
    "overlay-spawn",
    sizeof(RenderPrimitiveSpawn),
    overlay_spawn_start,
    overlay_spawn_finish,
    NULL,
    NULL,
    overlay_draw,
};