blobwarsAttrition/src/system/atlas.c

/*
Copyright (C) 2018-2019 Parallel Realities

This program 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 2
of the License, or (at your option) any later version.

This program 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 this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/

#include "atlas.h"

static void loadAtlasData(void);

static Atlas atlases[NUM_ATLAS_BUCKETS];

void initAtlas(void)
{
	memset(&atlases, 0, sizeof(Atlas) * NUM_ATLAS_BUCKETS);

	loadAtlasData();
}

Atlas *getImageFromAtlas(char *filename)
{
	Atlas *a;
	unsigned long i;

	i = hashcode(filename) % NUM_ATLAS_BUCKETS;

	for (a = atlases[i].next ; a != NULL ; a = a->next)
	{
		if (strcmp(a->filename, filename) == 0)
		{
			return a;
		}
	}

	if (!strstr(filename, "/tiles/"))
	{
		SDL_LogMessage(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_WARN, "No such atlas image '%s'", filename);
	}

	return NULL;
}

static void loadAtlasData(void)
{
	Atlas *atlas, *a;
	int x, y, w, h;
	cJSON *root, *node;
	char *text, *filename;
	unsigned long i;

	text = readFile("data/atlas/atlas.json");

	root = cJSON_Parse(text);

	for (node = root->child ; node != NULL ; node = node->next)
	{
		filename = cJSON_GetObjectItem(node, "filename")->valuestring;
		x = cJSON_GetObjectItem(node, "x")->valueint;
		y = cJSON_GetObjectItem(node, "y")->valueint;
		w = cJSON_GetObjectItem(node, "w")->valueint;
		h = cJSON_GetObjectItem(node, "h")->valueint;

		i = hashcode(filename) % NUM_ATLAS_BUCKETS;

		a = &atlases[i];

		/* horrible bit to look for the tail */
		while (a->next)
		{
			a = a->next;
		}

		atlas = malloc(sizeof(Atlas));
		memset(atlas, 0, sizeof(Atlas));
		a->next = atlas;

		STRNCPY(atlas->filename, filename, MAX_FILENAME_LENGTH);
		atlas->rect.x = x;
		atlas->rect.y = y;
		atlas->rect.w = w;
		atlas->rect.h = h;
	}

	cJSON_Delete(root);

	free(text);
}