/*
 * Icon generation helpers for slide puzzle game
 * Copyright © 2022 Nick Bowler
 *
 * 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 3 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, see <https://www.gnu.org/licenses/>.
 */

#ifndef RRACE_ICON_H_
#define RRACE_ICON_H_

/*
 * Generate one tile of the program icon at various sizes, which is a 3x3 grid
 * of coloured tiles.
 *
 * These functions all operate as follows:
 *
 *   - icon points to the start of the complete image buffer, in row-major
 *     order.  Each byte represents one pixel of the icon, so for example the
 *     16x16 icon requires a 256-byte buffer.
 *
 *   - c controls the byte values that are written to the icon for this tile.
 *     The least significant 8 bits of c encode the primary colour, bits 8-15
 *     encode the dark shade colour, and bits 16-23 encode the light shade
 *     colour.
 *
 *   - tile_x and tile_y select which tile to render (each may be 0, 1 or 2).
 *
 * By calling the function 9 times with all combinations of tile_x/tile_y
 * values, a complete icon is generated.
 */

void icon_tile16(unsigned char *icon, unsigned long c, int tile_x, int tile_y);
void icon_tile24(unsigned char *icon, unsigned long c, int tile_x, int tile_y);
void icon_tile32(unsigned char *icon, unsigned long c, int tile_x, int tile_y);
void icon_tile48(unsigned char *icon, unsigned long c, int tile_x, int tile_y);

#endif