borgware-2d/games/tetris/piece.c

70 lines
1.8 KiB
C

#include <stdlib.h>
#include <assert.h>
#include <stdint.h>
#include "../../compat/pgmspace.h"
#include "piece.h"
/*****************************
* construction/destruction *
*****************************/
tetris_piece_t *tetris_piece_construct(tetris_piece_shape_t s,
tetris_piece_angle_t a)
{
tetris_piece_t *p_piece = (tetris_piece_t*) malloc (sizeof(tetris_piece_t));
assert(p_piece != NULL);
p_piece->shape = s;
p_piece->angle = a;
return p_piece;
}
/****************************
* piece related functions *
****************************/
uint16_t tetris_piece_getBitmap(tetris_piece_t *pPc)
{
assert(pPc != NULL);
assert((pPc->angle < 4) && (pPc->shape < 7));
// Lookup table:
// A value in an array represents a piece in a specific angle (rotating
// clockwise from index 0).
static uint16_t const piece[][4] PROGMEM =
{{0x0F00, 0x2222, 0x0F00, 0x2222}, // LINE
{0x4E00, 0x4640, 0x0E40, 0x4C40}, // T
{0x0660, 0x0660, 0x0660, 0x0660}, // SQUARE
{0x2E00, 0x88C0, 0x0E80, 0xC440}, // L
{0x8E00, 0x6440, 0x0E20, 0x44C0}, // LBACK
{0x6C00, 0x4620, 0x6C00, 0x4620}, // S
{0xC600, 0x4C80, 0xC600, 0x4C80}}; // Z
return pgm_read_word(&piece[pPc->shape][pPc->angle]);
}
void tetris_piece_rotate(tetris_piece_t *pPc,
tetris_piece_rotation_t nRotation)
{
assert(pPc != NULL);
assert(nRotation < 2);
// we just rotate through the available angles in the given direction and
// wrap around (via modulo) where appropriate
pPc->angle = (pPc->angle + ((nRotation == TETRIS_PC_ROT_CW) ? 1 : 3)) % 4;
}
uint8_t tetris_piece_getAngleCount(tetris_piece_t *pPc)
{
assert(pPc != NULL);
static int8_t const angleCounts[] PROGMEM = {2, 4, 1, 4, 4, 2, 2};
return pgm_read_byte(&angleCounts[pPc->shape]);
}