Files
tetris_clone/src/game/tetromino/placing.c
2025-07-07 10:57:02 +02:00

119 lines
3.4 KiB
C

#include "placing.h"
#include <stdint.h>
#include <string.h>
#include <sys/cdefs.h>
#include "../../io/audio.h"
#include "../../io/input.h"
#include "../../util/types.h"
#include "../../util/vec.h"
#include "../game.h"
#include "shapes.h"
/* count the empty columns in the row */
__attribute_const__ static int count_empty(u8 const* restrict row) {
int cnt = 0;
#if defined(__clang__)
#pragma unroll COLUMNS
#elif defined(__GNUC__)
#pragma GCC unroll COLUMNS
#endif
for (int i = 0; i < COLUMNS; i++)
cnt += !row[i];
return cnt;
}
/* checks for filled rows, clearing a max of 4 consecutive rows, if present.
* all row pointers will be moved down to fill the gap, the filled rows will be inserted at the top, and zeroed-out */
static void clear_rows(u8* restrict* restrict rows, u16* const score) {
u8* cache[4] = {0}; // the I piece is 4 long, meaning only 4 rows can be cleared at a time
uint fillc = 0;
uint checkc = 0;
for (uint y = 0; y < (ROWS - fillc) && checkc <= 4; y++) {
int i = (ROWS - 1) - y; // invert the index direction, so we start at the highest index
rows[i] = rows[i - fillc]; // either assigns the current row to itself, or to the "next" row
if (count_empty(rows[i])) {
checkc += (fillc > 0 && checkc < 4);
continue;
}
cache[fillc] = rows[i]; // cache the current row address, since it's going to be overridden
fillc++;
checkc++;
y--;
}
*score += (8 << fillc) * !!fillc;
for (uint i = 0; i < fillc; i++) {
memset(cache[i], 0, COLUMNS);
rows[i] = cache[i];
}
}
/* writes a shape to the screen */
static void plcmnt_place(u8* restrict const* restrict row, u8 id, i8vec2 pos) {
u8 colour = colour_from_id(id);
i8vec2 bpos[4];
shape_getblocks(id, bpos);
bpos[0] += pos;
bpos[1] += pos;
bpos[2] += pos;
bpos[3] += pos;
row[bpos[0][VY]][bpos[0][VX]] = colour;
row[bpos[1][VY]][bpos[1][VX]] = colour;
row[bpos[2][VY]][bpos[2][VX]] = colour;
row[bpos[3][VY]][bpos[3][VX]] = colour;
}
static int plcmnt_valid(u8* restrict const* restrict const rows, i8vec2 pos) {
return pos[VX] >= 0 && pos[VX] < COLUMNS &&
pos[VY] >= 0 && pos[VY] < ROWS &&
!rows[pos[VY]][pos[VX]];
}
static int plcmnt_intersect(u8* restrict const* restrict const rows, u8 const id, i8vec2 pos) {
i8vec2 bpos[4];
shape_getblocks(id, bpos);
return !(plcmnt_valid(rows, pos + bpos[0]) &&
plcmnt_valid(rows, pos + bpos[1]) &&
plcmnt_valid(rows, pos + bpos[2]) &&
plcmnt_valid(rows, pos + bpos[3]));
}
int place_update(struct gamedata* gdat, int movdat) {
// store the current index and ID, only changes when placed (which yields no movement) and rotation (which occurs last)
int tmp;
u8 id = gdat->pdat.cur;
// update Y axis
tmp = !!(movdat & MOVD);
gdat->pdat.sel[VY] += tmp;
tmp = tmp && plcmnt_intersect(gdat->rows, id, gdat->pdat.sel);
if (tmp) {
gdat->pdat.sel[VY]--;
plcmnt_place(gdat->rows, id, gdat->pdat.sel);
clear_rows(gdat->rows, &gdat->pnts); // clear the rows that have been completed
next_shape();
audio_play(AUDIO_ID_PLACE);
if (plcmnt_intersect(gdat->rows, gdat->pdat.cur, gdat->pdat.sel))
return 1;
}
// update X axis
tmp = !!(movdat & MOVR) - !!(movdat & MOVL);
gdat->pdat.sel[VX] += (tmp && !plcmnt_intersect(gdat->rows, id, (i8vec2){gdat->pdat.sel[VX] + tmp, gdat->pdat.sel[VY]})) * tmp;
// update roll
tmp = id ^ (((!!(movdat & MOVRR) - !!(movdat & MOVRL)) * 8 + id) & 31);
gdat->pdat.cur ^= (tmp && !plcmnt_intersect(gdat->rows, id ^ tmp, gdat->pdat.sel)) * tmp;
return 0;
}