path: root/config/tetris.c

#include "ecex.h"

#define TETRIS_W 10
#define TETRIS_H 20
#define TETRIS_CELLS (TETRIS_W * TETRIS_H)
#define TETRIS_BUF "*tetris*"
#define TETRIS_MODE "tetris-mode"
#define TETRIS_VAR_BOARD "board"
#define TETRIS_VAR_NEXT "next_piece"

typedef struct tetris_state {
    ecex_plugin_t *plugin;
    int piece;
    int rot;
    int x;
    int y;
    int next_piece;
    unsigned int rng;
    int score;
    int lines;
    int level;
    int game_over;
    int paused;
    int last_drop_ms;
    int drop_interval_ms;
    int log_tick_count;
    int log_draw_count;
    int log_state_id;
} tetris_state_t;

static int tetris_idx(int x, int y) {
    return y * TETRIS_W + x;
}

static int tetris_shape_cell(int piece, int rot, int col, int row) {
    int p = piece % 7;
    int r = rot & 3;
    if (p < 0) p += 7;
    if (col < 0 || col >= 4 || row < 0 || row >= 4) return 0;

    if (p == 0) {
        if ((r & 1) == 0) return row == 1;
        return col == 1;
    }
    if (p == 1) return (row == 1 || row == 2) && (col == 1 || col == 2);
    if (p == 2) {
        if (r == 0) return (row == 1 && col >= 0 && col <= 2) || (row == 2 && col == 1);
        if (r == 1) return (col == 1 && row >= 0 && row <= 2) || (row == 1 && col == 2);
        if (r == 2) return (row == 1 && col >= 0 && col <= 2) || (row == 0 && col == 1);
        return (col == 1 && row >= 0 && row <= 2) || (row == 1 && col == 0);
    }
    if (p == 3) {
        if ((r & 1) == 0) return (row == 1 && (col == 1 || col == 2)) || (row == 2 && (col == 0 || col == 1));
        return (col == 1 && (row == 0 || row == 1)) || (col == 2 && (row == 1 || row == 2));
    }
    if (p == 4) {
        if ((r & 1) == 0) return (row == 1 && (col == 0 || col == 1)) || (row == 2 && (col == 1 || col == 2));
        return (col == 2 && (row == 0 || row == 1)) || (col == 1 && (row == 1 || row == 2));
    }
    if (p == 5) {
        if (r == 0) return (row == 1 && col >= 0 && col <= 2) || (row == 0 && col == 0);
        if (r == 1) return (col == 1 && row >= 0 && row <= 2) || (row == 0 && col == 2);
        if (r == 2) return (row == 1 && col >= 0 && col <= 2) || (row == 2 && col == 2);
        return (col == 1 && row >= 0 && row <= 2) || (row == 2 && col == 0);
    }
    if (r == 0) return (row == 1 && col >= 0 && col <= 2) || (row == 0 && col == 2);
    if (r == 1) return (col == 1 && row >= 0 && row <= 2) || (row == 2 && col == 2);
    if (r == 2) return (row == 1 && col >= 0 && col <= 2) || (row == 2 && col == 0);
    return (col == 1 && row >= 0 && row <= 2) || (row == 0 && col == 0);
}

static int *tetris_board(tetris_state_t *s) {
    if (!s) return 0;
    return (int *)ecex_plugin_slot_alloc(s->plugin, TETRIS_VAR_BOARD, (size_t)TETRIS_CELLS, sizeof(int));
}

static int tetris_next_piece(tetris_state_t *s) {
    return ecex_plugin_slot_i32_get_scalar(s ? s->plugin : 0, TETRIS_VAR_NEXT, 0);
}

static void tetris_set_next_piece(tetris_state_t *s, int piece) {
    if (piece < 0) piece = 0;
    if (piece > 6) piece = piece % 7;
    ecex_plugin_slot_i32_set_scalar(s ? s->plugin : 0, TETRIS_VAR_NEXT, piece);
}

static void tetris_clear_board(tetris_state_t *s) {
    int *board;
    if (!s) { ecex_log("tetris_clear_board: null state"); return; }
    board = tetris_board(s);
    ecex_log_ptr("tetris_clear_board: board=", board);
    ecex_mem_zero(board, (size_t)TETRIS_CELLS * sizeof(int));
    ecex_log("tetris_clear_board: done");
}

static int tetris_pick(tetris_state_t *s) {
    int piece;
    if (!s) { ecex_log("tetris_pick: null state"); return 0; }
    piece = ecex_random_bounded(7);
    if (piece < 0) piece = 0;
    if (piece > 6) piece = piece % 7;
    ecex_log_int("tetris_pick: piece=", piece);
    return piece;
}

static int tetris_collides(tetris_state_t *s, int piece, int rot, int px, int py) {
    int r;
    int c;

    int *board = tetris_board(s);
    if (!s || !board) return 1;
    for (r = 0; r < 4; ++r) {
        for (c = 0; c < 4; ++c) {
            int x;
            int y;
            if (!tetris_shape_cell(piece, rot, c, r)) continue;

            x = px + c;
            y = py + r;
            if (x < 0 || x >= TETRIS_W || y >= TETRIS_H) return 1;
            if (y >= 0 && ecex_i32_get(board, (size_t)tetris_idx(x, y))) return 1;
        }
    }

    return 0;
}

static void tetris_spawn(tetris_state_t *s) {
    int queued;

    ecex_log_ptr("tetris_spawn: state=", s);
    if (!s) return;

    queued = tetris_next_piece(s);
    if (queued < 0 || queued > 6) queued = tetris_pick(s);
    s->piece = queued;
    tetris_set_next_piece(s, tetris_pick(s));

    ecex_log_int("tetris_spawn: current_piece=", s->piece);
    ecex_log_int("tetris_spawn: preview_piece=", tetris_next_piece(s));

    s->rot = 0;
    s->x = 3;
    s->y = -1;
    s->last_drop_ms = 0;

    if (tetris_collides(s, s->piece, s->rot, s->x, s->y)) {
        ecex_log("tetris_spawn: immediate collision -> game over");
        s->game_over = 1;
    }
}

static void tetris_reset(tetris_state_t *s) {
    ecex_log_ptr("tetris_reset: state=", s);
    if (!s) return;

    tetris_clear_board(s);
    ecex_log("tetris_reset: after clear");
    /* Avoid calling libc/time-returning host functions from CCDJIT plugin code.
     * Seed from stable host-owned addresses instead; good enough for a toy game
     * and much safer for the tiny JIT ABI. */
    s->rng = 0x9e3779b9u ^ (unsigned int)(size_t)s ^ (unsigned int)(size_t)tetris_board(s);
    ecex_log_int("tetris_reset: rng=", (int)s->rng);
    s->score = 0;
    s->lines = 0;
    s->level = 1;
    s->game_over = 0;
    s->paused = 0;
    s->last_drop_ms = 0;
    s->drop_interval_ms = 650;
    tetris_set_next_piece(s, tetris_pick(s));
    s->log_tick_count = 0;
    s->log_draw_count = 0;
    ecex_log("tetris_reset: spawning first piece");
    tetris_spawn(s);
    ecex_log("tetris_reset: done");
}

static void tetris_lock(tetris_state_t *s) {
    ecex_log_ptr("tetris_lock: state=", s);
    int r;
    int c;
    int y;
    int cleared = 0;
    int *board;

    if (!s) return;
    board = tetris_board(s);
    if (!board) return;

    for (r = 0; r < 4; ++r) {
        for (c = 0; c < 4; ++c) {
            int x;
            int yy;
            if (!tetris_shape_cell(s->piece, s->rot, c, r)) continue;

            x = s->x + c;
            yy = s->y + r;
            if (x >= 0 && x < TETRIS_W && yy >= 0 && yy < TETRIS_H) {
                ecex_i32_set(board, (size_t)tetris_idx(x, yy), s->piece + 1);
            }
        }
    }

    for (y = TETRIS_H - 1; y >= 0; --y) {
        int x;
        int full = 1;
        for (x = 0; x < TETRIS_W; ++x) {
            if (!ecex_i32_get(board, (size_t)tetris_idx(x, y))) {
                full = 0;
                break;
            }
        }

        if (!full) continue;
        ++cleared;

        {
            int yy;
            for (yy = y; yy > 0; --yy) {
                for (x = 0; x < TETRIS_W; ++x) {
                    ecex_i32_set(board, (size_t)tetris_idx(x, yy), ecex_i32_get(board, (size_t)tetris_idx(x, yy - 1)));
                }
            }
        }

        for (x = 0; x < TETRIS_W; ++x) ecex_i32_set(board, (size_t)tetris_idx(x, 0), 0);
        ++y;
    }

    if (cleared) {
        int points = 0;
        if (cleared == 1) points = 100;
        else if (cleared == 2) points = 300;
        else if (cleared == 3) points = 500;
        else points = 800;

        s->score += points * s->level;
        s->lines += cleared;
        s->level = 1 + s->lines / 10;
        s->drop_interval_ms = 650 - (s->level - 1) * 45;
        if (s->drop_interval_ms < 80) s->drop_interval_ms = 80;
    }

    ecex_log_int("tetris_lock: cleared=", cleared);
    tetris_spawn(s);
}


static int tetris_piece_has_visible_cells(tetris_state_t *s) {
    int r;
    int c;

    if (!s) return 0;
    for (r = 0; r < 4; ++r) {
        for (c = 0; c < 4; ++c) {
            int y;
            if (!tetris_shape_cell(s->piece, s->rot, c, r)) continue;
            y = s->y + r;
            if (y >= 0) return 1;
        }
    }
    return 0;
}

static int tetris_top_out_if_hidden(tetris_state_t *s, const char *where) {
    if (!s) return 1;
    if (tetris_piece_has_visible_cells(s)) return 0;
    ecex_log(where);
    ecex_log_int("tetris_top_out: piece=", s->piece);
    ecex_log_int("tetris_top_out: y=", s->y);
    s->game_over = 1;
    return 1;
}

static int tetris_soft_drop(tetris_state_t *s) {
    if (!s) { ecex_log("tetris_soft_drop: null state"); return 0; }
    if (s->game_over || s->paused) return 0;

    if (!tetris_collides(s, s->piece, s->rot, s->x, s->y + 1)) {
        ++s->y;
        return 1;
    }

    ecex_log_int("tetris_soft_drop: locking piece=", s->piece);
    ecex_log_int("tetris_soft_drop: y=", s->y);
    if (tetris_top_out_if_hidden(s, "tetris_soft_drop: hidden lock -> game over")) return 1;
    tetris_lock(s);
    return 0;
}


static int tetris_move_horizontal(tetris_state_t *s, int dx) {
    int old_x;
    int old_y;
    int old_rot;

    if (!s) { ecex_log("tetris_move_horizontal: null state"); return 0; }
    if (s->game_over || s->paused) return 0;

    old_x = s->x;
    old_y = s->y;
    old_rot = s->rot;

    if (!tetris_collides(s, s->piece, s->rot, old_x + dx, old_y)) {
        s->x = old_x + dx;
        s->y = old_y;
        s->rot = old_rot;

        s->last_drop_ms = 0;
        ecex_log_int("tetris_move_horizontal: x=", s->x);
        ecex_log_int("tetris_move_horizontal: y=", s->y);
        return 1;
    }

    s->x = old_x;
    s->y = old_y;
    s->rot = old_rot;
    return 0;
}

static void tetris_hard_drop(tetris_state_t *s) {
    int moved = 0;
    if (!s || s->game_over || s->paused) return;

    while (!tetris_collides(s, s->piece, s->rot, s->x, s->y + 1)) {
        ++s->y;
        ++moved;
    }

    s->score += moved * 2;
    if (tetris_top_out_if_hidden(s, "tetris_hard_drop: hidden lock -> game over")) return;
    tetris_lock(s);
}

static tetris_state_t *tetris_state_for_ed(ecex_t *ed) {
    buffer_t *buffer;
    tetris_state_t *s;
    ecex_log("tetris_state_for_ed: enter");
    buffer = ecex_find_buffer(ed, TETRIS_BUF);
    ecex_log_ptr("tetris_state_for_ed: buffer=", buffer);
    if (!buffer) return 0;
    s = (tetris_state_t *)ecex_buffer_renderer_userdata(buffer);
    ecex_log_ptr("tetris_state_for_ed: state=", s);
    return s;
}

static int tetris_alpha8(int alpha) {
    if (alpha < 0) return 0;
    if (alpha > 255) return 255;
    return alpha;
}

static void tetris_color(ecex_draw_context_t *ctx, int cell, int alpha) {
    alpha = tetris_alpha8(alpha);
    if (cell == 1) ecex_draw_color_rgba8_i(ctx, 51, 191, 242, alpha);
    else if (cell == 2) ecex_draw_color_rgba8_i(ctx, 242, 217, 51, alpha);
    else if (cell == 3) ecex_draw_color_rgba8_i(ctx, 179, 89, 242, alpha);
    else if (cell == 4) ecex_draw_color_rgba8_i(ctx, 77, 217, 89, alpha);
    else if (cell == 5) ecex_draw_color_rgba8_i(ctx, 242, 64, 64, alpha);
    else if (cell == 6) ecex_draw_color_rgba8_i(ctx, 64, 102, 242, alpha);
    else if (cell == 7) ecex_draw_color_rgba8_i(ctx, 242, 140, 51, alpha);
    else ecex_draw_color_rgba8_i(ctx, 41, 41, 46, alpha);
}

static void tetris_draw_piece(ecex_draw_context_t *ctx,
                              int piece,
                              int rot,
                              int px,
                              int py,
                              int ox,
                              int oy,
                              int cell,
                              int alpha) {
    int r;
    int c;

    for (r = 0; r < 4; ++r) {
        for (c = 0; c < 4; ++c) {
            int bx;
            int by;
            if (!tetris_shape_cell(piece, rot, c, r)) continue;

            bx = px + c;
            by = py + r;
            if (by < 0) continue;
            tetris_color(ctx, piece + 1, alpha);
            ecex_draw_rect_i(ctx, ox + bx * cell + 1, oy + by * cell + 1, cell - 2, cell - 2);
        }
    }
}

static int tetris_tick(ecex_t *ed, buffer_t *buffer, int now_ms, void *userdata) {
    tetris_state_t *s = (tetris_state_t *)userdata;
    (void)ed;
    (void)buffer;

    if (!s) { ecex_log("tetris_tick: null state"); return 0; }
    s->log_tick_count += 1;
    if (s->log_tick_count <= 8 || (s->log_tick_count % 60) == 0) {
        ecex_log_int("tetris_tick: count=", s->log_tick_count);
        ecex_log_int("tetris_tick: now_ms=", now_ms);
    }

    if (s->last_drop_ms <= 0) {
        s->last_drop_ms = now_ms;
        return 1;
    }

    if (!s->game_over && !s->paused && now_ms - s->last_drop_ms >= s->drop_interval_ms) {
        ecex_log("tetris_tick: dropping piece");
        tetris_soft_drop(s);
        s->last_drop_ms = now_ms;
        return 1;
    }

    return 0;
}

static int tetris_draw(ecex_t *ed, buffer_t *buffer, ecex_draw_context_t *ctx, void *userdata) {
    tetris_state_t *s = (tetris_state_t *)userdata;
    int max_board_w;
    int max_board_h;
    int cell;
    int board_w;
    int board_h;
    int ox;
    int oy;
    int sx;
    int sy;
    int x;
    int y;
    int *board;
    (void)ed;
    (void)buffer;

    if (!s) { ecex_log("tetris_draw: null state"); return 0; }
    if (!ctx) { ecex_log("tetris_draw: null ctx"); return 0; }
    board = tetris_board(s);
    if (!board) { ecex_log("tetris_draw: no plugin board slot"); return 0; }
    s->log_draw_count += 1;
    if (s->log_draw_count <= 8 || (s->log_draw_count % 60) == 0) {
        ecex_log_int("tetris_draw: count=", s->log_draw_count);
        ecex_log_int("tetris_draw: ctx_w=", (int)ctx->w);
        ecex_log_int("tetris_draw: ctx_h=", (int)ctx->h);
    }

    if (s->log_draw_count <= 3) ecex_log("tetris_draw: background");
    ecex_draw_color_rgba8_i(ctx, 20, 23, 28, 255);
    ecex_draw_rect_i(ctx, 0, 0, (int)ctx->w, (int)ctx->h);

    max_board_w = ((int)ctx->content_w * 62) / 100;
    max_board_h = (int)ctx->content_h - 24;
    cell = max_board_w / TETRIS_W;
    if (cell * TETRIS_H > max_board_h) cell = max_board_h / TETRIS_H;
    if (cell < 6) cell = 6;

    board_w = cell * TETRIS_W;
    board_h = cell * TETRIS_H;
    ox = (int)ctx->content_x + 12;
    oy = (int)ctx->content_y + 12;

    if (s->log_draw_count <= 3) ecex_log("tetris_draw: board frame");
    ecex_draw_color_rgba8_i(ctx, 8, 9, 12, 255);
    ecex_draw_rect_i(ctx, ox - 6, oy - 6, board_w + 12, board_h + 12);
    ecex_draw_color_rgba8_i(ctx, 97, 102, 115, 255);
    ecex_draw_rect_outline_i(ctx, ox - 6, oy - 6, board_w + 12, board_h + 12, 2);

    if (s->log_draw_count <= 3) ecex_log("tetris_draw: cells");
    for (y = 0; y < TETRIS_H; ++y) {
        for (x = 0; x < TETRIS_W; ++x) {
            int cell_value = ecex_i32_get(board, (size_t)tetris_idx(x, y));
            tetris_color(ctx, cell_value, cell_value ? 255 : 140);
            ecex_draw_rect_i(ctx, ox + x * cell + 1, oy + y * cell + 1, cell - 2, cell - 2);
        }
    }

    if (s->log_draw_count <= 3) ecex_log("tetris_draw: active piece");
    tetris_draw_piece(ctx, s->piece, s->rot, s->x, s->y, ox, oy, cell, 255);

    sx = ox + board_w + 28;
    sy = oy;

    if (s->log_draw_count <= 3) ecex_log("tetris_draw: sidebar");
    ecex_draw_color_rgba8_i(ctx, 235, 235, 214, 255);
    ecex_log("tetris_draw: sidebar title");
    ecex_draw_label_i(ctx, sx, sy, 1);
    sy += ((int)ctx->line_height * 16) / 10;

    ecex_draw_stat_i(ctx, sx, sy, 2, s->score);
    sy += (int)ctx->line_height;

    ecex_draw_stat_i(ctx, sx, sy, 3, s->lines);
    sy += (int)ctx->line_height;

    ecex_draw_stat_i(ctx, sx, sy, 4, s->level);
    sy += ((int)ctx->line_height * 15) / 10;

    ecex_draw_label_i(ctx, sx, sy, 5);
    sy += ((int)ctx->line_height * 8) / 10;
    ecex_log_int("tetris_draw: preview_piece=", tetris_next_piece(s));
    ecex_draw_tetris_preview_i(ctx, tetris_next_piece(s), sx, sy, (cell * 72) / 100, 255);
    sy += cell * 4;

    ecex_draw_color_rgba8_i(ctx, 184, 189, 199, 255);
    ecex_log("tetris_draw: sidebar help");
    ecex_draw_label_i(ctx, sx, sy, 6); sy += (int)ctx->line_height;
    ecex_draw_label_i(ctx, sx, sy, 7); sy += (int)ctx->line_height;
    ecex_draw_label_i(ctx, sx, sy, 8); sy += (int)ctx->line_height;
    ecex_draw_label_i(ctx, sx, sy, 9); sy += (int)ctx->line_height;
    ecex_draw_label_i(ctx, sx, sy, 10); sy += (int)ctx->line_height;
    ecex_draw_label_i(ctx, sx, sy, 11);

    if (s->paused || s->game_over) {
        ecex_draw_color_rgba8_i(ctx, 0, 0, 0, 174);
        ecex_draw_rect_i(ctx, ox, oy + (board_h * 43) / 100, board_w, ((int)ctx->line_height * 22) / 10);
        ecex_draw_color_rgba8_i(ctx, 255, 235, 89, 255);
        ecex_draw_label_i(ctx, ox + cell, oy + (board_h * 43) / 100 + ((int)ctx->line_height * 55) / 100, s->game_over ? 12 : 13);
    }

    if (s->log_draw_count <= 3) ecex_log("tetris_draw: done");
    return 0;
}

static void tetris_free_state(void *userdata) {
    tetris_state_t *s = (tetris_state_t *)userdata;
    if (!s) return;
    ecex_plugin_object_free(s->plugin, s);
}

static int cmd_tetris(ecex_t *ed) {
    buffer_t *buffer;
    tetris_state_t *s;

    ecex_log("cmd_tetris: enter");
    ecex_log_ptr("cmd_tetris: ed=", ed);
    if (!ed) { ecex_log("cmd_tetris: no editor"); return -1; }

    buffer = ecex_find_buffer(ed, TETRIS_BUF);
    ecex_log_ptr("cmd_tetris: existing buffer=", buffer);
    if (!buffer) {
        ecex_log("cmd_tetris: creating interactive buffer");
        buffer = ecex_create_interactive_buffer(ed, TETRIS_BUF);
    }
    ecex_log_ptr("cmd_tetris: buffer=", buffer);
    if (!buffer) { ecex_log("cmd_tetris: buffer creation failed"); return -1; }

    s = (tetris_state_t *)ecex_buffer_renderer_userdata(buffer);
    ecex_log_ptr("cmd_tetris: existing state=", s);
    if (!s) {
        ecex_log_int("cmd_tetris: allocating state bytes=", (int)sizeof(*s));
        ecex_plugin_t *plugin = ecex_plugin_find(ed, "tetris");
        s = (tetris_state_t *)ecex_plugin_object_calloc(plugin, "state", 1, sizeof(*s));
        ecex_log_ptr("cmd_tetris: allocated state=", s);
        if (!s) { ecex_log("cmd_tetris: allocation failed"); return -1; }
        s->plugin = plugin;
        ecex_log_int("cmd_tetris: board slot bytes=", (int)((size_t)TETRIS_CELLS * sizeof(int)));
        ecex_log_ptr("cmd_tetris: board slot=", tetris_board(s));
        if (!tetris_board(s)) {
            ecex_log("cmd_tetris: board slot allocation failed");
            ecex_plugin_object_free(plugin, s);
            return -1;
        }

        tetris_reset(s);

        ecex_log("cmd_tetris: setting renderer");
        if (ecex_buffer_set_renderer(buffer, tetris_draw, s, tetris_free_state, ECEX_RENDER_REPLACE_CONTENT) != 0) {
            ecex_log("cmd_tetris: set_renderer failed");
            ecex_plugin_object_free(plugin, s);
            return -1;
        }

        ecex_log("cmd_tetris: setting animation");
        if (ecex_buffer_set_animation_ms(buffer, tetris_tick, s, 0, 60) != 0) {
            ecex_log("cmd_tetris: set_animation failed");
            ecex_buffer_clear_renderer(buffer);
            return -1;
        }
    }

    ecex_log("cmd_tetris: replacing text");
    if (ecex_buffer_replace_text(buffer, "Tetris renderer. Press n for a new game, q to quit the window.\n") != 0) {
        ecex_log("cmd_tetris: replace text failed");
        return -1;
    }

    ecex_log("cmd_tetris: setting modified false");
    ecex_buffer_set_modified(buffer, 0);
    ecex_log("cmd_tetris: setting major mode");
    if (ecex_buffer_set_major_mode_by_name(ed, buffer, TETRIS_MODE) != 0) { ecex_log("cmd_tetris: set mode failed"); return -1; }
    ecex_log("cmd_tetris: switching buffer");
    if (ecex_switch_buffer(ed, TETRIS_BUF) != 0) { ecex_log("cmd_tetris: switch failed"); return -1; }
    ecex_log("cmd_tetris: success");
    return 0;
}

static int cmd_tetris_new(ecex_t *ed) {
    ecex_log("cmd_tetris_new: enter");
    tetris_state_t *s = tetris_state_for_ed(ed);
    if (!s) return cmd_tetris(ed);
    tetris_reset(s);
    return 0;
}

static int cmd_tetris_left(ecex_t *ed) {
    ecex_log("cmd_tetris_left: enter");
    tetris_move_horizontal(tetris_state_for_ed(ed), -1);
    return 0;
}

static int cmd_tetris_right(ecex_t *ed) {
    ecex_log("cmd_tetris_right: enter");
    tetris_move_horizontal(tetris_state_for_ed(ed), 1);
    return 0;
}

static int cmd_tetris_down(ecex_t *ed) {
    ecex_log("cmd_tetris_down: enter");
    tetris_state_t *s = tetris_state_for_ed(ed);
    if (s) {
        if (tetris_soft_drop(s)) s->score += 1;
        s->last_drop_ms = 0;
    }
    return 0;
}

static int cmd_tetris_rotate(ecex_t *ed) {
    ecex_log("cmd_tetris_rotate: enter");
    tetris_state_t *s = tetris_state_for_ed(ed);
    int nr;

    if (!s || s->game_over || s->paused) return 0;

    nr = (s->rot + 1) & 3;
    if (!tetris_collides(s, s->piece, nr, s->x, s->y)) {
        s->rot = nr;
    } else if (!tetris_collides(s, s->piece, nr, s->x - 1, s->y)) {
        --s->x;
        s->rot = nr;
    } else if (!tetris_collides(s, s->piece, nr, s->x + 1, s->y)) {
        ++s->x;
        s->rot = nr;
    }

    return 0;
}

static int cmd_tetris_drop(ecex_t *ed) {
    ecex_log("cmd_tetris_drop: enter");
    tetris_hard_drop(tetris_state_for_ed(ed));
    return 0;
}

static int cmd_tetris_pause(ecex_t *ed) {
    ecex_log("cmd_tetris_pause: enter");
    tetris_state_t *s = tetris_state_for_ed(ed);
    if (s && !s->game_over) {
        s->paused = !s->paused;
        s->last_drop_ms = 0;
    }
    return 0;
}

static int cmd_tetris_quit(ecex_t *ed) {
    ecex_log("cmd_tetris_quit: enter");
    return ecex_execute_command(ed, "quit-window");
}

ECEX_PLUGIN_BEGIN(ecex_tetris_plugin, "tetris")
    ecex_log("ecex_tetris_plugin: enter");
    (void)plugin;
    ECEX_CONFIG_MODE(TETRIS_MODE);
    ECEX_CONFIG_COMMAND("tetris", cmd_tetris);
    ECEX_CONFIG_COMMAND("tetris-new", cmd_tetris_new);
    ECEX_CONFIG_COMMAND("tetris-left", cmd_tetris_left);
    ECEX_CONFIG_COMMAND("tetris-right", cmd_tetris_right);
    ECEX_CONFIG_COMMAND("tetris-down", cmd_tetris_down);
    ECEX_CONFIG_COMMAND("tetris-rotate", cmd_tetris_rotate);
    ECEX_CONFIG_COMMAND("tetris-drop", cmd_tetris_drop);
    ECEX_CONFIG_COMMAND("tetris-pause", cmd_tetris_pause);
    ECEX_CONFIG_COMMAND("tetris-quit", cmd_tetris_quit);

    ECEX_CONFIG_MODE_BIND(TETRIS_MODE, "LEFT", "tetris-left");
    ECEX_CONFIG_MODE_BIND(TETRIS_MODE, "h", "tetris-left");
    ECEX_CONFIG_MODE_BIND(TETRIS_MODE, "RIGHT", "tetris-right");
    ECEX_CONFIG_MODE_BIND(TETRIS_MODE, "l", "tetris-right");
    ECEX_CONFIG_MODE_BIND(TETRIS_MODE, "DOWN", "tetris-down");
    ECEX_CONFIG_MODE_BIND(TETRIS_MODE, "j", "tetris-down");
    ECEX_CONFIG_MODE_BIND(TETRIS_MODE, "UP", "tetris-rotate");
    ECEX_CONFIG_MODE_BIND(TETRIS_MODE, "k", "tetris-rotate");
    ECEX_CONFIG_MODE_BIND(TETRIS_MODE, "SPC", "tetris-drop");
    ECEX_CONFIG_MODE_BIND(TETRIS_MODE, "p", "tetris-pause");
    ECEX_CONFIG_MODE_BIND(TETRIS_MODE, "n", "tetris-new");
    ECEX_CONFIG_MODE_BIND(TETRIS_MODE, "q", "tetris-quit");

    ecex_log("ecex_tetris_plugin: registered all commands and keybinds");
    return 0;
ECEX_PLUGIN_END

#ifndef ECEX_NO_STANDALONE_CONFIG
ECEX_CONFIG_BEGIN
    ECEX_CONFIG_INCLUDE(ecex_tetris_plugin);
ECEX_CONFIG_END
#endif