Mechanic · input & timing · rhythm

Timing window

The span of time around a note in which a rhythm game takes a press as on time, and how it grades presses inside and outside it.

stubAlso: judgement window, judgment window, hit window, timing judgementUpdated 2026-10-22
On this page
  1. Related
  2. Games
  3. References
  4. Sources

A timing window is how far from the beat a press can land and still count. PaRappa the Rapper 2 doesn’t measure the distance to a note. It sorts each press into a slot of a grid fixed to the beat: a press in a scoring run counts, and one in the gap between runs costs, so 16 of every 24 ticks1 take a press1.

  • Beat gridPaRappa the Rapper 2 (2001). Each press falls in a 4-tick slot of a 96-tick cycle, a beat at the computed tempo scale; runs from 4 ticks before to 11 after each quarter beat score, and the 8-tick gaps between them cost.1

See also

Mentioned in

Games

GameYearHowNote
PaRappa the Rapper 22001Beat grideach press falls in a 4-tick slot of a 96-tick cycle, a beat at the computed tempo scale; runs from 4 ticks before to 11 after each quarter beat score, and the 8-tick gaps between them cost
Every claim about this mechanic, by game (1)
PaRappa the Rapper 2 2001In the July 12th NTSC-J prototype of PaRappa the Rapper 2, a press is judged by which slot of a fixed grid it lands in, not by its distance from the teacher's note. The line clock converts a vsync count to ticks as count × 96 × tempo / 3600, so with 60 vsyncs a second and tempo in beats per minute a beat is 96 ticks (computed). Each press is stored with its time less the line's start time (ofs_frame); on_th_make adds that start modulo 96, plus 96, and divides by 4, which puts the press in the 4-tick slot of its own time modulo 96 (computed). thnum_get reads the slot in a 24-bit pattern that repeats every beat and numbers its runs of equal bits, so a press in a run of 1s gets an even th_num and a press in a run of 0s an odd one. For the main grid (CK_TH_NORMAL, 0x00e79e79) the 1s cover ticks 92 to 11, 20 to 35, 44 to 59, and 68 to 83 of each beat, that is from 4 ticks before to 11 ticks after each multiple of 24 (a quarter of the beat), and the 0s cover the 8 ticks from 12 to 19 after it (computed). In the first of a line's three checks, exh_normal_add counts each press in a 1-run whose key the teacher's line uses (otehon_all; while the rank is Cool, any key, and in one-button play, triangle) and exh_normal_sub takes one off for each such press in a 0-run, each weighted 48/16, that is ±3 (computed); a press anywhere in a run scores the same. The same check's imitation test (exh_mane, weight 8/16) runs over every pair of a teacher's note and a press and counts each pair with the same th_num and, outside one-button play, the same key, so one press can count once for each note in its run; it scores 2 × that count − presses; it runs again on a late grid (CK_TH_LATE, 0x00f3cf3c, with the teacher's notes moved 2 slots later) and keeps the better result. The third check uses a swing grid (CK_TH_HANE, 0x00c1cc1c). A line's score (now_score) is the sum of the three checks' totals, and in the game play step (PSTEP_GAME) it is then halved as (now_score + 1) / 2 in one-button play (PLAY_TYPE_ONE) and halved that way again in the easy table mode (PLAY_TABLE_EASY), so twice when both apply; a check's total is 0 when its all-keys test fails and −100 when the presses reach the line's length in 24-tick steps, rounded up, plus 3 (exh_renda_out). In the hook play step (PSTEP_HOOK) a line is scored by an imitation test alone (manemane_check), on the main grid.Code

References

  1. ^ abcIn the July 12th NTSC-J prototype of PaRappa the Rapper 2, a press is judged by which slot of a fixed grid it lands in, not by its distance from the teacher's note. The line clock converts a vsync count to ticks as count × 96 × tempo / 3600, so with 60 vsyncs a second and tempo in beats per minute a beat is 96 ticks (computed). Each press is stored with its time less the line's start time (ofs_frame); on_th_make adds that start modulo 96, plus 96, and divides by 4, which puts the press in the 4-tick slot of its own time modulo 96 (computed). thnum_get reads the slot in a 24-bit pattern that repeats every beat and numbers its runs of equal bits, so a press in a run of 1s gets an even th_num and a press in a run of 0s an odd one. For the main grid (CK_TH_NORMAL, 0x00e79e79) the 1s cover ticks 92 to 11, 20 to 35, 44 to 59, and 68 to 83 of each beat, that is from 4 ticks before to 11 ticks after each multiple of 24 (a quarter of the beat), and the 0s cover the 8 ticks from 12 to 19 after it (computed). In the first of a line's three checks, exh_normal_add counts each press in a 1-run whose key the teacher's line uses (otehon_all; while the rank is Cool, any key, and in one-button play, triangle) and exh_normal_sub takes one off for each such press in a 0-run, each weighted 48/16, that is ±3 (computed); a press anywhere in a run scores the same. The same check's imitation test (exh_mane, weight 8/16) runs over every pair of a teacher's note and a press and counts each pair with the same th_num and, outside one-button play, the same key, so one press can count once for each note in its run; it scores 2 × that count − presses; it runs again on a late grid (CK_TH_LATE, 0x00f3cf3c, with the teacher's notes moved 2 slots later) and keeps the better result. The third check uses a swing grid (CK_TH_HANE, 0x00c1cc1c). A line's score (now_score) is the sum of the three checks' totals, and in the game play step (PSTEP_GAME) it is then halved as (now_score + 1) / 2 in one-button play (PLAY_TYPE_ONE) and halved that way again in the easy table mode (PLAY_TABLE_EASY), so twice when both apply; a check's total is 0 when its all-keys test fails and −100 when the presses reach the line's length in 24-tick steps, rounded up, plus 3 (exh_renda_out). In the hook play step (PSTEP_HOOK) a line is scored by an imitation test alone (manemane_check), on the main grid.Codeparappadev/parappa2revised
    How we know
    3990        if (scr_main_pp->scr_ctrl_pp[i].gtime_type == GTIME_VSYNC) {
3991            scr_main_pp->scr_ctrl_pp[i].lineTime =  ((TimeCallbackTimeGetChan(i) * 96.0f * GetLineTempo(i) + 1800.0f)  / 3600.0f);
    src/main/scrctrl.c lines 3990–3991 at 45694de · upstream ↗
    2141        SCR_TAP_MEMORY *mkey_pp = &sindv_pp->scr_tap_memory[sindv_pp->scr_tap_memory_cnt];
⋮
2145        mkey_pp->ofs_frame = onKeyTime - tapset_pp->taptimeStart - sindv_pp->current_time;
    src/main/scrctrl.c lines 2141–2145 at 45694de · upstream ↗
    2765        exam_check[i].tapset_pp = IndvGetTapSetAdrs(sindv_pp);
⋮
2770            exam_check[i].ofs_tick = exam_check[i].tapset_pp->taptimeStart + sindv_pp->current_time;
⋮
2776            exam_check[i].otehon_all = otehon_all_make(&exam_check[i]);
⋮
2785        if (global_data.play_typeL == PLAY_TYPE_ONE) {
2786            exam_check[i].otehon_all = KcTR;
    src/main/scrctrl.c lines 2765–2787 at 45694de · upstream ↗
    136static u_int thnum_tbl[] = { 0x00e79e79, 0x00f3cf3c, 0x00c1cc1c, 0x00000000 };
    src/main/scrctrl.c line 136 at 45694de · upstream ↗
    2222static int thnum_get(int p96_num, CK_TH_ENUM ckth) {
⋮
2230    thnum_data = thnum_tbl[ckth];
⋮
2232    for (i = 0; i <= p96_num; i++) {
2233        ck_dat = (thnum_data >> (23 - (i % 24))) & 1;
⋮
2235        if (ck_bit < 0) {
2236            if (ck_dat == 0) {
2237                ret_cnt = 1;
⋮
2239        } else if (ck_dat != ck_bit) {
2240            ret_cnt++;
    src/main/scrctrl.c lines 2222–2247 at 45694de · upstream ↗
    2253static void on_th_make(EXAM_CHECK *ec_pp, CK_TH_ENUM ckth) {
⋮
2267    ofsT = ec_pp->ofs_tick % 96;
2268    ofsT += 96;
⋮
2273        frame   = ec_pp->stm_pp[i].ofs_frame;
2274        p96_num = (frame + ofsT) / 4;
⋮
2277        ec_pp->ted[i].th_num = thnum_get(p96_num, ckth);
⋮
2304            p96_num = (frame + ofsT) / 4;
⋮
2306            if (ckth == CK_TH_LATE) {
2307                p96_num += 2;
⋮
2311            ec_pp->oth[i].th_num = thnum_get(p96_num, ckth);
    src/main/scrctrl.c lines 2253–2312 at 45694de · upstream ↗
    2317static int exh_normal_add(EXAM_CHECK *ec_pp) {
⋮
2322        if (!(ec_pp->ted[i].th_num & 1)) {
2323            if (GetIndex2KeyCode(ec_pp->ted[i].key) & ec_pp->otehon_all) {
2324                ret++;
⋮
2332static int exh_normal_sub(EXAM_CHECK *ec_pp) {
⋮
2337        if (GetIndex2KeyCode(ec_pp->ted[i].key) & ec_pp->otehon_all) {
2338            ret -= ec_pp->ted[i].th_num & 1;
    src/main/scrctrl.c lines 2317–2343 at 45694de · upstream ↗
    99static EXH_STR exh_str_normal[] = {
100    { .score_prg = exh_normal_add,    .save_p = EXH_NORMAL_ADD,    .bairitu = 48 },
101    { .score_prg = exh_normal_sub,    .save_p = EXH_NORMAL_SUB,    .bairitu = 48 },
⋮
108    { .score_prg = exh_mane,          .save_p = EXH_MANE,          .bairitu = 8  },
109    { .score_prg = exh_all_add,       .save_p = EXH_TOTAL,         .bairitu = 16 },
    src/main/scrctrl.c lines 99–110 at 45694de · upstream ↗
    2583static int exh_renda_out(EXAM_CHECK *ec_pp) {
⋮
2586    renda_ck = ec_pp->tapset_pp->taptimeEnd - ec_pp->tapset_pp->taptimeStart;
2587    renda_ck = ((renda_ck + 23) / 24);
2588    renda_ck += 3;
⋮
2590    if (ec_pp->ted_num >= renda_ck) {
2591        return -1;
⋮
2597static int manemane_check_sub(EXAM_CHECK *ec_pp) {
⋮
2605            if (global_data.play_typeL == PLAY_TYPE_ONE) {
2606                if (ec_pp->oth[i].th_num == ec_pp->ted[j].th_num) {
2607                    mane_cnt++;
⋮
2610                if (ec_pp->oth[i].th_num == ec_pp->ted[j].th_num) {
2611                    if (ec_pp->oth[i].key == ec_pp->ted[j].key) {
⋮
    src/main/scrctrl.c lines 2583–2684 at 45694de · upstream ↗
    2790    if (global_data.play_step == PSTEP_HOOK) {
⋮
2796        scrprgstr_pp  = scrprgstr_hook;
⋮
2813            exam_check_pp->each_point[scrprgstr_pp->exh_str_pp[j].save_p] = (ret * scrprgstr_pp->exh_str_pp[j].bairitu) / 16;
⋮
2816        CK_TH_ENUM  ck_th_enum_tbl[3] = { 
2817            CK_TH_NORMAL, 
2818            CK_TH_NORMAL, 
2819            CK_TH_HANE
⋮
2829            on_th_make(exam_check_pp, ck_th_enum_tbl[i]);
⋮
2844                exam_check_pp->each_point[scrprgstr_pp->exh_str_pp[j].save_p] = (ret * scrprgstr_pp->exh_str_pp[j].bairitu) / 16;
⋮
2853        sum += exam_check[i].each_point[EXH_TOTAL];
⋮
2856    sindv_pp->global_ply->now_score = sum;
    src/main/scrctrl.c lines 2790–2856 at 45694de · upstream ↗
    3077        if (scex_pp->exam_do == EXAM_DO_NON) {
3078            ExamScoreCheck(sindv_pp);
⋮
3080            if (global_data.play_step == PSTEP_GAME) {
3081                if (global_data.play_typeL == PLAY_TYPE_ONE) {
3082                    sindv_pp->global_ply->now_score = (sindv_pp->global_ply->now_score + 1) / 2;
⋮
3084                if (global_data.play_table_modeL == PLAY_TABLE_EASY) {
3085                    sindv_pp->global_ply->now_score = (sindv_pp->global_ply->now_score + 1) / 2;
    src/main/scrctrl.c lines 3077–3087 at 45694de · upstream ↗
    131static EXH_STR exh_str_hook[] = {
132    { .score_prg = manemane_check,    .save_p = EXH_MANE,          .bairitu = 16 },
133    { .score_prg = exh_all_add,       .save_p = EXH_TOTAL,         .bairitu = 16 },
    src/main/scrctrl.c lines 131–134 at 45694de · upstream ↗

    Checked against the evidence by its author, an AI model, 2026-10-22.

    Revised after a check by a second AI model, 2026-10-22.

    In the claim ledger

Sources

Code