tdkpin/original/reconstructed/tdkpin_player_state.c

/* Player initialization and multi-player redraw paths from TDKPIN Code1. */

#include "tdkpin_player_state.h"

#include "tdkpin_arithmetic.h"

static Win16FarPtr caller_receiver(uint16_t caller_bp)
{
    uint16_t offset = win16_read_stack_u16((uint16_t)(caller_bp + 6));
    uint16_t selector = win16_read_stack_u16((uint16_t)(caller_bp + 8));
    return win16_make_far_pointer(selector, offset);
}

/*
 * 1000:a72c -- initialize collision mirrors and all configured player state.
 * The collision field at record +43 is copied into four receiver rows even
 * when fewer than four players are configured, exactly as the binary does.
 */
void tdkpin_initialize_player_state(uint16_t caller_bp)
{
    Win16FarPtr receiver = caller_receiver(caller_bp);
    for (uint16_t record_id = 1; record_id <= 175; record_id++) {
        tdkpin_refresh_collision_record(caller_bp, record_id);
        uint16_t mirrored = win16_read_u16(win16_dgroup_pointer((uint16_t)(
            0x095b + record_id * 0x53u + 0x43u)));
        for (uint16_t player = 1; player <= 4; player++) {
            win16_write_u16(
                receiver,
                (uint16_t)(0x036c + player * 0x015eu + record_id * 2u),
                mirrored);
        }
    }
    for (uint16_t item = 1; item <= 5; item++) {
        tdkpin_restore_record_b(caller_bp, (uint16_t)(1000 + item));
    }
    tdkpin_draw_score_from_caller_frame(caller_bp, 0, 0);
    win16_write_u8(win16_dgroup_pointer(0x0874), 0);

    for (uint8_t player = 1; player <= 4; player++) {
        if (player <= g_player_count) {
            g_current_player = player;
            win16_write_u32(
                win16_dgroup_pointer((uint16_t)(0x097e + player * 4u)),
                0,
                0);
            win16_write_u32(
                win16_dgroup_pointer((uint16_t)(0x098e + player * 4u)),
                0,
                0);
            win16_write_u8(
                win16_dgroup_pointer((uint16_t)(0x09a1 + player)), 1);
            win16_write_u16(
                win16_dgroup_pointer((uint16_t)(0x09a4 + player * 2u)),
                0,
                0);
            tdkpin_add_score_from_caller_frame(caller_bp, 0);
            win16_write_u8(
                win16_dgroup_pointer((uint16_t)(0x0816 + player)), 1);
            win16_write_u16(
                win16_dgroup_pointer((uint16_t)(0x081f + player * 2u)),
                0,
                player < 2 ? 2 : 3);
            tdkpin_refresh_player_progress_markers(caller_bp);
            win16_write_u32(
                win16_dgroup_pointer((uint16_t)(0x0835 + player * 4u)),
                0,
                1);
            win16_write_u8(
                win16_dgroup_pointer((uint16_t)(0x081a + player)), 1);
            for (uint16_t item = 1; item <= 20; item++) {
                win16_write_u8(
                    win16_far_add_offset(receiver, (uint16_t)(
                        0x0467 + player * 0x14u + item)),
                    0);
            }
        }
    }

    g_current_player = 1;
    win16_write_u8(win16_dgroup_pointer(0x07d2), 0);
    for (uint16_t item = 1; item <= 20; item++) {
        tdkpin_refresh_player_item(caller_bp, item);
    }
}

/* 1000:acc2 -- redraw each configured player and emphasize the active row. */
void tdkpin_redraw_all_players(uint16_t caller_bp)
{
    Win16FarPtr receiver = caller_receiver(caller_bp);
    HWND16 window = win16_read_u16(win16_far_add_offset(receiver, 4));
    HDC16 dc = GetDC16(window);
    uint8_t saved_player = g_current_player;
    uint8_t count = g_player_count;
    for (uint8_t player = 1; player <= count; player++) {
        INT16 row_y = (INT16)((uint16_t)(player - 1u) * 44u + 276u);
        tdkpin_restore_background_region_a(31, 139, row_y, 472, dc);
        tdkpin_present_background_region(31, 139, row_y, 472, dc);
        g_current_player = player;
        INT16 marker_y = (INT16)((uint16_t)(player - 1u) * 44u + 280u);
        if (player == saved_player) {
            tdkpin_add_score_from_caller_frame(caller_bp, 0);
            uint32_t secondary = win16_read_u32(
                win16_dgroup_pointer((uint16_t)(0x098e + player * 4u)));
            uint8_t multiplier = win16_read_u8(
                win16_dgroup_pointer((uint16_t)(0x09a1 + player)));
            int32_t shown = borland_multiply_i32(
                (int32_t)secondary, multiplier);
            tdkpin_draw_score_from_caller_frame(
                caller_bp, (uint16_t)shown, (uint16_t)((uint32_t)shown >> 16));
            uint16_t sprite = win16_read_u16(
                win16_dgroup_pointer((uint16_t)(0x09a4 + player * 2u)));
            tdkpin_composite_player_sprite(sprite, dc);
            tdkpin_present_background_region(123, 42, 79, 55, dc);
            tdkpin_restore_background_region_a(11, 11, marker_y, 372, dc);
        } else {
            tdkpin_add_score_from_caller_frame(caller_bp, -1);
            tdkpin_restore_background_region_b(11, 11, marker_y, 372, dc);
        }
        tdkpin_present_background_region(11, 11, marker_y, 372, dc);
    }
    g_current_player = saved_player;
    (void)ReleaseDC16(window, dc);
}

static Win16FarPtr active_secondary_score(void)
{
    return win16_dgroup_pointer((uint16_t)(
        0x098e + (uint16_t)g_current_player * 4u));
}

static uint8_t active_score_multiplier(void)
{
    return win16_read_u8(win16_dgroup_pointer((uint16_t)(
        0x09a1 + (uint16_t)g_current_player)));
}

static void draw_active_secondary_score(uint16_t caller_bp)
{
    int32_t shown = borland_multiply_i32(
        (int32_t)win16_read_u32(active_secondary_score()),
        active_score_multiplier());
    tdkpin_draw_score_from_caller_frame(
        caller_bp, (uint16_t)shown, (uint16_t)((uint32_t)shown >> 16));
}

/* 1000:c4e1 -- apply the effect selected by the active player's sprite index. */
void tdkpin_apply_player_sprite_effect(
    uint16_t caller_bp, int16_t argument)
{
    uint16_t effect = win16_read_u16(win16_dgroup_pointer((uint16_t)(
        0x09a4 + (uint16_t)g_current_player * 2u)));
    static const uint32_t additions[5] = {
        10000u, 20000u, 50000u, 100000u, 200000u};
    if (effect >= 1 && effect <= 5) {
        Win16FarPtr secondary = active_secondary_score();
        win16_write_u32(
            secondary,
            0,
            win16_read_u32(secondary) + additions[effect - 1u]);
        draw_active_secondary_score(caller_bp);
    } else if (effect == 6) {
        int32_t transfer = borland_multiply_i32(
            (int32_t)win16_read_u32(active_secondary_score()),
            active_score_multiplier());
        tdkpin_add_score_from_caller_frame(caller_bp, transfer);
        win16_write_u32(active_secondary_score(), 0, 0);
        tdkpin_draw_score_from_caller_frame(caller_bp, 0, 0);
    } else if (effect == 7) {
        uint16_t required = win16_read_u16(
            win16_dgroup_pointer(0x399a));
        if (required != 0 &&
            (argument < 0 || required != (uint16_t)argument)) {
            Win16FarPtr receiver = caller_receiver(caller_bp);
            win16_write_u8(win16_far_add_offset(receiver, 0x0be0), 1);
            win16_write_u8(win16_dgroup_pointer(0x0874), 1);
        }
    }
}