#include "bootpack.h"

#define SHEET_USE 1

struct SHTCTL *shtctl_init(struct MEMMAN *memman, unsigned char *vram, int xsize, int ysize)
{
    struct SHTCTL *ctl;
    int i;
    ctl = (struct SHTCTL *)memman_alloc_4k(memman, sizeof(struct SHTCTL));
    if (ctl == 0)
    {
        goto err;
    }
    ctl->map = (unsigned char *)memman_alloc_4k(memman, xsize * ysize);
    if (ctl->map == 0)
    {
        memman_free_4k(memman, (int)ctl, sizeof(struct SHTCTL));
        goto err;
    }
    ctl->vram = vram;
    ctl->xsize = xsize;
    ctl->ysize = ysize;
    ctl->top = -1; /* 一个图层都没有 */
    for (i = 0; i < MAX_SHEETS; i++)
    {
        ctl->sheets0[i].flags = 0; /* 标记为未使用 */
        ctl->sheets0[i].ctl = ctl;
    }
err:
    return ctl;
}

struct SHEET *sheet_alloc(struct SHTCTL *ctl)
{
    struct SHEET *sht;
    int i;
    for (i = 0; i < MAX_SHEETS; i++)
    {
        if (ctl->sheets0[i].flags == 0)
        {
            sht = &ctl->sheets0[i];
            sht->flags = SHEET_USE; /* 标记为正在使用 */
            sht->height = -1;       /* 隐藏 */
            return sht;
        }
    }
    return 0; /* 所有的SHEET都处于正在使用状态 */
}

void sheet_setbuf(struct SHEET *sht, unsigned char *buf, int xsize, int ysize, int col_inv)
{
    sht->buf = buf;
    sht->bxsize = xsize;
    sht->bysize = ysize;
    sht->col_inv = col_inv;
    return;
}

void sheet_refreshmap(struct SHTCTL *ctl, int vx0, int vy0, int vx1, int vy1, int h0)
{
    int h, bx, by, vx, vy, bx0, by0, bx1, by1;
    unsigned char *buf, sid, *map = ctl->map;
    struct SHEET *sht;
    if (vx0 < 0)
    {
        vx0 = 0;
    }
    if (vy0 < 0)
    {
        vy0 = 0;
    }
    if (vx1 > ctl->xsize)
    {
        vx1 = ctl->xsize;
    }
    if (vy1 > ctl->ysize)
    {
        vy1 = ctl->ysize;
    }
    for (h = h0; h <= ctl->top; h++)
    {
        sht = ctl->sheets[h];
        sid = sht - ctl->sheets0; /* 将进行了减法计算的地址作为图层号码使用 */
        buf = sht->buf;
        bx0 = vx0 - sht->vx0;
        by0 = vy0 - sht->vy0;
        bx1 = vx1 - sht->vx0;
        by1 = vy1 - sht->vy0;
        if (bx0 < 0)
        {
            bx0 = 0;
        }
        if (by0 < 0)
        {
            by0 = 0;
        }
        if (bx1 > sht->bxsize)
        {
            bx1 = sht->bxsize;
        }
        if (by1 > sht->bysize)
        {
            by1 = sht->bysize;
        }
        for (by = by0; by < by1; by++)
        {
            vy = sht->vy0 + by;
            for (bx = bx0; bx < bx1; bx++)
            {
                vx = sht->vx0 + bx;
                if (buf[by * sht->bxsize + bx] != sht->col_inv)
                {
                    map[vy * ctl->xsize + vx] = sid;
                }
            }
        }
    }
    return;
}

void sheet_updown(struct SHEET *sht, int height)
{
    int h, old = sht->height; /* 存储设置前的高度 */
    struct SHTCTL *ctl = sht->ctl;
    /* 如果指定的高度过高或过低, 则进行修正 */
    if (height > ctl->top + 1)
    {
        height = ctl->top + 1;
    }
    if (height < -1)
    {
        height = -1;
    }
    sht->height = height; /* 设定高度 */

    /* 对sheets[] 进行重排序 */
    if (old > height)
    { /* 比以前低 */
        if (height >= 0)
        {
            /* 把中间的往上提 */
            for (h = old; h > height; h--)
            {
                ctl->sheets[h] = ctl->sheets[h - 1];
                ctl->sheets[h]->height = h;
            }
            ctl->sheets[height] = sht;
            sheet_refreshmap(ctl, sht->vx0, sht->vy0, sht->vx0 + sht->bxsize, sht->vy0 + sht->bysize, height + 1);
			sheet_refreshsub(ctl, sht->vx0, sht->vy0, sht->vx0 + sht->bxsize, sht->vy0 + sht->bysize, height + 1, old);
        }
        else
        { /* 隐藏 */
            if (ctl->top > old)
            {
                /* 把上面的降下来 */
                for (h = old; h < ctl->top; h++)
                {
                    ctl->sheets[h] = ctl->sheets[h + 1];
                    ctl->sheets[h]->height = h;
                }
            }
            ctl->top--; /* 由于显示中的图层减少了一个, 所以最上面的图层高度下降 */
            sheet_refreshmap(ctl, sht->vx0, sht->vy0, sht->vx0 + sht->bxsize, sht->vy0 + sht->bysize, 0);
			sheet_refreshsub(ctl, sht->vx0, sht->vy0, sht->vx0 + sht->bxsize, sht->vy0 + sht->bysize, 0, old - 1);
        }
    }
    else if (old < height)
    { /* 比以前高 */
        if (old >= 0)
        {
            /* 把中间的图层降低 */
            for (h = old; h < height; h++)
            {
                ctl->sheets[h] = ctl->sheets[h + 1];
                ctl->sheets[h]->height = h;
            }
            ctl->sheets[height] = sht;
        }
        else
        { /* 由隐藏的状态转为显示的状态 */
            /* 将已在上面的提上来 */
            for (h = ctl->top; h >= height; h--)
            {
                ctl->sheets[h + 1] = ctl->sheets[h];
                ctl->sheets[h + 1]->height = h + 1;
            }
            ctl->sheets[height] = sht;
            ctl->top++; /* 由于已显示的图层增加了1个, 所以最上面的图层高度增加 */
        }
        sheet_refreshmap(ctl, sht->vx0, sht->vy0, sht->vx0 + sht->bxsize, sht->vy0 + sht->bysize, height);
		sheet_refreshsub(ctl, sht->vx0, sht->vy0, sht->vx0 + sht->bxsize, sht->vy0 + sht->bysize, height, height);
    }
    return;
}

// 自底向上的渲染图层
void sheet_refresh(struct SHEET *sht, int bx0, int by0, int bx1, int by1)
{
    if (sht->height >= 0)
    { /* 如果正在显示, 则按图层刷新画面 */
        sheet_refreshsub(sht->ctl, sht->vx0 + bx0, sht->vy0 + by0, sht->vx0 + bx1, sht->vy0 + by1, sht->height);
    }
    return;
}

void sheet_slide(struct SHEET *sht, int vx0, int vy0)
{
    struct SHTCTL *ctl = sht->ctl;
    int old_vx0 = sht->vx0, old_vy0 = sht->vy0;
    sht->vx0 = vx0;
    sht->vy0 = vy0;
    if (sht->height >= 0)
    {
        sheet_refreshmap(ctl, old_vx0, old_vy0, old_vx0 + sht->bxsize, old_vy0 + sht->bysize, 0);
        sheet_refreshmap(ctl, vx0, vy0, vx0 + sht->bxsize, vy0 + sht->bysize, sht->height);
        sheet_refreshsub(ctl, old_vx0, old_vy0, old_vx0 + sht->bxsize, old_vy0 + sht->bysize, 0, sht->height - 1);
        sheet_refreshsub(ctl, vx0, vy0, vx0 + sht->bxsize, vy0 + sht->bysize, sht->height, sht->height);
    }
    return;
}

void sheet_free(struct SHEET *sht)
{
    if (sht->height >= 0)
    {
        sheet_updown(sht, -1); /* 如果正在显示,则设为隐藏 */
    }
    sht->flags = 0; /* "未使用" 状态 */
    return;
}

void sheet_refreshsub(struct SHTCTL *ctl, int vx0, int vy0, int vx1, int vy1, int h0)
{
    int h, bx, by, vx, vy, bx0, by0, bx1, by1;
    unsigned char *buf, *vram = ctl->vram, *map = ctl->map, sid;
    struct SHEET *sht;
    /* 如果refresh的范围超出了画面则修正 */
    if (vx0 < 0)
    {
        vx0 = 0;
    }
    if (vy0 < 0)
    {
        vy0 = 0;
    }
    if (vx1 > ctl->xsize)
    {
        vx1 = ctl->xsize;
    }
    if (vy1 > ctl->ysize)
    {
        vy1 = ctl->ysize;
    }
    for (h = h0; h <= ctl->top; h++)
    {
        sht = ctl->sheets[h];
        buf = sht->buf;
        sid = sht - ctl->sheets0;

        bx0 = vx0 - sht->vx0;
        by0 = vy0 - sht->vy0;
        bx1 = vx1 - sht->vx0;
        by1 = vy1 - sht->vy0;
        if (bx0 < 0)
        {
            bx0 = 0;
        }
        if (by0 < 0)
        {
            by0 = 0;
        }
        if (bx1 > sht->bxsize)
        {
            bx1 = sht->bxsize;
        }
        if (by1 > sht->bysize)
        {
            by1 = sht->bysize;
        }
        for (by = by0; by < by1; by++)
        {
            vy = sht->vy0 + by;
            for (bx = bx0; bx < bx1; bx++)
            {
                vx = sht->vx0 + bx;
                if (map[vy * ctl->xsize + vx] == sid)
                {
                    vram[vy * ctl->xsize + vx] = buf[by * sht->bxsize + bx];
                }
            }
        }
    }
    return;
}