《30天自制操作系统》读书笔记Day10

1.叠加处理
为了让以后操作系统各个窗口正常显示，这里采用叠加显示的概念。最终显示的画面由不同的图层叠加显示。
这里图层的信息使用结构体表示：

#define MAX_SHEETS256//SHEET结构体储存图层相关信息struct SHEET {unsigned char *buf;//记录图层上所描画内容的地址int bxsize, bysize, vx0, vy0, col_inv, height, flags;/* * bxsize*bysize图层大小 * vx0,vy0图层位置坐标 * col_inv透明色色号 * height图层高度 * flags图层的标记信息 */};//SHTCTL结构体管理图层struct SHTCTL {unsigned char *vram;//VRAM地址int xsize, ysize, top;//xsize,ysize画面大小，top最上面图层的高度struct SHEET *sheets[MAX_SHEETS];//按高度排序的图层信息struct SHEET sheets0[MAX_SHEETS];//图层信息};

接下来创建sheet.c文件添加相关的函数：

/*  * sheet.c * 叠加显示相关函数 */#include "bootpack.h"#define SHEET_USE1struct SHTCTL *shtctl_init(struct MEMMAN *memman, unsigned char *vram, int xsize, int ysize)/* 图层控制初始化 */{struct SHTCTL *ctl;int i;ctl = (struct SHTCTL *) memman_alloc_4k(memman, sizeof (struct SHTCTL));//分配内存if (ctl == 0) {goto err;}ctl->vram = vram;ctl->xsize = xsize;ctl->ysize = ysize;ctl->top = -1; /* 一个SHEEL都没有 */for (i = 0; i < MAX_SHEETS; i++) {ctl->sheets0[i].flags = 0; /* 标记为未使用 */}err:return ctl;}struct SHEET *sheet_alloc(struct SHTCTL *ctl)/* 取得新生成的未使用图层 */{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;/* 所有的图层都处于正在使用的状态，即分配失败 */}void sheet_setbuf(struct SHEET *sht, unsigned char *buf, int xsize, int ysize, int col_inv)/* 设置图层相关信息 */{sht->buf = buf;sht->bxsize = xsize;sht->bysize = ysize;sht->col_inv = col_inv;return;}void sheet_updown(struct SHTCTL *ctl, struct SHEET *sht, int height)/* 设定图层高度 */{int h, old = sht->height; /* 储存设置前的高度信息 *//* 修正高度 */if (height > ctl->top + 1) {height = ctl->top + 1;}if (height < -1) {height = -1;}sht->height = height; /* 设定高度 *//* 进行sheets[]的排列 */if (old > height) {/* 比以前低 */if (height >= 0) {/* 把中间的向上提 */for (h = old; h > height; h--) {ctl->sheets[h] = ctl->sheets[h - 1];ctl->sheets[h]->height = h;}ctl->sheets[height] = sht;} 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--; /* 因为有图层被隐藏，所以图层总高度减小 */}sheet_refresh(ctl); /* 重新绘制 */} else if (old < height) {/* 比以前高 */if (old >= 0) {/* 把中间的拉下去 */for (h = old; h < height; h++) {ctl->sheets[h] = ctl->sheets[h + 1];ctl->sheets[h]->height = h;}ctl->sheets[height] = sht;} else {/* 由隐藏变为显示 *//* 把上面的提上去 */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++; /* 图层总高度加一 */}sheet_refresh(ctl); /* 重新绘制 */}return;}void sheet_refresh(struct SHTCTL *ctl)/* 刷新图层函数 */{int h, bx, by, vx, vy;unsigned char *buf, c, *vram = ctl->vram;struct SHEET *sht;for (h = 0; h <= ctl->top; h++) {sht = ctl->sheets[h];buf = sht->buf;for (by = 0; by < sht->bysize; by++) {vy = sht->vy0 + by;for (bx = 0; bx < sht->bxsize; bx++) {vx = sht->vx0 + bx;c = buf[by * sht->bxsize + bx];if (c != sht->col_inv) {vram[vy * ctl->xsize + vx] = c;}}}}return;}void sheet_slide(struct SHTCTL *ctl, struct SHEET *sht, int vx0, int vy0)/* 移动图层 */{sht->vx0 = vx0;sht->vy0 = vy0;if (sht->height >= 0) { /* 如果图层不是隐藏的 */sheet_refresh(ctl); /* 刷新 */}return;}void sheet_free(struct SHTCTL *ctl, struct SHEET *sht)/* 删除图层 */{if (sht->height >= 0) {sheet_updown(ctl, sht, -1); /* 先把图层隐藏 */}sht->flags = 0; /* 设定图层未使用 */return;}

最后在bootpack.c中修改HariMain函数即可：

/* *bootpack.c *其他处理 */#include "bootpack.h"#include <stdio.h>void HariMain(void){struct BOOTINFO *binfo = (struct BOOTINFO *) ADR_BOOTINFO;char s[40], mcursor[256], keybuf[32], mousebuf[128];int mx, my, i;unsigned int memtotal;struct MOUSE_DEC mdec;struct MEMMAN *memman = (struct MEMMAN *) MEMMAN_ADDR;struct SHTCTL *shtctl;struct SHEET *sht_back, *sht_mouse;unsigned char *buf_back, buf_mouse[256];init_gdtidt();init_pic();io_sti(); fifo8_init(&keyfifo, 32 , keybuf);fifo8_init(&mousefifo, 128 , mousebuf);io_out8(PIC0_IMR, 0xf9); /* PIC1以外全部禁止(11111001) */io_out8(PIC1_IMR, 0xef); init_keyboard();enable_mouse(&mdec);memtotal = memtest(0x00400000, 0xbfffffff);memman_init(memman);memman_free(memman, 0x00001000, 0x0009e000); /* 0x00001000 - 0x0009efff */memman_free(memman, 0x00400000, memtotal - 0x00400000);init_palette();shtctl = shtctl_init(memman, binfo->vram, binfo->scrnx, binfo->scrny);sht_back  = sheet_alloc(shtctl);sht_mouse = sheet_alloc(shtctl);buf_back  = (unsigned char *) memman_alloc_4k(memman, binfo->scrnx * binfo->scrny);sheet_setbuf(sht_back, buf_back, binfo->scrnx, binfo->scrny, -1); /* 没有透明色 */sheet_setbuf(sht_mouse, buf_mouse, 16, 16, 99);//透明色号99init_screen8(buf_back, binfo->scrnx, binfo->scrny);init_mouse_cursor8(buf_mouse, 99);//背景色号99..背景色与透明色相同可以消除鼠标方块sheet_slide(shtctl, sht_back, 0, 0);mx = (binfo->scrnx - 16) / 2; /* 按显示在画面中央来计算最终坐标 */my = (binfo->scrny - 28 - 16) / 2;sheet_slide(shtctl, sht_mouse, mx, my);sheet_updown(shtctl, sht_back,  0);sheet_updown(shtctl, sht_mouse, 1);sprintf(s, "(%3d, %3d)", mx, my);putfonts8_asc(buf_back, binfo->scrnx, 0, 0, COL8_FFFFFF, s);sprintf(s, "memory %dMB   free : %dKB",memtotal / (1024 * 1024), memman_total(memman) / 1024);putfonts8_asc(buf_back, binfo->scrnx, 0, 32, COL8_FFFFFF, s);sheet_refresh(shtctl);for (;;) {io_cli();if (fifo8_status(&keyfifo) + fifo8_status(&mousefifo) == 0) {io_stihlt();} else {if (fifo8_status(&keyfifo) != 0) {i = fifo8_get(&keyfifo);io_sti();sprintf(s, "%02X", i);boxfill8(buf_back, binfo->scrnx, COL8_008484,  0, 16, 15, 31);putfonts8_asc(buf_back, binfo->scrnx, 0, 16, COL8_FFFFFF, s);sheet_refresh(shtctl);} else if (fifo8_status(&mousefifo) != 0) {i = fifo8_get(&mousefifo);io_sti();if (mouse_decode(&mdec, i) != 0) {sprintf(s, "[lcr %4d %4d]", mdec.x, mdec.y);if ((mdec.btn & 0x01) != 0) {s[1] = 'L';}if ((mdec.btn & 0x02) != 0) {s[3] = 'R';}if ((mdec.btn & 0x04) != 0) {s[2] = 'C';}boxfill8(buf_back, binfo->scrnx, COL8_008484, 32, 16, 32 + 15 * 8 - 1, 31);putfonts8_asc(buf_back, binfo->scrnx, 32, 16, COL8_FFFFFF, s);/* 移动光标 */mx += mdec.x;my += mdec.y;if (mx < 0) {mx = 0;}if (my < 0) {my = 0;}if (mx > binfo->scrnx - 16) {mx = binfo->scrnx - 16;}if (my > binfo->scrny - 16) {my = binfo->scrny - 16;}sprintf(s, "(%3d, %3d)", mx, my);boxfill8(buf_back, binfo->scrnx, COL8_008484, 0, 0, 79, 15); /* 消坐标 */putfonts8_asc(buf_back, binfo->scrnx, 0, 0, COL8_FFFFFF, s); /* 写坐标 */sheet_slide(shtctl, sht_mouse, mx, my); /* 包含sheet_refresh */}}}}}

make run 可以正常运行。


2.叠加处理加速


前面鼠标移动会刷新所有的像素，因此会很慢，而且画面可能会闪烁，因此需要对叠加处理进行优化。


将变化的部分刷新即可，而不是刷新全部。
在sheet.c中添加函数：

void sheet_refreshsub(struct SHTCTL *ctl, int vx0, int vy0, int vx1, int vy1)/* 刷新部分界面 */{int h, bx, by, vx, vy;unsigned char *buf, c, *vram = ctl->vram;struct SHEET *sht;for (h = 0; h <= ctl->top; h++) {sht = ctl->sheets[h];buf = sht->buf;for (by = 0; by < sht->bysize; by++) {vy = sht->vy0 + by;for (bx = 0; bx < sht->bxsize; bx++) {vx = sht->vx0 + bx;if (vx0 <= vx && vx < vx1 && vy0 <= vy && vy < vy1) {c = buf[by * sht->bxsize + bx];if (c != sht->col_inv) {vram[vy * ctl->xsize + vx] = c;}}}}}return;}

然后在sheet_slide中改为调用sheet_refreshsub：

void sheet_slide(struct SHTCTL *ctl, struct SHEET *sht, int vx0, int vy0)/* 移动图层 */{int old_vx0 = sht->vx0, old_vy0 = sht->vy0;//记住原来的位置sht->vx0 = vx0;//获得新的位置sht->vy0 = vy0;if (sht->height >= 0) {  //如果图层不是隐藏的则刷新 sheet_refreshsub(ctl, old_vx0, old_vy0, old_vx0 + sht->bxsize, old_vy0 + sht->bysize);//只是刷新原来的位置和新的位置sheet_refreshsub(ctl, vx0, vy0, vx0 + sht->bxsize, vy0 + sht->bysize);}return;}

接着修改sheet_refresh:

void sheet_refresh(struct SHTCTL *ctl, struct SHEET *sht, int bx0, int by0, int bx1, int by1)/* 刷新图层函数 */{if (sht->height >= 0) { /* 如果图层显示才刷新 */sheet_refreshsub(ctl, sht->vx0 + bx0, sht->vy0 + by0, sht->vx0 + bx1, sht->vy0 + by1);}return;}

把sheet_updown中的：

sheet_refresh(ctl);

修改为

sheet_refreshsub(ctl, sht->vx0, sht->vy0, sht->vx0 + sht->bxsize, sht->vy0 + sht->bysize);

最后在HariMain中继续把sheet_refresh改为sheet_refreshsub并添加几处sheet_refreshsub即可
不过在sheet_refreshsub中，即使不写入像素也有较多的判断语句，需要优化：

void sheet_refreshsub(struct SHTCTL *ctl, int vx0, int vy0, int vx1, int vy1)/* 刷新部分界面 */{int h, bx, by, vx, vy, bx0, by0, bx1, by1;unsigned char *buf, c, *vram = ctl->vram;struct SHEET *sht;for (h = 0; h <= ctl->top; h++) {sht = ctl->sheets[h];buf = sht->buf;/* 使用vx0~vy1对bx0~by1进行倒推 */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;c = buf[by * sht->bxsize + bx];if (c != sht->col_inv) {vram[vy * ctl->xsize + vx] = c;}}}}return;}

这样就完成了优化工作。


3.鼠标显示问题
运行系统发现鼠标在向右和向下移动不能移出界面，与Windows系统不相同，不怎么适应，因此修改一下，修改HariMain函数中：

if(ma > binfo->scrnx - 16)    mx = binfo->scrnx - 16;if(my > binfo->scrny - 16)    my = binfo->scrny - 16;

为：

if(mx > binfo->scrnx - 1)    mx = binfo->scrnx - 1;if(my > binfo->scrny - 1)    my = binfo->scrny - 1;

但是发现鼠标在右侧超出界面后左侧的显示会出现bug，这是sheet_regreshsub的问题：

...struct SHEET *sht;/* 如果refresh范围超出了画面则进行修正 */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 = 0; h <= ctl->top; h++) {...}