C语言中的VGA编程：鼠标单击时绘制像素

Question

我正在开发一个类似Microsoft的类似绘画的程序，用于在C上学习VGA 256色编程。

我可以在用户点击屏幕时绘制一个像素，并在按下鼠标按钮时继续绘制像素。但是，如果我在屏幕上快速移动鼠标，我就无法获得连续的线条。相反，我得到了这个结果

即使鼠标快速移动，如何使线条连续？

直到现在我的代码：

/**************************************************************************
 *  paint_screen                                                      *
 *    show  main screen paint                                           *
 **************************************************************************/
void paint_screen(BITMAP *fondo){
    int mantenido;
    BITMAP barra,barra_color,normal_ptr_image;
    int anterior_presionado;
    word last_time;
    word redraw,press,release;
    sword dx,dy=0;
    MOUSEBITMAP *mouse_new=NULL;    
    int i,done = 0;
    accion =1;
    /*Pintando fondo blanco*/
    clear_screen();
    /*Pintando barra de herramientas*/
    load_bmp("normal.bmp",&normal_ptr_image);
    load_bmp("mainbar.bmp",&barra);
    load_bmp("colores.bmp",&barra_color);
    set_pallete(fondo->pallete);
    draw_bitmap(&barra,0,0);
    draw_bitmap(&barra_color,0,180);
    load_mouse(&mouse_g);
    show_mouse(&mouse_g);
    wait(50);
    while(!done){
        do {                              // check mouse status 
            anterior_presionado = press;
            get_mouse_motion(&dx,&dy);
            press   = get_mouse_press(LEFT_BUTTON);
            release = get_mouse_release(LEFT_BUTTON);
            //Si el estado estaba presionado y no se ha soltado.. el boton esta mantenido
            if(anterior_presionado==1 &&release==0){
              mantenido =1;

            }
        } while (dx==0 && dy==0 && press==0 && release==0&&*my_clock==last_time);    
        if (release){
            mouse_g.button1=0;
            mantenido=0;
            boton_soltado();


        }       

        if (press){

            mouse_g.button1=1;
            boton_presionado();


        } 
        //El boton se mantiene presionado
        else if(mantenido){
            boton_mantenido();
        }
        else{
            release=1;
        }


        if (dx || dy)                     // calculate movement 
        {
          new_x1 = mouse_g.x+dx;
          new_y1 = mouse_g.y+dy; //Actualizamos posicion mouse
          if (new_x1<0)   new_x1=0;
          if (new_y1<0)   new_y1=0;
          if (new_x1>319) new_x1=319;
          if (new_y1>199) new_y1=199;
          redraw=1;
        }
         if(redraw){
             wait_for_retrace();
             hide_mouse(&mouse_g);
             if (mouse_new!=NULL) mouse_g.bmp=mouse_new;
             mouse_g.x = new_x1;
             mouse_g.y=new_y1;
             show_mouse(&mouse_g);
             redraw=0;
             mouse_new=NULL;
         }

        if(new_x1>=287 && new_x1 <320
            && new_y1>=180 && new_y1 < 200 &&press){

        set_mode(TEXT_MODE); 
        printf("Adios!!");
        wait(25);
        done=0;
        return;


    }   
    }
}


void realizar_accion(){
    /*Caso1: Pintar pixel simple (lapiz)*/
    if(accion==1){

        plot_pixel(mouse_g.x,mouse_g.y,2);
        plot_pixel(mouse_g.x-1,mouse_g.y,2);
        plot_pixel(mouse_g.x,mouse_g.y-1,2);
        plot_pixel(mouse_g.x-1,mouse_g.y-1,2);

    }

}
void realizar_accion_mantenido(){
    if(accion==1){

        plot_pixel(mouse_g.x,mouse_g.y,2);
        plot_pixel(mouse_g.x-1,mouse_g.y,2);
        plot_pixel(mouse_g.x,mouse_g.y-1,2);
        plot_pixel(mouse_g.x-1,mouse_g.y-1,2);


    }


}

int sobre_barra(){
    if(new_x1>0 && new_x1<33 &&new_y1>0 &&new_y1<181){


        return 1;

    }
    else{

        return -1;
    }


}
void boton_mantenido(){

    /*Verificar que este dento del buffer de dibujo....*/
    if(sobre_barra()!=1){
        realizar_accion_mantenido();

    }
}
void boton_presionado(){

    if(sobre_barra()==1){
        cambiar_herramienta();

    }
    else{

        realizar_accion();

    }   

}