nvesa.h

NEO SDK是一个跨平台的免费开源图形软件开发包。它支持基本绘图、多种格式图形显示、鼠标操 作、扩展内存和扩充内存的操作、时钟、音频播放、多种字体的汉字及英文显示等等特性；更激动人心的是

{
   mode_info_t mode_info;

   struct   SREGS segs;
   union    REGS r;
   int      mode = 0;
   int      temp;
   unsigned min_mode = 0x100;
   unsigned max_mode = 0x1ff;
   unsigned far *p = &min_mode;
   char   far *modeinfo = (char far *)&mode_info;

   refresh += 0; /*该参数暂时未使用*/
   if (g_vbe_version < 0)
   {
      #ifndef NEO_sys_report_error_unused
      Errinfo_t error = {"set_video_mode", N_NEO_NOT_INIT, 0};
      throw_error(error);
      #endif     
   }

   temp = (flags & 0xff80) >> 7;
   if (temp == 0)
   {
      for (; *p < max_mode; (*p)++)
      {
         if (get_mode_info(*p, modeinfo))
         {
            if (w == mode_info.x_resolution && h == mode_info.y_resolution && bpp == mode_info.bits_per_pixel)
            {
               mode = *p;
               break;
            }
         }
      }
      if (mode == 0)
      {
         #ifndef NEO_sys_report_error_unused
         Errinfo_t error = {"set_video_mode", ERR_VIDEO_MODE, 1};
         throw_error(error);
         return FALSE;
         #endif
      }
   }
   else
   {
      if (!get_mode_info(mode = temp, modeinfo))
      {
         return FALSE;
      }
   }
   /*线性寻址  real_mode |= 0x4000;*/
   /*调整刷新率real_mode |= 0x0800;*/
   /*{
      CRTC_T   crtc;
      unsigned long vclk;
      double f0;
      _refresh_rate_request = refresh;
      calc_crtc_timing(&crtc, w, h, 0, 0);

      vclk = (double)crtc.horizontal_total * crtc.vertical_total * _refresh_rate_request;
      vclk = get_closest_pixel_clock(vesa_mode, vclk);

      if (vclk != 0) {
    f0 = (double)vclk / (crtc.horizontal_total * crtc.vertical_total);

    _set_current_refresh_rate((int)(f0 + 0.5));

    crtc.pixel_clock  = vclk;
    crtc.refresh_rate = _refresh_rate_request * 100;

    r.x.di = FP_OFF(&crtc);
    segs.es = FP_SEG(&crtc);
      }
   }*/

   if (mode >= 0x100)
   {  /*mode |= 0x0800;*/
      mode |= g_clear_vram;
      /*切换到指定图形模式*/
      r.x.ax = 0x4f02;
      r.x.bx = mode;
      int86x(0x10, &r, &r, &segs);
      if (r.x.ax != 0x4F) return FALSE; /*切换失败*/
   }
   else
   {
      if (mode == 0x13)/*该模式不支持硬件换页机制*/
      {
         r.h.ah=0;
         r.h.al=mode;
         int86(0x10,&r,&r);
         g_color_depth = 8;
         g_color_byte  = (char)(g_color_depth / 7);
         g_rect_left   = g_rect_top = 0;
         g_rect_right  = (g_screen_h = 320) - 1;
         g_rect_bottom = (g_screen_v = 200) - 1;
         g_screen_size = g_screen_h * g_screen_v;
         g_tptcolor    = MASK_COLOR_8;
         screen(0, 0, g_rect_right, g_rect_bottom);
         #ifndef NEO_color_depth_8_unused
         #ifndef NEO_palette_unused
         update_sys_pal();
         #endif
         #endif
         return TRUE;
      }
      else
         return FALSE; /* 忽略其它非VESA标准模式*/
   }

   g_videoptr    = (char far *)MK_FP(0xa000, 0);
   g_green_mask  = mode_info.green_mask_size;
   g_color_depth = mode_info.bits_per_pixel;
   g_color_byte  = (char)(g_color_depth / 7);
   g_rect_left   = g_rect_top = 0;
   g_rect_right  = (g_screen_h = mode_info.x_resolution) - 1;
   g_rect_bottom = (g_screen_v = mode_info.y_resolution) - 1;
   g_screen_size = g_screen_h * g_screen_v;
   g_page_num    = get_page_num();
   screen(0, 0, g_rect_right, g_rect_bottom);
   g_total_surfaces = mode_info.number_of_image_pages * 2;
   if (mode == 0x101) g_total_surfaces += 3;
   else if (mode == 0x116 || mode == 0x117) g_total_surfaces = 3; /*处理特殊情况*/
   else if (mode == 0x10e || mode == 0x111 || mode == 0x103) g_total_surfaces += 1;

   if (g_page_num == -1)
   {
      g_page_num = g_screen_size / (bpp * 0xffff) + 1;
   }
   switch (g_color_depth)
   {
      case 8:
      g_tptcolor = MASK_COLOR_8;
      #ifndef NEO_color_depth_8_unused
      #ifndef NEO_palette_unused
      update_sys_pal();
      #endif
      #endif
      break;
      case 15:
      g_tptcolor = MASK_COLOR_15;
      g_green_bit= 3;
      break;
      case 16:
      g_tptcolor = MASK_COLOR_16;
      g_green_bit= 2;
      break;
      /*case 24:
      g_tptcolor = TPT24;
      break;
      case 32:
      g_tptcolor = TPT32;
      break;*/
      default:
      g_tptcolor = TPT8;
      break;
   }
   g_routines |= 1;

   return TRUE;
}

/*获得SVGA的显示模式*/
int get_vbe_mode(void)
{
   _AX = 0x4f03;
   __int__(0x10); 

   return _BX;
}

void set_vga_mode(int mode)
{
   _AX = mode;  /*回到VGA模式下*/
   __int__(0x10);
}

char get_page_num(void)
{
   char pages[28] = {4, 5, 4, 8, 6, 12, 10, 20, -1, -1, -1, -1, -1, 2, 2, 3, 10, 10, 15,
                     15, 15,  22, 24, 24, 36, 40, 40, 60};
   int tmp;
   _AX = 0x4f03;
   __int__(0x10);   
   tmp = _BX;
   if (tmp >= 0x100 && tmp <= 0x11c)
   {
      return pages[tmp - 256];
   }
   else if (tmp == 0x13)
   {
      return 1;
   }
   return -1;
}


/*设置扫描线的起点*/
void set_display_start(unsigned fir_scan_dot, unsigned fir_scan_line)
{
   union REGS r;
   r.x.ax = 0x4f07;
   r.x.bx = 0;
   r.x.cx = fir_scan_dot;
   r.x.dx = fir_scan_line;
   int86(0x10, &r, &r);
}


/*指定剪切输出域(包括边线)*/
char screen_rect(int left, int top, int right, int bottom)
{
   if(left>g_screen_h||top>g_screen_v||right<0||bottom<0||right<=left||bottom<=top)
      {return -1;}
   #ifndef NEO_rect_unused
   if (left < 0)
      {left = 0;}
   if (top < 0)
      {top = 0;}
   if (right >= g_screen_h)
      {right =  g_screen_h - 1;}
   if (bottom >=g_screen_v)
      {bottom = g_screen_v - 1;}

   g_rect_left  = left;
   g_rect_right = right;
   g_rect_top   = top;
   g_rect_bottom= bottom;
   #else
   g_rect_left  = left = g_rect_top   = top  = 0;
   g_rect_right = right= g_screen_h - 1;
   g_rect_bottom= bottom=g_screen_v - 1;
   #endif
   return 0;
}

#ifndef NEO_rect_unused
void rect_store(void)
{
   g_temp_top = g_rect_top;
   g_temp_left= g_rect_left;
   g_temp_right = g_rect_right;
   g_temp_bottom= g_rect_bottom;
}

void rect_restore(void)
{
   g_rect_top = g_temp_top;
   g_rect_left= g_temp_left;
   g_rect_right = g_temp_right;
   g_rect_bottom= g_temp_bottom;
}
#endif


/*显存换页函数*/
void set_vbe_page(int page)
{
   if (g_cur_vbe_page != page)
   {
      _BX = 0;
      _DX = g_cur_vbe_page = page;
      _AX = 0x4f05;
      __int__(0x10);
   }
}
/*下面这个函数功能与上面一样，但效率似乎更高些*/
/*void set_vbe_page(int page)
{
   if (g_cur_vbe_page != page)
   {
      _BX=0;
      _DX=g_cur_vbe_page = page;
      g_win_func();
   }
}*/


/*void set_logic_scanl_len(unsigned length)
{
   union REGS r;
   r.x.ax=0x4F06;*/
   /* BL = 00h Set Scan Line Length in Pixels
         = 01h Get Scan Line Length
         = 02h Set Scan Line Length in Bytes
         = 03h Get Maximum Scan Line Length */
   /*r.h.bl = 0;
   r.x.cx = length;
   int86(0x10, &r, &r);
}*/


#ifndef NEO_surface_unused
char surface_alloc(unsigned sur_num, int clear_flag)
{ 
   g_alloc_surface = (sur_num <= g_total_surfaces? sur_num : g_total_surfaces);

   if (clear_flag)
   {
      int i;
      #ifndef NEO_rect_unused
      rect_store();
      #endif
      screen(0, 0, g_screen_h - 1, g_screen_v - 1);
      for (i = 1; i <= g_alloc_surface; ++i)
      {
         set_work_surface(i);
         #ifndef NEO_basic_draw_unused
         rectfill(0, 0, g_rect_right, g_rect_bottom, 0);
         #endif
      }
      #ifndef NEO_rect_unused
      rect_restore();
      #endif
      set_work_surface(0);
   }
   return g_alloc_surface;
}


char set_work_surface(unsigned sur_num)
{
   if (sur_num <= g_alloc_surface && sur_num > 0)
   {
      g_sl_offset = g_screen_v * ((g_work_surface = sur_num) - 1) + (g_screen_v * g_reserved_page)/*跳过系统保留页*/;
   }
   else
   {
      g_work_surface = g_sl_offset = 0;
   }
   return g_work_surface;
}

       
char flip_surface(unsigned sur_num)
{                                                                                           /*跳过系统保留页*/
   unsigned temp = (sur_num <= g_alloc_surface && sur_num > 0)?g_screen_v * (sur_num - 1) + (g_screen_v * g_reserved_page) : 0;

   #ifndef NEO_draw_smooth_unused
   vsync();
   #endif
   if (g_routines & 2)
   {
      #ifndef NEO_mouse_adv_unused
      hide_mouse();   /*隐藏Patch原来的光标*/
      #endif
   }

   set_display_start(0, temp);
   g_look_surface = (sur_num <= g_alloc_surface?sur_num : 0);
   if (g_routines & 2)
   {
      #ifndef NEO_mouse_adv_unused
      show_mouse();   /*绘制redraw新的光标*/
      #endif
   }
   return g_look_surface;
}


void flip(void)
{
   static unsigned last = 0;                 /*跳过系统保留页*/

   #ifndef NEO_draw_smooth_unused
   vsync();
   #endif
   if (g_routines & 2)
   {
      #ifndef NEO_mouse_adv_unused
      hide_mouse();
      #endif
   }

   set_display_start(0, last = (last == 0?g_screen_v * g_reserved_page : 0));
   g_look_surface = last != 0?1 : 0;
   if (g_routines & 2)
   {
      #ifndef NEO_mouse_adv_unused
      show_mouse();
      #endif
   }
}
#endif


#ifndef NEO_draw_mode_unused
void set_draw_mode(int draw_mode)
{
   if ((draw_mode>=COPY_PUT)&&(draw_mode<=NOT_PUT)) g_draw_mode=draw_mode;
}
#endif

void vsync(void)
{
   while  ( inportb(0x3da)&0x08 ) ;
   while (!(inportb(0x3da)&0x08)) ;
}


#endif