video.cpp

DOS下利用VESA实现高分辨率、16bit色显示并输出汉字

#include "video.h"
typedef unsigned long DWORD;
static DWORD _inpd(int portnum);
static DWORD _outpd(int portnum, DWORD val);
unsigned long VIDDID(int iBus, int iDevice);

FILE *fpE;
FILE *fpC;
unsigned char *pFontE;
unsigned char *pFontC;
unsigned far int * pVideoMem;    //Base Address for Memory Buffer
int iOldPage = 0;		 //Store Video Page number
//double asp_ratio = 1.0;		 //Aspection ration of circle

/****************************************************
Function:
    Initial to specified graphics mode
Input parameter:
    iMode: Graph Mode.
	0x114 for 800*600*16bit,
	0x3 for 80*25 text mode
Output parameter:
    0: Error
    1: OK
****************************************************/
int Graph_Mode(int iMode)
{
    if(VIDDID(0, 0)!=0x71008086)
	return 0;

    pVideoMem = (unsigned int *)MK_FP(0xA000, 0);
    union REGS in, out;
    if(iMode>=0x100)
    {
	in.x.bx=iMode;
	in.x.ax=0x4F02;
	int86(0x10,&in,&out);
	return 1;
    }
    else
    {
	in.x.ax=iMode;
	int86(0x10,&in,&out);
	return 1;
    }
}

/****************************************************
Function:
    Initial to graphics mode
Input parameter:
    None
Output parameter:
    0: Error
    1: OK
****************************************************/
int InitGraph()
{
    if(VIDDID(0, 0)!=0x71008086)
	return 0;
    return Graph_Mode(0x114);  //or, 0x114 for SVGA
}

/****************************************************
Function:
    close graphics mode
Input parameter:
    None
Output parameter:
    None
****************************************************/
void CloseGraph()
{
    Graph_Mode(0x3);
}

/****************************************************
Function:
    Switch to specified video page
Input parameter:
    iPageNumber
Output parameter:
    None
****************************************************/
void VideoPage(int iPageNumber)
{
    union REGS in, out;
    in.x.bx=0;
    in.x.dx=iPageNumber;
    //i.x.dx=iPageNumber*16;
    in.x.ax=0x4F05;
    int86(0x10,&in,&out);
    iOldPage = iPageNumber;
    return;
}

/****************************************************
Function:
    Paint the whole screen with chaned color
Input parameter:
    None
Output parameter:
    None
****************************************************/
void PaintScreen()
{
    unsigned int i;
    unsigned long iCount;
    int iPage, iBlue;
    iCount=0;
    for(iPage=0; iPage<15; iPage++)
    {
	VideoPage(iPage);
	for(i=0; i<32768; i++)
	{
	    iCount++;
	    iBlue = iCount*256/(15*32768);
	    *(pVideoMem+i) = RGB(0, 0, iBlue);
	}
    }
}

/****************************************************
Function Name:
    ClearDevice
Function:
    Clear the screen with specified color
Input parameter:
    iBackColor: Specified back ground color
Output parameter:
    None
****************************************************/
void ClearDevice(int iBackColor)
{
    unsigned int i;
    int iPage;
    for(iPage=0; iPage<15; iPage++)
    {
	VideoPage(iPage);
	for(i=0; i<32768; i++)
	{
	    *(pVideoMem+i) = iBackColor;
	}
    }
}

/****************************************************
Function:
    Fill whole screen with black. like cleardevice
Input parameter:
    None
Output parameter:
    None
****************************************************/
void ClearToBlack()
{
    unsigned int i;
    int iPage;
    for(iPage=0; iPage<15; iPage++)
    {
	VideoPage(iPage);
	for(i=0; i<32768; i++)
	    *(pVideoMem+i) = 0;
    }
}

/****************************************************
Function:
    Draw a point with specified color
Input parameter:
    x, y: coordinate
    iColor: specified color
Output parameter:
    None
****************************************************/
void SetPoint(int x, int y, unsigned int iColor)
{
    unsigned long iDist, iTemp;
    unsigned int iPos;
    int iPN;
    iDist = 800l*y+x;
    iTemp = iDist;
    iPN = 0;
    while(iTemp>32768)
    {
	iTemp = iTemp - 32768;
	iPN++;
    }
    iPos = iTemp;
    if(iPN != iOldPage)
	VideoPage(iPN);
    *(pVideoMem+iPos) = iColor;
}

/****************************************************
Function:
    Draw a line with specified color
Input parameter:
    startx, starty: coordinate of start point
    endx, endy: coordinate of end point
    iColor: specified color
Output parameter:
    0: Error
    1: OK
****************************************************/
int MemLine(int startx, int starty, int endx, int endy, unsigned int color)
{
    register int t, distance;
    int xerr=0, yerr=0, delta_x, delta_y;
    int incx, incy;

    delta_x = endx-startx;
    delta_y = endy-starty;

    if(delta_x>0) incx = 1;
    else if (delta_x == 0 ) incx = 0;
    else incx = -1;

    //Compute the direcxtion of the increment,
    //an increment of 0 means either a vertical of horizontral line.
    if(delta_y>0) incy = 1;
    else if (delta_y == 0 ) incy = 0;
    else incy = -1;

    //Determine which distance is greater
    delta_x = abs(delta_x);
    delta_y = abs(delta_y);
    if(delta_x>delta_y) distance = delta_x;
    else distance = delta_y;

    //Draw the line
    for(t=0; t<=distance+1; t++)
    {
	SetPoint(startx, starty, color);
	xerr+=delta_x;
	yerr+=delta_y;
	if(xerr>distance)
	{
	    xerr-=distance;
	    startx+=incx;
	}
	if(yerr>distance)
	{
	    yerr-=distance;
	    starty+=incy;
	}
    }
    return 1;
}

/****************************************************
Function:
    Draw a box
Input parameter:
    startx, starty: coordinate of left - top
    endx, endy: coordinate of right - bottom
    iColor: specified color
Output parameter:
    None
****************************************************/
void MemBox(int startx, int starty, int endx, int endy, unsigned int color)
{
    MemLine(startx, starty, endx, starty, color);
    MemLine(endx, starty, endx, endy, color);
    MemLine(endx, endy, startx, endy, color);
    MemLine(startx, endy, startx, starty, color);
}

/****************************************************
Function:
    Draw a box with specified color filled
Input parameter:
    startx, starty: coordinate of left - top
    endx, endy: coordinate of right - bottom
    iColor: specified color
Output parameter:
    None
****************************************************/
void MemFillBox(int startx, int starty, int endx, int endy, unsigned color)
{
    register int i, begin, end;
    begin = startx<endx? startx:endx;
    end = startx>endx? startx:endx;
    for(i=begin; i<end; i++)
	MemLine(i, starty, i, endy, color);
}

/****************************************************
Function:
    Draw a circle with specified color
Input parameter:
    x_center, y_center: coordinate of circle center
    radius: radius of circle
    iColor: specified color
Output parameter:
    None
****************************************************/
void MemCircle(int x_center, int y_center, int radius, unsigned int color)
{
    register int x, y, delta;
    y=radius;
    delta = 3-2*radius;
    for(x=0; x<y; )
    {
	plot_circle(x, y, x_center, y_center, color);
	if(delta < 0)
	{
	    delta+=4*x+6;
	}
	else
	{
	    delta+=4*(x-y)+10;
	    y--;
	}
	x++;
    }
    x=y;
    if(y)
	plot_circle(x, y, x_center, y_center, color);
}

//Internal used by MemCircle
void plot_circle(int x, int y, int x_center, int y_center, unsigned int color)
{
    int startx, endx, x1, starty, endy, y1;
    starty=y;  //*asp_ratio;
    endy=(y+1); //*asp_ratio;
    startx=x; //*asp_ratio;
    endx=(x+1); //*asp_ratio;
    for(x1=startx; x1<endx; ++x1)
    {
	SetPoint(x1+x_center, y+y_center, color);
	SetPoint(x1+x_center, y_center-y, color);
	SetPoint(x_center-x1, y_center-y, color);
	SetPoint(x_center-x1, y+y_center, color);
    }
    for(y1=starty; y1<endy; ++y1)
    {
	SetPoint(y1+x_center, x+y_center, color);
	SetPoint(y1+x_center, y_center-x, color);
	SetPoint(x_center-y1, y_center-x, color);
	SetPoint(x_center-y1, x+y_center, color);
    }
}

/****************************************************
Function:
    Draw a circle with specified color filled
Input parameter:
    x_center, y_center: coordinate of circle center
    radius: radius of circle
    iColor: specified color
Output parameter:
    None
****************************************************/
void MemFillCircle(int x, int y, int r, unsigned int color)
{
    while(r)
    {
	MemCircle(x, y, r, color);
	r--;
    }
}

/****************************************************
Function:
    Open Font to get information for DrawEnglish,
    must call this function before draw any text.
Input parameter:
    None
Output parameter:
    0: Error
    1: Succesfully
****************************************************/
int OpenEFont()
{
    if(VIDDID(0, 7)!=0x71108086)
	return 0;
    fpE=fopen("asc16", "rb");
    if(fpE == NULL)
    {
	printf("Error opening asc16\n");
	printf("Press any key to exit...\n");
	getch();
	return 0;
    }
    pFontE = (unsigned char *)malloc(sizeof(char)*16);
    return 1;
}

/****************************************************
Function:
    Close Font, must call it before exit.
Input parameter:
    None
Output parameter:
    None
****************************************************/
void CloseEFont()
{
    fclose(fpE);
    free(pFontE);
}

/****************************************************
Function:
    Draw an English character
Input parameter:
    x, y: coordinate of character
    c: character
    iColor: specified color
Output parameter:
    None
****************************************************/
void DrawEnglish(int x, int y, int c, int iColor)
{
    int ix, iy;

    fseek(fpE, 16l*c, SEEK_SET);