hal_graphics.c

一款SmartPhone的驱动代码

/**********************************************************************
;	Function:		SetPixel()
;	Description:	This routine writes a pixel.to display memory.
;	Parameters:	
;		x - horizontal coordinate (0 = left of image)
;		y - vertical cooridinate (0 = top of image)
;		color - color of pixel
;				For 1, 2, 4, and 8 bpp, color is an index into LUT.
;				For 16 bpp, color is in RGB format.
;	Returns:		Nothing.
;	Modifies:		Display memory.
;**********************************************************************/
void SetPixel(long  x, long  y, unsigned long   color)
{
	if (gpfnPixel != NULL)
		(*gpfnPixel)(x, y, color);
}

/**********************************************************************
;	FUNCTION:		DrawLine()
;	DESCRIPTION:	This routine writes a line.to display memory.
;						Note that the last point (x2, y2) is written.
;	PARAMETERS:
;		x1 - horizontal coordinate of top left corner
;		y1 - vertical cooridinate of top left corner
;		x2 - horizontal coordinate of bottom right corner
;		y2 - vertical cooridinate of bottom right corner
;		color - color of pixel
;	RETURNS:		Nothing.
;	MODIFIES:		Display memory.
;**********************************************************************/
void DrawLine(long  x1, long  y1, long  x2, long  y2, unsigned long   color)
{
	long  d, dx, dy;
	long  Aincr, Bincr, xincr, yincr;
	long  x, y;

	if (gpfnPixel == NULL)
		return;

	if (x1 > x2)
	{
		x=x1;x1=x2;x2=x;
		y=y1;y1=y2;y2=y;
	}

	dx = x2 - x1;

	if (dx < 0)
		dx = -dx;

	dy = y2 - y1;

	if (dy < 0)
		dy = -dy;

	if (dx > dy)
	{
		if (x1 > x2)
		{
			x=x1;x1=x2;x2=x;
			y=y1;y1=y2;y2=y;
		}

		if (y2 > y1)
			yincr = 1;
		else
			yincr = -1;

		dx = x2 - x1;

		dy = y2 - y1;					/* dy = abs(y2 - y1); */
		if (dy < 0)
			dy = -dy;
	
		d = 2 * dy - dx;

		Aincr = 2 * (dy - dx);
		Bincr = 2 * dy;

		x = x1;
		y = y1;

		(*gpfnPixel)(x, y, color);

		for (x = x1 + 1; x <= x2; ++x)
		{
			if (d >= 0)
			{
				y += yincr;
				d += Aincr;
			}
			else
				d += Bincr;

			(*gpfnPixel)(x, y, color);
		}
	}
	else
	{
		if (y1 > y2)
		{
				x=x1;x1=x2;x2=x;
			y=y1;y1=y2;y2=y;
		}

		if (x2 > x1)
			xincr = 1;
		else
			xincr = -1;

		dy = y2 - y1;

		dx = x2 - x1;	/* dx = abs(x2 - x1); */
		if (dx < 0)
			dx = -dx;
	
		d = 2 * dx - dy;

		Aincr = 2 * (dx - dy);
		Bincr = 2 * dx;

		x = x1;
		y = y1;

		(*gpfnPixel)(x, y, color);

		for (y = y1 + 1; y <= y2; ++y)
		{
			if (d >= 0)
			{
				x += xincr;
				d += Aincr;
			}
			else
				d += Bincr;

			(*gpfnPixel)(x, y, color);
		}
	}
}

/**********************************************************************
;	FUNCTION:		DrawRect()
;	DESCRIPTION:	This routine writes a line.to display memory.
;	PARAMETERS:
;		x1 - horizontal coordinate of top left corner
;		y1 - vertical cooridinate of top left corner
;		width  - width in pixels
;		height - height in lines
;		color - color of pixel
;		SolidFill - SOLIDFILL_ON if rectangle is solid color
;				SOLIDFILL_OFF if rectangle shows only border
;	RETURNS:;		Nothing.
;	MODIFIES:;		Display memory.
;**********************************************************************/
void DrawRect(long  x1, long  y1, long  width, long  height, unsigned long   color, BOOL SolidFill)
{
	long  y;
	long  x2, y2;

	if (gpfnLine == NULL)
		return;

	x2 = x1 + width - 1;		// Set x2,y2 to be right/bottom INCLUSIVE coordinates
	y2 = y1 + height - 1;

	if (SolidFill == SOLIDFILL_ON)
	{
		for (y = y1; y <= y2; y++)
			(*gpfnLine)(x1, y, x2, y, color);
	}
	else
	{
		(*gpfnLine)(x1, y1, x2, y1, color);
		(*gpfnLine)(x1, y2, x2, y2, color);
		(*gpfnLine)(x1, y1, x1, y2, color);
		(*gpfnLine)(x2, y1, x2, y2, color);
	}
}



/**********************************************************************
;	Function:		DrawText()
;	Description:
;		This routine draws colored text to display memory.
;		If colorFG==colorBG, then text is drawn transparently.
;		Text can be from 0x20 to 0x7F, and '\n' will work.
;	Parameters:
;		x - horizontal coordinate of top left corner
;		y - vertical cooridinate of top left corner
;		pszText - Text to draw
;		colorFG - Color of font ink
;		colorBG - Color of font background
;	Returns:		Nothing.
;	Modifies:		Display memory.
;**********************************************************************/
void DrawText(long  x, long  y, CONST CHAR *pszText, unsigned long   colorFG, unsigned long   colorBG)
{
	long  xl, x1, y1;
	UCHAR c, b;
	CONST UCHAR *pBits;

	if (gpfnPixel == NULL)
		return;

	xl = x;
	while (*pszText)
	{
		c = *pszText++;
		if ( c >= ' ' && c <= 0x7F )
		{
			pBits = &aCharSet8[(c-' ')*8];

			for (y1 = y; y1 < y+8; y1++)
			{
				c = *pBits++;
				for (b = 0x80, x1 = x; b; b >>= 1, x1++)
				{
					if ( (c & b) )
						(*gpfnPixel)( x1, y1, colorFG );
					else if ( colorBG != colorFG )
						(*gpfnPixel)( x1, y1, colorBG );
				}
			}
			x += 8;
		}
		else if ( c == '\n' )
		{
			x = xl;
			y += 8;
		}
	}
}

/************************************************************************
;	Function:		InitGraphics()
;	Description:	This routine initializes the graphics library.
;	Parameters:		
;		Stride - number of bytes per line
;		BitsPerPixel - bits per pixel
;		fISVRAM - GRAPHICS_VRAM if the graphics library is to be used on display memory.
;				- GRAPHICS_OFFSCREEN if the graphics library is used on offscreen memory.
;		Offset - If fISVRAM is GRAPHICS_VRAM, Offset is the offset address from the beginning 
;				 of display memory. (the first byte in display memory is at Offset=0).
;				 If fISVRAM is GRAPHICS_OFFSCREEN, Offset is a pointer to the start of the image 
;				 in display memory. 
;			    (for example, *((UCHAR *) addr)=0 sets the first byte of the image to 0)
;	Returns:	Nothing.
;	Modifies:	Nothing.
;	Format:		void InitGraphics(unsigned long   Stride, int BitsPerPixel, BOOL fISVRAM, unsigned long   Offset)
;***********************************************************************/
void InitGraphics(unsigned long   Stride, long  BitsPerPixel, BOOL fISVRAM, unsigned long   Offset)
{
	gStride = Stride;
	gAddr = Offset;
	gOffset = Offset;
	gBitsPerPixel = BitsPerPixel;
	gUseIndirectMode = (HalInfo.dwFlags & fINDIRECT_INTERFACE) ? TRUE : FALSE;

	if (fISVRAM)						// Dispatch to appropriate pixel drawing function.		
	{
		switch (gBitsPerPixel)
		{
			case 8:		gpfnPixel = _vramPixel8bpp;		gpfnLine = _vramLine8bpp;		break;
			case 16:	gpfnPixel = _vramPixel16bpp;		gpfnLine = _vramLine16bpp;		break;
			case 32:	gpfnPixel = _vramPixel32bpp;		gpfnLine = _vramLine32bpp;		break;
			default:	gpfnPixel = NULL;			gpfnLine = NULL;				break;
		}
	}
	else
	{
		switch (gBitsPerPixel)
		{
			case 8:		gpfnPixel = _Pixel8bpp;		gpfnLine = _Line8bpp;		break;
			case 16:	gpfnPixel = _Pixel16bpp;	gpfnLine = _Line16bpp;		break;
			case 32:	gpfnPixel = _Pixel32bpp;	gpfnLine = _Line32bpp;		break;
			default:	gpfnPixel = NULL;		gpfnLine = NULL;			break;
		}
	}

	
}