wbmp.c

WBMP格式图片解码器

 
#define _WBMP_C_
#include "wbmp.h"
#define GLOBAL
/*******************************************************************************
** Name	:
** Funct:
** Input:
** Retun:
** Note	:
********************************************************************************/
GLOBAL void ParseWBMP(
	Int16	xpos,                    /*X pixel position in out buffer to put the result image upper left pixel >=0*/
	Int16	ypos,                    /*Y pixel position in out buffer to put the result image upper left pixel >=0*/
	const UInt8	*buf,              /*wbmp file source data*/
	COLORBITS_t	img_color_bit, /*demand color bit of result image*/
	UInt8	*outBuffer,
	UInt16	destWidth,             /*the width of outBuffer*/
	UInt16	destHeight             /*the height of outBuffer*/
	)
{
	if(outBuffer != NULL && destWidth > 0 && destHeight > 0)
	{
		UInt32 p;
		UInt8 TypeField,FixHeaderField,index;
		const UInt8 *DataBuf;
		UInt16	i,j,z,img_width,img_height;
		UInt8 c_r,c_g,c_b,HiByte,LoByte;

	    TypeField = buf[0];
		FixHeaderField = buf[1];
		index = 2;
		if(buf[index] & 0x80)
		{
			UInt16 hi_byte;
			UInt8 lo_byte;
			hi_byte = ((UInt16)buf[index++] << 7) & 0x3F80;
			lo_byte = buf[index++] & 0x7F;
			img_width = hi_byte | lo_byte; 
		}
		else
		{
			img_width = buf[index++];	
		}

		if(buf[index] & 0x80)
		{
			UInt16 hi_byte;
			UInt8 lo_byte;
			hi_byte = ((UInt16)buf[index++] << 7) & 0x3F80;
			lo_byte = buf[index++] & 0x7F;
			img_height = hi_byte | lo_byte; 
		}
		else
		{
			img_height = buf[index++];	
		}
		DataBuf = &buf[index];
	    
	    z = (img_width / 8) + ((img_width % 8) ? 1 : 0);

		switch(img_color_bit)
		{
			case PIXEL_16BIT:
				for ( j = 0; j < img_height && j + ypos < destHeight; j++)
				{
					for ( i = 0; i < img_width && i + xpos < destWidth; i++)
					{
						if((DataBuf[i / 8 + j * z] & Mask1[i & 0x07]))	/*COLORREF_WHITE*/
						{
							HiByte = 0xFF;
							LoByte = 0xFF;
						}
						else										 /*COLORREF_BLACK*/
						{
							HiByte = 0x00;
							LoByte = 0x00;
						}
						p = ((ypos + j) * img_width + (xpos + i)) << 1;
						*(outBuffer + p) = HiByte;
						*(outBuffer + p + 1) = LoByte;
					}
				}
				break;
			case PIXEL_24BIT:
				for ( j = 0; j < img_height && j + ypos < destHeight; j++)
				{
					for ( i = 0; i < img_width && i + xpos < destWidth; i++)
					{
						if((DataBuf[i / 8 + j * z] & Mask1[i & 0x07]))	/*COLORREF_WHITE*/
						{
							c_r = 0xFF;
							c_g = 0xFF;
							c_b = 0xFE;
						}
						else										/*COLORREF_BLACK*/
						{
							c_r = 0x00;
							c_g = 0x00;
							c_b = 0x00;
						}
						p = ((ypos + j) * img_width * 3) + ((xpos + i) * 3);
						*(outBuffer + p) = c_r;
						*(outBuffer + p + 1) = c_g;
						*(outBuffer + p + 2) = c_b;
					}
				}
				break;
			case PIXEL_8BIT:
				for ( j = 0; j < img_height && j + ypos < destHeight; j++)
				{
					for ( i = 0; i < img_width && i + xpos < destWidth; i++)
					{
						p = j*img_width + i;
						if((DataBuf[i / 8 + j * z] & Mask1[i & 0x07]))	/*COLORREF_WHITE*/
						{
							*(outBuffer + p) = 0xFF;
						}
						else									       /*COLORREF_BLACK*/
						{
							*(outBuffer + p) = 0x00;
						}
					}
				}				
				break;
			default:
				return;
		}
	}	
}
/*******************************************************************************
** Name	:
** Funct:
** Input:
** Retun: whether the given file is in wbmp format
** Note	:
********************************************************************************/
GLOBAL Bool1 GetWBMPInfo(
				UInt16 *img_width, 
				UInt16 *img_height,
				const UInt8 *buf
				)
{
	Bool1 is_WBMP;
	UInt8 TypeField,FixHeaderField,index;

    TypeField = buf[0];
	FixHeaderField = buf[1];
	if((TypeField == 0) && ((FixHeaderField & 0x9F) == 0))	/*wbmp type */
	{
		index = 2;
		if(buf[index] & 0x80)
		{
			UInt16 hi_byte;
			UInt8 lo_byte;
			hi_byte = ((UInt16)buf[index++] << 7) & 0x3F80;
			lo_byte = buf[index++] & 0x7F;
			*img_width = hi_byte | lo_byte; 
		}
		else
		{
			*img_width = buf[index++];	
		}

		if(buf[index] & 0x80)
		{
			UInt16 hi_byte;
			UInt8 lo_byte;
			hi_byte = ((UInt16)buf[index++] << 7) & 0x3F80;
			lo_byte = buf[index++] & 0x7F;
			*img_height = hi_byte | lo_byte; 
		}
		else
		{
			*img_height = buf[index++];	
		}
		is_WBMP = TRUE;
	}
	else
	{
		*img_width = 0;
		*img_height = 0;
		is_WBMP = FALSE;
	}
	return is_WBMP;
}

#undef _WBMP_C_