textoverlay.c

ADI的ADSP-BF561下实现视频叠加的demo。

/*****************************************************************************************/
//
// Name: 	BF561 EZ-KIT video streamer based on DMA interaction
//
/*****************************************************************************************

(C) Copyright 2003 - Analog Devices, Inc.  All rights reserved.

File Name:				TextOverlay.c

Date Modified:			8/26/04		TL		Rev 1.1

Software:       		VisualDSP++3.5, Compiler 7.0.7.0, Assembler 2.6.5.3, Linker 3.4.0.0

Hardware:				BF561 EZ-KIT Board (rev 1.2)
					       
******************************************************************************************/
#include "font.h"	// Font taken for the Textoverlay
#include "main.h"
/*****************************************************************************************/
// Program Define Section
/*****************************************************************************************/

/*****************************************************************************************/
// Program Variable Section
/*****************************************************************************************/

volatile unsigned short BGcolor  = 0xFFFF;	// Textbackground will be filled before placing text
unsigned short font_offset,font_image_size;
unsigned char *font, *font_w;

/*****************************************************************************************/
// Global and extern subroutines
/*****************************************************************************************/

/*****************************************************************************************/
// Program
/*****************************************************************************************/

void TextOverlay(void){
   unsigned short color, error=0,posx,posy;
   unsigned short lCnt,lCnt1,lCnt2,lCnt3;  
  
	clear_vmem(BGcolor);	// fills the whole buffer with a color (Background color)
	register_font(arial, arial_w);	// handles the distance of the letters
	put_string("Analog Devices Video HandlerAAAAAA", 0 ,0,0x00FF);	// takes the actual string to print
}


//Clear display memory
void clear_vmem(unsigned short color){
	
unsigned short lCnt;
unsigned short error=0;

	for (lCnt = 0; lCnt < sizeof(uiTextOverlay); lCnt++)
	{
		*(pMem+lCnt/2) = color;
	}

}


//One pixel at position (x,y)
inline void plot_xy(unsigned short x,unsigned short y,unsigned short color){

	*(pMem + ( ( y * (S1D_DISPLAY_WIDTH ) ) + x )) = color;
	
}






unsigned short put_char (unsigned char c, unsigned short x, unsigned short y, unsigned short color) {
	
    unsigned short start_pos,lCntx,lCnty;
	unsigned char value,mask = 0x80;
	
	start_pos = font_offset + (c%16)*2 + (((c/16)+1)*512);
    
    for (lCnty=16 ; lCnty > 0 ; lCnty-- ){
			  
			mask = 0x80; 
			value = font[start_pos];
			
			for (lCntx=0 ; lCntx < font_w[c]+1 ; lCntx++ ){
				
				if ( (value & mask)) plot_xy( x+lCntx, y+lCnty, color );

				mask = mask >> 1;
					
				if ( !mask ) {  
					mask = 0x80;
					value = font[start_pos+1];
				}
			}
				
			start_pos-=32;
	}	

		return (font_w[c]+x);
}


void register_font(unsigned char *rfont,unsigned char *rfont_w) {
	
	font_offset= rfont[10] + (rfont[11] << 8) + (rfont[12] << 16) + (rfont[13] << 24);
	font_image_size = rfont[18] + (rfont[19] << 8) + (rfont[20] << 16) + (rfont[21] << 24);
	
    font = &rfont[0];
	font_w = &rfont_w[0];
}


//   Writes a zero terminated string to the specified display position
unsigned short put_string(unsigned char *string, unsigned short x,unsigned short y,unsigned short color  ) {

	while(*string) {
        x=put_char(*string,x,y,color);
        string++;
    }

  return(x);
}