drawbox.c

CHP 2 - Real-Time Digital Signal Processing: Implementations and Applications, Second Edition by Sen

// 
//  Project: Experiment 2.10.4 Configure EMIF - Chapter 2 
//  File name: drawBox.c   
//  Function(s): drawBox()        
//
//  Description: This function writes data in a block shape to SDRAM
//
//  For the book "Real Time Digital Signal Processing: 
//                Implementation and Application, 2nd Ed"
//                By Sen M. Kuo, Bob H. Lee, and Wenshun Tian
//                Publisher: John Wiley and Sons, Ltd
//
//  Tools used: CCS v.2.12.07
//              TMS320VC5510 DSK Rev-C
//


#define WIDTH       320           // Color checker image width
#define HEIGHT      240           // Color checker image height
#define BOXWIDTH    48            // Color box width
#define BOXHEIGHT   50            // Color box height
#define SDRAM_START 0x28000       // DSK SDRAM physical starting address
#define SDRAM_R  SDRAM_START
#define SDRAM_G (SDRAM_R+0x9600)  // The offset 0x9600 is for 320x240 bytes
#define SDRAM_B (SDRAM_G+0x9600)  // The offset 0x9600 is for 320x240 bytes

#pragma CODE_SECTION(drawBox,    ".text:example:drawBox");

void drawBox(unsigned long vOffset, unsigned long hOffset, 
             unsigned long r, unsigned long g, unsigned long b)
{
  unsigned long mPtrR,mPtrR2; 
  unsigned long mPtrG,mPtrG2; 
  unsigned long mPtrB,mPtrB2;  
  short width,height,i,j;

  if ((vOffset == 0)&&(hOffset==0)) // Paint black background        
  {
    width = WIDTH>>2;
    height = HEIGHT;
  }
  else                             // Paint the RGB color block
  {
    width = BOXWIDTH>>2;
    height = BOXHEIGHT;
  }

  // Set up the pointers to SDRAM
  mPtrR = SDRAM_R+(WIDTH*vOffset)+hOffset;
  mPtrG = SDRAM_G+(WIDTH*vOffset)+hOffset;
  mPtrB = SDRAM_B+(WIDTH*vOffset)+hOffset;
  mPtrR2 = mPtrR;      
  mPtrG2 = mPtrG;      
  mPtrB2 = mPtrB;  

  // Paint a box of widthxheight    
  for (i=0; i<height; i++)         // Total height of the drawing                   
  {    
    for (j=0; j<width; j++)        // Draw one line a time
    {
      *((unsigned long*)mPtrR) = r; 
      *((unsigned long*)mPtrG) = g; 
      *((unsigned long*)mPtrB) = b; 
      mPtrR += 2; 
      mPtrG += 2; 
      mPtrB += 2; 
    }              
    // Adjust SDRAM address pointers for next line
    mPtrR2 += WIDTH>>1;
    mPtrG2 += WIDTH>>1;
    mPtrB2 += WIDTH>>1;
    mPtrR = mPtrR2; 
    mPtrG = mPtrG2; 
    mPtrB = mPtrB2; 
  }
}