#pragma windows              // this command is needed to create a window
#include <stdio.h>
#include <math.h>
#include <\DBOS\graphics.h>  // These libraries must be included
#include <windows.h>         // to use graphics functions          

void Plot_2D_Array(int *);   // Function to plot grey-scale graph

int main(void)

       {
         FILE *fp;
         int data[128][128];    // Data held as 128 x 128 array of ints
         int *pointer;          // declare pointer to variable of type int
         int time,wavelength,ctrl;
                        
         fp=fopen("light.dat","r");      
         
         for (time=0;time<128;time++)          // load data into 2D array
            {
              for (wavelength=0;wavelength<128;wavelength++)
              fscanf(fp,"%d",&data[time][wavelength]);              
            }  
         fclose(fp);
                 
         // The following line uses the Salford compiler's 
         // ClearWin+ winio() function to open a window that
         // is then used to display graphics.
         // The winio() function may be supplied with a very large
         // number of parameters that control the layout, appearance
         // and function of the window. We will only need to use a few of 
         // those parameters for the programs in the Computing II module.
         // 
         // The parameters needed to open a simple graphics window are:
         // %gr -      this provides a rectangular area for graphics
         //            In this case 128 x 128 pixels 
         // [black]    paints the area black        
         // %lw        a parameter that is needed to enable the window 
         //            to be closed; when the window is closed "ctrl" is
         //            set to zero
         

         winio("%gr[black]%lw",128,128,&ctrl);                  
         
         pointer=&data[0][0];           // the variable "pointer" points to the data array                                                                  
         Plot_2D_Array(pointer);        // pass the data array to the Plot_2D_Array function
       }
       
void Plot_2D_Array(int *array)
       {               
         short i,rows,cols;
         
         // The following loop sets up the colour palette
         // It is possible to create any colour by mixing
         // red, green and blue. Using the set_video_dac() function
         // we can mix red, green and blue as we please to create
         // a range of colours. 
         // The format is: set_video_dac(index, red, green, blue)
         // where index, red, green and blue all have values between 0 and 255
         // So to assign colour no. 255 as white we use:
         // set_video_dac(255,255,255,255);
         // The following loop sets up a grey scale with black having
         // colour index 0 and white having colour index 255
         
         for (i=0;i<256;i++)            
         set_video_dac(i,i,i,i);     
                       
         // The following loop colours the pixels on the screen using
         // the set_pixel() function.
         // set_pixel() has the following arguments:
         // set_pixel(x co-ordinate, y co-ordinate, colour)
         // Each pixel is given a shade of grey dependent
         // on the value in "array"
          
         for (rows=0;rows<128;rows++)
                {
                  for (cols=0;cols<128;cols++)  
                  set_pixel(cols,rows, *(array+cols+(128*rows)));         
                } 
         return;       
        }