/* A simple plug-in that returns the image that is an average of
   two input images */

#include "EF.h"
#include <stdio.h>
#include <string.h>

void averageImages(EF_Image *image1, EF_Image *image2,
		   EF_Image *result, float);

/* This is called when the plug-in is loaded by the video editor. 
   We register the plug-in with the editor by filling in the options
   structure */

void pluginInit(EF_PluginOptions *options)
{
    if (options->structSize!=sizeof(EF_PluginOptions))
	{ puts("Plugin is wrong version"); return; }

    /* Set the pluginComposite field in options to point to our
       averageImages() function.  Also set name to be the name
       of this plugin. */
    options->pluginComposite = averageImages;
    strcpy(options->name,"Average");
}

void averageImages(EF_Image *image1, EF_Image *image2,
		   EF_Image *result, float)
{
    /* Loop over all of the pixels in each image */
    for (int x = 0; x < image1->xSize; x++)
	for(int y = 0; y < image1->ySize; y++) 
	    {
		/* Get the pixel from each image */
		long pix1 = EF_ImageXY(image1, x, y);
		long pix2 = EF_ImageXY(image2, x, y);
		long pixAvg;

		/* Compute the average of each component */
		RED(pixAvg) = (RED(pix1) + RED(pix2)) / 2;
		GREEN(pixAvg) = (GREEN(pix1) + GREEN(pix2)) / 2;
		BLUE(pixAvg) = (BLUE(pix1) + BLUE(pix2)) / 2;
		ALPHA(pixAvg) = (ALPHA(pix1) + ALPHA(pix2)) / 2;

		/* Set the corresponding pixel in the result image
		   with the average pixel */
		EF_ImageXY(result, x, y)= pixAvg;
	    }
}