test_blend.c

/*--------------------------------------------------------------------------
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License version 2 as
published by the Free Software Foundation.

A simple test for displaying PNG files with input alpha value for deducing.

Usage: test_blend path alpha_value

Midas Zhou
midaszhou@yahoo.com
----------------------------------------------------------------------------*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <png.h>
#include "egi_fbgeom.h"
#include "egi_bjp.h"
#include "egi_image.h"
#include "egi_color.h"

#define PNG_FIXED_POINT_SUPPORTED /* for read */
#define PNG_READ_EXPAND_SUPPORTED

int main(int argc, char **argv)
{
	int ret=0;
	int py;
	int da; /* delta alpha */
	int i;
	EGI_IMGBUF  *eimg=egi_imgbuf_new();

	if( argc<2 ) {
		printf("Please enter png file name!\n");
		return -1;
	}
	if( argc > 2)
		py=atoi(argv[2]);
	else
		py=0;
	if( argc > 3)
		da=atoi(argv[3]);
	else
		da=0;

        /* --- prepare fb device --- */
        init_fbdev(&gv_fb_dev);

	/* load image data to EGI_IMGBUF */
	if( egi_imgbuf_loadpng(argv[1], eimg ) ==0 ) {
	}
	else if( egi_imgbuf_loadjpg(argv[1], eimg ) ==0 ) {
	}
	else {
		egi_imgbuf_free(eimg);
		return -2;
	}

	/* adjust opacity */
	for(i=0; i< (eimg->width * eimg->height); i++) {
		if(eimg->alpha[i]!=0) {
		   if((int)(eimg->alpha)[i] < da)
			(eimg->alpha)[i]=0;
		   else
			(eimg->alpha)[i]-=da;
		}
	}

        /* window_position displaying */
#if 1
	int dw,dh; /* displaying window width and height */
	dw=eimg->width>240?240:eimg->width;
	dh=eimg->height>320?320:eimg->height;
        egi_imgbuf_windisplay(eimg, &gv_fb_dev, -1, 0, 0, 0, py, dw, dh);
#else
        egi_imgbuf_windisplay(eimg, &gv_fb_dev, 0, 0, 70, 220, eimg->width, eimg->height);
#endif


	egi_imgbuf_free(eimg);
	release_fbdev(&gv_fb_dev);

	return ret;
}