ben-blinkenlights/ubb-vga/grabfb.c

/*
 * grabfb.c - Grab the Ben's main frame buffer
 *
 * Written 2011 by Werner Almesberger
 * Copyright 2011 Werner Almesberger
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */


#include <stdint.h>
#include <assert.h>

#include "ubb-vga.h"


uint8_t thres = 63;


static uint8_t pattern(int r, int g, int b)
{
	return ((r ? R_VAL : 0) | (g ? G_VAL : 0) | (b ? B_VAL : 0))*0x11;
}


void grabfb(void *f, int xres, int yres)
{
	uint32_t *fb = map(0x01d00000, 4*320*240);
	uint8_t *p = f;
	int x, y;
	uint32_t pix;
	uint8_t r, g, b;

	assert(xres == 640);
	assert(yres == 480);
	for (y = 0; y != 240; y++) {
		for (x = 0; x != 320; x++) {
			pix = *fb++;
			r = pix >> 16;
			g = pix >> 8;
			b = pix;
			p[0] = p[320] =
			    pattern(r >= thres, g >= thres, b >= thres);
			p++;
		}
		p += 320;
	}
}