#define _GNU_SOURCE
#include <netinet/ip.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <assert.h>
#include <unistd.h>
#include <png.h>
#define QUEUE_LEN 1000
#define MSGSIZE (2 + 7 * 160)
#define DISPLAY_HOST "100.65.0.2"
#define DISPLAY_PORT 5005
#define DISPLAY_WIDTH 1920
#define DISPLAY_HEIGHT 1080
struct mmsghdr msg[QUEUE_LEN];
struct iovec iovec[QUEUE_LEN];
uint8_t bufs[QUEUE_LEN][MSGSIZE];
int send_next = 0;
int next = 0;
int pos = 0;
static void
setup(void)
{
for (int i=0;i<QUEUE_LEN;i++) {
iovec[i].iov_base = bufs[i];
msg[i].msg_hdr.msg_iov = &iovec[i];
msg[i].msg_hdr.msg_iovlen = 1;
bufs[i][0] = 0x00;
bufs[i][1] = 0x01;
}
}
static void
flush_frame(void)
{
if (pos == 0) return;
iovec[next].iov_len = 2 + (pos * 7);
if (++next == QUEUE_LEN) next = 0;
}
static void
set_pixel(uint16_t x, uint16_t y, uint8_t r, uint8_t b, uint8_t g)
{
uint8_t *buf = bufs[next] + 2 + pos * 7;
buf[0] = x & 0xff;
buf[1] = (x >> 8) & 0xff;
buf[2] = y & 0xff;
buf[3] = (y >> 8) & 0xff;
buf[4] = r;
buf[5] = b;
buf[6] = g;
if (++pos == 160) {
flush_frame();
pos = 0;
}
}
static void
blank_screen(void)
{
for (int x=0;x<DISPLAY_WIDTH;x++) {
for (int y=0;y<DISPLAY_HEIGHT;y++) {
set_pixel(x, y, 0, 0, 0);
}
}
}
struct data_png {
int width, height;
png_byte color_type;
png_byte bit_depth;
png_structp png_ptr;
png_infop info_ptr;
int number_of_passes;
png_bytep * row_pointers;
};
static struct data_png *
open_png(const char *pngname)
{
char header[8];
FILE *fp = fopen(pngname, "rb");
struct data_png *d = malloc(sizeof(struct data_png));
assert(fp);
assert(d != NULL);
fread(header, 1, 8, fp);
assert(png_sig_cmp(header, 0, 8) == 0);
d->png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
assert(d->png_ptr);
d->info_ptr = png_create_info_struct(d->png_ptr);
assert(d->info_ptr);
png_init_io(d->png_ptr, fp);
png_set_sig_bytes(d->png_ptr, 8);
png_read_info(d->png_ptr, d->info_ptr);
d->width = png_get_image_width(d->png_ptr, d->info_ptr);
d->height = png_get_image_height(d->png_ptr, d->info_ptr);
d->color_type = png_get_color_type(d->png_ptr, d->info_ptr);
d->bit_depth = png_get_bit_depth(d->png_ptr, d->info_ptr);
d->number_of_passes = png_set_interlace_handling(d->png_ptr);
png_read_update_info(d->png_ptr, d->info_ptr);
d->row_pointers = (png_bytep*) malloc(sizeof(png_bytep) * d->height);
for (int y=0; y<d->height; y++)
d->row_pointers[y] = (png_byte*) malloc(png_get_rowbytes(d->png_ptr,d->info_ptr));
png_read_image(d->png_ptr, d->row_pointers);
fclose(fp);
return d;
}
static void
draw_png(struct data_png *d, int x, int y)
{
for (int sy=0; sy < d->height; sy++) {
png_byte *row = d->row_pointers[sy];
for (int sx=0; sx < d->width; sx++) {
uint8_t *rbga = &row[sx*4];
if (rbga[3] > 0)
set_pixel(x+sx, y+sy, rbga[0], rbga[1], rbga[2]);
}
}
}
struct bb_info {
int x;
int y;
int x1, y1, x2, y2;
int move_x;
int move_y;
int rate;
struct data_png *img;
const char *imgfile;
};
static void
bb_init(struct bb_info *bb, struct data_png *img, int x, int y, int w, int h)
{
bb->img = img;
bb->x1 = x;
bb->y1 = y;
bb->x2 = w - img->width;
bb->y2 = h - img->height;
if (bb->x == -1) bb->x = (bb->x1 + bb->x2) / 2;
if (bb->y == -1) bb->y = (bb->y1 + bb->y2) / 2;
}
static void
bb_draw(struct bb_info *bb)
{
draw_png(bb->img, bb->x, bb->y);
bb->x += bb->move_x;
bb->y += bb->move_y;
if (bb->x < bb->x1 || bb->x > bb->x2)
bb->move_x *= -1;
if (bb->y < bb->y1 || bb->y > bb->y2)
bb->move_y *= -1;
}
struct bb_info images[] = {
{
.imgfile = "images/unicorn_cc.png",
.move_x = 13,
.move_y = -10,
.x = -1,
.y = -1,
},
{
.imgfile = "images/windows_logo.png",
.move_x = -8,
.move_y = 3,
.rate = 2,
.x = -1,
.y = -1,
},
{
.imgfile = "images/spade.png",
.move_x = 32,
.move_y = -12,
.x = 0,
.y = 0,
},
{
.imgfile = "images/dvdvideo.png",
.move_x = 200,
.move_y = 60,
.rate = 5,
.x = -1,
.y = -1,
.x = 1000,
.y = 800,
},
{
.imgfile = "images/hackaday.png",
.move_x = 40,
.move_y = 18,
.rate = 3,
.x = -1,
.y = -1,
.x = 500,
.y = 800,
},
{}
};
static void
draw_frame(unsigned int frameno)
{
for (struct bb_info *bb = &images[0];bb->img;bb++) {
if (bb->rate && frameno % bb->rate != 0)
continue;
bb_draw(bb);
}
flush_frame();
}
static void
send_stuff(int fd)
{
int retval;
int len;
int from = send_next;
if (next == send_next) {
next = 0;
send_next = 0;
return;
} else if (next > send_next) {
len = next - send_next;
} else {
len = QUEUE_LEN - send_next;
}
retval = sendmmsg(fd, &msg[from], len, 0);
if (retval == -1) {
perror("sendmmsg()");
return;
}
send_next += retval;
if (send_next >= QUEUE_LEN) send_next = 0;
//printf("%d/%d messages sent from %d, continuing from %d\n", retval, len, from, send_next);
}
int
main(void)
{
int sockfd;
struct sockaddr_in addr;
struct hostent *hp;
for (struct bb_info *bb = &images[0];bb->imgfile;bb++) {
bb_init(bb, open_png(bb->imgfile), 0, 0, DISPLAY_WIDTH, DISPLAY_HEIGHT);
}
setup();
sockfd = socket(AF_INET, SOCK_DGRAM, 0);
if (sockfd == -1) {
perror("socket()");
exit(EXIT_FAILURE);
}
if ((hp = gethostbyname(DISPLAY_HOST)) == NULL) {
return -1;
}
addr.sin_family = AF_INET;
addr.sin_port = htons(DISPLAY_PORT);
addr.sin_addr.s_addr = *( u_long * ) hp->h_addr;
if (connect(sockfd, (struct sockaddr *) &addr, sizeof(addr)) == -1) {
perror("connect()");
exit(EXIT_FAILURE);
}
//blank_screen();
unsigned int frame = 0;
while (1) {
//printf("draw_frame\n");
draw_frame(frame++);
int old = send_next;
for (int i=0;i<25;i++) {
send_stuff(sockfd);
send_next = old;
//usleep(15000);
}
send_stuff(sockfd);
//usleep(15000);
//break;
}
exit(0);
}
