+static int advance_chunk(struct rfb_state *state) {
+
+ state->chunk_xnum += 1;
+
+ if (state->chunk_xnum == SCREEN_CHUNKS_X) {
+ state->chunk_ynum += 1;
+ state->chunk_xnum = 0;
+ }
+
+ if (state->chunk_ynum == SCREEN_CHUNKS_Y) {
+ state->chunk_ynum = 0;
+ state->send_state = SST_IDLE;
+ if (!(state->chunk_actually_sent))
+ state->try_in_a_bit = 1;
+ return 1;
+ }
+
+ return 0;
+}
+
+static int ceildiv(int a, int b) {
+ int res = a / b;
+ if (a % b != 0) {
+ res++;
+ }
+ return res;
+}
+
+static void send_fsm(struct tcp_pcb *pcb, struct rfb_state *state) {
+ struct update_header hdr;
+ int bytes_left;
+ int totaldim;
+ err_t err;
+
+ while(1) {
+
+ switch (state->send_state) {
+
+ case SST_IDLE:
+ /* Nothing to do */
+
+ if (state->update_requested) {
+ outputf("RFB send: update requested");
+ state->update_requested = 0;
+ state->chunk_actually_sent = 0;
+ state->send_state = SST_HEADER;
+ } else {
+ return;
+ }
+
+ /* FALL THROUGH to SST_HEADER */
+
+ case SST_HEADER:
+
+ /* Calculate the width and height for this chunk, remembering
+ * that if SCREEN_CHUNKS_[XY] do not evenly divide the width and
+ * height, we may need to have shorter chunks at the edge of
+ * the screen. */
+
+ state->chunk_width = ceildiv(fb->curmode.xres, SCREEN_CHUNKS_X);
+ state->chunk_xpos = state->chunk_width * state->chunk_xnum;
+ totaldim = state->chunk_width * (state->chunk_xnum + 1);
+ if (totaldim > fb->curmode.xres) {
+ state->chunk_width -= (totaldim - fb->curmode.xres);
+ }
+
+ state->chunk_height = ceildiv(fb->curmode.yres, SCREEN_CHUNKS_Y);
+ state->chunk_ypos = state->chunk_height
+ * state->chunk_ynum;
+ totaldim = state->chunk_height * (state->chunk_ynum + 1);
+ if (totaldim > fb->curmode.yres) {
+ state->chunk_height -= (totaldim - fb->curmode.yres);
+ }
+
+ /* Do we _actually_ need to send this chunk? */
+ if (fb->checksum_rect) {
+ state->chunk_checksum = fb->checksum_rect(state->chunk_xpos, state->chunk_ypos,
+ state->chunk_width, state->chunk_height);
+
+ if (state->chunk_checksum == state->checksums[state->chunk_xnum][state->chunk_ynum]) {
+ if (advance_chunk(state))
+ return;
+ continue;
+ }
+ /* Checksum gets set in data block, AFTER the data has been sent. */
+ }
+
+ state->chunk_actually_sent = 1;
+
+ /* Send a header */
+ hdr.msgtype = 0;
+ state->chunk_bytes_sent = 0;
+ hdr.nrects = htons(1);
+ hdr.xpos = htons(state->chunk_xpos);
+ hdr.ypos = htons(state->chunk_ypos);
+ hdr.width = htons(state->chunk_width);
+ hdr.height= htons(state->chunk_height);
+ hdr.enctype = htonl(0);
+
+ err = tcp_write(pcb, &hdr, sizeof(hdr), TCP_WRITE_FLAG_COPY);
+
+ if (err != ERR_OK) {
+ if (err != ERR_MEM)
+ outputf("RFB: header send error %d", err);
+
+ /* Try again later. */
+ return;
+ }
+
+ state->send_state = SST_DATA;
+
+ /* Snag the data. */
+ fb->copy_pixels(state->blockbuf,
+ state->chunk_xpos, state->chunk_ypos,
+ state->chunk_width, state->chunk_height);
+
+ /* FALL THROUGH to SST_DATA */
+
+ case SST_DATA:
+
+ bytes_left = 4 * state->chunk_width * state->chunk_height - state->chunk_bytes_sent;
+
+ if (bytes_left == 0) {
+ state->send_state = SST_HEADER;
+ state->checksums[state->chunk_xnum][state->chunk_ynum] = state->chunk_checksum;
+ if (advance_chunk(state))
+ return;
+ break;
+ }
+
+ /* That's enough. */
+ if (bytes_left > 1400) {
+ bytes_left = 1400;
+ }
+
+ err = tcp_write(pcb, state->blockbuf + state->chunk_bytes_sent,
+ bytes_left, TCP_WRITE_FLAG_COPY);
+
+ if (err == ERR_OK) {
+ state->chunk_bytes_sent += bytes_left;
+ } else {
+ if (err != ERR_MEM)
+ outputf("RFB: send error %d", err);
+
+ return;
+ }
+
+ if (tcp_sndbuf(pcb) == 0) {
+ return;
+ }
+ }
+ }
+
+ if (tcp_output(pcb) != ERR_OK)
+ outputf("RFB: tcp_output bailed in send_fsm?");
+}
+
+static err_t rfb_sent(void *arg, struct tcp_pcb *pcb, uint16_t len) {
+ struct rfb_state *state = arg;
+ send_fsm(pcb, state);
+ return ERR_OK;
+}
+
+static err_t rfb_poll(void *arg, struct tcp_pcb *pcb) {
+ struct rfb_state *state = arg;
+ if (state->try_in_a_bit) {
+ state->try_in_a_bit--;
+ if (!(state->try_in_a_bit)) {
+ state->update_requested = 1;
+ }
+ }
+ send_fsm(pcb, state);
+/*
+ stats_display();
+*/
+ return ERR_OK;