guacamole-spice-protocol/src/protocols/vnc/cursor.c

/*
 * Copyright (C) 2013 Glyptodon LLC
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "config.h"

#include "client.h"
#include "guac_cursor.h"
#include "guac_display.h"
#include "guac_surface.h"
#include "vnc.h"

#include <cairo/cairo.h>
#include <guacamole/client.h>
#include <guacamole/layer.h>
#include <guacamole/protocol.h>
#include <guacamole/socket.h>
#include <rfb/rfbclient.h>
#include <rfb/rfbproto.h>

/* Define cairo_format_stride_for_width() if missing */
#ifndef HAVE_CAIRO_FORMAT_STRIDE_FOR_WIDTH
#define cairo_format_stride_for_width(format, width) (width*4)
#endif

#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <syslog.h>

void guac_vnc_cursor(rfbClient* client, int x, int y, int w, int h, int bpp) {

    guac_client* gc = rfbClientGetClientData(client, GUAC_VNC_CLIENT_KEY);
    guac_vnc_client* vnc_client = (guac_vnc_client*) gc->data;

    /* Cairo image buffer */
    int stride = cairo_format_stride_for_width(CAIRO_FORMAT_ARGB32, w);
    unsigned char* buffer = malloc(h*stride);
    unsigned char* buffer_row_current = buffer;

    /* VNC image buffer */
    unsigned int fb_stride = bpp * w;
    unsigned char* fb_row_current = client->rcSource;
    unsigned char* fb_mask = client->rcMask;

    int dx, dy;

    /* Copy image data from VNC client to RGBA buffer */
    for (dy = 0; dy<h; dy++) {

        unsigned int*  buffer_current;
        unsigned char* fb_current;
        
        /* Get current buffer row, advance to next */
        buffer_current      = (unsigned int*) buffer_row_current;
        buffer_row_current += stride;

        /* Get current framebuffer row, advance to next */
        fb_current      = fb_row_current;
        fb_row_current += fb_stride;

        for (dx = 0; dx<w; dx++) {

            unsigned char alpha, red, green, blue;
            unsigned int v;

            /* Read current pixel value */
            switch (bpp) {
                case 4:
                    v = *((unsigned int*)   fb_current);
                    break;

                case 2:
                    v = *((unsigned short*) fb_current);
                    break;

                default:
                    v = *((unsigned char*)  fb_current);
            }

            /* Translate mask to alpha */
            if (*(fb_mask++)) alpha = 0xFF;
            else              alpha = 0x00;

            /* Translate value to RGB */
            red   = (v >> client->format.redShift)   * 0x100 / (client->format.redMax  + 1);
            green = (v >> client->format.greenShift) * 0x100 / (client->format.greenMax+ 1);
            blue  = (v >> client->format.blueShift)  * 0x100 / (client->format.blueMax + 1);

            /* Output ARGB */
            if (vnc_client->settings->swap_red_blue)
                *(buffer_current++) = (alpha << 24) | (blue << 16) | (green << 8) | red;
            else
                *(buffer_current++) = (alpha << 24) | (red  << 16) | (green << 8) | blue;

            /* Next VNC pixel */
            fb_current += bpp;

        }
    }

    /* Update stored cursor information */
    guac_common_cursor_set_argb(vnc_client->display->cursor, x, y,
            buffer, w, h, stride);

    /* Free surface */
    free(buffer);

    /* libvncclient does not free rcMask as it does rcSource */
    free(client->rcMask);
}