GUAC-667: Implement clipping within common surface.

src/common/guac_surface.c

@@ -67,6 +67,49 @@
 #define cairo_format_stride_for_width(format, width) (width*4)
 #endif
 
+/**
+ * Updates the coordinates of the given rectangle to be within the bounds of the given surface.
+ * 
+ * @param surface The surface to use for clipping.
+ * @param x The X coordinate of the rectangle to clip.
+ * @param y The Y coordinate of the rectangle to clip.
+ * @param w The width of the rectangle to clip.
+ * @param h The height of the rectangle to clip.
+ * @param sx The X coordinate of the source rectangle, if any.
+ * @param sy The Y coordinate of the source rectangle, if any.
+ */
+static void __guac_common_bound_rect(guac_common_surface* surface, int* x, int* y, int* w, int* h,
+                                     int* sx, int* sy) {
+
+    int bounds_left   = surface->bounds_x;
+    int bounds_top    = surface->bounds_y;
+    int bounds_right  = bounds_left + surface->bounds_width;
+    int bounds_bottom = bounds_top  + surface->bounds_height;
+
+    /* Get rect coordinates */
+    int clipped_left   = *x;
+    int clipped_top    = *y;
+    int clipped_right  = clipped_left + *w;
+    int clipped_bottom = clipped_top  + *h;
+
+    /* Clip to bounds */
+    if (clipped_left   < bounds_left)   clipped_left   = bounds_left;
+    if (clipped_top    < bounds_top)    clipped_top    = bounds_top;
+    if (clipped_right  > bounds_right)  clipped_right  = bounds_right;
+    if (clipped_bottom > bounds_bottom) clipped_bottom = bounds_bottom;
+
+    /* Update source X/Y if given */
+    if (sx != NULL) *sx += clipped_left - *x;
+    if (sy != NULL) *sy += clipped_top  - *y;
+
+    /* Store new rect dimensions */
+    *x = clipped_left;
+    *y = clipped_top;
+    *w = clipped_right  - clipped_left;
+    *h = clipped_bottom - clipped_top;
+
+}
+
 /**
  * Returns whether the given rectangle should be combined into the existing
  * dirty rectangle, to be eventually flushed as a "png" instruction.
@@ -257,13 +300,16 @@ static void __guac_common_surface_transfer_int(guac_transfer_function op, uint32
 static void __guac_common_surface_rect(guac_common_surface* dst, int dx, int dy, int w, int h,
                                        int red, int green, int blue) {
 
-    int dst_stride = dst->stride;
-    unsigned char* dst_buffer = dst->buffer + dst_stride*dy + 4*dx;
-
     int x, y;
 
+    int dst_stride;
+    unsigned char* dst_buffer;
+
     uint32_t color = 0xFF000000 | (red << 16) | (green << 8) | blue;
 
+    dst_stride = dst->stride;
+    dst_buffer = dst->buffer + dst_stride*dy + 4*dx;
+
     /* For each row */
     for (y=0; y<h; y++) {
 
@@ -305,7 +351,7 @@ static void __guac_common_surface_put(unsigned char* src_buffer, int src_stride,
         for (x=0; x<w; x++) {
 
             if (opaque || (*src_current & 0xFF000000))
-                *dst_current = *src_current;
+                *dst_current = *src_current | 0xFF000000;
 
             src_current++;
             dst_current++;
@@ -382,6 +428,9 @@ guac_common_surface* guac_common_surface_alloc(guac_socket* socket, const guac_l
     surface->stride = cairo_format_stride_for_width(CAIRO_FORMAT_RGB24, w);
     surface->buffer = malloc(surface->stride * h);
 
+    /* Reset clipping rect */
+    guac_common_surface_reset_clip(surface);
+
     /* Init with black */
     __guac_common_surface_rect(surface, 0, 0, w, h, 0x00, 0x00, 0x00); 
 
@@ -430,7 +479,12 @@ void guac_common_surface_resize(guac_common_surface* surface, int w, int h) {
     surface->stride = stride;
     surface->buffer = buffer;
 
+    /* Reset clipping rect */
+    guac_common_surface_reset_clip(surface);
+
     /* Init with old data */
+    if (old_width > w)  old_width = w;
+    if (old_height > h) old_height = h;
     __guac_common_surface_put(old_buffer, old_stride, 0, 0, old_width, old_height,
                               surface, 0, 0, 1);
 
@@ -477,6 +531,14 @@ void guac_common_surface_draw(guac_common_surface* surface, int x, int y, cairo_
     int w = cairo_image_surface_get_width(src);
     int h = cairo_image_surface_get_height(src);
 
+    int sx = 0;
+    int sy = 0;
+
+    /* Clip operation */
+    __guac_common_bound_rect(surface, &x, &y, &w, &h, &sx, &sy);
+    if (w <= 0 || h <= 0)
+        return;
+
     /* Flush if not combining */
     if (!__guac_common_should_combine(surface, x, y, w, h, 0))
         guac_common_surface_flush(surface);
@@ -485,7 +547,7 @@ void guac_common_surface_draw(guac_common_surface* surface, int x, int y, cairo_
     __guac_common_mark_dirty(surface, x, y, w, h);
 
     /* Update backing surface */
-    __guac_common_surface_put(buffer, stride, 0, 0, w, h, surface, x, y, format != CAIRO_FORMAT_ARGB32);
+    __guac_common_surface_put(buffer, stride, sx, sy, w, h, surface, x, y, format != CAIRO_FORMAT_ARGB32);
 
 }
 
@@ -496,6 +558,11 @@ void guac_common_surface_copy(guac_common_surface* src, int sx, int sy, int w, i
     const guac_layer* src_layer = src->layer;
     const guac_layer* dst_layer = dst->layer;
 
+    /* Clip operation */
+    __guac_common_bound_rect(dst, &dx, &dy, &w, &h, &sx, &sy);
+    if (w <= 0 || h <= 0)
+        return;
+
     /* Defer if combining */
     if (__guac_common_should_combine(dst, dx, dy, w, h, 1))
         __guac_common_mark_dirty(dst, dx, dy, w, h);
@@ -520,6 +587,11 @@ void guac_common_surface_transfer(guac_common_surface* src, int sx, int sy, int
     const guac_layer* src_layer = src->layer;
     const guac_layer* dst_layer = dst->layer;
 
+    /* Clip operation */
+    __guac_common_bound_rect(dst, &dx, &dy, &w, &h, &sx, &sy);
+    if (w <= 0 || h <= 0)
+        return;
+
     /* Defer if combining */
     if (__guac_common_should_combine(dst, dx, dy, w, h, 1))
         __guac_common_mark_dirty(dst, dx, dy, w, h);
@@ -544,6 +616,11 @@ void guac_common_surface_rect(guac_common_surface* surface,
     guac_socket* socket = surface->socket;
     const guac_layer* layer = surface->layer;
 
+    /* Clip operation */
+    __guac_common_bound_rect(surface, &x, &y, &w, &h, NULL, NULL);
+    if (w <= 0 || h <= 0)
+        return;
+
     /* Defer if combining */
     if (__guac_common_should_combine(surface, x, y, w, h, 1))
         __guac_common_mark_dirty(surface, x, y, w, h);
@@ -561,6 +638,43 @@ void guac_common_surface_rect(guac_common_surface* surface,
 
 }
 
+void guac_common_surface_clip(guac_common_surface* surface, int x, int y, int w, int h) {
+
+    /* Calculate extents of existing bounds rect */
+    int bounds_left   = surface->bounds_x;
+    int bounds_top    = surface->bounds_y;
+    int bounds_right  = bounds_left + surface->bounds_width;
+    int bounds_bottom = bounds_top  + surface->bounds_height;
+
+    /* Calculate missing extents of given new rect */
+    int right  = x + w;
+    int bottom = y + h;
+
+    /* Update maximums */
+    if (x      > bounds_left)   bounds_left   = x;
+    if (y      > bounds_top)    bounds_top    = y;
+    if (right  < bounds_right)  bounds_right  = right;
+    if (bottom < bounds_bottom) bounds_bottom = bottom;
+
+    /* Commit rect */
+    surface->bounds_x      = bounds_left;
+    surface->bounds_y      = bounds_top;
+    surface->bounds_width  = bounds_right  - bounds_left;
+    surface->bounds_height = bounds_bottom - bounds_top;
+
+    /* Clamp dimensions at 0x0 */
+    if (surface->bounds_width  < 0) surface->bounds_width  = 0;
+    if (surface->bounds_height < 0) surface->bounds_height = 0;
+
+}
+
+void guac_common_surface_reset_clip(guac_common_surface* surface) {
+    surface->bounds_x = 0;
+    surface->bounds_y = 0;
+    surface->bounds_width = surface->width;
+    surface->bounds_height = surface->height;
+}
+
 void guac_common_surface_flush(guac_common_surface* surface) {
 
     if (surface->dirty) {

src/common/guac_surface.h

@@ -100,6 +100,26 @@ typedef struct guac_common_surface {
      */
     int realized;
 
+    /**
+     * The X coordinate of the upper-left corner of the bounding rectangle.
+     */
+    int bounds_x;
+
+    /**
+     * The Y coordinate of the upper-left corner of the bounding rectangle.
+     */
+    int bounds_y;
+
+    /**
+     * The width of the bounding rectangle.
+     */
+    int bounds_width;
+
+    /**
+     * The height of the bounding rectangle.
+     */
+    int bounds_height;
+
 } guac_common_surface;
 
 /**
@@ -187,6 +207,26 @@ void guac_common_surface_rect(guac_common_surface* surface,
                               int x, int y, int w, int h,
                               int red, int green, int blue);
 
+/**
+ * Given the coordinates and dimensions of a rectangle, clips all future
+ * operations within that rectangle.
+ *
+ * @param surface The surface whose clipping rectangle should be changed.
+ * @param x The X coordinate of the upper-left corner of the bounding rectangle.
+ * @param y The Y coordinate of the upper-left corner of the bounding rectangle.
+ * @param w The width of the bounding rectangle.
+ * @param h The height of the bounding rectangle.
+ */
+void guac_common_surface_clip(guac_common_surface* surface, int x, int y, int w, int h);
+
+/**
+ * Resets the clipping rectangle, allowing drawing operations throughout the
+ * entire surface.
+ *
+ * @param surface The surface whose clipping rectangle should be reset.
+ */
+void guac_common_surface_reset_clip(guac_common_surface* surface);
+
 /**
  * Flushes the given surface, drawing any pending operations on the remote
  * display.

src/protocols/rdp/client.c

@@ -648,7 +648,6 @@ int guac_client_init(guac_client* client, int argc, char** argv) {
 
     /* Store client data */
     guac_client_data->rdp_inst = rdp_inst;
-    guac_client_data->bounded = FALSE;
     guac_client_data->mouse_button_mask = 0;
     guac_client_data->clipboard = guac_common_clipboard_alloc(GUAC_RDP_CLIPBOARD_MAX_LENGTH);
     guac_client_data->requested_clipboard_format = CB_FORMAT_TEXT;
@@ -726,41 +725,3 @@ int guac_client_init(guac_client* client, int argc, char** argv) {
 
 }
 
-int guac_rdp_clip_rect(rdp_guac_client_data* data, int* x, int* y, int* w, int* h) {
-
-    if (data->bounded) {
-
-        /* Get rect coordinates */
-        int clipped_left   = *x;
-        int clipped_top    = *y;
-        int clipped_right  = clipped_left + *w - 1;
-        int clipped_bottom = clipped_top  + *h - 1;
-
-        /* Clip left */
-        if      (clipped_left < data->bounds_left)  clipped_left = data->bounds_left;
-        else if (clipped_left > data->bounds_right) return 1;
-
-        /* Clip right */
-        if      (clipped_right < data->bounds_left)  return 1;
-        else if (clipped_right > data->bounds_right) clipped_right = data->bounds_right;
-
-        /* Clip top */
-        if      (clipped_top < data->bounds_top)    clipped_top = data->bounds_top;
-        else if (clipped_top > data->bounds_bottom) return 1;
-
-        /* Clip bottom */
-        if      (clipped_bottom < data->bounds_top)    return 1;
-        else if (clipped_bottom > data->bounds_bottom) clipped_bottom = data->bounds_bottom;
-
-        /* Store new rect dimensions */
-        *x = clipped_left;
-        *y = clipped_top;
-        *w = clipped_right  - clipped_left + 1;
-        *h = clipped_bottom - clipped_top  + 1;
-
-    }
-
-    return 0;
-
-}
-

src/protocols/rdp/client.h

@@ -131,36 +131,6 @@ typedef struct rdp_guac_client_data {
      */
     guac_common_surface* current_surface;
 
-    /**
-     * Whether graphical operations are restricted to a specific bounding
-     * rectangle.
-     */
-    int bounded;
-
-    /**
-     * The X coordinate of the upper-left corner of the bounding rectangle,
-     * if any.
-     */
-    int bounds_left;
-
-    /**
-     * The Y coordinate of the upper-left corner of the bounding rectangle,
-     * if any.
-     */
-    int bounds_top;
-
-    /**
-     * The X coordinate of the lower-right corner of the bounding rectangle,
-     * if any.
-     */
-    int bounds_right;
-
-    /**
-     * The Y coordinate of the lower-right corner of the bounding rectangle,
-     * if any.
-     */
-    int bounds_bottom;
-
     /**
      * The keymap to use when translating keysyms into scancodes or sequences
      * of scancodes for RDP.
@@ -241,14 +211,5 @@ typedef struct rdp_freerdp_context {
 
 } rdp_freerdp_context;
 
-/**
- * Given the coordinates and dimensions of a rectangle, clips the rectangle to be
- * within the clipping bounds of the client data, if clipping is active.
- *
- * Returns 0 if the rectangle given is visible at all, and 1 if the entire
- * rectangls is outside the clipping rectangle and this invisible.
- */
-int guac_rdp_clip_rect(rdp_guac_client_data* data, int* x, int* y, int* w, int* h);
-
 #endif
 

src/protocols/rdp/rdp_gdi.c

@@ -104,11 +104,6 @@ void guac_rdp_gdi_dstblt(rdpContext* context, DSTBLT_ORDER* dstblt) {
     int w = dstblt->nWidth;
     int h = dstblt->nHeight;
 
-    /* Clip operation to bounds */
-    rdp_guac_client_data* data = (rdp_guac_client_data*) client->data;
-    if (guac_rdp_clip_rect(data, &x, &y, &w, &h))
-        return;
-
     switch (dstblt->bRop) {
 
         /* Blackness */
@@ -165,8 +160,6 @@ void guac_rdp_gdi_patblt(rdpContext* context, PATBLT_ORDER* patblt) {
     int w = patblt->nWidth;
     int h = patblt->nHeight;
 
-    rdp_guac_client_data* data = (rdp_guac_client_data*) client->data;
-
     /*
      * Warn that rendering is a fallback, as the server should not be sending
      * this order.
@@ -174,10 +167,6 @@ void guac_rdp_gdi_patblt(rdpContext* context, PATBLT_ORDER* patblt) {
     guac_client_log_info(client, "Using fallback PATBLT (server is ignoring "
             "negotiated client capabilities)");
 
-    /* Clip operation to bounds */
-    if (guac_rdp_clip_rect(data, &x, &y, &w, &h))
-        return;
-
     /* Render rectangle based on ROP */
     switch (patblt->bRop) {
 
@@ -226,14 +215,7 @@ void guac_rdp_gdi_scrblt(rdpContext* context, SCRBLT_ORDER* scrblt) {
     int x_src = scrblt->nXSrc;
     int y_src = scrblt->nYSrc;
 
-    /* Clip operation to bounds */
     rdp_guac_client_data* data = (rdp_guac_client_data*) client->data;
-    if (guac_rdp_clip_rect(data, &x, &y, &w, &h))
-        return;
-
-    /* Update source coordinates */
-    x_src += x - scrblt->nLeftRect;
-    y_src += y - scrblt->nTopRect;
 
     /* Copy screen rect to current surface */
     guac_common_surface_copy(data->default_surface, x_src, y_src, w, h,
@@ -255,22 +237,12 @@ void guac_rdp_gdi_memblt(rdpContext* context, MEMBLT_ORDER* memblt) {
     int x_src = memblt->nXSrc;
     int y_src = memblt->nYSrc;
 
-    rdp_guac_client_data* data = (rdp_guac_client_data*) client->data;
-
     /* Make sure that the recieved bitmap is not NULL before processing */
     if (bitmap == NULL) {
         guac_client_log_info(client, "NULL bitmap found in memblt instruction.");
         return;
     }
 
-    /* Clip operation to bounds */
-    if (guac_rdp_clip_rect(data, &x, &y, &w, &h))
-        return;
-
-    /* Update source coordinates */
-    x_src += x - memblt->nLeftRect;
-    y_src += y - memblt->nTopRect;
-
     switch (memblt->bRop) {
 
         /* If blackness, send black rectangle */
@@ -352,17 +324,11 @@ void guac_rdp_gdi_opaquerect(rdpContext* context, OPAQUE_RECT_ORDER* opaque_rect
 
     guac_common_surface* current_surface = ((rdp_guac_client_data*) client->data)->current_surface;
 
-    rdp_guac_client_data* data = (rdp_guac_client_data*) client->data;
-
     int x = opaque_rect->nLeftRect;
     int y = opaque_rect->nTopRect;
     int w = opaque_rect->nWidth;
     int h = opaque_rect->nHeight;
 
-    /* Clip operation to bounds */
-    if (guac_rdp_clip_rect(data, &x, &y, &w, &h))
-        return;
-
     guac_common_surface_rect(current_surface, x, y, w, h,
             (color >> 16) & 0xFF,
             (color >> 8 ) & 0xFF,
@@ -389,16 +355,12 @@ void guac_rdp_gdi_set_bounds(rdpContext* context, rdpBounds* bounds) {
 
     /* If no bounds given, clear bounding rect */
     if (bounds == NULL)
-        data->bounded = FALSE;
+        guac_common_surface_reset_clip(data->default_surface);
 
     /* Otherwise, set bounding rectangle */
-    else {
+    else
-        data->bounded = TRUE;
+        guac_common_surface_clip(data->default_surface, bounds->left, bounds->top,
-        data->bounds_left   = bounds->left;
+                                 bounds->right - bounds->left + 1, bounds->bottom - bounds->top + 1);
-        data->bounds_top    = bounds->top;
-        data->bounds_right  = bounds->right;
-        data->bounds_bottom = bounds->bottom;
-    }
 
 }
 

src/protocols/rdp/rdp_glyph.c

@@ -214,9 +214,6 @@ void guac_rdp_glyph_enddraw(rdpContext* context,
     if (width > max_width) width = max_width;
     if (height > max_height) height = max_height;
 
-    /* Clip operation to clipping region, if any */
-    if (!guac_rdp_clip_rect(guac_client_data, &x, &y, &width, &height)) {
-
     /* Ensure data is ready */
     cairo_surface_flush(glyph_surface);
 
@@ -232,8 +229,6 @@ void guac_rdp_glyph_enddraw(rdpContext* context,
     /* Destroy surface */
     cairo_surface_destroy(surface);
 
-    }
-
     /* Destroy cairo instance */
     cairo_destroy(guac_client_data->glyph_cairo);