svn merge ^/trunk/blender -c54904 -c54936 -c54937 -c55010 -c55011 -c55012 -c55021 -c55027 -c55028 -c55047 -c55048 -c55051

19 files changed, 159 insertions, 27 deletions

diff --git a/release/scripts/startup/bl_ui/space_sequencer.py b/release/scripts/startup/bl_ui/space_sequencer.py
index 7841acf01b3..aa445b9500d 100644
--- a/release/scripts/startup/bl_ui/space_sequencer.py
+++ b/release/scripts/startup/bl_ui/space_sequencer.py
@@ -89,6 +89,7 @@ class SEQUENCER_HT_header(Header):
                 layout.separator()
                 layout.operator("sequencer.refresh_all")
 
+            layout.prop(st, "preview_channels", expand=True, text="")
             layout.prop(st, "display_channel", text="Channel")
 
             ed = context.scene.sequence_editor
diff --git a/source/blender/blenkernel/BKE_tracking.h b/source/blender/blenkernel/BKE_tracking.h
index 9bdc96e187d..ebf29fde8ee 100644
--- a/source/blender/blenkernel/BKE_tracking.h
+++ b/source/blender/blenkernel/BKE_tracking.h
@@ -162,7 +162,7 @@ void BKE_tracking_max_undistortion_delta_across_bound(struct MovieTracking *trac
 /* **** Image sampling **** */
 struct ImBuf *BKE_tracking_sample_pattern(int frame_width, int frame_height,
                                           struct ImBuf *struct_ibuf, struct MovieTrackingTrack *track,
-                                          struct MovieTrackingMarker *marker, int use_mask,
+                                          struct MovieTrackingMarker *marker, int from_anchor, int use_mask,
                                           int num_samples_x, int num_samples_y, float pos[2]);
 struct ImBuf *BKE_tracking_get_pattern_imbuf(struct ImBuf *ibuf, struct MovieTrackingTrack *track,
                                              struct MovieTrackingMarker *marker, int anchored, int disable_channels);
diff --git a/source/blender/blenkernel/intern/blender.c b/source/blender/blenkernel/intern/blender.c
index fb2d1a3aaf7..54bfee79793 100644
--- a/source/blender/blenkernel/intern/blender.c
+++ b/source/blender/blenkernel/intern/blender.c
@@ -899,7 +899,9 @@ static void copybuffer_doit(void *UNUSED(handle), Main *UNUSED(bmain), void *vid
 {
 	if (vid) {
 		ID *id = vid;
-		id->flag |= LIB_NEED_EXPAND | LIB_DOIT;
+		/* only tag for need-expand if not done, prevents eternal loops */
+		if ((id->flag & LIB_DOIT) == 0)
+			id->flag |= LIB_NEED_EXPAND | LIB_DOIT;
 	}
 }
 
diff --git a/source/blender/blenkernel/intern/node.c b/source/blender/blenkernel/intern/node.c
index af2c23cc3f6..51205b5ba75 100644
--- a/source/blender/blenkernel/intern/node.c
+++ b/source/blender/blenkernel/intern/node.c
@@ -571,6 +571,12 @@ void nodeInternalRelink(bNodeTree *ntree, bNode *node)
 					link->fromnode = fromlink->fromnode;
 					link->fromsock = fromlink->fromsock;
 					
+					/* if the up- or downstream link is invalid,
+					 * the replacement link will be invalid too.
+					 */
+					if (!(fromlink->flag & NODE_LINK_VALID))
+						link->flag &= ~NODE_LINK_VALID;
+					
 					ntree->update |= NTREE_UPDATE_LINKS;
 				}
 				else
diff --git a/source/blender/blenkernel/intern/tracking.c b/source/blender/blenkernel/intern/tracking.c
index a6519f8005c..a0a4b2417f0 100644
--- a/source/blender/blenkernel/intern/tracking.c
+++ b/source/blender/blenkernel/intern/tracking.c
@@ -1677,7 +1677,7 @@ static void disable_imbuf_channels(ImBuf *ibuf, MovieTrackingTrack *track, int g
 
 ImBuf *BKE_tracking_sample_pattern(int frame_width, int frame_height, ImBuf *search_ibuf,
                                    MovieTrackingTrack *track, MovieTrackingMarker *marker,
-                                   int use_mask, int num_samples_x, int num_samples_y,
+                                   int from_anchor, int use_mask, int num_samples_x, int num_samples_y,
                                    float pos[2])
 {
 #ifdef WITH_LIBMV
@@ -1697,6 +1697,28 @@ ImBuf *BKE_tracking_sample_pattern(int frame_width, int frame_height, ImBuf *sea
 
 	get_marker_coords_for_tracking(frame_width, frame_height, marker, src_pixel_x, src_pixel_y);
 
+	/* from_anchor means search buffer was obtained for an anchored position,
+	 * which means applying track offset rounded to pixel space (we could not
+	 * store search buffer with sub-pixel precision)
+	 *
+	 * in this case we need to alter coordinates a bit, to compensate rounded
+	 * fractional part of offset
+	 */
+	if (from_anchor) {
+		int a;
+
+		for (a = 0; a < 5; a++) {
+			src_pixel_x[a] += ((track->offset[0] * frame_width) - ((int) (track->offset[0] * frame_width)));
+			src_pixel_y[a] += ((track->offset[1] * frame_height) - ((int) (track->offset[1] * frame_height)));
+
+			/* when offset is negative, rounding happens in opposite direction */
+			if (track->offset[0] < 0.0f)
+				src_pixel_x[a] += 1.0f;
+			if (track->offset[1] < 0.0f)
+				src_pixel_y[a] += 1.0f;
+		}
+	}
+
 	if (use_mask) {
 		mask = BKE_tracking_track_get_mask(frame_width, frame_height, track, marker);
 	}
@@ -1757,7 +1779,7 @@ ImBuf *BKE_tracking_get_pattern_imbuf(ImBuf *ibuf, MovieTrackingTrack *track, Mo
 
 	if (search_ibuf) {
 		pattern_ibuf = BKE_tracking_sample_pattern(ibuf->x, ibuf->y, search_ibuf, track, marker,
-		                                           FALSE, num_samples_x, num_samples_y, NULL);
+		                                           anchored, FALSE, num_samples_x, num_samples_y, NULL);
 
 		IMB_freeImBuf(search_ibuf);
 	}
diff --git a/source/blender/blenloader/intern/writefile.c b/source/blender/blenloader/intern/writefile.c
index e7a53670849..ac63d18ae62 100644
--- a/source/blender/blenloader/intern/writefile.c
+++ b/source/blender/blenloader/intern/writefile.c
@@ -796,14 +796,15 @@ typedef struct RenderInfo {
 static void write_renderinfo(WriteData *wd, Main *mainvar)
 {
 	bScreen *curscreen;
-	Scene *sce;
+	Scene *sce, *curscene = NULL;
 	RenderInfo data;
 
 	/* XXX in future, handle multiple windows with multiple screens? */
 	current_screen_compat(mainvar, &curscreen);
-
+	if (curscreen) curscene = curscreen->scene;
+	
 	for (sce= mainvar->scene.first; sce; sce= sce->id.next) {
-		if (sce->id.lib == NULL && (sce == curscreen->scene || (sce->r.scemode & R_BG_RENDER))) {
+		if (sce->id.lib == NULL && (sce == curscene || (sce->r.scemode & R_BG_RENDER))) {
 			data.sfra = sce->r.sfra;
 			data.efra = sce->r.efra;
 			memset(data.scene_name, 0, sizeof(data.scene_name));
diff --git a/source/blender/compositor/operations/COM_TextureOperation.cpp b/source/blender/compositor/operations/COM_TextureOperation.cpp
index 23a3abe61ee..08f6f8ada4a 100644
--- a/source/blender/compositor/operations/COM_TextureOperation.cpp
+++ b/source/blender/compositor/operations/COM_TextureOperation.cpp
@@ -25,7 +25,7 @@
 #include "BLI_listbase.h"
 #include "BKE_image.h"
 
-TextureBaseOperation::TextureBaseOperation() : NodeOperation()
+TextureBaseOperation::TextureBaseOperation() : SingleThreadedNodeOperation()
 {
 	this->addInputSocket(COM_DT_VECTOR); //offset
 	this->addInputSocket(COM_DT_VECTOR); //size
@@ -48,6 +48,7 @@ void TextureBaseOperation::initExecution()
 	this->m_inputOffset = getInputSocketReader(0);
 	this->m_inputSize = getInputSocketReader(1);
 	this->m_pool = BKE_image_pool_new();
+	SingleThreadedNodeOperation::initExecution();
 }
 void TextureBaseOperation::deinitExecution()
 {
@@ -55,6 +56,7 @@ void TextureBaseOperation::deinitExecution()
 	this->m_inputOffset = NULL;
 	BKE_image_pool_free(this->m_pool);
 	this->m_pool = NULL;
+	SingleThreadedNodeOperation::deinitExecution();
 }
 
 void TextureBaseOperation::determineResolution(unsigned int resolution[2], unsigned int preferredResolution[2])
@@ -89,8 +91,8 @@ void TextureBaseOperation::executePixel(float output[4], float x, float y, Pixel
 	int retval;
 	const float cx = this->getWidth() / 2;
 	const float cy = this->getHeight() / 2;
-	const float u = (cx - x) / this->getWidth() * 2;
-	const float v = (cy - y) / this->getHeight() * 2;
+	const float u = (x - cx) / this->getWidth() * 2;
+	const float v = (y - cy) / this->getHeight() * 2;
 
 	this->m_inputSize->read(textureSize, x, y, sampler);
 	this->m_inputOffset->read(textureOffset, x, y, sampler);
@@ -115,3 +117,26 @@ void TextureBaseOperation::executePixel(float output[4], float x, float y, Pixel
 		output[0] = output[1] = output[2] = output[3];
 	}
 }
+
+MemoryBuffer *TextureBaseOperation::createMemoryBuffer(rcti *rect2)
+{
+	int height = getHeight();
+	int width = getWidth();
+
+	rcti rect;
+	rect.xmin = 0;
+	rect.ymin = 0;
+	rect.xmax = width;
+	rect.ymax = height;
+	MemoryBuffer *result = new MemoryBuffer(NULL, &rect);
+
+	float *data = result->getBuffer();
+
+	for (int y = 0; y < height; y++) {
+		for (int x = 0; x < width; x++, data += 4) {
+			this->executePixel(data, x, y, COM_PS_NEAREST);
+		}
+	}
+
+	return result;
+}
diff --git a/source/blender/compositor/operations/COM_TextureOperation.h b/source/blender/compositor/operations/COM_TextureOperation.h
index 227ad37579a..fc9369099a6 100644
--- a/source/blender/compositor/operations/COM_TextureOperation.h
+++ b/source/blender/compositor/operations/COM_TextureOperation.h
@@ -24,7 +24,7 @@
 #ifndef _COM_TextureOperation_h
 #define _COM_TextureOperation_h
 
-#include "COM_NodeOperation.h"
+#include "COM_SingleThreadedNodeOperation.h"
 #include "DNA_texture_types.h"
 #include "BLI_listbase.h"
 extern "C" {
@@ -39,7 +39,7 @@ extern "C" {
  *
  * @todo: rename to operation.
  */
-class TextureBaseOperation : public NodeOperation {
+class TextureBaseOperation : public SingleThreadedNodeOperation {
 private:
 	Tex *m_texture;
 	const RenderData *m_rd;
@@ -59,6 +59,7 @@ protected:
 	 */
 	TextureBaseOperation();
 
+	MemoryBuffer *createMemoryBuffer(rcti *rect2);
 public:
 	void executePixel(float output[4], float x, float y, PixelSampler sampler);
 
diff --git a/source/blender/editors/interface/interface_draw.c b/source/blender/editors/interface/interface_draw.c
index e19e89af5da..c0aa195ec78 100644
--- a/source/blender/editors/interface/interface_draw.c
+++ b/source/blender/editors/interface/interface_draw.c
@@ -1602,7 +1602,7 @@ void ui_draw_but_TRACKPREVIEW(ARegion *ar, uiBut *but, uiWidgetColors *UNUSED(wc
 
 		tmpibuf = BKE_tracking_sample_pattern(scopes->frame_width, scopes->frame_height,
 		                                            scopes->track_search, scopes->track,
-		                                            &scopes->undist_marker, scopes->use_track_mask,
+		                                            &scopes->undist_marker, TRUE, scopes->use_track_mask,
 		                                            width, height, scopes->track_pos);
 
 		if (tmpibuf) {
diff --git a/source/blender/editors/space_node/node_relationships.c b/source/blender/editors/space_node/node_relationships.c
index 8d7eef22822..fd934ddfbdb 100644
--- a/source/blender/editors/space_node/node_relationships.c
+++ b/source/blender/editors/space_node/node_relationships.c
@@ -840,7 +840,9 @@ static int cut_links_exec(bContext *C, wmOperator *op)
 	if (i > 1) {
 		int found = FALSE;
 		bNodeLink *link, *next;
-
+		
+		ED_preview_kill_jobs(C);
+		
 		for (link = snode->edittree->links.first; link; link = next) {
 			next = link->next;
 
diff --git a/source/blender/editors/space_sequencer/sequencer_draw.c b/source/blender/editors/space_sequencer/sequencer_draw.c
index 249ba986fd3..396878cbfeb 100644
--- a/source/blender/editors/space_sequencer/sequencer_draw.c
+++ b/source/blender/editors/space_sequencer/sequencer_draw.c
@@ -1059,8 +1059,10 @@ void draw_image_seq(const bContext *C, Scene *scene, ARegion *ar, SpaceSeq *sseq
 
 	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, ibuf->x, ibuf->y, 0, GL_RGBA, GL_UNSIGNED_BYTE, display_buffer);
 
-	glEnable(GL_BLEND);
-	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+	if (sseq->flag & SEQ_USE_ALPHA) {
+		glEnable(GL_BLEND);
+		glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+	}
 
 	glBegin(GL_QUADS);
 
@@ -1093,7 +1095,8 @@ void draw_image_seq(const bContext *C, Scene *scene, ARegion *ar, SpaceSeq *sseq
 	glEnd();
 	glBindTexture(GL_TEXTURE_2D, last_texid);
 	glDisable(GL_TEXTURE_2D);
-	glDisable(GL_BLEND);
+	if (sseq->flag & SEQ_USE_ALPHA)
+		glDisable(GL_BLEND);
 	glDeleteTextures(1, &texid);
 
 	if (sseq->mainb == SEQ_DRAW_IMG_IMBUF) {
diff --git a/source/blender/editors/space_sequencer/space_sequencer.c b/source/blender/editors/space_sequencer/space_sequencer.c
index d541e1d6c07..4c6b909882c 100644
--- a/source/blender/editors/space_sequencer/space_sequencer.c
+++ b/source/blender/editors/space_sequencer/space_sequencer.c
@@ -120,7 +120,7 @@ static SpaceLink *sequencer_new(const bContext *C)
 	sseq->chanshown = 0;
 	sseq->view = SEQ_VIEW_SEQUENCE;
 	sseq->mainb = SEQ_DRAW_IMG_IMBUF;
-	sseq->flag = SEQ_SHOW_GPENCIL;
+	sseq->flag = SEQ_SHOW_GPENCIL | SEQ_USE_ALPHA;
 
 	/* header */
 	ar = MEM_callocN(sizeof(ARegion), "header for sequencer");
diff --git a/source/blender/imbuf/intern/colormanagement.c b/source/blender/imbuf/intern/colormanagement.c
index ff297d70cc3..cfeacff7f4a 100644
--- a/source/blender/imbuf/intern/colormanagement.c
+++ b/source/blender/imbuf/intern/colormanagement.c
@@ -1702,13 +1702,11 @@ ImBuf *IMB_colormanagement_imbuf_for_write(ImBuf *ibuf, int save_as_render, int
 	int do_colormanagement;
 	int is_movie = BKE_imtype_is_movie(image_format_data->imtype);
 	int requires_linear_float = BKE_imtype_requires_linear_float(image_format_data->imtype);
+	int do_alpha_under = image_format_data->planes != R_IMF_PLANES_RGBA;
 
 	do_colormanagement = save_as_render && (is_movie || !requires_linear_float);
 
-	if (do_colormanagement) {
-		int make_byte = FALSE;
-		ImFileType *type;
-
+	if (do_colormanagement || do_alpha_under) {
 		if (allocate_result) {
 			colormanaged_ibuf = IMB_dupImBuf(ibuf);
 		}
@@ -1727,6 +1725,41 @@ ImBuf *IMB_colormanagement_imbuf_for_write(ImBuf *ibuf, int save_as_render, int
 				ibuf->mall |= IB_rectfloat;
 			}
 		}
+	}
+
+	/* If we're saving from RGBA to RGB buffer then it's not
+	 * so much useful to just ignore alpha -- it leads to bad
+	 * artifacts especially when saving byte images.
+	 *
+	 * What we do here is we're overing our image on top of
+	 * background color (which is currently black).
+	 *
+	 * This is quite much the same as what Gimp does and it
+	 * seems to be what artists expects from saving.
+	 *
+	 * Do a conversion here, so image format writers could
+	 * happily assume all the alpha tricks were made already.
+	 * helps keep things locally here, not spreading it to
+	 * all possible image writers we've got.
+	 */
+	if (do_alpha_under) {
+		float color[3] = {0, 0, 0};
+
+		if (colormanaged_ibuf->rect_float && colormanaged_ibuf->channels == 4) {
+			IMB_alpha_under_color_float(colormanaged_ibuf->rect_float, colormanaged_ibuf->x,
+			                            colormanaged_ibuf->y, color);
+		}
+
+		if (colormanaged_ibuf->rect) {
+			IMB_alpha_under_color_byte((unsigned char *)colormanaged_ibuf->rect,
+			                           colormanaged_ibuf->x, colormanaged_ibuf->y,
+			                           color);
+		}
+	}
+
+	if (do_colormanagement) {
+		int make_byte = FALSE;
+		ImFileType *type;
 
 		/* for proper check whether byte buffer is required by a format or not
 		 * should be pretty safe since this image buffer is supposed to be used for
diff --git a/source/blender/imbuf/intern/imageprocess.c b/source/blender/imbuf/intern/imageprocess.c
index 59282c9d207..26dd0f2977a 100644
--- a/source/blender/imbuf/intern/imageprocess.c
+++ b/source/blender/imbuf/intern/imageprocess.c
@@ -367,9 +367,9 @@ void IMB_alpha_under_color_byte(unsigned char *rect, int x, int y, float backcol
 		else {
 			int mul = 255 - cp[3];
 
-			cp[0] += mul * backcol[0] / 255;
-			cp[1] += mul * backcol[1] / 255;
-			cp[2] += mul * backcol[2] / 255;
+			cp[0] = (cp[0] * cp[3] >> 8) + mul * backcol[0] / 255;
+			cp[1] = (cp[1] * cp[3] >> 8) + mul * backcol[1] / 255;
+			cp[2] = (cp[2] * cp[3] >> 8) + mul * backcol[2] / 255;
 		}
 
 		cp[3] = 255;
diff --git a/source/blender/makesdna/DNA_space_types.h b/source/blender/makesdna/DNA_space_types.h
index 1dfcff4a3c4..b8ba58d7a6d 100644
--- a/source/blender/makesdna/DNA_space_types.h
+++ b/source/blender/makesdna/DNA_space_types.h
@@ -497,6 +497,7 @@ typedef enum eSpaceSeq_Flag {
 	SEQ_DRAW_SAFE_MARGINS       = (1 << 3),
 	SEQ_SHOW_GPENCIL            = (1 << 4),
 	SEQ_NO_DRAW_CFRANUM         = (1 << 5),
+	SEQ_USE_ALPHA               = (1 << 6), /* use RGBA display mode for preview */
 } eSpaceSeq_Flag;
 
 /* sseq->view */
diff --git a/source/blender/makesrna/intern/rna_space.c b/source/blender/makesrna/intern/rna_space.c
index 0ab74fb617f..6db863a267b 100644
--- a/source/blender/makesrna/intern/rna_space.c
+++ b/source/blender/makesrna/intern/rna_space.c
@@ -2248,6 +2248,13 @@ static void rna_def_space_sequencer(BlenderRNA *brna)
 		{0, NULL, 0, NULL, NULL}
 	};
 
+	static EnumPropertyItem preview_channels_items[] = {
+		{SEQ_USE_ALPHA, "COLOR_ALPHA", ICON_IMAGE_RGB_ALPHA, "Color and Alpha",
+		                "Draw image with RGB colors and alpha transparency"},
+		{0, "COLOR", ICON_IMAGE_RGB, "Color", "Draw image with RGB colors"},
+		{0, NULL, 0, NULL, NULL}
+	};
+
 	srna = RNA_def_struct(brna, "SpaceSequenceEditor", "Space");
 	RNA_def_struct_sdna(srna, "SpaceSeq");
 	RNA_def_struct_ui_text(srna, "Space Sequence Editor", "Sequence editor space data");
@@ -2265,7 +2272,7 @@ static void rna_def_space_sequencer(BlenderRNA *brna)
 	RNA_def_property_enum_items(prop, display_mode_items);
 	RNA_def_property_ui_text(prop, "Display Mode", "View mode to use for displaying sequencer output");
 	RNA_def_property_update(prop, NC_SPACE | ND_SPACE_SEQUENCER, NULL);
-		
+
 	/* flags */
 	prop = RNA_def_property(srna, "show_frame_indicator", PROP_BOOLEAN, PROP_NONE);
 	RNA_def_property_boolean_negative_sdna(prop, NULL, "flag", SEQ_NO_DRAW_CFRANUM);
@@ -2310,7 +2317,13 @@ static void rna_def_space_sequencer(BlenderRNA *brna)
 	                         "The channel number shown in the image preview. 0 is the result of all strips combined");
 	RNA_def_property_range(prop, -5, MAXSEQ);
 	RNA_def_property_update(prop, NC_SPACE | ND_SPACE_SEQUENCER, NULL);
-	
+
+	prop = RNA_def_property(srna, "preview_channels", PROP_ENUM, PROP_NONE);
+	RNA_def_property_enum_bitflag_sdna(prop, NULL, "flag");
+	RNA_def_property_enum_items(prop, preview_channels_items);
+	RNA_def_property_ui_text(prop, "Draw Channels", "Channels of the preview to draw");
+	RNA_def_property_update(prop, NC_SPACE | ND_SPACE_SEQUENCER, NULL);
+
 	prop = RNA_def_property(srna, "draw_overexposed", PROP_INT, PROP_NONE);
 	RNA_def_property_int_sdna(prop, NULL, "zebra");
 	RNA_def_property_ui_text(prop, "Show Overexposed", "Show overexposed areas with zebra stripes");
diff --git a/source/blender/windowmanager/intern/wm_operators.c b/source/blender/windowmanager/intern/wm_operators.c
index 9562f6d698f..bd1e7fa4e7a 100644
--- a/source/blender/windowmanager/intern/wm_operators.c
+++ b/source/blender/windowmanager/intern/wm_operators.c
@@ -2785,7 +2785,18 @@ int WM_gesture_circle_modal(bContext *C, wmOperator *op, wmEvent *event)
 			gesture_circle_apply(C, op);
 	}
 	else if (event->type == EVT_MODAL_MAP) {
+		float fac;
+		
 		switch (event->val) {
+			case GESTURE_MODAL_CIRCLE_SIZE:
+				fac = 0.3f * (event->y - event->prevy);
+				if (fac > 0)
+					rect->xmax += ceil(fac);
+				else
+					rect->xmax += floor(fac);
+				if (rect->xmax < 1) rect->xmax = 1;
+				wm_gesture_tag_redraw(C);
+				break;
 			case GESTURE_MODAL_CIRCLE_ADD:
 				rect->xmax += 2 + rect->xmax / 10;
 				wm_gesture_tag_redraw(C);
@@ -4060,6 +4071,7 @@ static void gesture_circle_modal_keymap(wmKeyConfig *keyconf)
 		{GESTURE_MODAL_CONFIRM, "CONFIRM", 0, "Confirm", ""},
 		{GESTURE_MODAL_CIRCLE_ADD, "ADD", 0, "Add", ""},
 		{GESTURE_MODAL_CIRCLE_SUB, "SUBTRACT", 0, "Subtract", ""},
+		{GESTURE_MODAL_CIRCLE_SIZE, "SIZE", 0, "Size", ""},
 
 		{GESTURE_MODAL_SELECT,  "SELECT", 0, "Select", ""},
 		{GESTURE_MODAL_DESELECT, "DESELECT", 0, "DeSelect", ""},
@@ -4098,6 +4110,7 @@ static void gesture_circle_modal_keymap(wmKeyConfig *keyconf)
 	WM_modalkeymap_add_item(keymap, PADMINUS, KM_PRESS, 0, 0, GESTURE_MODAL_CIRCLE_SUB);
 	WM_modalkeymap_add_item(keymap, WHEELDOWNMOUSE, KM_PRESS, 0, 0, GESTURE_MODAL_CIRCLE_ADD);
 	WM_modalkeymap_add_item(keymap, PADPLUSKEY, KM_PRESS, 0, 0, GESTURE_MODAL_CIRCLE_ADD);
+	WM_modalkeymap_add_item(keymap, MOUSEPAN, 0, 0, 0, GESTURE_MODAL_CIRCLE_SIZE);
 
 	/* assign map to operators */
 	WM_modalkeymap_assign(keymap, "VIEW3D_OT_select_circle");
diff --git a/source/blender/windowmanager/intern/wm_playanim.c b/source/blender/windowmanager/intern/wm_playanim.c
index fd44f4a7169..b510956dbc1 100644
--- a/source/blender/windowmanager/intern/wm_playanim.c
+++ b/source/blender/windowmanager/intern/wm_playanim.c
@@ -252,8 +252,15 @@ static void playanim_toscreen(PlayAnimPict *picture, struct ImBuf *ibuf, int fon
 
 	glRasterPos2f(0.0f, 0.0f);
 
+	glEnable(GL_BLEND);
+	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
+	fdrawcheckerboard(0.0f, 0.0f, ibuf->x, ibuf->y);
+
 	glDrawPixels(ibuf->x, ibuf->y, GL_RGBA, GL_UNSIGNED_BYTE, ibuf->rect);
 
+	glDisable(GL_BLEND);
+
 	pupdate_time();
 
 	if (picture && (g_WS.qual & (WS_QUAL_SHIFT | WS_QUAL_LMOUSE)) && (fontid != -1)) {
diff --git a/source/blender/windowmanager/wm_event_types.h b/source/blender/windowmanager/wm_event_types.h
index bc7e7efdcfd..338ef8bc65b 100644
--- a/source/blender/windowmanager/wm_event_types.h
+++ b/source/blender/windowmanager/wm_event_types.h
@@ -384,6 +384,8 @@ enum {
 #define GESTURE_MODAL_IN			9
 #define GESTURE_MODAL_OUT			10
 
+#define GESTURE_MODAL_CIRCLE_SIZE	11 /* circle sel: size brush (for trackpad event) */
+
 
 #endif	/* __WM_EVENT_TYPES_H__ */