Sequencer display overlay option, this can show a border area from another time to help compare for color grading.

- Okey sets the border in the display.
- Okey resets the frame offset in the sequencer timeline.
- ghost icon in the header can enable/disable.
- frame offset can be relative or absolute (lock icon)

Not very happy that this commit adds a call to BKE_animsys_evaluate_animdata(scene, ...) in do_build_seq_array_recursively()
without this the offset frames dont have fcurves applied.
Though we will need something like this for prefetch frames to work too.

9 files changed, 212 insertions, 13 deletions

diff --git a/source/blender/blenkernel/intern/sequencer.c b/source/blender/blenkernel/intern/sequencer.c
index cfe2a6bb207..82ed85a1983 100644
--- a/source/blender/blenkernel/intern/sequencer.c
+++ b/source/blender/blenkernel/intern/sequencer.c
@@ -2544,6 +2544,10 @@ static TStripElem* do_build_seq_array_recursively(
 	int i;
 	TStripElem* se = 0;
 
+	// XXX for prefetch and overlay offset!..., very bad!!!
+	AnimData *adt= BKE_animdata_from_id(&scene->id);
+	BKE_animsys_evaluate_animdata(&scene->id, adt, cfra, ADT_RECALC_ANIM);
+
 	count = get_shown_sequences(seqbasep, cfra, chanshown, 
 					(Sequence **)&seq_arr);
 
diff --git a/source/blender/editors/space_sequencer/sequencer_draw.c b/source/blender/editors/space_sequencer/sequencer_draw.c
index 1e5735006ab..30f0f84c092 100644
--- a/source/blender/editors/space_sequencer/sequencer_draw.c
+++ b/source/blender/editors/space_sequencer/sequencer_draw.c
@@ -690,7 +690,7 @@ void set_special_seq_update(int val)
 	else special_seq_update= 0;
 }
 
-void draw_image_seq(const bContext* C, Scene *scene, ARegion *ar, SpaceSeq *sseq)
+void draw_image_seq(const bContext* C, Scene *scene, ARegion *ar, SpaceSeq *sseq, int cfra, int frame_ofs)
 {
 	extern void gl_round_box(int mode, float minx, float miny, float maxx, float maxy, float rad);
 	struct ImBuf *ibuf;
@@ -726,9 +726,11 @@ void draw_image_seq(const bContext* C, Scene *scene, ARegion *ar, SpaceSeq *sseq
 		viewrecty /= proxy_size / 100.0;
 	}
 
-	/* XXX TODO: take color from theme */
-	glClearColor(0.0, 0.0, 0.0, 0.0);
-	glClear(GL_COLOR_BUFFER_BIT);
+	if(frame_ofs == 0) {
+		/* XXX TODO: take color from theme */
+		glClearColor(0.0, 0.0, 0.0, 0.0);
+		glClear(GL_COLOR_BUFFER_BIT);
+	}
 
 	/* without this colors can flicker from previous opengl state */
 	glColor4ub(255, 255, 255, 255);
@@ -746,13 +748,13 @@ void draw_image_seq(const bContext* C, Scene *scene, ARegion *ar, SpaceSeq *sseq
 	else {
 		recursive= 1;
 		if (special_seq_update) {
-			ibuf= give_ibuf_seq_direct(scene, rectx, recty, (scene->r.cfra), proxy_size, special_seq_update);
+			ibuf= give_ibuf_seq_direct(scene, rectx, recty, cfra + frame_ofs, proxy_size, special_seq_update);
 		} 
 		else if (!U.prefetchframes) { // XXX || (G.f & G_PLAYANIM) == 0) {
-			ibuf= (ImBuf *)give_ibuf_seq(scene, rectx, recty, (scene->r.cfra), sseq->chanshown, proxy_size);
+			ibuf= (ImBuf *)give_ibuf_seq(scene, rectx, recty, cfra + frame_ofs, sseq->chanshown, proxy_size);
 		} 
 		else {
-			ibuf= (ImBuf *)give_ibuf_seq_threaded(scene, rectx, recty, (scene->r.cfra), sseq->chanshown, proxy_size);
+			ibuf= (ImBuf *)give_ibuf_seq_threaded(scene, rectx, recty, cfra + frame_ofs, sseq->chanshown, proxy_size);
 		}
 		recursive= 0;
 		
@@ -812,11 +814,26 @@ void draw_image_seq(const bContext* C, Scene *scene, ARegion *ar, SpaceSeq *sseq
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 
 	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, ibuf->x, ibuf->y, 0, GL_RGBA, GL_UNSIGNED_BYTE, ibuf->rect);
-	glBegin(GL_QUADS); 
-		glTexCoord2f(0.0f, 0.0f); glVertex2f(v2d->tot.xmin, v2d->tot.ymin);
-		glTexCoord2f(0.0f, 1.0f);glVertex2f(v2d->tot.xmin, v2d->tot.ymax); 
+	glBegin(GL_QUADS);
+
+	if(frame_ofs) {
+		rctf tot_clip;
+		tot_clip.xmin= v2d->tot.xmin + (ABS(v2d->tot.xmax - v2d->tot.xmin) * scene->ed->over_border.xmin);
+		tot_clip.ymin= v2d->tot.ymin + (ABS(v2d->tot.ymax - v2d->tot.ymin) * scene->ed->over_border.ymin);
+		tot_clip.xmax= v2d->tot.xmin + (ABS(v2d->tot.xmax - v2d->tot.xmin) * scene->ed->over_border.xmax);
+		tot_clip.ymax= v2d->tot.ymin + (ABS(v2d->tot.ymax - v2d->tot.ymin) * scene->ed->over_border.ymax);
+
+		glTexCoord2f(scene->ed->over_border.xmin, scene->ed->over_border.ymin);glVertex2f(tot_clip.xmin, tot_clip.ymin);
+		glTexCoord2f(scene->ed->over_border.xmin, scene->ed->over_border.ymax);glVertex2f(tot_clip.xmin, tot_clip.ymax);
+		glTexCoord2f(scene->ed->over_border.xmax, scene->ed->over_border.ymax);glVertex2f(tot_clip.xmax, tot_clip.ymax);
+		glTexCoord2f(scene->ed->over_border.xmax, scene->ed->over_border.ymin);glVertex2f(tot_clip.xmax, tot_clip.ymin);
+	}
+	else {
+		glTexCoord2f(0.0f, 0.0f);glVertex2f(v2d->tot.xmin, v2d->tot.ymin);
+		glTexCoord2f(0.0f, 1.0f);glVertex2f(v2d->tot.xmin, v2d->tot.ymax);
 		glTexCoord2f(1.0f, 1.0f);glVertex2f(v2d->tot.xmax, v2d->tot.ymax);
-		glTexCoord2f(1.0f, 0.0f);glVertex2f(v2d->tot.xmax, v2d->tot.ymin); 
+		glTexCoord2f(1.0f, 0.0f);glVertex2f(v2d->tot.xmax, v2d->tot.ymin);
+	}
 	glEnd( );
 	glBindTexture(GL_TEXTURE_2D, last_texid);
 	glDisable(GL_TEXTURE_2D);
@@ -1056,6 +1073,19 @@ void draw_timeline_seq(const bContext *C, ARegion *ar)
 	/* preview range */
 	UI_view2d_view_ortho(C, v2d);
 	ANIM_draw_previewrange(C, v2d);
+
+	/* overlap playhead */
+	if(scene->ed && scene->ed->over_flag & SEQ_EDIT_OVERLAY_SHOW) {
+		int cfra_over= (scene->ed->over_flag & SEQ_EDIT_OVERLAY_ABS) ? scene->ed->over_cfra : scene->r.cfra + scene->ed->over_ofs;
+		glColor3f(0.2, 0.2, 0.2);
+		// glRectf(cfra_over, v2d->cur.ymin, scene->ed->over_ofs + scene->r.cfra + 1, v2d->cur.ymax);
+
+		glBegin(GL_LINES);
+			glVertex2f(cfra_over, v2d->cur.ymin);
+			glVertex2f(cfra_over, v2d->cur.ymax);
+		glEnd();
+
+	}
 	
 	/* reset view matrix */
 	UI_view2d_view_restore(C);
diff --git a/source/blender/editors/space_sequencer/sequencer_edit.c b/source/blender/editors/space_sequencer/sequencer_edit.c
index 75774043c68..19b8e9d7a79 100644
--- a/source/blender/editors/space_sequencer/sequencer_edit.c
+++ b/source/blender/editors/space_sequencer/sequencer_edit.c
@@ -1117,6 +1117,15 @@ int sequencer_edit_poll(bContext *C)
 	return (seq_give_editing(CTX_data_scene(C), FALSE) != NULL);
 }
 
+int sequencer_view_poll(bContext *C)
+{
+	SpaceSeq *sseq= CTX_wm_space_seq(C);
+	Editing *ed= seq_give_editing(CTX_data_scene(C), FALSE);
+	if (ed && sseq && (sseq->mainb == SEQ_DRAW_IMG_IMBUF))
+		return 1;
+
+	return 0;
+}
 
 /* snap operator*/
 static int sequencer_snap_exec(bContext *C, wmOperator *op)
@@ -2723,3 +2732,62 @@ void SEQUENCER_OT_swap_data(wmOperatorType *ot)
 	/* properties */
 }
 
+/* borderselect operator */
+static int view_ghost_border_exec(bContext *C, wmOperator *op)
+{
+	Scene *scene= CTX_data_scene(C);
+	Editing *ed= seq_give_editing(scene, FALSE);
+	View2D *v2d= UI_view2d_fromcontext(C);
+
+	rctf rect;
+
+	/* convert coordinates of rect to 'tot' rect coordinates */
+	UI_view2d_region_to_view(v2d, RNA_int_get(op->ptr, "xmin"), RNA_int_get(op->ptr, "ymin"), &rect.xmin, &rect.ymin);
+	UI_view2d_region_to_view(v2d, RNA_int_get(op->ptr, "xmax"), RNA_int_get(op->ptr, "ymax"), &rect.xmax, &rect.ymax);
+
+	if(ed==NULL)
+		return OPERATOR_CANCELLED;
+
+	rect.xmin /=  (float)(ABS(v2d->tot.xmax - v2d->tot.xmin));
+	rect.ymin /=  (float)(ABS(v2d->tot.ymax - v2d->tot.ymin));
+
+	rect.xmax /=  (float)(ABS(v2d->tot.xmax - v2d->tot.xmin));
+	rect.ymax /=  (float)(ABS(v2d->tot.ymax - v2d->tot.ymin));
+
+	rect.xmin+=0.5;
+	rect.xmax+=0.5;
+	rect.ymin+=0.5;
+	rect.ymax+=0.5;
+
+	CLAMP(rect.xmin, 0.0f, 1.0f);
+	CLAMP(rect.ymin, 0.0f, 1.0f);
+	CLAMP(rect.xmax, 0.0f, 1.0f);
+	CLAMP(rect.ymax, 0.0f, 1.0f);
+
+	scene->ed->over_border= rect;
+
+	WM_event_add_notifier(C, NC_SCENE|ND_SEQUENCER, scene);
+
+	return OPERATOR_FINISHED;
+}
+
+/* ****** Border Select ****** */
+void SEQUENCER_OT_view_ghost_border(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name= "Border Offset View";
+	ot->idname= "SEQUENCER_OT_view_ghost_border";
+	ot->description="Enable border select mode";
+
+	/* api callbacks */
+	ot->invoke= WM_border_select_invoke;
+	ot->exec= view_ghost_border_exec;
+	ot->modal= WM_border_select_modal;
+	ot->poll= sequencer_view_poll;
+
+	/* flags */
+	ot->flag= 0;
+
+	/* rna */
+	WM_operator_properties_gesture_border(ot, FALSE);
+}
diff --git a/source/blender/editors/space_sequencer/sequencer_intern.h b/source/blender/editors/space_sequencer/sequencer_intern.h
index df426e91075..bf0dfff8e98 100644
--- a/source/blender/editors/space_sequencer/sequencer_intern.h
+++ b/source/blender/editors/space_sequencer/sequencer_intern.h
@@ -48,7 +48,7 @@ struct ARegion *sequencer_has_buttons_region(struct ScrArea *sa);
 
 /* sequencer_draw.c */
 void draw_timeline_seq(const struct bContext *C, struct ARegion *ar);
-void draw_image_seq(const struct bContext* C, struct Scene *scene,struct  ARegion *ar, struct SpaceSeq *sseq);
+void draw_image_seq(const struct bContext* C, struct Scene *scene,struct  ARegion *ar, struct SpaceSeq *sseq, int cfra, int offset);
 
 void seq_reset_imageofs(struct SpaceSeq *sseq);
 
@@ -69,6 +69,7 @@ struct Sequence *alloc_sequence(struct ListBase *lb, int cfra, int machine);
 
 /* operator helpers */
 int sequencer_edit_poll(struct bContext *C);
+int sequencer_view_poll(struct bContext *C);
 
 /* externs */
 extern EnumPropertyItem sequencer_prop_effect_types[];
@@ -103,6 +104,7 @@ void SEQUENCER_OT_view_toggle(struct wmOperatorType *ot);
 void SEQUENCER_OT_view_all(struct wmOperatorType *ot);
 void SEQUENCER_OT_view_selected(struct wmOperatorType *ot);
 void SEQUENCER_OT_view_zoom_ratio(struct wmOperatorType *ot);
+void SEQUENCER_OT_view_ghost_border(struct wmOperatorType *ot);
 
 void SEQUENCER_OT_copy(struct wmOperatorType *ot);
 void SEQUENCER_OT_paste(struct wmOperatorType *ot);
diff --git a/source/blender/editors/space_sequencer/sequencer_ops.c b/source/blender/editors/space_sequencer/sequencer_ops.c
index 9f5a97d4446..430553890d7 100644
--- a/source/blender/editors/space_sequencer/sequencer_ops.c
+++ b/source/blender/editors/space_sequencer/sequencer_ops.c
@@ -82,6 +82,7 @@ void sequencer_operatortypes(void)
 	WM_operatortype_append(SEQUENCER_OT_view_all_preview);
 	WM_operatortype_append(SEQUENCER_OT_view_toggle);
 	WM_operatortype_append(SEQUENCER_OT_view_zoom_ratio);
+	WM_operatortype_append(SEQUENCER_OT_view_ghost_border);
 
 	/* sequencer_select.c */
 	WM_operatortype_append(SEQUENCER_OT_select_all_toggle);
@@ -223,6 +224,10 @@ void sequencer_keymap(wmKeyConfig *keyconf)
 
 	WM_keymap_add_menu(keymap, "SEQUENCER_MT_add", AKEY, KM_PRESS, KM_SHIFT, 0);
 	
+	kmi= WM_keymap_add_item(keymap, "WM_OT_context_set_int", OKEY, KM_PRESS, 0, 0);
+	RNA_string_set(kmi->ptr, "data_path", "scene.sequence_editor.overlay_frame");
+	RNA_int_set(kmi->ptr, "value", 0);
+
 	transform_keymap_for_space(keyconf, keymap, SPACE_SEQ);
 
 	keymap= WM_keymap_find(keyconf, "SequencerPreview", SPACE_SEQ, 0);
@@ -232,6 +237,8 @@ void sequencer_keymap(wmKeyConfig *keyconf)
 
 	keymap= WM_keymap_find(keyconf, "SequencerPreview", SPACE_SEQ, 0);
 
+	WM_keymap_add_item(keymap, "SEQUENCER_OT_view_ghost_border", OKEY, KM_PRESS, 0, 0);
+
 	/* would prefer to use numpad keys for job */
 	RNA_float_set(WM_keymap_add_item(keymap, "SEQUENCER_OT_view_zoom_ratio", PAD8, KM_PRESS, KM_SHIFT, 0)->ptr, "ratio", 8.0f);
 	RNA_float_set(WM_keymap_add_item(keymap, "SEQUENCER_OT_view_zoom_ratio", PAD4, KM_PRESS, KM_SHIFT, 0)->ptr, "ratio", 4.0f);
diff --git a/source/blender/editors/space_sequencer/space_sequencer.c b/source/blender/editors/space_sequencer/space_sequencer.c
index 8b7670a55bc..586b76268e4 100644
--- a/source/blender/editors/space_sequencer/space_sequencer.c
+++ b/source/blender/editors/space_sequencer/space_sequencer.c
@@ -396,7 +396,21 @@ static void sequencer_preview_area_draw(const bContext *C, ARegion *ar)
 	
 	/* XXX temp fix for wrong setting in sseq->mainb */
 	if (sseq->mainb == SEQ_DRAW_SEQUENCE) sseq->mainb = SEQ_DRAW_IMG_IMBUF;
-	draw_image_seq(C, scene, ar, sseq);
+
+	draw_image_seq(C, scene, ar, sseq, scene->r.cfra, 0);
+
+	if(scene->ed && scene->ed->over_flag & SEQ_EDIT_OVERLAY_SHOW && sseq->mainb == SEQ_DRAW_IMG_IMBUF) {
+		int over_cfra;
+
+		if(scene->ed->over_flag & SEQ_EDIT_OVERLAY_ABS)
+			over_cfra= scene->ed->over_cfra;
+		else
+			over_cfra= scene->r.cfra + scene->ed->over_ofs;
+
+		if(over_cfra != scene->r.cfra)
+			draw_image_seq(C, scene, ar, sseq, scene->r.cfra, over_cfra - scene->r.cfra);
+	}
+
 }
 
 static void sequencer_preview_area_listener(ARegion *ar, wmNotifier *wmn)
diff --git a/source/blender/makesdna/DNA_sequence_types.h b/source/blender/makesdna/DNA_sequence_types.h
index f5ca32c6b32..3ab7cb73d56 100644
--- a/source/blender/makesdna/DNA_sequence_types.h
+++ b/source/blender/makesdna/DNA_sequence_types.h
@@ -196,6 +196,10 @@ typedef struct Editing {
 	Sequence *act_seq;
 	char act_imagedir[256];
 	char act_sounddir[256];
+
+	int over_ofs, over_cfra;
+	int over_flag, pad;
+	rctf over_border;
 } Editing;
 
 /* ************* Effect Variable Structs ********* */
@@ -242,6 +246,10 @@ typedef struct SpeedControlVars {
 	int lastValidFrame;
 } SpeedControlVars;
 
+/* Editor->over_flag */
+#define SEQ_EDIT_OVERLAY_SHOW			1
+#define SEQ_EDIT_OVERLAY_ABS			2
+
 #define SEQ_STRIP_OFSBOTTOM		0.2f
 #define SEQ_STRIP_OFSTOP		0.8f
 
diff --git a/source/blender/makesrna/intern/rna_sequencer.c b/source/blender/makesrna/intern/rna_sequencer.c
index c8b7299b539..0c60f04c2c2 100644
--- a/source/blender/makesrna/intern/rna_sequencer.c
+++ b/source/blender/makesrna/intern/rna_sequencer.c
@@ -521,6 +521,55 @@ static char *rna_SequenceColorBalance_path(PointerRNA *ptr)
 		return BLI_strdup("");
 }
 
+static void rna_SequenceEditor_overlay_lock_set(PointerRNA *ptr, int value)
+{
+	Scene *scene= ptr->id.data;
+	Editing *ed= seq_give_editing(scene, FALSE);
+
+	if(ed==NULL)
+		return;
+
+	/* convert from abs to relative and back */
+	if((ed->over_flag & SEQ_EDIT_OVERLAY_ABS)==0 && value) {
+		ed->over_cfra= scene->r.cfra + ed->over_ofs;
+		ed->over_flag |= SEQ_EDIT_OVERLAY_ABS;
+	}
+	else if((ed->over_flag & SEQ_EDIT_OVERLAY_ABS) && !value) {
+		ed->over_ofs= ed->over_cfra - scene->r.cfra;
+		ed->over_flag &= ~SEQ_EDIT_OVERLAY_ABS;
+	}
+}
+
+static int rna_SequenceEditor_overlay_frame_get(PointerRNA *ptr)
+{
+	Scene *scene= (Scene *)ptr->id.data;
+	Editing *ed= seq_give_editing(scene, FALSE);
+
+	if(ed==NULL)
+		return scene->r.cfra;
+
+	if(ed->over_flag & SEQ_EDIT_OVERLAY_ABS)
+		return ed->over_cfra - scene->r.cfra;
+	else
+		return ed->over_ofs;
+
+}
+
+static void rna_SequenceEditor_overlay_frame_set(PointerRNA *ptr, int value)
+{
+	Scene *scene= (Scene *)ptr->id.data;
+	Editing *ed= seq_give_editing(scene, FALSE);
+
+	if(ed==NULL)
+		return;
+
+
+	if(ed->over_flag & SEQ_EDIT_OVERLAY_ABS)
+		ed->over_cfra= (scene->r.cfra + value);
+	else
+		ed->over_ofs= value;
+}
+
 #else
 
 static void rna_def_strip_element(BlenderRNA *brna)
@@ -887,6 +936,22 @@ static void rna_def_editor(BlenderRNA *brna)
 	RNA_def_property_pointer_sdna(prop, NULL, "act_seq");
 	RNA_def_property_flag(prop, PROP_EDITABLE);
 
+	prop= RNA_def_property(srna, "show_overlay", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "over_flag", SEQ_EDIT_OVERLAY_SHOW);
+	RNA_def_property_ui_text(prop, "Draw Axes", "Partial overlay ontop of the sequencer");
+	RNA_def_property_update(prop, NC_SPACE|ND_SPACE_SEQUENCER, NULL);
+
+	prop= RNA_def_property(srna, "overlay_lock", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "over_flag", SEQ_EDIT_OVERLAY_ABS);
+	RNA_def_property_ui_text(prop, "Overlay Lock", "");
+	RNA_def_property_boolean_funcs(prop, NULL, "rna_SequenceEditor_overlay_lock_set");
+	RNA_def_property_update(prop, NC_SPACE|ND_SPACE_SEQUENCER, NULL);
+
+	/* access to fixed and relative frame */
+	prop= RNA_def_property(srna, "overlay_frame", PROP_INT, PROP_NONE);
+	RNA_def_property_ui_text(prop, "Overlay Offset", "");
+	RNA_def_property_int_funcs(prop, "rna_SequenceEditor_overlay_frame_get", "rna_SequenceEditor_overlay_frame_set", NULL);
+	RNA_def_property_update(prop, NC_SPACE|ND_SPACE_SEQUENCER, NULL);
 	RNA_def_property_ui_text(prop, "Active Strip", "Sequencers active strip");
 }
 
diff --git a/source/blender/windowmanager/intern/wm_operators.c b/source/blender/windowmanager/intern/wm_operators.c
index 7c11c7ff3af..d6f457fdea9 100644
--- a/source/blender/windowmanager/intern/wm_operators.c
+++ b/source/blender/windowmanager/intern/wm_operators.c
@@ -3141,6 +3141,7 @@ static void gesture_border_modal_keymap(wmKeyConfig *keyconf)
 	WM_modalkeymap_assign(keymap, "NODE_OT_select_border");
 //	WM_modalkeymap_assign(keymap, "SCREEN_OT_border_select"); // template
 	WM_modalkeymap_assign(keymap, "SEQUENCER_OT_select_border");
+	WM_modalkeymap_assign(keymap, "SEQUENCER_OT_view_ghost_border");
 	WM_modalkeymap_assign(keymap, "UV_OT_select_border");
 	WM_modalkeymap_assign(keymap, "VIEW2D_OT_zoom_border");
 	WM_modalkeymap_assign(keymap, "VIEW3D_OT_clip_border");