== Preview Range ==

Preview Range is a useful tool for animating (espcially on longer timelines). It allows you to only run through a limited set of frames to quickly preview the timing of a section of movement without going through the whole timeline. It means you don't have to set/reset start/end frame for rendering everytime you wish to only preview a region of frames.

Hi Ton,

Attached is a patch (I know you've already got lots of them in the tracker ;-) ) for a feature that I've sometimes wanted. It seems that this sort of thing is supported in other packages, but I can't be sure.

Note: I may have left in a few bits and pieces I didn't mean to in the patch (this is off a source tree which had quite a few revisions in it, all of which was experimental)



== Preview Range ==
Preview range is useful for animating (espcially on longer timelines). It allows you to only run through a limited set of frames to quickly preview the timing of a section of movement without going through the whole timeline. It means you don't have to set/reset start/end frame for rendering everytime you wish to only preview a region of frames.

* 'Ctrl P' in Action/NLA/Timeline sets preview range. Click+drag to form selection-box defining region of frames to preview
* 'Alt P' in Action/NLA/Timeline to clear preview range
* 'Pre' button beside Start/End fields in timeline toggles whether start/end fields refer to scene or preview
* 'Ctrl Rightarrow' and 'Ctrl Leftarrow' jump to start/end of preview region when it is set
* 'S' and 'E' set the start/end frames of preview region when it is set (just like normally) in Timeline only
* In Action/NLA editors, frames out of preview region are now drawn darkened when preview-region is set


See the following page for more info later:
http://wiki.blender.org/index.php/User:Aligorith/Preview_Range

14 files changed, 269 insertions, 36 deletions

diff --git a/source/blender/include/BSE_time.h b/source/blender/include/BSE_time.h
index fa398ee7da5..459101f592d 100644
--- a/source/blender/include/BSE_time.h
+++ b/source/blender/include/BSE_time.h
@@ -56,6 +56,12 @@ void make_marker_cfra_list(struct ListBase *lb, short only_sel);
 
 void draw_markers_timespace(void);
 
+/* ******** Animation - Preview Range ************* */
+void anim_previewrange_set(void);
+void anim_previewrange_clear(void);
+
+void draw_anim_preview_timespace(void);
+
 /* *********** TimeLine Specific  ***************/
 void timeline_frame_to_center(void);
 void nextprev_timeline_key(short dir);
diff --git a/source/blender/include/blendef.h b/source/blender/include/blendef.h
index 20b5f4a5da6..dc0d1998808 100644
--- a/source/blender/include/blendef.h
+++ b/source/blender/include/blendef.h
@@ -109,6 +109,8 @@
 #define	F_CFRA			((float)(G.scene->r.cfra))
 #define	SFRA			(G.scene->r.sfra)
 #define	EFRA			(G.scene->r.efra)
+#define PSFRA			((G.scene->r.psfra != 0)? (G.scene->r.psfra): (G.scene->r.sfra))
+#define PEFRA			((G.scene->r.psfra != 0)? (G.scene->r.pefra): (G.scene->r.efra))
 
 #define ISPOIN(a, b, c)			( (a->b) && (a->c) )
 #define ISPOIN3(a, b, c, d)		( (a->b) && (a->c) && (a->d) )
@@ -392,6 +394,7 @@
 #define B_TL_PREVKEY	754
 #define B_TL_NEXTKEY	755
 #define B_TL_STOP		756
+#define B_TL_PREVIEWON	757
 
 /* NLA: 801-850 */
 #define B_NLAHOME		801
diff --git a/source/blender/makesdna/DNA_scene_types.h b/source/blender/makesdna/DNA_scene_types.h
index 99f4cc10944..e61f08c5836 100644
--- a/source/blender/makesdna/DNA_scene_types.h
+++ b/source/blender/makesdna/DNA_scene_types.h
@@ -162,7 +162,8 @@ typedef struct RenderData {
 	struct QuicktimeCodecData *qtcodecdata;
 	struct FFMpegCodecData ffcodecdata;
 
-	int cfra, sfra, efra;	/* fames as in 'images' */
+	int cfra, sfra, efra;	/* frames as in 'images' */
+	int psfra, pefra;		/* start+end frames of preview range */
 
 	int images, framapto;
 	short flag, threads;
diff --git a/source/blender/src/drawaction.c b/source/blender/src/drawaction.c
index 9a90cbfa523..7bdf27beab5 100644
--- a/source/blender/src/drawaction.c
+++ b/source/blender/src/drawaction.c
@@ -692,7 +692,7 @@ void drawactionspace(ScrArea *sa, void *spacedata)
 		draw_mesh_strips(G.saction, key);
 	}
 	
-	/* Draw current frame */
+	/* reset matrices for stuff to be drawn on top of keys*/
 	glViewport(ofsx+G.v2d->mask.xmin,  
              ofsy+G.v2d->mask.ymin, 
              ( ofsx+G.v2d->mask.xmax-1)-(ofsx+G.v2d->mask.xmin)+1, 
@@ -702,10 +702,15 @@ void drawactionspace(ScrArea *sa, void *spacedata)
             ( ofsx+G.v2d->mask.xmax-1)-(ofsx+G.v2d->mask.xmin)+1, 
             ( ofsy+G.v2d->mask.ymax-1)-( ofsy+G.v2d->mask.ymin)+1);
 	myortho2(G.v2d->cur.xmin, G.v2d->cur.xmax,  G.v2d->cur.ymin, G.v2d->cur.ymax);
+	
+	/* Draw current frame */
 	draw_cfra_action();
 	
 	/* Draw markers */
 	draw_markers_timespace();
+	
+	/* Draw 'curtains' for preview */
+	draw_anim_preview_timespace();
 
 	/* Draw scroll */
 	mywinset(curarea->win);	// reset scissor too
diff --git a/source/blender/src/drawnla.c b/source/blender/src/drawnla.c
index 0368f2984ea..6704d360f96 100644
--- a/source/blender/src/drawnla.c
+++ b/source/blender/src/drawnla.c
@@ -711,14 +711,19 @@ void drawnlaspace(ScrArea *sa, void *spacedata)
 	/* the right hand side, with strips and keys */
 	draw_nla_strips_keys(G.snla);
 
-	/* Draw current frame */
+	
 	glViewport(ofsx+G.v2d->mask.xmin,  ofsy+G.v2d->mask.ymin, ( ofsx+G.v2d->mask.xmax-1)-(ofsx+G.v2d->mask.xmin)+1, ( ofsy+G.v2d->mask.ymax-1)-( ofsy+G.v2d->mask.ymin)+1); 
 	glScissor(ofsx+G.v2d->mask.xmin,  ofsy+G.v2d->mask.ymin, ( ofsx+G.v2d->mask.xmax-1)-(ofsx+G.v2d->mask.xmin)+1, ( ofsy+G.v2d->mask.ymax-1)-( ofsy+G.v2d->mask.ymin)+1);
 	myortho2 (G.v2d->cur.xmin, G.v2d->cur.xmax, G.v2d->cur.ymin, G.v2d->cur.ymax);
+	
+	/* Draw current frame */
 	draw_cfra_action();
 	
 	/* draw markers */
 	draw_markers_timespace();
+	
+	/* Draw preview 'curtains' */
+	draw_anim_preview_timespace();
 
 	/* Draw scroll */
 	mywinset(curarea->win);	// reset scissor too
diff --git a/source/blender/src/drawtime.c b/source/blender/src/drawtime.c
index a06541b8665..9b9cba4dc98 100644
--- a/source/blender/src/drawtime.c
+++ b/source/blender/src/drawtime.c
@@ -210,22 +210,42 @@ void draw_markers_timespace()
 
 }
 
+void draw_anim_preview_timespace()
+{
+	/* only draw this if preview range is set */
+	if (G.scene->r.psfra) {
+		glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
+		glEnable(GL_BLEND);
+		glColor4f(0, 0, 0, 0.4);
+	
+		if (PSFRA < PEFRA) {
+			glRectf(G.v2d->cur.xmin, G.v2d->cur.ymin, PSFRA, G.v2d->cur.ymax);
+			glRectf(PEFRA, G.v2d->cur.ymin, G.v2d->cur.xmax, G.v2d->cur.ymax);	
+		} 
+		else {
+			glRectf(G.v2d->cur.xmin, G.v2d->cur.ymin, G.v2d->cur.xmax, G.v2d->cur.ymax);
+		}
+		
+		glDisable(GL_BLEND);
+	}
+}
+
 static void draw_sfra_efra()
 {
 	BIF_ThemeColorShade(TH_BACK, -25);
 	
-	if (G.scene->r.sfra < G.scene->r.efra) {
-		glRectf(G.v2d->cur.xmin, G.v2d->cur.ymin, G.scene->r.sfra, G.v2d->cur.ymax);
-		
-		glRectf(G.scene->r.efra, G.v2d->cur.ymin, G.v2d->cur.xmax, G.v2d->cur.ymax);	
-	} else {
+	if (PSFRA < PEFRA) {
+		glRectf(G.v2d->cur.xmin, G.v2d->cur.ymin, PSFRA, G.v2d->cur.ymax);
+		glRectf(PEFRA, G.v2d->cur.ymin, G.v2d->cur.xmax, G.v2d->cur.ymax);	
+	} 
+	else {
 		glRectf(G.v2d->cur.xmin, G.v2d->cur.ymin, G.v2d->cur.xmax, G.v2d->cur.ymax);
 	}
 	
 	BIF_ThemeColorShade(TH_BACK, -60);
 	/* thin lines where the actual frames are */
-	fdrawline(G.scene->r.sfra, G.v2d->cur.ymin, G.scene->r.sfra, G.v2d->cur.ymax);
-	fdrawline(G.scene->r.efra, G.v2d->cur.ymin, G.scene->r.efra, G.v2d->cur.ymax);
+	fdrawline(PSFRA, G.v2d->cur.ymin, PSFRA, G.v2d->cur.ymax);
+	fdrawline(PEFRA, G.v2d->cur.ymin, PEFRA, G.v2d->cur.ymax);
 	
 	glDisable(GL_BLEND);
 }
@@ -325,7 +345,9 @@ void drawtimespace(ScrArea *sa, void *spacedata)
 	
 	myortho2(stime->v2d.cur.xmin, stime->v2d.cur.xmax, stime->v2d.cur.ymin, stime->v2d.cur.ymax);
 
-	/* draw darkened area outside of active timeline */
+	/* draw darkened area outside of active timeline 
+	 *	frame range used is preview range or scene range
+	 */
 	draw_sfra_efra();
 	
 	/* boundbox_seq(); */
diff --git a/source/blender/src/drawview.c b/source/blender/src/drawview.c
index ab317ce4826..8970a4d9b7c 100644
--- a/source/blender/src/drawview.c
+++ b/source/blender/src/drawview.c
@@ -3116,9 +3116,9 @@ void inner_play_anim_loop(int init, int mode)
 	tottime -= swaptime;
 	while (update_time()) PIL_sleep_ms(1);
 
-	if(CFRA>=EFRA) {
+	if(CFRA>=PEFRA) {
 		if (tottime > 0.0) tottime = 0.0;
-		CFRA= SFRA;
+		CFRA= PSFRA;
 		audiostream_stop();
 		audiostream_start( CFRA );
 	}
@@ -3144,7 +3144,7 @@ int play_anim(int mode)
 	if(SFRA==0) SFRA= 1;
 	if(EFRA==0) EFRA= 250;
 
-	if(SFRA>EFRA) return 0;
+	if(PSFRA>PEFRA) return 0;
 	
 	update_time();
 
@@ -3196,7 +3196,7 @@ int play_anim(int mode)
 		inner_play_anim_loop(0, 0);
 		screen_swapbuffers();
 				
-		if((mode & 2) && CFRA==EFRA) break; /* no replay */	
+		if((mode & 2) && CFRA==PEFRA) break; /* no replay */	
 	}
 
 	if(event==SPACEKEY);
diff --git a/source/blender/src/edit.c b/source/blender/src/edit.c
index 60fd064d873..0b5a32c4d5e 100644
--- a/source/blender/src/edit.c
+++ b/source/blender/src/edit.c
@@ -139,7 +139,9 @@ void circle_selectCB(select_CBfunc func);
 /* local protos ---------------*/
 void snap_curs_to_firstsel(void);
 
-/* flag==2 only border, flag==3 cross+border */
+/* flag==2 only border, flag==3 cross+border
+   flag==5 cross + border + start&end frame
+ */
 int get_border(rcti *rect, short flag)
 {
 	float dvec[4], fac1, fac2;
@@ -294,6 +296,49 @@ int get_border(rcti *rect, short flag)
 					glColor3f(0.9, 0.9, 0.9); 
 					BMF_DrawString(G.fonts, str);
 				}
+				else if ((ELEM3(curarea->spacetype, SPACE_ACTION, SPACE_NLA, SPACE_TIME)) && flag==5) {
+					/* only while setting preview range */
+					View2D *v2d;
+					
+					switch (curarea->spacetype) 
+					{
+						case SPACE_ACTION:
+						{
+							SpaceAction *saaction= curarea->spacedata.first;
+							v2d= &saaction->v2d;
+						}
+							break;
+						case SPACE_NLA:
+						{
+							SpaceNla *snla= curarea->spacedata.first;
+							v2d= &snla->v2d;
+						}
+							break;
+						default:
+							v2d= G.v2d;
+							break;
+					}
+					
+					mvalo[2]= x1;
+					mvalo[3]= y1;
+					areamouseco_to_ipoco(v2d, mval, dvec, dvec+1);
+					areamouseco_to_ipoco(v2d, mvalo+2, dvec+2, dvec+3);
+					
+					if (dvec[0] < dvec[2])
+						sprintf(str, "Preview Range: %d to %d", (int)dvec[0], (int)dvec[2]);
+					else
+						sprintf(str, "Preview Range: %d to %d", (int)dvec[2], (int)dvec[0]);
+					
+					BIF_ThemeColor(TH_BACK);
+					glRecti(14, 24, 165, 38);
+					
+					glColor3f(0.0, 0.0, 0.0); 
+					glRasterPos2i(15,  27);
+					BMF_DrawString(G.fonts, str);
+					glColor3f(0.8, 0.8, 0.8); 
+					glRasterPos2i(16,  28);
+					BMF_DrawString(G.fonts, str);
+				}
 
 				bglFlush();
 
@@ -343,6 +388,9 @@ int get_border(rcti *rect, short flag)
 		if ELEM(curarea->spacetype, SPACE_VIEW3D, SPACE_IPO) {
 			scrarea_queue_winredraw(curarea);
 		}
+		else if ELEM3(curarea->spacetype, SPACE_ACTION, SPACE_NLA, SPACE_TIME) {
+			scrarea_queue_winredraw(curarea); // only really needed for 
+		}
 	}
 	
 	bglFlush();
diff --git a/source/blender/src/editaction.c b/source/blender/src/editaction.c
index 06bc73bb957..78290f7f413 100644
--- a/source/blender/src/editaction.c
+++ b/source/blender/src/editaction.c
@@ -3049,6 +3049,17 @@ void winqreadactionspace(ScrArea *sa, void *spacedata, BWinEvent *evt)
 				clean_actionchannels(act);
 			break;
 			
+		case PKEY:
+			if (G.qual & LR_CTRLKEY) /* set preview range */
+				anim_previewrange_set();
+			else if (G.qual & LR_ALTKEY) /* clear preview range */
+				anim_previewrange_clear();
+			allqueue(REDRAWTIME, 0);
+			allqueue(REDRAWBUTSALL, 0);
+			allqueue(REDRAWACTION, 0);
+			allqueue(REDRAWNLA, 0);
+			break;
+			
 		case SKEY: 
 			if (mval[0]>=ACTWIDTH) {
 				if(G.qual & LR_SHIFTKEY) {
diff --git a/source/blender/src/editnla.c b/source/blender/src/editnla.c
index eb620644cb5..4b3f4cca4b4 100644
--- a/source/blender/src/editnla.c
+++ b/source/blender/src/editnla.c
@@ -1914,6 +1914,17 @@ void winqreadnlaspace(ScrArea *sa, void *spacedata, BWinEvent *evt)
 				relink_active_strip();
 				break;
 				
+			case PKEY:
+				if (G.qual & LR_CTRLKEY) /* set preview range */
+					anim_previewrange_set();
+				else if (G.qual & LR_ALTKEY) /* clear preview range */
+					anim_previewrange_clear();
+				allqueue(REDRAWTIME, 0);
+				allqueue(REDRAWBUTSALL, 0);
+				allqueue(REDRAWACTION, 0);
+				allqueue(REDRAWNLA, 0);
+				break;
+				
 			case SKEY:
 				if(G.qual==LR_ALTKEY) {
 					val= pupmenu("Action Strip Scale%t|Clear Strip Scale%x1|Remap Start/End%x2");
diff --git a/source/blender/src/editscreen.c b/source/blender/src/editscreen.c
index 801e9727999..64481a3e31b 100644
--- a/source/blender/src/editscreen.c
+++ b/source/blender/src/editscreen.c
@@ -1054,8 +1054,8 @@ int has_screenhandler(bScreen *sc, short eventcode)
 static void animated_screen(bScreen *sc, short val)
 {
 	if (U.mixbufsize && (val & TIME_WITH_SEQ_AUDIO)) {
-		if(CFRA>=EFRA) {
-			CFRA= SFRA;
+		if(CFRA>=PEFRA) {
+			CFRA= PSFRA;
 			audiostream_stop();
 			audiostream_start( CFRA );
 		}
@@ -1067,7 +1067,7 @@ static void animated_screen(bScreen *sc, short val)
 	}
 	else {
 		CFRA++;
-		if(CFRA > EFRA) CFRA= SFRA;
+		if(CFRA > PEFRA) CFRA= PSFRA;
 	}
 	
 	update_for_newframe_nodraw(1);
diff --git a/source/blender/src/edittime.c b/source/blender/src/edittime.c
index 5bbcd1098bb..29bcbac79df 100644
--- a/source/blender/src/edittime.c
+++ b/source/blender/src/edittime.c
@@ -577,6 +577,61 @@ static void select_timeline_marker_frame(int frame, unsigned char shift)
 
 /* *********** end Markers - TimeLine *************** */
 
+/* set the animation preview range of scene */
+void anim_previewrange_set()
+{
+	extern float get_action_frame(Object *ob, float cframe);
+	rcti rect;
+	rctf rectf;
+	short val, mval[2];
+	
+	/* set range by drawing border-select rectangle */
+	if ( (val = get_border(&rect, 5)) ) {	
+		/* get frame numbers */
+		mval[0]= rect.xmin;
+		mval[1]= rect.ymin+2;
+		areamouseco_to_ipoco(G.v2d, mval, &rectf.xmin, &rectf.ymin);
+		mval[0]= rect.xmax;
+		mval[1]= rect.ymax-2;
+		areamouseco_to_ipoco(G.v2d, mval, &rectf.xmax, &rectf.ymax);
+		
+		/* check if this is called from the action editor (with scaling) */
+		if (curarea->spacetype == SPACE_ACTION) {
+			/* if action is mapped in NLA, it returns a correction */
+			if(G.saction->pin==0 && OBACT) {
+				rectf.xmin= get_action_frame(OBACT, rectf.xmin);
+				rectf.xmax= get_action_frame(OBACT, rectf.xmax);
+			}
+		}
+			
+		/* set preview-range */
+		G.scene->r.psfra= rectf.xmin;
+		G.scene->r.pefra= rectf.xmax;
+		
+		BIF_undo_push("Set anim-preview range");
+		allqueue(REDRAWTIME, 0);
+		allqueue(REDRAWACTION, 0);
+		allqueue(REDRAWNLA, 0);
+		allqueue(REDRAWBUTSALL, 0);
+	}
+}
+
+/* clear the animation preview range for scene */
+void anim_previewrange_clear()
+{
+	G.scene->r.psfra = 0;
+	G.scene->r.pefra = 0;
+	
+	BIF_undo_push("Clear anim-preview range");
+	allqueue(REDRAWTIME, 0);
+	allqueue(REDRAWACTION, 0);
+	allqueue(REDRAWNLA, 0);
+	allqueue(REDRAWBUTSALL, 0);
+}
+
+/* ************ end Animation Preview Range ********** */
+
+
 static int float_to_frame(float frame) 
 {
 	int to= (int) floor(0.5 + frame/G.scene->r.framelen );
@@ -875,7 +930,13 @@ void winqreadtimespace(ScrArea *sa, void *spacedata, BWinEvent *evt)
 			transform_markers('g', 0);
 			break;
 		case EKEY: /* set end frame */
-			G.scene->r.efra = CFRA;
+			if (G.scene->r.psfra) {
+				if (CFRA > G.scene->r.psfra)
+					G.scene->r.psfra= CFRA;
+				G.scene->r.pefra= CFRA;
+			}				
+			else
+				G.scene->r.efra = CFRA;
 			allqueue(REDRAWBUTSALL, 0);
 			allqueue(REDRAWTIME, 1);
 			break;
@@ -890,8 +951,19 @@ void winqreadtimespace(ScrArea *sa, void *spacedata, BWinEvent *evt)
 			allqueue(REDRAWNLA, 0);
 			allqueue(REDRAWSOUND, 0);
 			break;
+		case PKEY:	/* preview-range stuff */
+			if (G.qual & LR_CTRLKEY) /* set preview range */
+				anim_previewrange_set();
+			else if (G.qual & LR_ALTKEY) /* clear preview range */
+				anim_previewrange_clear();
+			break;
 		case SKEY: /* set start frame */
-			G.scene->r.sfra = CFRA;
+			if (G.scene->r.psfra) {
+				G.scene->r.psfra= CFRA;
+				G.scene->r.pefra= (EFRA > CFRA)? (EFRA):(CFRA);
+			}				
+			else
+				G.scene->r.sfra = CFRA;
 			allqueue(REDRAWBUTSALL, 0);
 			allqueue(REDRAWTIME, 1);
 			break;
diff --git a/source/blender/src/header_time.c b/source/blender/src/header_time.c
index 968a34d1dbc..6f278a8e7fe 100644
--- a/source/blender/src/header_time.c
+++ b/source/blender/src/header_time.c
@@ -76,7 +76,7 @@ void do_time_buttons(ScrArea *sa, unsigned short event)
 	switch(event) {
 
 	case B_TL_REW:
-		CFRA= SFRA;
+		CFRA= PSFRA;
 		update_for_newframe();
 		break;
 	case B_TL_PLAY:
@@ -94,7 +94,7 @@ void do_time_buttons(ScrArea *sa, unsigned short event)
 		break;
 	case B_TL_FF:
 		/* end frame */
-		CFRA= EFRA;
+		CFRA= PEFRA;
 		update_for_newframe();
 		break;
 	case B_TL_PREVKEY:
@@ -105,6 +105,21 @@ void do_time_buttons(ScrArea *sa, unsigned short event)
 		/* next keyframe */
 		nextprev_timeline_key(1);
 		break;
+		
+	case B_TL_PREVIEWON:
+		if (G.scene->r.psfra) {
+			/* turn on preview range */
+			G.scene->r.psfra= G.scene->r.sfra;
+			G.scene->r.pefra= G.scene->r.efra;
+		}
+		else {
+			/* turn off preview range */
+			G.scene->r.psfra= 0;
+			G.scene->r.pefra= 0;
+		}
+		BIF_undo_push("Set anim-preview range");
+		allqueue(REDRAWALL, 0);
+		break;
 	}
 }
 
@@ -286,11 +301,22 @@ static void do_time_framemenu(void *arg, int event)
 {
 	switch(event) {
 		case 1: /*Set as Start */
-			G.scene->r.sfra = CFRA;
+			if (G.scene->r.psfra) {
+				G.scene->r.psfra= CFRA;
+				G.scene->r.pefra= (EFRA > CFRA)? (EFRA):(CFRA);
+			}				
+			else
+				G.scene->r.sfra = CFRA;
 			allqueue(REDRAWALL, 1);
 			break;
 		case 2: /* Set as End */
-			G.scene->r.efra = CFRA;
+			if (G.scene->r.psfra) {
+				if (CFRA > G.scene->r.psfra)
+					G.scene->r.psfra= CFRA;
+				G.scene->r.pefra= CFRA;
+			}				
+			else
+				G.scene->r.efra = CFRA;
 			allqueue(REDRAWALL, 1);
 			break;
 		case 3: /* Add Marker */
@@ -424,17 +450,40 @@ void time_buttons(ScrArea *sa)
 	uiBlockSetEmboss(block, UI_EMBOSS);
 	
 	uiBlockBeginAlign(block);
-	uiDefButI(block, NUM, REDRAWALL,"Start:",	
-		xco,0, 4.5*XIC, YIC,
-		&G.scene->r.sfra,MINFRAMEF, MAXFRAMEF, 0, 0,
-		"The start frame of the animation");
+	
+	uiDefButI(block, TOG, B_TL_PREVIEWON,"Preview",	
+		xco,0, XIC, YIC,
+		&G.scene->r.psfra,0, 1, 0, 0,
+		"Show settings for frame range of animation preview");
+		
+	xco += XIC;
+	
+	if (G.scene->r.psfra) {
+		uiDefButI(block, NUM, REDRAWALL,"Start:",	
+			xco,0, 4.5*XIC, YIC,
+			&G.scene->r.psfra,MINFRAMEF, MAXFRAMEF, 0, 0,
+			"The start frame of the animation preview");
+
+		xco += 4.5*XIC;
+
+		uiDefButI(block, NUM, REDRAWALL,"End:",	
+			xco,0,4.5*XIC,YIC,
+			&G.scene->r.pefra,PSFRA,MAXFRAMEF, 0, 0,
+			"The end frame of the animation preview");
+	}
+	else {
+		uiDefButI(block, NUM, REDRAWALL,"Start:",	
+ 		xco,0, 4.5*XIC, YIC,
+ 		&G.scene->r.sfra,MINFRAMEF, MAXFRAMEF, 0, 0,
+ 		"The start frame of the animation");
 
-	xco += 4.5*XIC;
+		xco += 4.5*XIC;
 
-	uiDefButI(block, NUM, REDRAWALL,"End:",	
-		xco,0,4.5*XIC,YIC,
-		&G.scene->r.efra,SFRA,MAXFRAMEF, 0, 0,
-		"The end  frame of the animation");
+		uiDefButI(block, NUM, REDRAWALL,"End:",	
+			xco,0,4.5*XIC,YIC,
+			&G.scene->r.efra,SFRA,MAXFRAMEF, 0, 0,
+			"The end frame of the animation");
+	}
 	uiBlockEndAlign(block);
 
 	xco += 4.5*XIC+16;
diff --git a/source/blender/src/toets.c b/source/blender/src/toets.c
index 04b21d32203..f35eb4320f4 100644
--- a/source/blender/src/toets.c
+++ b/source/blender/src/toets.c
@@ -603,7 +603,7 @@ int blenderqread(unsigned short event, short val)
 				CFRA--;
 			
 			if(G.qual==LR_SHIFTKEY)
-				CFRA= SFRA;
+				CFRA= PSFRA;
 			if(CFRA<1) CFRA=1;
 	
 			update_for_newframe();
@@ -631,7 +631,7 @@ int blenderqread(unsigned short event, short val)
 				CFRA++;
 
 			if(G.qual==LR_SHIFTKEY)
-				CFRA= EFRA;
+				CFRA= PEFRA;
 			
 			update_for_newframe();
 		}