F-Curve Modifiers: Groundwork for getting these working

- Completed cleaning up the drawing code so that F-Curves with modifiers now get drawn to reflect this.
- Added a temporary operator to add modifiers (hotkey Ctrl-Shift-M) 

6 files changed, 404 insertions, 256 deletions

diff --git a/source/blender/editors/space_graph/graph_buttons.c b/source/blender/editors/space_graph/graph_buttons.c
index 859aab9283e..7c078ad184d 100644
--- a/source/blender/editors/space_graph/graph_buttons.c
+++ b/source/blender/editors/space_graph/graph_buttons.c
@@ -52,6 +52,7 @@
 #include "BKE_curve.h"
 #include "BKE_customdata.h"
 #include "BKE_depsgraph.h"
+#include "BKE_fcurve.h"
 #include "BKE_object.h"
 #include "BKE_global.h"
 #include "BKE_scene.h"
@@ -218,32 +219,92 @@ static void graph_panel_drivers(const bContext *C, ARegion *ar, short cntrl, bAn
 
 /* -------------- */
 
+#define B_FMODIFIER_REDRAW		20
+
 static void do_graph_region_modifier_buttons(bContext *C, void *arg, int event)
 {
-	//Scene *scene= CTX_data_scene(C);
-	
 	switch(event) {
+		case B_REDR:
+		case B_FMODIFIER_REDRAW:
+			ED_area_tag_redraw(CTX_wm_area(C));
+			return; /* no notifier! */
+	}
+}
+
 
+/* for now, just print name of modifier */
+static void graph_panel_modifier_draw(uiBlock *block, FCurve *fcu, FModifier *fcm, int *yco)
+{
+	FModifierTypeInfo *fmi= fmodifier_get_typeinfo(fcm);
+	uiBut *but;
+	short active= (fcm->flag & FMODIFIER_FLAG_ACTIVE);
+	short width= 314;
+	short height = 0; 
+	int rb_col;
+	
+	/* draw header */
+	{
+		uiBlockSetEmboss(block, UI_EMBOSSN);
+		
+		/* rounded header */
+		if (active) uiBlockSetCol(block, TH_BUT_ACTION);
+			rb_col= (active)?-20:20;
+			uiDefBut(block, ROUNDBOX, B_REDR, "", 10-8, *yco-2, width, 24, NULL, 5.0, 0.0, 15.0, (float)(rb_col-20), ""); 
+		if (active) uiBlockSetCol(block, TH_AUTO);
+		
+		/* expand */
+		uiDefIconButBitS(block, ICONTOG, FMODIFIER_FLAG_EXPANDED, B_REDR, ICON_TRIA_RIGHT,	10-7, *yco-1, 20, 20, &fcm->flag, 0.0, 0.0, 0, 0, "Modifier is expanded");
+		
+		/* name */
+		if (fmi)
+			uiDefBut(block, LABEL, 1, fmi->name,	10+35, *yco, 240, 20, NULL, 0.0, 0.0, 0, 0, "F-Curve Modifier Type");
+		else
+			uiDefBut(block, LABEL, 1, "<Unknown Modifier>",	10+35, *yco, 240, 20, NULL, 0.0, 0.0, 0, 0, "F-Curve Modifier Type");
+		
+		/* delete button */
+		but= uiDefIconBut(block, BUT, B_REDR, ICON_X, 10+(width-30), *yco, 19, 19, NULL, 0.0, 0.0, 0.0, 0.0, "Delete layer");
+		//uiButSetFunc(but, gp_ui_dellayer_cb, gpd, NULL);
+		uiBlockSetEmboss(block, UI_EMBOSS);
 	}
 	
-	/* default for now */
-	//WM_event_add_notifier(C, NC_OBJECT|ND_TRANSFORM, ob);
+	/* when modifier is expanded, draw settings */
+	if (fcm->flag & FMODIFIER_FLAG_EXPANDED) {
+		height= 97;
+		
+		/* draw backdrop */
+		if (active) uiBlockSetCol(block, TH_BUT_ACTION);
+			uiDefBut(block, ROUNDBOX, B_REDR, "", 10-8, *yco-height, width, height-1, NULL, 5.0, 0.0, 12.0, (float)rb_col, ""); 
+		if (active) uiBlockSetCol(block, TH_AUTO);
+	}
+	
+	/* adjust height for new to start */
+	(*yco) -= (height + 27); 
 }
 
 static void graph_panel_modifiers(const bContext *C, ARegion *ar, short cntrl, bAnimListElem *ale)	
 {
-	//FCurve *fcu= (FCurve *)ale->data;
-	//FModifier *fcm;
+	FCurve *fcu= (FCurve *)ale->data;
+	FModifier *fcm;
 	uiBlock *block;
+	int yco= 190;
 
 	block= uiBeginBlock(C, ar, "graph_panel_modifiers", UI_EMBOSS, UI_HELV);
 	if (uiNewPanel(C, ar, block, "Modifiers", "Graph", 340, 30, 318, 254)==0) return;
 	uiBlockSetHandleFunc(block, do_graph_region_modifier_buttons, NULL);
-
-	/* to force height */
-	uiNewPanelHeight(block, 204); // XXX variable height!
 	
+	/* 'add modifier' button at top of panel */
+	// XXX for now, this will be a operator button which calls a temporary 'add modifier' operator
+	uiDefButO(block, BUT, "GRAPHEDIT_OT_fmodifier_add", WM_OP_INVOKE_REGION_WIN, "Add Modifier", 10, 225, 150, 20, "Adds a new F-Curve Modifier for the active F-Curve");
+	
+	/* draw each modifier */
+	for (fcm= fcu->modifiers.first; fcm; fcm= fcm->next)
+		graph_panel_modifier_draw(block, fcu, fcm, &yco);
 	
+	/* since these buttons can have variable height */
+	if (yco < 0)
+		uiNewPanelHeight(block, (204 - yco));
+	else
+		uiNewPanelHeight(block, 204);
 }
 
 /* -------------- */
@@ -253,7 +314,7 @@ static void graph_panel_modifiers(const bContext *C, ARegion *ar, short cntrl, b
  * when the caller is done with it.
  */
 // TODO: move this to anim api with another name?
-static bAnimListElem *get_active_fcurve_channel (bAnimContext *ac)
+bAnimListElem *get_active_fcurve_channel (bAnimContext *ac)
 {
 	ListBase anim_data = {NULL, NULL};
 	int filter= (ANIMFILTER_VISIBLE | ANIMFILTER_FOREDIT | ANIMFILTER_ACTIVE | ANIMFILTER_CURVESONLY);
diff --git a/source/blender/editors/space_graph/graph_draw.c b/source/blender/editors/space_graph/graph_draw.c
index 1efa257c317..bd57e9750eb 100644
--- a/source/blender/editors/space_graph/graph_draw.c
+++ b/source/blender/editors/space_graph/graph_draw.c
@@ -27,6 +27,7 @@
 #include <stdio.h>
 #include <math.h>
 #include <string.h>
+#include <float.h>
 
 #ifdef HAVE_CONFIG_H
 #include <config.h>
@@ -401,9 +402,62 @@ static void draw_fcurve_samples (SpaceIpo *sipo, ARegion *ar, FCurve *fcu)
 
 /* Curve ---------------- */
 
+/* minimum pixels per gridstep 
+ * XXX: defined in view2d.c - must keep these in sync or relocate to View2D header!
+ */
+#define MINGRIDSTEP 	35
+
+/* helper func - just draw the F-Curve by sampling the visible region (for drawing curves with modifiers) */
+static void draw_fcurve_curve (FCurve *fcu, SpaceIpo *sipo, View2D *v2d, View2DGrid *grid)
+{
+	ChannelDriver *driver;
+	float samplefreq, ctime;
+	float stime, etime;
+	
+	/* disable any drivers temporarily */
+	driver= fcu->driver;
+	fcu->driver= NULL;
+	
+	
+	/* Note about sampling frequency:
+	 * 	Ideally, this is chosen such that we have 1-2 pixels = 1 segment
+	 *	which means that our curves can be as smooth as possible. However,
+	 * 	this does mean that curves may not be fully accurate (i.e. if they have
+	 * 	sudden spikes which happen at the sampling point, we may have problems).
+	 * 	Also, this may introduce lower performance on less densely detailed curves,'
+	 *	though it is impossible to predict this from the modifiers!
+	 *
+	 *	If the automatically determined sampling frequency is likely to cause an infinite
+	 *	loop (i.e. too close to FLT_EPSILON), fall back to default of 0.001
+	 */
+		/* grid->dx is the first float in View2DGrid struct, so just cast to float pointer, and use it
+		 * It represents the number of 'frames' between gridlines, but we divide by MINGRIDSTEP to get pixels-steps
+		 */
+		// TODO: perhaps we should have 1.0 frames as upper limit so that curves don't get too distorted?
+	samplefreq= *((float *)grid) / MINGRIDSTEP;
+	if (IS_EQ(samplefreq, 0)) samplefreq= 0.001f;
+	
+	
+	/* the start/end times are simply the horizontal extents of the 'cur' rect */
+	stime= v2d->cur.xmin;
+	etime= v2d->cur.xmax;
+	
+	
+	/* at each sampling interval, add a new vertex */
+	glBegin(GL_LINE_STRIP);
+	
+	for (ctime= stime; ctime <= etime; ctime += samplefreq)
+		glVertex2f( ctime, evaluate_fcurve(fcu, ctime) );
+	
+	glEnd();
+	
+	/* restore driver */
+	fcu->driver= driver;
+}
+
 /* helper func - draw a samples-based F-Curve */
 // TODO: add offset stuff...
-static void draw_fcurve_repeat_samples (FCurve *fcu, View2D *v2d)
+static void draw_fcurve_curve_samples (FCurve *fcu, View2D *v2d)
 {
 	FPoint *prevfpt= fcu->fpt;
 	FPoint *fpt= prevfpt + 1;
@@ -412,26 +466,23 @@ static void draw_fcurve_repeat_samples (FCurve *fcu, View2D *v2d)
 	
 	glBegin(GL_LINE_STRIP);
 	
-	/* extrapolate to left? */
-	if ( (fcu->modifiers.first == NULL)/* || ( ((FModifier *)fcu->modifiers.first)->type != FMODIFIER_TYPE_CYCLES) */) {
-		/* left-side of view comes before first keyframe, so need to extend as not cyclic */
-		if (prevfpt->vec[0] > v2d->cur.xmin) {
-			v[0]= v2d->cur.xmin;
-			
-			/* y-value depends on the interpolation */
-			if ((fcu->extend==FCURVE_EXTRAPOLATE_CONSTANT) || (fcu->flag & FCURVE_INT_VALUES) || (fcu->totvert==1)) {
-				/* just extend across the first keyframe's value */
-				v[1]= prevfpt->vec[1];
-			} 
-			else {
-				/* extrapolate linear dosnt use the handle, use the next points center instead */
-				fac= (prevfpt->vec[0]-fpt->vec[0])/(prevfpt->vec[0]-v[0]);
-				if (fac) fac= 1.0f/fac;
-				v[1]= prevfpt->vec[1]-fac*(prevfpt->vec[1]-fpt->vec[1]);
-			}
-			
-			glVertex2fv(v);
+	/* extrapolate to left? - left-side of view comes before first keyframe? */
+	if (prevfpt->vec[0] > v2d->cur.xmin) {
+		v[0]= v2d->cur.xmin;
+		
+		/* y-value depends on the interpolation */
+		if ((fcu->extend==FCURVE_EXTRAPOLATE_CONSTANT) || (fcu->flag & FCURVE_INT_VALUES) || (fcu->totvert==1)) {
+			/* just extend across the first keyframe's value */
+			v[1]= prevfpt->vec[1];
+		} 
+		else {
+			/* extrapolate linear dosnt use the handle, use the next points center instead */
+			fac= (prevfpt->vec[0]-fpt->vec[0])/(prevfpt->vec[0]-v[0]);
+			if (fac) fac= 1.0f/fac;
+			v[1]= prevfpt->vec[1]-fac*(prevfpt->vec[1]-fpt->vec[1]);
 		}
+		
+		glVertex2fv(v);
 	}
 	
 	/* if only one sample, add it now */
@@ -440,7 +491,6 @@ static void draw_fcurve_repeat_samples (FCurve *fcu, View2D *v2d)
 	
 	/* loop over samples, drawing segments */
 	/* draw curve between first and last keyframe (if there are enough to do so) */
-	// XXX this doesn't take into account modifiers, or sample data
 	while (b--) {
 		/* Linear interpolation: just add one point (which should add a new line segment) */
 		glVertex2fv(prevfpt->vec);
@@ -455,95 +505,90 @@ static void draw_fcurve_repeat_samples (FCurve *fcu, View2D *v2d)
 	}
 	
 	/* extrapolate to right? (see code for left-extrapolation above too) */
-	if ( (fcu->modifiers.first == NULL)/* || ( ((FModifier *)fcu->modifiers.first)->type != FMODIFIER_TYPE_CYCLES) */) {
-		if (prevfpt->vec[0] < v2d->cur.xmax) {
-			v[0]= v2d->cur.xmax;
-			
-			/* y-value depends on the interpolation */
-			if ((fcu->extend==FCURVE_EXTRAPOLATE_CONSTANT) || (fcu->flag & FCURVE_INT_VALUES) || (fcu->totvert==1)) {
-				/* based on last keyframe's value */
-				v[1]= prevfpt->vec[1];
-			} 
-			else {
-				/* extrapolate linear dosnt use the handle, use the previous points center instead */
-				fpt = prevfpt-1;
-				fac= (prevfpt->vec[0]-fpt->vec[0])/(prevfpt->vec[0]-v[0]);
-				if (fac) fac= 1.0f/fac;
-				v[1]= prevfpt->vec[1]-fac*(prevfpt->vec[1]-fpt->vec[1]);
-			}
-			
-			glVertex2fv(v);
+	if (prevfpt->vec[0] < v2d->cur.xmax) {
+		v[0]= v2d->cur.xmax;
+		
+		/* y-value depends on the interpolation */
+		if ((fcu->extend==FCURVE_EXTRAPOLATE_CONSTANT) || (fcu->flag & FCURVE_INT_VALUES) || (fcu->totvert==1)) {
+			/* based on last keyframe's value */
+			v[1]= prevfpt->vec[1];
+		} 
+		else {
+			/* extrapolate linear dosnt use the handle, use the previous points center instead */
+			fpt = prevfpt-1;
+			fac= (prevfpt->vec[0]-fpt->vec[0])/(prevfpt->vec[0]-v[0]);
+			if (fac) fac= 1.0f/fac;
+			v[1]= prevfpt->vec[1]-fac*(prevfpt->vec[1]-fpt->vec[1]);
 		}
+		
+		glVertex2fv(v);
 	}
 	
 	glEnd();
 }
 
 /* helper func - draw one repeat of an F-Curve */
-static void draw_fcurve_repeat (FCurve *fcu, View2D *v2d, float cycxofs, float cycyofs, float *facp)
+static void draw_fcurve_curve_bezts (FCurve *fcu, View2D *v2d, View2DGrid *grid)
 {
 	BezTriple *prevbezt= fcu->bezt;
 	BezTriple *bezt= prevbezt+1;
 	float v1[2], v2[2], v3[2], v4[2];
 	float *fp, data[120];
-	float fac= *(facp);
+	float fac= 0.0f;
 	int b= fcu->totvert-1;
 	int resol;
 	
 	glBegin(GL_LINE_STRIP);
 	
 	/* extrapolate to left? */
-	if ( (fcu->modifiers.first == NULL)/* || ( ((FModifier *)fcu->modifiers.first)->type != FMODIFIER_TYPE_CYCLES) */) {
+	if (prevbezt->vec[1][0] > v2d->cur.xmin) {
 		/* left-side of view comes before first keyframe, so need to extend as not cyclic */
-		if (prevbezt->vec[1][0] > v2d->cur.xmin) {
-			v1[0]= v2d->cur.xmin;
-			
-			/* y-value depends on the interpolation */
-			if ((fcu->extend==FCURVE_EXTRAPOLATE_CONSTANT) || (fcu->flag & FCURVE_INT_VALUES) || (prevbezt->ipo==BEZT_IPO_CONST) || (fcu->totvert==1)) {
-				/* just extend across the first keyframe's value */
-				v1[1]= prevbezt->vec[1][1];
-			} 
-			else if (prevbezt->ipo==BEZT_IPO_LIN) {
-				/* extrapolate linear dosnt use the handle, use the next points center instead */
-				fac= (prevbezt->vec[1][0]-bezt->vec[1][0])/(prevbezt->vec[1][0]-v1[0]);
-				if (fac) fac= 1.0f/fac;
-				v1[1]= prevbezt->vec[1][1]-fac*(prevbezt->vec[1][1]-bezt->vec[1][1]);
-			} 
-			else {
-				/* based on angle of handle 1 (relative to keyframe) */
-				fac= (prevbezt->vec[0][0]-prevbezt->vec[1][0])/(prevbezt->vec[1][0]-v1[0]);
-				if (fac) fac= 1.0f/fac;
-				v1[1]= prevbezt->vec[1][1]-fac*(prevbezt->vec[0][1]-prevbezt->vec[1][1]);
-			}
-			
-			glVertex2fv(v1);
+		v1[0]= v2d->cur.xmin;
+		
+		/* y-value depends on the interpolation */
+		if ((fcu->extend==FCURVE_EXTRAPOLATE_CONSTANT) || (fcu->flag & FCURVE_INT_VALUES) || (prevbezt->ipo==BEZT_IPO_CONST) || (fcu->totvert==1)) {
+			/* just extend across the first keyframe's value */
+			v1[1]= prevbezt->vec[1][1];
+		} 
+		else if (prevbezt->ipo==BEZT_IPO_LIN) {
+			/* extrapolate linear dosnt use the handle, use the next points center instead */
+			fac= (prevbezt->vec[1][0]-bezt->vec[1][0])/(prevbezt->vec[1][0]-v1[0]);
+			if (fac) fac= 1.0f/fac;
+			v1[1]= prevbezt->vec[1][1]-fac*(prevbezt->vec[1][1]-bezt->vec[1][1]);
+		} 
+		else {
+			/* based on angle of handle 1 (relative to keyframe) */
+			fac= (prevbezt->vec[0][0]-prevbezt->vec[1][0])/(prevbezt->vec[1][0]-v1[0]);
+			if (fac) fac= 1.0f/fac;
+			v1[1]= prevbezt->vec[1][1]-fac*(prevbezt->vec[0][1]-prevbezt->vec[1][1]);
 		}
+		
+		glVertex2fv(v1);
 	}
 	
 	/* if only one keyframe, add it now */
 	if (fcu->totvert == 1) {
-		v1[0]= prevbezt->vec[1][0] + cycxofs;
-		v1[1]= prevbezt->vec[1][1] + cycyofs;
+		v1[0]= prevbezt->vec[1][0];
+		v1[1]= prevbezt->vec[1][1];
 		glVertex2fv(v1);
 	}
 	
 	/* draw curve between first and last keyframe (if there are enough to do so) */
-	// XXX this doesn't take into account modifiers, or sample data
 	while (b--) {
 		if ((fcu->flag & FCURVE_INT_VALUES) || (prevbezt->ipo==BEZT_IPO_CONST)) {
 			/* Constant-Interpolation: draw segment between previous keyframe and next, but holding same value */
-			v1[0]= prevbezt->vec[1][0]+cycxofs;
-			v1[1]= prevbezt->vec[1][1]+cycyofs;
+			v1[0]= prevbezt->vec[1][0];
+			v1[1]= prevbezt->vec[1][1];
 			glVertex2fv(v1);
 			
-			v1[0]= bezt->vec[1][0]+cycxofs;
-			v1[1]= prevbezt->vec[1][1]+cycyofs;
+			v1[0]= bezt->vec[1][0];
+			v1[1]= prevbezt->vec[1][1];
 			glVertex2fv(v1);
 		}
 		else if (prevbezt->ipo==BEZT_IPO_LIN) {
 			/* Linear interpolation: just add one point (which should add a new line segment) */
-			v1[0]= prevbezt->vec[1][0]+cycxofs;
-			v1[1]= prevbezt->vec[1][1]+cycyofs;
+			v1[0]= prevbezt->vec[1][0];
+			v1[1]= prevbezt->vec[1][1];
 			glVertex2fv(v1);
 		}
 		else {
@@ -560,23 +605,23 @@ static void draw_fcurve_repeat (FCurve *fcu, View2D *v2d, float cycxofs, float c
 			
 			if (resol < 2) {
 				/* only draw one */
-				v1[0]= prevbezt->vec[1][0]+cycxofs;
-				v1[1]= prevbezt->vec[1][1]+cycyofs;
+				v1[0]= prevbezt->vec[1][0];
+				v1[1]= prevbezt->vec[1][1];
 				glVertex2fv(v1);
 			}
 			else {
 				/* clamp resolution to max of 32 */
 				if (resol > 32) resol= 32;
 				
-				v1[0]= prevbezt->vec[1][0]+cycxofs;
-				v1[1]= prevbezt->vec[1][1]+cycyofs;
-				v2[0]= prevbezt->vec[2][0]+cycxofs;
-				v2[1]= prevbezt->vec[2][1]+cycyofs;
+				v1[0]= prevbezt->vec[1][0];
+				v1[1]= prevbezt->vec[1][1];
+				v2[0]= prevbezt->vec[2][0];
+				v2[1]= prevbezt->vec[2][1];
 				
-				v3[0]= bezt->vec[0][0]+cycxofs;
-				v3[1]= bezt->vec[0][1]+cycyofs;
-				v4[0]= bezt->vec[1][0]+cycxofs;
-				v4[1]= bezt->vec[1][1]+cycyofs;
+				v3[0]= bezt->vec[0][0];
+				v3[1]= bezt->vec[0][1];
+				v4[0]= bezt->vec[1][0];
+				v4[1]= bezt->vec[1][1];
 				
 				correct_bezpart(v1, v2, v3, v4);
 				
@@ -594,152 +639,41 @@ static void draw_fcurve_repeat (FCurve *fcu, View2D *v2d, float cycxofs, float c
 		
 		/* last point? */
 		if (b == 0) {
-			v1[0]= prevbezt->vec[1][0]+cycxofs;
-			v1[1]= prevbezt->vec[1][1]+cycyofs;
+			v1[0]= prevbezt->vec[1][0];
+			v1[1]= prevbezt->vec[1][1];
 			glVertex2fv(v1);
 		}
 	}
 	
 	/* extrapolate to right? (see code for left-extrapolation above too) */
-	if ( (fcu->modifiers.first == NULL)/* || ( ((FModifier *)fcu->modifiers.first)->type != FMODIFIER_TYPE_CYCLES) */) {
-		if (prevbezt->vec[1][0] < v2d->cur.xmax) {
-			v1[0]= v2d->cur.xmax;
-			
-			/* y-value depends on the interpolation */
-			if ((fcu->extend==FCURVE_EXTRAPOLATE_CONSTANT) || (fcu->flag & FCURVE_INT_VALUES) || (prevbezt->ipo==BEZT_IPO_CONST) || (fcu->totvert==1)) {
-				/* based on last keyframe's value */
-				v1[1]= prevbezt->vec[1][1];
-			} 
-			else if (prevbezt->ipo==BEZT_IPO_LIN) {
-				/* extrapolate linear dosnt use the handle, use the previous points center instead */
-				bezt = prevbezt-1;
-				fac= (prevbezt->vec[1][0]-bezt->vec[1][0])/(prevbezt->vec[1][0]-v1[0]);
-				if (fac) fac= 1.0f/fac;
-				v1[1]= prevbezt->vec[1][1]-fac*(prevbezt->vec[1][1]-bezt->vec[1][1]);
-			} 
-			else {
-				/* based on angle of handle 1 (relative to keyframe) */
-				fac= (prevbezt->vec[2][0]-prevbezt->vec[1][0])/(prevbezt->vec[1][0]-v1[0]);
-				if (fac) fac= 1.0f/fac;
-				v1[1]= prevbezt->vec[1][1]-fac*(prevbezt->vec[2][1]-prevbezt->vec[1][1]);
-			}
-			
-			glVertex2fv(v1);
+	if (prevbezt->vec[1][0] < v2d->cur.xmax) {
+		v1[0]= v2d->cur.xmax;
+		
+		/* y-value depends on the interpolation */
+		if ((fcu->extend==FCURVE_EXTRAPOLATE_CONSTANT) || (fcu->flag & FCURVE_INT_VALUES) || (prevbezt->ipo==BEZT_IPO_CONST) || (fcu->totvert==1)) {
+			/* based on last keyframe's value */
+			v1[1]= prevbezt->vec[1][1];
+		} 
+		else if (prevbezt->ipo==BEZT_IPO_LIN) {
+			/* extrapolate linear dosnt use the handle, use the previous points center instead */
+			bezt = prevbezt-1;
+			fac= (prevbezt->vec[1][0]-bezt->vec[1][0])/(prevbezt->vec[1][0]-v1[0]);
+			if (fac) fac= 1.0f/fac;
+			v1[1]= prevbezt->vec[1][1]-fac*(prevbezt->vec[1][1]-bezt->vec[1][1]);
+		} 
+		else {
+			/* based on angle of handle 1 (relative to keyframe) */
+			fac= (prevbezt->vec[2][0]-prevbezt->vec[1][0])/(prevbezt->vec[1][0]-v1[0]);
+			if (fac) fac= 1.0f/fac;
+			v1[1]= prevbezt->vec[1][1]-fac*(prevbezt->vec[2][1]-prevbezt->vec[1][1]);
 		}
+		
+		glVertex2fv(v1);
 	}
 	
 	glEnd();
-	
-	/* return fac, as we alter it */
-	*(facp) = fac;
 } 
 
-#if 0 // XXX old animation system unconverted code!
-
-/* draw all ipo-curves */
-static void draw_ipocurves(SpaceIpo *sipo, ARegion *ar, int sel)
-{
-	View2D *v2d= &ar->v2d;
-	EditIpo *ei;
-	int nr, val/*, pickselcode=0*/;
-	
-	/* if we're drawing for GL_SELECT, reset pickselcode first 
-	 * 	- there's only one place that will do this, so it should be fine
-	 */
-	//if (G.f & G_PICKSEL)
-	//	pickselcode= 1;
-	
-	ei= sipo->editipo;
-	for (nr=0; nr<sipo->totipo; nr++, ei++) {
-		if ISPOIN3(ei, flag & IPO_VISIBLE, icu, icu->bezt) {
-			/* val is used to indicate if curve can be edited */
-			//if (G.f & G_PICKSEL) {
-			//	/* when using OpenGL to select stuff (on mouseclick) */
-			//	glLoadName(pickselcode++);
-			//	val= 1;
-			//}
-			//else {
-				/* filter to only draw those that are selected or unselected (based on drawing mode */
-				val= (ei->flag & (IPO_SELECT+IPO_EDIT)) != 0;
-				val= (val==sel);
-			//}
-			
-			/* only draw those curves that we can draw */
-			if (val) {
-				IpoCurve *icu= ei->icu;
-				float cycdx=0.0f, cycdy=0.0f, cycxofs=0.0f, cycyofs=0.0f;
-				const int lastindex= (icu->totvert-1);
-				float fac= 0.0f;
-				int cycount=1;
-				
-				/* set color for curve curve:
-				 *	- bitflag curves (evil) must always be drawn coloured as they cannot work with IPO-Keys
-				 *	- when IPO-Keys are shown, individual curves are not editable, so we show by drawing them all black
-				 */
-				if ((sipo->showkey) && (ei->disptype!=IPO_DISPBITS)) UI_ThemeColor(TH_TEXT); 
-				else cpack(ei->col);
-				
-				/* cyclic curves - get offset and number of repeats to display */
-				if (icu->extrap & IPO_CYCL) {
-					BezTriple *bezt= icu->bezt;
-					BezTriple *lastbezt= bezt + lastindex;
-					
-					/* calculate cycle length and amplitude  */
-					cycdx= lastbezt->vec[1][0] - bezt->vec[1][0];
-					cycdy= lastbezt->vec[1][1] - bezt->vec[1][1];
-					
-					/* check that the cycle does have some length */
-					if (cycdx > 0.01f) {
-						/* count cycles before first frame  */
-						while (icu->bezt->vec[1][0]+cycxofs > v2d->cur.xmin) {
-							cycxofs -= cycdx;
-							if (icu->extrap & IPO_DIR) cycyofs-= cycdy;
-							cycount++;
-						}
-						
-						/* count cycles after last frame (and adjust offset) */
-						fac= 0.0f;
-						while (lastbezt->vec[1][0]+fac < v2d->cur.xmax) {
-							cycount++;
-							fac += cycdx;
-						}
-					}
-				}
-				
-				/* repeat process for each repeat */
-				while (cycount--) {
-					/* bitflag curves are drawn differently to normal curves */
-					if (ei->disptype==IPO_DISPBITS)
-						draw_ipocurve_repeat_bits(icu, v2d, cycxofs);
-					else
-						draw_ipocurve_repeat_normal(icu, v2d, cycxofs, cycyofs, &fac);
-					
-					/* prepare for next cycle by adjusing offsets */
-					cycxofs += cycdx;
-					if (icu->extrap & IPO_DIR) cycyofs += cycdy;
-				}
-				
-				/* vertical line that indicates the end of a speed curve */
-				if ((sipo->blocktype==ID_CU) && (icu->adrcode==CU_SPEED)) {
-					int b= icu->totvert-1;
-					
-					if (b) {
-						BezTriple *bezt= icu->bezt+b;
-						
-						glColor3ub(0, 0, 0);
-						
-						glBegin(GL_LINES);
-							glVertex2f(bezt->vec[1][0], 0.0f);
-							glVertex2f(bezt->vec[1][0], bezt->vec[1][1]);
-						glEnd();
-					}
-				}
-			}
-		}
-	}
-}
-#endif // XXX old animation system unconverted code
-
 #if 0
 static void draw_ipokey(SpaceIpo *sipo, ARegion *ar)
 {
@@ -758,7 +692,9 @@ static void draw_ipokey(SpaceIpo *sipo, ARegion *ar)
 }
 #endif
 
-void graph_draw_curves (bAnimContext *ac, SpaceIpo *sipo, ARegion *ar)
+/* Public Curve-Drawing API  ---------------- */
+
+void graph_draw_curves (bAnimContext *ac, SpaceIpo *sipo, ARegion *ar, View2DGrid *grid)
 {
 	ListBase anim_data = {NULL, NULL};
 	bAnimListElem *ale;
@@ -774,20 +710,22 @@ void graph_draw_curves (bAnimContext *ac, SpaceIpo *sipo, ARegion *ar)
 	 */
 	for (ale=anim_data.first; ale; ale=ale->next) {
 		FCurve *fcu= (FCurve *)ale->key_data;
-		Object *nob= ANIM_nla_mapping_get(ac, ale);
-		float fac=0.0f; // dummy var
+		//FModifier *fcm= fcurve_active_modifier(fcu);
+		//Object *nob= ANIM_nla_mapping_get(ac, ale);
 		
 		/* map keyframes for drawing if scaled F-Curve */
-		if (nob)
-			ANIM_nla_mapping_apply_fcurve(nob, ale->key_data, 0, 0); 
+		//if (nob)
+		//	ANIM_nla_mapping_apply_fcurve(nob, ale->key_data, 0, 0); 
 		
-		/* draw curve - if there's an active modifier (or a stack of modifiers) drawing these takes presidence,
-		 * unless modifiers in use will not alter any of the values within the keyframed area...
+		/* draw curve:
+		 *	- curve line may be result of one or more destructive modifiers or just the raw data,
+		 *	  so we need to check which method should be used
+		 *	- controls from active modifier take precidence over keyframes
+		 *	  (XXX! editing tools need to take this into account!)
 		 */
-		
-		
-		/* draw curve - as defined by keyframes */
-		if ( ((fcu->bezt) || (fcu->fpt)) && (fcu->totvert) ) { 
+		 
+		/* 1) draw curve line */
+		{
 			/* set color/drawing style for curve itself */
 			if ( ((fcu->grp) && (fcu->grp->flag & AGRP_PROTECTED)) || (fcu->flag & FCURVE_PROTECTED) ) {
 				/* protected curves (non editable) are drawn with dotted lines */
@@ -803,18 +741,35 @@ void graph_draw_curves (bAnimContext *ac, SpaceIpo *sipo, ARegion *ar)
 				glColor3fv(fcu->color);
 			}
 			
+			/* anti-aliased lines for less jagged appearance */
+			glEnable(GL_LINE_SMOOTH);
+			glEnable(GL_BLEND);
+			
 			/* draw F-Curve */
-			if (fcu->bezt)
-				draw_fcurve_repeat(fcu, &ar->v2d, 0, 0, &fac); // XXX this call still needs a lot more work
-			else if (fcu->fpt)
-				draw_fcurve_repeat_samples(fcu, &ar->v2d);
-			/*else  modifiers? */
+			if (fcu->modifiers.first) {
+				/* draw a curve affected by modifiers by sampling its points  */
+				draw_fcurve_curve(fcu, sipo, &ar->v2d, grid);
+			}
+			else if ( ((fcu->bezt) || (fcu->fpt)) && (fcu->totvert) ) { 
+				/* just draw curve based on defined data (i.e. no modifiers) */
+				if (fcu->bezt)
+					draw_fcurve_curve_bezts(fcu, &ar->v2d, grid);
+				else if (fcu->fpt)
+					draw_fcurve_curve_samples(fcu, &ar->v2d);
+			}
 			
 			/* restore settings */
 			setlinestyle(0);
 			
-			
-			/* draw handles and vertices as appropriate */
+			glDisable(GL_LINE_SMOOTH);
+			glDisable(GL_BLEND);
+		}
+		
+		/* 2) draw handles and vertices as appropriate based on active */
+		if ((fcu->modifiers.first) && (fcm) && (fcm->type != FMODIFIER_TYPE_CYCLES)) {
+			// TODO: need to add code to show these... for cycles modifier, should fall through though...
+		}
+		else if ( ((fcu->bezt) || (fcu->fpt)) && (fcu->totvert) ) { 
 			if (fcu->bezt) {
 				/* only draw handles/vertices on keyframes */
 				draw_fcurve_handles(sipo, ar, fcu);
@@ -827,8 +782,8 @@ void graph_draw_curves (bAnimContext *ac, SpaceIpo *sipo, ARegion *ar)
 		}
 		
 		/* undo mapping of keyframes for drawing if scaled F-Curve */
-		if (nob)
-			ANIM_nla_mapping_apply_fcurve(nob, ale->key_data, 1, 0); 
+		//if (nob)
+		//	ANIM_nla_mapping_apply_fcurve(nob, ale->key_data, 1, 0); 
 	}
 	
 	/* free list of curves */
diff --git a/source/blender/editors/space_graph/graph_edit.c b/source/blender/editors/space_graph/graph_edit.c
index d98ed38da9c..43a3b3628ad 100644
--- a/source/blender/editors/space_graph/graph_edit.c
+++ b/source/blender/editors/space_graph/graph_edit.c
@@ -1018,12 +1018,25 @@ void GRAPHEDIT_OT_keyframes_handletype (wmOperatorType *ot)
  * of values to -180 degrees to 180 degrees.
  */
 
+#if 0 // XXX this is not ready for the primetime yet
+ 
+/* set of three euler-rotation F-Curves */
+typedef struct tEulerFilter {
+	ID *id;							/* ID-block which owns the channels */
+	FCurve *fcu1, *fcu2, *fcu3;		/* x,y,z rotation curves */
+	int i1, i2, i3;					/* current index for each curve */
+} tEulerFilter;
+ 
 static int graphkeys_euler_filter_exec (bContext *C, wmOperator *op)
 {
 	bAnimContext ac;
-	//ListBase anim_data= {NULL, NULL};
-	//bAnimListElem *ale;
-	//int filter;
+	
+	ListBase anim_data= {NULL, NULL};
+	bAnimListElem *ale;
+	int filter;
+	
+	ListBase eulers = {NULL, NULL};
+	tEulerFilter *euf= NULL;	
 	
 	/* get editor data */
 	if (ANIM_animdata_get_context(C, &ac) == 0)
@@ -1035,7 +1048,33 @@ static int graphkeys_euler_filter_exec (bContext *C, wmOperator *op)
 	 *	 2) Each set of three F-Curves is processed for each keyframe, with the values being
 	 * 		processed according to one of several ways.
 	 */
+	 
+	/* step 1: extract only the rotation f-curves */
+	filter= (ANIMFILTER_VISIBLE | ANIMFILTER_SEL | ANIMFILTER_CURVEVISIBLE | ANIMFILTER_CURVESONLY);
+	ANIM_animdata_filter(&ac, &anim_data, filter, ac.data, ac.datatype);
 	
+	for (ale= anim_data.first; ale; ale= ale->next) {
+		FCurve *fcu = (FCurve *)ale->data;
+		
+		/* check if this is an appropriate F-Curve 
+		 *	- only rotation curves
+		 *	- for pchan curves, make sure we're only using the euler curves
+		 */
+		if (ELEM(0, fcu->rna_path, strstr(fcu->rna_path, "rotation")))
+			continue;
+		if (strstr(fcu->rna_path, "pose.pose_channels")) {
+			if (strstr(fcu->rna_path, "euler_rotation") == 0)
+				continue;
+		}
+		
+		/* check if current set of 3-curves is suitable to add this curve to 
+		 *	- things like whether the current set of curves is 'full' should be checked later only
+		 *	- first check if id-blocks are compatible
+		 */
+		if ((euf) && (ale->id != euf->id)) {
+			
+		}
+	}
 	
 	// XXX for now
 	return OPERATOR_CANCELLED;
@@ -1055,6 +1094,8 @@ void GRAPHEDIT_OT_keyframes_euler_filter (wmOperatorType *ot)
 	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;
 }
 
+#endif // XXX this is not ready for the primetime yet
+
 /* ***************** Snap Current Frame Operator *********************** */
 
 /* helper callback for graphkeys_cfrasnap_exec() -> used to help get the average time of all selected beztriples */
@@ -1376,3 +1417,76 @@ void GRAPHEDIT_OT_keyframes_smooth (wmOperatorType *ot)
 }
 
 /* ************************************************************************** */
+/* F-CURVE MODIFIERS */
+
+/* ******************** Add F-Curve Modifier Operator *********************** */
+
+/* F-Modifier types - duplicate of existing codes...  */
+	// XXX how can we have this list from the RNA definitions instead?
+EnumPropertyItem prop_fmodifier_types[] = {
+	{FMODIFIER_TYPE_GENERATOR, "GENERATOR", "Generator", ""},
+	{FMODIFIER_TYPE_ENVELOPE, "ENVELOPE", "Envelope", ""},
+	{FMODIFIER_TYPE_CYCLES, "CYCLES", "Cycles", ""},
+	{FMODIFIER_TYPE_NOISE, "NOISE", "Noise", ""},
+	{FMODIFIER_TYPE_FILTER, "FILTER", "Filter", ""},
+	{FMODIFIER_TYPE_PYTHON, "PYTHON", "Python", ""},
+	{0, NULL, NULL, NULL}
+};
+
+static int graph_fmodifier_add_exec(bContext *C, wmOperator *op)
+{
+	bAnimContext ac;
+	bAnimListElem *ale;
+	FCurve *fcu;
+	short type;
+	
+	/* get editor data */
+	if (ANIM_animdata_get_context(C, &ac) == 0)
+		return OPERATOR_CANCELLED;
+		
+		// xxx call the raw methods here instead?
+	ale= get_active_fcurve_channel(&ac);
+	if (ale == NULL) 
+		return OPERATOR_CANCELLED;
+	
+	fcu= (FCurve *)ale->data;
+	MEM_freeN(ale);
+	if (fcu == NULL) 
+		return OPERATOR_CANCELLED;
+		
+	
+	/* get type of modifier to add */
+	type= RNA_enum_get(op->ptr, "type");
+	
+	/* add F-Modifier of specified type to active F-Curve */
+	fcurve_add_modifier(fcu, type);
+	
+	
+	/* validate keyframes after editing */
+	ANIM_editkeyframes_refresh(&ac);
+	
+	/* set notifier that things have changed */
+	ANIM_animdata_send_notifiers(C, &ac, ANIM_CHANGED_BOTH);
+	
+	return OPERATOR_FINISHED;
+}
+ 
+void GRAPHEDIT_OT_fmodifier_add (wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name= "Add F-Curve Modifier";
+	ot->idname= "GRAPHEDIT_OT_fmodifier_add";
+	
+	/* api callbacks */
+	ot->invoke= WM_menu_invoke;
+	ot->exec= graph_fmodifier_add_exec;
+	ot->poll= ED_operator_areaactive; // XXX need active F-Curve
+	
+	/* flags */
+	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;
+	
+	/* id-props */
+	RNA_def_enum(ot->srna, "type", prop_fmodifier_types, 0, "Type", "");
+}
+
+/* ************************************************************************** */
diff --git a/source/blender/editors/space_graph/graph_intern.h b/source/blender/editors/space_graph/graph_intern.h
index 6144556378a..ab915a97232 100644
--- a/source/blender/editors/space_graph/graph_intern.h
+++ b/source/blender/editors/space_graph/graph_intern.h
@@ -31,9 +31,11 @@
 struct bContext;
 struct wmWindowManager;
 struct bAnimContext;
+struct bAnimListElem;
 struct SpaceIpo;
 struct ScrArea;
 struct ARegion;
+struct View2DGrid;
 
 /* internal exports only */
 
@@ -44,7 +46,7 @@ struct ARegion *graph_has_buttons_region(struct ScrArea *sa);
 /* ***************************************** */
 /* graph_draw.c */
 void graph_draw_channel_names(struct bAnimContext *ac, struct SpaceIpo *sipo, struct ARegion *ar);
-void graph_draw_curves(struct bAnimContext *ac, struct SpaceIpo *sipo, struct ARegion *ar);
+void graph_draw_curves(struct bAnimContext *ac, struct SpaceIpo *sipo, struct ARegion *ar, struct View2DGrid *grid);
 
 /* ***************************************** */
 /* graph_header.c */
@@ -119,11 +121,17 @@ enum {
 	GRAPHKEYS_MIRROR_MARKER,
 } eGraphKeys_Mirror_Mode;
 
+/* ----------- */
+
+void GRAPHEDIT_OT_fmodifier_add(struct wmOperatorType *ot);
+
 /* ***************************************** */
 /* graph_buttons.c */
 void GRAPHEDIT_OT_properties(struct wmOperatorType *ot);
 void graph_region_buttons(const struct bContext *C, struct ARegion *ar);
 
+struct bAnimListElem *get_active_fcurve_channel(struct bAnimContext *ac);
+
 /* ***************************************** */
 /* graph_ops.c */
 void graphedit_keymap(struct wmWindowManager *wm);
diff --git a/source/blender/editors/space_graph/graph_ops.c b/source/blender/editors/space_graph/graph_ops.c
index 80b8dcbf0ff..91cc7557476 100644
--- a/source/blender/editors/space_graph/graph_ops.c
+++ b/source/blender/editors/space_graph/graph_ops.c
@@ -126,6 +126,10 @@ void graphedit_operatortypes(void)
 	WM_operatortype_append(GRAPHEDIT_OT_keyframes_paste);
 	
 	//TODO: insertkey...
+	
+	/* F-Curve Modifiers */
+	// XXX temporary?
+	WM_operatortype_append(GRAPHEDIT_OT_fmodifier_add);
 }
 
 /* ************************** registration - keymaps **********************************/
@@ -195,6 +199,11 @@ static void graphedit_keymap_keyframes (wmWindowManager *wm, ListBase *keymap)
 	WM_keymap_add_item(keymap, "GRAPHEDIT_OT_set_previewrange", PKEY, KM_PRESS, KM_CTRL|KM_ALT, 0);
 	WM_keymap_add_item(keymap, "GRAPHEDIT_OT_view_all", HOMEKEY, KM_PRESS, 0, 0);
 	
+		/* F-Curve Modifiers */
+		// XXX these are temporary? operators...
+	WM_keymap_add_item(keymap, "GRAPHEDIT_OT_fmodifier_add", MKEY, KM_PRESS, KM_CTRL|KM_SHIFT, 0);
+	
+	
 	/* transform system */
 	transform_keymap_for_space(wm, keymap, SPACE_IPO);
 }
diff --git a/source/blender/editors/space_graph/space_graph.c b/source/blender/editors/space_graph/space_graph.c
index e6365db92ad..9466a0674d1 100644
--- a/source/blender/editors/space_graph/space_graph.c
+++ b/source/blender/editors/space_graph/space_graph.c
@@ -230,12 +230,13 @@ static void graph_main_area_draw(const bContext *C, ARegion *ar)
 	unitx= (sipo->flag & SIPO_DRAWTIME)? V2D_UNIT_SECONDS : V2D_UNIT_FRAMESCALE;
 	grid= UI_view2d_grid_calc(C, v2d, unitx, V2D_GRID_NOCLAMP, unity, V2D_GRID_NOCLAMP, ar->winx, ar->winy);
 	UI_view2d_grid_draw(C, v2d, grid, V2D_GRIDLINES_ALL);
-	UI_view2d_grid_free(grid);
 	
 	/* draw data */
-	if (ANIM_animdata_get_context(C, &ac)) {
-		graph_draw_curves(&ac, sipo, ar);
-	}
+	if (ANIM_animdata_get_context(C, &ac))
+		graph_draw_curves(&ac, sipo, ar, grid);
+	
+	/* only free grid after drawing data, as we need to use it to determine sampling rate */
+	UI_view2d_grid_free(grid);
 	
 	/* current frame */
 	if (sipo->flag & SIPO_DRAWTIME) 	flag |= DRAWCFRA_UNIT_SECONDS;