Fix T40372: Slow Graph Editor drawing

For FCurves where all the keyframes use the "simple" interpolation types
(i.e. Constant, Linear, and Bezier), we now use the old FCurve drawing
code that was used prior to the Easing Equations changes. This should
be generally faster in general.

1 files changed, 35 insertions, 12 deletions

diff --git a/source/blender/editors/space_graph/graph_draw.c b/source/blender/editors/space_graph/graph_draw.c
index 5eec5c2a85a..9093734f25f 100644
--- a/source/blender/editors/space_graph/graph_draw.c
+++ b/source/blender/editors/space_graph/graph_draw.c
@@ -33,6 +33,7 @@
 #include <float.h>
 
 #include "BLI_blenlib.h"
+#include "BLI_math.h"
 #include "BLI_utildefines.h"
 
 #include "DNA_anim_types.h"
@@ -42,6 +43,7 @@
 #include "DNA_userdef_types.h"
 
 #include "BKE_context.h"
+#include "BKE_curve.h"
 #include "BKE_fcurve.h"
 
 
@@ -636,8 +638,24 @@ static void draw_fcurve_curve_samples(bAnimContext *ac, ID *id, FCurve *fcu, Vie
 	glPopMatrix();
 }
 
-#if 0
-/* helper func - draw one repeat of an F-Curve */
+/* helper func - check if the F-Curve only contains easily drawable segments 
+ * (i.e. no easing equation interpolations) 
+ */
+static bool fcurve_can_use_simple_bezt_drawing(FCurve *fcu)
+{
+	BezTriple *bezt;
+	int i;
+	
+	for (i = 0, bezt = fcu->bezt; i < fcu->totvert; i++, bezt++) {
+		if (ELEM(bezt->ipo, BEZT_IPO_CONST, BEZT_IPO_LIN, BEZT_IPO_BEZ) == false) {
+			return false;
+		}
+	}
+	
+	return true;
+}
+
+/* helper func - draw one repeat of an F-Curve (using Bezier curve approximations) */
 static void draw_fcurve_curve_bezts(bAnimContext *ac, ID *id, FCurve *fcu, View2D *v2d)
 {
 	BezTriple *prevbezt = fcu->bezt;
@@ -649,12 +667,12 @@ static void draw_fcurve_curve_bezts(bAnimContext *ac, ID *id, FCurve *fcu, View2
 	int resol;
 	float unit_scale;
 	short mapping_flag = ANIM_get_normalization_flags(ac);
-
+	
 	/* apply unit mapping */
 	glPushMatrix();
 	unit_scale = ANIM_unit_mapping_get_factor(ac->scene, id, fcu, mapping_flag);
 	glScalef(1.0f, unit_scale, 1.0f);
-
+	
 	glBegin(GL_LINE_STRIP);
 	
 	/* extrapolate to left? */
@@ -709,17 +727,19 @@ static void draw_fcurve_curve_bezts(bAnimContext *ac, ID *id, FCurve *fcu, View2
 			v1[1] = prevbezt->vec[1][1];
 			glVertex2fv(v1);
 		}
-		else {
+		else if (prevbezt->ipo == BEZT_IPO_BEZ) {
 			/* Bezier-Interpolation: draw curve as series of segments between keyframes 
 			 *	- resol determines number of points to sample in between keyframes
 			 */
 			
 			/* resol depends on distance between points (not just horizontal) OR is a fixed high res */
 			/* TODO: view scale should factor into this someday too... */
-			if (fcu->driver) 
+			if (fcu->driver) {
 				resol = 32;
-			else 
+			}
+			else {
 				resol = (int)(5.0f * len_v2v2(bezt->vec[1], prevbezt->vec[1]));
+			}
 			
 			if (resol < 2) {
 				/* only draw one */
@@ -793,7 +813,6 @@ static void draw_fcurve_curve_bezts(bAnimContext *ac, ID *id, FCurve *fcu, View2
 	glEnd();
 	glPopMatrix();
 }
-#endif
 
 /* Debugging -------------------------------- */
 
@@ -1009,11 +1028,15 @@ void graph_draw_curves(bAnimContext *ac, SpaceIpo *sipo, ARegion *ar, View2DGrid
 			}
 			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(ac, ale->id, fcu, &ar->v2d);
-					draw_fcurve_curve(ac, ale->id, fcu, &ar->v2d, grid);  // XXX: better to do an optimised integration here instead, but for now, this works
-				else if (fcu->fpt)
+				if (fcu->bezt) {
+					if (fcurve_can_use_simple_bezt_drawing(fcu))
+						draw_fcurve_curve_bezts(ac, ale->id, fcu, &ar->v2d);
+					else
+						draw_fcurve_curve(ac, ale->id, fcu, &ar->v2d, grid);
+				}
+				else if (fcu->fpt) {
 					draw_fcurve_curve_samples(ac, ale->id, fcu, &ar->v2d);
+				}
 			}
 			
 			/* restore settings */