diff --git a/source/blender/editors/interface/interface_templates.c b/source/blender/editors/interface/interface_templates.c
index 4c79b57a16d..458ca9edc5c 100644
--- a/source/blender/editors/interface/interface_templates.c
+++ b/source/blender/editors/interface/interface_templates.c
@@ -1893,32 +1893,45 @@ static uiBlock *curvemap_clipping_func(bContext *C, ARegion *ar, void *cumap_v)
 	return block;
 }
 
+/* only for curvemap_tools_dofunc */
+enum {
+	UICURVE_FUNC_RESET_NEG,
+	UICURVE_FUNC_RESET_POS,
+	UICURVE_FUNC_RESET_VIEW,
+	UICURVE_FUNC_HANDLE_VECTOR,
+	UICURVE_FUNC_HANDLE_AUTO,
+	UICURVE_FUNC_EXTEND_HOZ,
+	UICURVE_FUNC_EXTEND_EXP,
+};
+
 static void curvemap_tools_dofunc(bContext *C, void *cumap_v, int event)
 {
 	CurveMapping *cumap = cumap_v;
 	CurveMap *cuma = cumap->cm + cumap->cur;
 
 	switch (event) {
-		case 0: /* reset */
-			curvemap_reset(cuma, &cumap->clipr, cumap->preset, CURVEMAP_SLOPE_POSITIVE);
+		case UICURVE_FUNC_RESET_NEG:
+		case UICURVE_FUNC_RESET_POS: /* reset */
+			curvemap_reset(cuma, &cumap->clipr, cumap->preset,
+			               (event == -1) ? CURVEMAP_SLOPE_NEGATIVE : CURVEMAP_SLOPE_POSITIVE);
 			curvemapping_changed(cumap, FALSE);
 			break;
-		case 1:
+		case UICURVE_FUNC_RESET_VIEW:
 			cumap->curr = cumap->clipr;
 			break;
-		case 2: /* set vector */
+		case UICURVE_FUNC_HANDLE_VECTOR: /* set vector */
 			curvemap_sethandle(cuma, 1);
 			curvemapping_changed(cumap, FALSE);
 			break;
-		case 3: /* set auto */
+		case UICURVE_FUNC_HANDLE_AUTO: /* set auto */
 			curvemap_sethandle(cuma, 0);
 			curvemapping_changed(cumap, FALSE);
 			break;
-		case 4: /* extend horiz */
+		case UICURVE_FUNC_EXTEND_HOZ: /* extend horiz */
 			cuma->flag &= ~CUMA_EXTEND_EXTRAPOLATE;
 			curvemapping_changed(cumap, FALSE);
 			break;
-		case 5: /* extend extrapolate */
+		case UICURVE_FUNC_EXTEND_EXP: /* extend extrapolate */
 			cuma->flag |= CUMA_EXTEND_EXTRAPOLATE;
 			curvemapping_changed(cumap, FALSE);
 			break;
@@ -1935,17 +1948,17 @@ static uiBlock *curvemap_tools_func(bContext *C, ARegion *ar, void *cumap_v)
 	uiBlockSetButmFunc(block, curvemap_tools_dofunc, cumap_v);
 
 	uiDefIconTextBut(block, BUTM, 1, ICON_BLANK1, IFACE_("Reset View"),          0, yco -= UI_UNIT_Y,
-	                 menuwidth, UI_UNIT_Y, NULL, 0.0, 0.0, 0, 1, "");
+	                 menuwidth, UI_UNIT_Y, NULL, 0.0, 0.0, 0, UICURVE_FUNC_RESET_VIEW, "");
 	uiDefIconTextBut(block, BUTM, 1, ICON_BLANK1, IFACE_("Vector Handle"),       0, yco -= UI_UNIT_Y,
-	                 menuwidth, UI_UNIT_Y, NULL, 0.0, 0.0, 0, 2, "");
+	                 menuwidth, UI_UNIT_Y, NULL, 0.0, 0.0, 0, UICURVE_FUNC_HANDLE_VECTOR, "");
 	uiDefIconTextBut(block, BUTM, 1, ICON_BLANK1, IFACE_("Auto Handle"),         0, yco -= UI_UNIT_Y,
-	                 menuwidth, UI_UNIT_Y, NULL, 0.0, 0.0, 0, 3, "");
+	                 menuwidth, UI_UNIT_Y, NULL, 0.0, 0.0, 0, UICURVE_FUNC_HANDLE_AUTO, "");
 	uiDefIconTextBut(block, BUTM, 1, ICON_BLANK1, IFACE_("Extend Horizontal"),   0, yco -= UI_UNIT_Y,
-	                 menuwidth, UI_UNIT_Y, NULL, 0.0, 0.0, 0, 4, "");
+	                 menuwidth, UI_UNIT_Y, NULL, 0.0, 0.0, 0, UICURVE_FUNC_EXTEND_HOZ, "");
 	uiDefIconTextBut(block, BUTM, 1, ICON_BLANK1, IFACE_("Extend Extrapolated"), 0, yco -= UI_UNIT_Y,
-	                 menuwidth, UI_UNIT_Y, NULL, 0.0, 0.0, 0, 5, "");
+	                 menuwidth, UI_UNIT_Y, NULL, 0.0, 0.0, 0, UICURVE_FUNC_EXTEND_EXP, "");
 	uiDefIconTextBut(block, BUTM, 1, ICON_BLANK1, IFACE_("Reset Curve"),         0, yco -= UI_UNIT_Y,
-	                 menuwidth, UI_UNIT_Y, NULL, 0.0, 0.0, 0, 0, "");
+	                 menuwidth, UI_UNIT_Y, NULL, 0.0, 0.0, 0, UICURVE_FUNC_RESET_POS, "");
 
 	uiBlockSetDirection(block, UI_RIGHT);
 	uiTextBoundsBlock(block, 50);
@@ -1963,13 +1976,13 @@ static uiBlock *curvemap_brush_tools_func(bContext *C, ARegion *ar, void *cumap_
 	uiBlockSetButmFunc(block, curvemap_tools_dofunc, cumap_v);
 
 	uiDefIconTextBut(block, BUTM, 1, ICON_BLANK1, IFACE_("Reset View"),    0, yco -= UI_UNIT_Y,
-	                 menuwidth, UI_UNIT_Y, NULL, 0.0, 0.0, 0, 1, "");
+	                 menuwidth, UI_UNIT_Y, NULL, 0.0, 0.0, 0, UICURVE_FUNC_RESET_VIEW, "");
 	uiDefIconTextBut(block, BUTM, 1, ICON_BLANK1, IFACE_("Vector Handle"), 0, yco -= UI_UNIT_Y,
-	                 menuwidth, UI_UNIT_Y, NULL, 0.0, 0.0, 0, 2, "");
+	                 menuwidth, UI_UNIT_Y, NULL, 0.0, 0.0, 0, UICURVE_FUNC_HANDLE_VECTOR, "");
 	uiDefIconTextBut(block, BUTM, 1, ICON_BLANK1, IFACE_("Auto Handle"),   0, yco -= UI_UNIT_Y,
-	                 menuwidth, UI_UNIT_Y, NULL, 0.0, 0.0, 0, 3, "");
+	                 menuwidth, UI_UNIT_Y, NULL, 0.0, 0.0, 0, UICURVE_FUNC_HANDLE_AUTO, "");
 	uiDefIconTextBut(block, BUTM, 1, ICON_BLANK1, IFACE_("Reset Curve"),   0, yco -= UI_UNIT_Y,
-	                 menuwidth, UI_UNIT_Y, NULL, 0.0, 0.0, 0, 0, "");
+	                 menuwidth, UI_UNIT_Y, NULL, 0.0, 0.0, 0, UICURVE_FUNC_RESET_NEG, "");
 
 	uiBlockSetDirection(block, UI_RIGHT);
 	uiTextBoundsBlock(block, 50);