UI: take zoom into account w/ curves widget

The Curves widget has buttons to zoom in on the curve. However the
click detection code doesn't take it into account, and at full zoom
in click on curve is detected very far from the actual visible curve.

Change it to compare the position to the actual line segments
in the UI coordinate space, i.e. with curve zoom applied.

1 files changed, 29 insertions, 29 deletions

diff --git a/source/blender/editors/interface/interface_handlers.c b/source/blender/editors/interface/interface_handlers.c
index f941993a9e1..e0b8003d8a9 100644
--- a/source/blender/editors/interface/interface_handlers.c
+++ b/source/blender/editors/interface/interface_handlers.c
@@ -6014,20 +6014,15 @@ static int ui_do_but_CURVE(bContext *C, uiBlock *block, uiBut *but, uiHandleButt
 			CurveMapping *cumap = (CurveMapping *)but->poin;
 			CurveMap *cuma = cumap->cm + cumap->cur;
 			CurveMapPoint *cmp;
-			float fx, fy, zoomx, zoomy, offsx, offsy;
-			float dist, mindist = 200.0f; // 14 pixels radius
+			const float m_xy[2] = {mx, my};
+			float dist_min_sq = SQUARE(14.0f);  /* 14 pixels radius */
 			int sel = -1;
 
-			zoomx = BLI_rctf_size_x(&but->rect) / BLI_rctf_size_x(&cumap->curr);
-			zoomy = BLI_rctf_size_y(&but->rect) / BLI_rctf_size_y(&cumap->curr);
-			offsx = cumap->curr.xmin;
-			offsy = cumap->curr.ymin;
-
 			if (event->ctrl) {
-				fx = ((float)mx - but->rect.xmin) / zoomx + offsx;
-				fy = ((float)my - but->rect.ymin) / zoomy + offsy;
+				float f_xy[2];
+				BLI_rctf_transform_pt_v(&cumap->curr, &but->rect, f_xy, m_xy);
 				
-				curvemap_insert(cuma, fx, fy);
+				curvemap_insert(cuma, f_xy[0], f_xy[1]);
 				curvemapping_changed(cumap, false);
 				changed = true;
 			}
@@ -6035,33 +6030,37 @@ static int ui_do_but_CURVE(bContext *C, uiBlock *block, uiBut *but, uiHandleButt
 			/* check for selecting of a point */
 			cmp = cuma->curve;   /* ctrl adds point, new malloc */
 			for (a = 0; a < cuma->totpoint; a++) {
-				fx = but->rect.xmin + zoomx * (cmp[a].x - offsx);
-				fy = but->rect.ymin + zoomy * (cmp[a].y - offsy);
-				dist = (fx - mx) * (fx - mx) + (fy - my) * (fy - my);
-				if (dist < mindist) {
+				float f_xy[2];
+				BLI_rctf_transform_pt_v(&but->rect, &cumap->curr, f_xy, &cmp[a].x);
+				const float dist_sq = len_squared_v2v2(m_xy, f_xy);
+				if (dist_sq < dist_min_sq) {
 					sel = a;
-					mindist = dist;
+					dist_min_sq = dist_sq;
 				}
 			}
 
 			if (sel == -1) {
 				int i;
+				float f_xy[2], f_xy_prev[2];
 
 				/* if the click didn't select anything, check if it's clicked on the 
 				 * curve itself, and if so, add a point */
-				fx = ((float)mx - but->rect.xmin) / zoomx + offsx;
-				fy = ((float)my - but->rect.ymin) / zoomy + offsy;
-				
 				cmp = cuma->table;
 
-				/* loop through the curve segment table and find what's near the mouse.
-				 * 0.05 is kinda arbitrary, but seems to be what works nicely. */
-				for (i = 0; i <= CM_TABLE; i++) {
-					if ((fabsf(fx - cmp[i].x) < 0.05f) &&
-					    (fabsf(fy - cmp[i].y) < 0.05f))
-					{
-					
-						curvemap_insert(cuma, fx, fy);
+				BLI_rctf_transform_pt_v(&but->rect, &cumap->curr, f_xy, &cmp[0].x);
+
+				/* with 160px height 8px should translate to the old 0.05 coefficient at no zoom */
+				dist_min_sq = SQUARE(8.0f);
+
+				/* loop through the curve segment table and find what's near the mouse. */
+				for (i = 1; i <= CM_TABLE; i++) {
+					copy_v2_v2(f_xy_prev, f_xy);
+					BLI_rctf_transform_pt_v(&but->rect, &cumap->curr, f_xy, &cmp[i].x);
+
+					if (dist_squared_to_line_segment_v2(m_xy, f_xy_prev, f_xy) < dist_min_sq) {
+						BLI_rctf_transform_pt_v(&cumap->curr, &but->rect, f_xy, m_xy);
+
+						curvemap_insert(cuma, f_xy[0], f_xy[1]);
 						curvemapping_changed(cumap, false);
 
 						changed = true;
@@ -6070,10 +6069,11 @@ static int ui_do_but_CURVE(bContext *C, uiBlock *block, uiBut *but, uiHandleButt
 						cmp = cuma->curve;
 						
 						/* find newly added point and make it 'sel' */
-						for (a = 0; a < cuma->totpoint; a++)
-							if (cmp[a].x == fx)
+						for (a = 0; a < cuma->totpoint; a++) {
+							if (cmp[a].x == f_xy[0]) {
 								sel = a;
-							
+							}
+						}
 						break;
 					}
 				}