Fix T63605: Assert squeezing a template_curve_mapping in a panel to

almost zero horizontally

Reviewers: brecht

Maniphest Tasks: T63605

Differential Revision: https://developer.blender.org/D4690

1 files changed, 13 insertions, 8 deletions

diff --git a/source/blender/editors/interface/interface_draw.c b/source/blender/editors/interface/interface_draw.c
index 671a004f9fe..e29fcfb3b43 100644
--- a/source/blender/editors/interface/interface_draw.c
+++ b/source/blender/editors/interface/interface_draw.c
@@ -1804,12 +1804,12 @@ static void ui_draw_but_curve_grid(
                       1.0f);
 
   immBegin(GPU_PRIM_LINES, (int)line_count * 2);
-  while (fx < rect->xmax) {
+  while (fx <= rect->xmax) {
     immVertex2f(pos, fx, rect->ymin);
     immVertex2f(pos, fx, rect->ymax);
     fx += dx;
   }
-  while (fy < rect->ymax) {
+  while (fy <= rect->ymax) {
     immVertex2f(pos, rect->xmin, fy);
     immVertex2f(pos, rect->xmax, fy);
     fy += dy;
@@ -1849,6 +1849,17 @@ void ui_draw_but_CURVE(ARegion *ar, uiBut *but, const uiWidgetColors *wcol, cons
     cumap = (CurveMapping *)but->poin;
   }
 
+  /* calculate offset and zoom */
+  float zoomx = (BLI_rcti_size_x(rect) - 2.0f) / BLI_rctf_size_x(&cumap->curr);
+  float zoomy = (BLI_rcti_size_y(rect) - 2.0f) / BLI_rctf_size_y(&cumap->curr);
+  float offsx = cumap->curr.xmin - (1.0f / zoomx);
+  float offsy = cumap->curr.ymin - (1.0f / zoomy);
+
+  /* exit early if too narrow */
+  if (zoomx == 0.0f) {
+    return;
+  }
+
   CurveMap *cuma = &cumap->cm[cumap->cur];
 
   /* need scissor test, curve can draw outside of boundary */
@@ -1867,12 +1878,6 @@ void ui_draw_but_CURVE(ARegion *ar, uiBut *but, const uiWidgetColors *wcol, cons
               BLI_rcti_size_x(&scissor_new),
               BLI_rcti_size_y(&scissor_new));
 
-  /* calculate offset and zoom */
-  float zoomx = (BLI_rcti_size_x(rect) - 2.0f) / BLI_rctf_size_x(&cumap->curr);
-  float zoomy = (BLI_rcti_size_y(rect) - 2.0f) / BLI_rctf_size_y(&cumap->curr);
-  float offsx = cumap->curr.xmin - (1.0f / zoomx);
-  float offsy = cumap->curr.ymin - (1.0f / zoomy);
-
   /* Do this first to not mess imm context */
   if (but->a1 == UI_GRAD_H) {
     /* magic trigger for curve backgrounds */