From 1ddc6732012429a32f9a7fa0795b96389f96ce9f Mon Sep 17 00:00:00 2001
From: t-bltg <t-bltg@users.noreply.github.com>
Date: Thu, 1 Jul 2021 14:02:30 +0200
Subject: [PATCH] GR: 3D, warn on invalid rotation or tilt

---
 src/backends/gr.jl | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/backends/gr.jl b/src/backends/gr.jl
index ca31f3d3..b3da0cb4 100644
--- a/src/backends/gr.jl
+++ b/src/backends/gr.jl
@@ -1326,7 +1326,13 @@ function gr_draw_axes(sp, viewport_plotarea)
         # set space
         xmin, xmax, ymin, ymax = gr_xy_axislims(sp)
         zmin, zmax = gr_z_axislims(sp)
-        GR.setspace(zmin, zmax, round.(Int, sp[:camera])...)
+
+        camera = round.(Int, sp[:camera])
+
+        warn_invalid(val) = if val < 0 || val > 90 @warn "camera: $(val)° ∉ [0°, 90°]" end
+        warn_invalid.(camera)
+
+        GR.setspace(zmin, zmax, camera...)
 
         # fill the plot area
         gr_set_fill(plot_color(sp[:background_color_inside]))