Fix picking functions when framebuffer resolution differs from screen

GLMakie/src/picking.jl

@@ -7,15 +7,17 @@ function pick_native(screen::Screen, rect::Rect2i)
     isopen(screen) || return Matrix{SelectionID{Int}}(undef, 0, 0)
     ShaderAbstractions.switch_context!(screen.glscreen)
     window_size = size(screen)
+    sf = screen.px_per_unit[]
     fb = screen.framebuffer
     buff = fb.buffers[:objectid]
     glBindFramebuffer(GL_FRAMEBUFFER, fb.id[1])
     glReadBuffer(GL_COLOR_ATTACHMENT1)
     rx, ry = minimum(rect)
     rw, rh = widths(rect)
     w, h = window_size
-    sid = zeros(SelectionID{UInt32}, widths(rect)...)
     if rx > 0 && ry > 0 && rx + rw <= w && ry + rh <= h
+        rx, ry, rw, rh = round.(Int, sf .* (rx, ry, rw, rh))
+        sid = zeros(SelectionID{UInt32}, rw, rh)
         glReadPixels(rx, ry, rw, rh, buff.format, buff.pixeltype, sid)
         return sid
     else
@@ -26,15 +28,17 @@ end
 function pick_native(screen::Screen, xy::Vec{2, Float64})
     isopen(screen) || return SelectionID{Int}(0, 0)
     ShaderAbstractions.switch_context!(screen.glscreen)
-    sid = Base.RefValue{SelectionID{UInt32}}()
     window_size = size(screen)
+    sf = screen.px_per_unit[]
     fb = screen.framebuffer
     buff = fb.buffers[:objectid]
     glBindFramebuffer(GL_FRAMEBUFFER, fb.id[1])
     glReadBuffer(GL_COLOR_ATTACHMENT1)
     x, y = floor.(Int, xy)
     w, h = window_size
     if x > 0 && y > 0 && x <= w && y <= h
+        sid = Base.RefValue{SelectionID{UInt32}}()
+        x, y = round.(Int, sf .* (x, y))
         glReadPixels(x, y, 1, 1, buff.format, buff.pixeltype, sid)
         return convert(SelectionID{Int}, sid[])
     end