Allow GLMakie to display surfaces transformed by a 3d transform func

CHANGELOG.md

@@ -6,6 +6,7 @@
 - Bring back `poly` convert arguments for matrix with points as row [#4266](https://github.com/MakieOrg/Makie.jl/pull/4258).
 - Fix gl_ClipDistance related segfault on WSL with GLMakie [#4270](https://github.com/MakieOrg/Makie.jl/pull/4270)
 - Added option `label_position = :center` to place labels centered over each bar [#4274](https://github.com/MakieOrg/Makie.jl/pull/4274).
+- Fix GLMakie `surface` implementation for 3D `transform_func` [#4243](https://github.com/MakieOrg/Makie.jl/pull/4243)
 
 ## [0.21.9] - 2024-08-27
 

GLMakie/src/drawing_primitives.jl

@@ -820,33 +820,34 @@ function draw_atomic(screen::Screen, scene::Scene, plot::Surface)
  if all(T -> T <: Union{AbstractMatrix, AbstractVector}, types)
  t = Makie.transform_func_obs(plot)
  mat = plot[3]
- xypos = lift(plot, pop!(gl_attributes, :f32c), plot.model, t, plot[1], plot[2], space) do f32c, model, t, x, y, space
+ xyzpos = lift(plot, pop!(gl_attributes, :f32c), plot.model, t, plot[1], plot[2], mat, space) do f32c, model, t, x, y, z, space
  # Only if transform doesn't do anything, we can stay linear in 1/2D
  if Makie.is_identity_transform(t) && isnothing(f32c)
- return (x, y)
+ return (x, y, z)
  elseif Makie.is_translation_scale_matrix(model)
  matrix = if x isa AbstractMatrix && y isa AbstractMatrix
- Makie.f32_convert(f32c, apply_transform.((t,), Point.(x, y), space), space)
+ [Makie.f32_convert(f32c, apply_transform(t, Point3(x, y, z[ix, iy]), space), space) for (ix, x) in pairs(x), (iy, y) in pairs(y)]
  else
  # If we do any transformation, we have to assume things aren't on the grid anymore
  # so x + y need to become matrices.
- [Makie.f32_convert(f32c, apply_transform(t, Point(x, y), space), space) for x in x, y in y]
+ [Makie.f32_convert(f32c, apply_transform(t, Point3(x, y, z[ix, iy]), space), space) for (ix, x) in pairs(x), (iy, y) in pairs(y)]
  end
- return (first.(matrix), last.(matrix))
+ return (getindex.(matrix, 1), getindex.(matrix, 2), getindex.(matrix, 3))
  else
  matrix = if x isa AbstractMatrix && y isa AbstractMatrix
- Makie.f32_convert(f32c, apply_transform_and_model.((model,), (t,), Point.(x, y), space, Point2d), space)
+ [Makie.f32_convert(f32c, apply_transform_and_model(model, t, Point3.(x, y, z[ix, iy]), space, Point3d), space) for (ix, x) in pairs(x), (iy, y) in pairs(y)]
  else
  # If we do any transformation, we have to assume things aren't on the grid anymore
  # so x + y need to become matrices.
- [Makie.f32_convert(f32c, apply_transform_and_model(model, t, Point(x, y), space, Point2d), space) for x in x, y in y]
+ [Makie.f32_convert(f32c, apply_transform_and_model(model, t, Point3(x, y, z[ix, iy]), space, Point3d), space) for (ix, x) in pairs(x), (iy, y) in pairs(y)]
  end
- return (first.(matrix), last.(matrix))
+ return (getindex.(matrix, 1), getindex.(matrix, 2), getindex.(matrix, 3))
  end
  end
- xpos = lift(first, plot, xypos)
- ypos = lift(last, plot, xypos)
- args = map((xpos, ypos, mat)) do arg
+ xpos = lift(Base.Fix2(getindex, 1), plot, xyzpos)
+ ypos = lift(Base.Fix2(getindex, 2), plot, xyzpos)
+ zpos = lift(Base.Fix2(getindex, 3), plot, xyzpos)
+ args = map((xpos, ypos, zpos)) do arg
  Texture(lift(x-> convert(Array, el32convert(x)), plot, arg); minfilter=:linear)
  end
  if isnothing(img)

ReferenceTests/src/tests/examples3d.jl

@@ -734,3 +734,32 @@ end
  ls2, pl = surface(f[1, 2], Makie.peaks(20); interpolate=false, axis=(; show_axis=false))
  f
 end
+
+@reference_test "Surface with 3D transform_func" begin
+
+ SPHERICAL_TRANSFORM = Makie.PointTrans{3}() do geographic_point
+ # Longitude is directly translatable to a spherical coordinate
+ # θ (azimuth)
+ θ = deg2rad(geographic_point[1])
+ # The polar angle is 90 degrees minus the latitude
+ # ϕ (polar angle)
+ ϕ = deg2rad(90 - geographic_point[2])
+ # Finally, we define the base radius as 1, 
+ # and all z values are offset by 1.
+ r = 1 + geographic_point[3]
+ # and we don't need to multiply by it.
+ return Point3(
+ r * sin(ϕ) * cos(θ),
+ r * sin(ϕ) * sin(θ),
+ r * cos(ϕ)
+ )
+ end
+
+ xs = -180:180
+ ys = -90:90
+ field = [exp(cosd(x)) + 3(y/90) for x in xs, y in ys] ./ 10
+
+ f, a, p = surface(xs, ys, field; axis = (; type = LScene,), shading = NoShading)
+ p.transformation.transform_func[] = SPHERICAL_TRANSFORM
+ f
+end