From c82ceee2edce72419959eaf1b980f12251ed008c Mon Sep 17 00:00:00 2001
From: Jan Tojnar <jtojnar@gmail.com>
Date: Wed, 1 Sep 2021 16:26:46 +0200
Subject: [PATCH 1/3] vtk_9: fix Qt support

Passing enableQt to the package does not build QVTK and CMake warns:
    Manually-specified variables were not used by the project:
        VTK_Group_Qt
---
 pkgs/development/libraries/vtk/generic.nix | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/pkgs/development/libraries/vtk/generic.nix b/pkgs/development/libraries/vtk/generic.nix
index 482e6be7bbcf..fb2b11511b99 100644
--- a/pkgs/development/libraries/vtk/generic.nix
+++ b/pkgs/development/libraries/vtk/generic.nix
@@ -73,8 +73,9 @@ in stdenv.mkDerivation rec {
     "-DCMAKE_INSTALL_LIBDIR=lib"
     "-DCMAKE_INSTALL_INCLUDEDIR=include"
     "-DCMAKE_INSTALL_BINDIR=bin"
+  ] ++ optionals enableQt [
+    "-D${if lib.versionOlder version "9.0" then "VTK_Group_Qt:BOOL=ON" else "VTK_GROUP_ENABLE_Qt:STRING=YES"}"
   ]
-    ++ optionals enableQt [ "-DVTK_Group_Qt:BOOL=ON" ]
     ++ optionals stdenv.isDarwin [ "-DOPENGL_INCLUDE_DIR=${OpenGL}/Library/Frameworks" ]
     ++ optionals enablePython [
       "-DVTK_WRAP_PYTHON:BOOL=ON"

From e6caf52f64d5a6347913a0d75c68edf63a66a302 Mon Sep 17 00:00:00 2001
From: Jan Tojnar <jtojnar@gmail.com>
Date: Wed, 1 Sep 2021 17:04:55 +0200
Subject: [PATCH 2/3] vtk_9: do not vendor libpng and libtiff

Previously ldd did not show the dependencies so presumably,
VTK 9 started linking them statically after build system changes,
as hinted by the following CMake warning:
    Manually-specified variables were not used by the project:
        VTK_USE_SYSTEM_PNG
        VTK_USE_SYSTEM_TIFF
---
 pkgs/development/libraries/vtk/generic.nix | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pkgs/development/libraries/vtk/generic.nix b/pkgs/development/libraries/vtk/generic.nix
index fb2b11511b99..a3d3824a5410 100644
--- a/pkgs/development/libraries/vtk/generic.nix
+++ b/pkgs/development/libraries/vtk/generic.nix
@@ -67,8 +67,8 @@ in stdenv.mkDerivation rec {
   cmakeFlags = [
     "-DCMAKE_C_FLAGS=-fPIC"
     "-DCMAKE_CXX_FLAGS=-fPIC"
-    "-DVTK_USE_SYSTEM_PNG=ON"
-    "-DVTK_USE_SYSTEM_TIFF=1"
+    "-D${if lib.versionOlder version "9.0" then "VTK_USE_SYSTEM_PNG" else "VTK_MODULE_USE_EXTERNAL_vtkpng"}=ON"
+    "-D${if lib.versionOlder version "9.0" then "VTK_USE_SYSTEM_TIFF" else "VTK_MODULE_USE_EXTERNAL_vtktiff"}=1"
     "-DOPENGL_INCLUDE_DIR=${libGL}/include"
     "-DCMAKE_INSTALL_LIBDIR=lib"
     "-DCMAKE_INSTALL_INCLUDEDIR=include"

From e6f94dea3ea3df9d84c6c1870779b8867ab16290 Mon Sep 17 00:00:00 2001
From: Jan Tojnar <jtojnar@gmail.com>
Date: Wed, 1 Sep 2021 17:17:59 +0200
Subject: [PATCH 3/3] vtk_7: Fix enableQt build
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

VTK 7 builds with Qt 4 by default but we only support Qt 5, so let’s switch to that.
Also Qt changed some headers so let’s backport the VTK patch to fix the build.
---
 pkgs/development/libraries/vtk/7.x.nix     | 24 ++++++++++++++--------
 pkgs/development/libraries/vtk/generic.nix |  2 ++
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/pkgs/development/libraries/vtk/7.x.nix b/pkgs/development/libraries/vtk/7.x.nix
index 860f17639454..615553f80f22 100644
--- a/pkgs/development/libraries/vtk/7.x.nix
+++ b/pkgs/development/libraries/vtk/7.x.nix
@@ -2,13 +2,21 @@ import ./generic.nix {
   majorVersion = "7.1";
   minorVersion = "1";
   sourceSha256 = "0nm7xwwj7rnsxjdv2ssviys8nhci4n9iiiqm2y14s520hl2dsp1d";
-  patchesToFetch = [{
-   url = "https://gitlab.kitware.com/vtk/vtk/-/commit/706f1b397df09a27ab8981ab9464547028d0c322.diff";
-   sha256 = "1q3pi5h40g05pzpbqp75xlgzvbfvyw8raza51svmi7d8dlslqybx";
- }
- {
-    url = "https://gitweb.gentoo.org/repo/gentoo.git/plain/sci-libs/vtk/files/vtk-8.2.0-gcc-10.patch?id=c4256f68d3589570443075eccbbafacf661f785f";
-    sha256 = "sha256:0bpwrdfmi15grsg4jy7bzj2z6511a0c160cmw5lsi65aabyh7cl5";
-  }
+  patchesToFetch = [
+    {
+      url = "https://gitlab.kitware.com/vtk/vtk/-/commit/706f1b397df09a27ab8981ab9464547028d0c322.diff";
+      sha256 = "1q3pi5h40g05pzpbqp75xlgzvbfvyw8raza51svmi7d8dlslqybx";
+    }
+
+    {
+      url = "https://gitweb.gentoo.org/repo/gentoo.git/plain/sci-libs/vtk/files/vtk-8.2.0-gcc-10.patch?id=c4256f68d3589570443075eccbbafacf661f785f";
+      sha256 = "sha256:0bpwrdfmi15grsg4jy7bzj2z6511a0c160cmw5lsi65aabyh7cl5";
+    }
+
+    # Add missing include required with recent Qt.
+    {
+      url = "https://gitlab.kitware.com/vtk/vtk/-/commit/797f28697d5ba50c1fa2bc5596af626a3c277826.diff";
+      sha256 = "BFjoKws1hVD3Ly9RS4lGN62J6RTyI1E8ATHrZdzg7ds=";
+    }
   ];
 }
diff --git a/pkgs/development/libraries/vtk/generic.nix b/pkgs/development/libraries/vtk/generic.nix
index a3d3824a5410..c180b05e9521 100644
--- a/pkgs/development/libraries/vtk/generic.nix
+++ b/pkgs/development/libraries/vtk/generic.nix
@@ -75,6 +75,8 @@ in stdenv.mkDerivation rec {
     "-DCMAKE_INSTALL_BINDIR=bin"
   ] ++ optionals enableQt [
     "-D${if lib.versionOlder version "9.0" then "VTK_Group_Qt:BOOL=ON" else "VTK_GROUP_ENABLE_Qt:STRING=YES"}"
+  ] ++ optionals (enableQt && lib.versionOlder version "8.0") [
+    "-DVTK_QT_VERSION=5"
   ]
     ++ optionals stdenv.isDarwin [ "-DOPENGL_INCLUDE_DIR=${OpenGL}/Library/Frameworks" ]
     ++ optionals enablePython [