package/ci: add an iOS GLES3 build.

I don't think GLES2 is worth bothering with on this platform, given that
GL as a whole is deprecated by that company.

package/ci/circleci.yml

@@ -561,6 +561,17 @@ jobs:
     - build:
         script: android-x86-vulkan.sh
 
+  ios-gles3:
+    executor: xcode-11_4
+    environment:
+      # STUPID yml interprets unquoted ON as a boolean
+      TARGET_GLES2: "OFF"
+    steps:
+    - install-base-macos:
+        extra: xcbeautify
+    - build:
+        script: ios-simulator-gles.sh
+
 workflows:
   version: 2
   build:
@@ -583,3 +594,4 @@ workflows:
     - android-x86-gles2
     - android-x86-gles3
     - android-x86-vulkan
+    - ios-gles3

package/ci/ios-simulator-gles.sh

@@ -0,0 +1,88 @@
+#!/bin/bash
+set -ev
+
+git submodule update --init
+
+# Corrade
+git clone --depth 1 https://github.com/mosra/corrade.git
+cd corrade
+
+# Build native corrade-rc
+mkdir build && cd build
+cmake .. \
+    -DCMAKE_BUILD_TYPE=Release \
+    -DCMAKE_INSTALL_PREFIX=$HOME/deps-native \
+    -DWITH_INTERCONNECT=OFF \
+    -DWITH_PLUGINMANAGER=OFF \
+    -DWITH_TESTSUITE=OFF \
+    -DWITH_UTILITY=OFF \
+    -G Ninja
+ninja install
+cd ..
+
+# Crosscompile Corrade
+mkdir build-ios && cd build-ios
+cmake .. \
+    -DCMAKE_TOOLCHAIN_FILE=../../toolchains/generic/iOS.cmake \
+    -DCMAKE_OSX_SYSROOT=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk \
+    -DCMAKE_OSX_ARCHITECTURES="x86_64" \
+    -DCORRADE_RC_EXECUTABLE=$HOME/deps-native/bin/corrade-rc \
+    -DCMAKE_INSTALL_PREFIX=$HOME/deps \
+    -DBUILD_STATIC=ON \
+    -DTESTSUITE_TARGET_XCTEST=ON \
+    -DWITH_INTERCONNECT=OFF \
+    -G Xcode
+set -o pipefail && cmake --build . --config Release --target install | xcbeautify
+cd ../..
+
+# Crosscompile SDL. On 2022-14-02 curl says the certificate is expired, so
+# ignore that.
+# TODO use a CMake build instead
+curl --insecure -O https://www.libsdl.org/release/SDL2-2.0.10.tar.gz
+tar -xzvf SDL2-2.0.10.tar.gz
+cd SDL2-2.0.10/Xcode-iOS/SDL
+set -o pipefail && xcodebuild -sdk iphonesimulator13.4 | xcbeautify
+cp build/Release-iphonesimulator/libSDL2.a $HOME/deps/lib
+mkdir -p $HOME/deps/include/SDL2
+cp -R ../../include/* $HOME/deps/include/SDL2
+cd ../../..
+
+# Crosscompile Magnum
+mkdir build-ios && cd build-ios
+cmake .. \
+    -DCMAKE_TOOLCHAIN_FILE=../toolchains/generic/iOS.cmake \
+    -DCMAKE_OSX_SYSROOT=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk \
+    -DCMAKE_OSX_ARCHITECTURES="x86_64" \
+    -DCORRADE_RC_EXECUTABLE=$HOME/deps-native/bin/corrade-rc \
+    -DCMAKE_PREFIX_PATH="$HOME/deps" \
+    -DTARGET_GLES2=$TARGET_GLES2 \
+    -DWITH_AUDIO=ON \
+    -DWITH_VK=OFF \
+    -DWITH_SDL2APPLICATION=ON \
+    -DWITH_WINDOWLESSIOSAPPLICATION=ON \
+    -DWITH_EGLCONTEXT=ON \
+    -DWITH_OPENGLTESTER=ON \
+    -DWITH_ANYAUDIOIMPORTER=ON \
+    -DWITH_ANYIMAGECONVERTER=ON \
+    -DWITH_ANYIMAGEIMPORTER=ON \
+    -DWITH_ANYSCENECONVERTER=ON \
+    -DWITH_ANYSCENEIMPORTER=ON \
+    -DWITH_ANYSHADERCONVERTER=ON \
+    -DWITH_MAGNUMFONT=ON \
+    -DWITH_MAGNUMFONTCONVERTER=ON \
+    -DWITH_OBJIMPORTER=ON \
+    -DWITH_TGAIMAGECONVERTER=ON \
+    -DWITH_TGAIMPORTER=ON \
+    -DWITH_WAVAUDIOIMPORTER=ON \
+    -DBUILD_STATIC=ON \
+    -DBUILD_TESTS=ON \
+    -DBUILD_GL_TESTS=ON \
+    -G Xcode
+set -o pipefail && cmake --build . --config Release | xcbeautify
+# TODO: find a better way to avoid
+# Library not loaded: /System/Library/Frameworks/OpenGLES.framework/OpenGLES
+# error
+DYLD_FALLBACK_LIBRARY_PATH="/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 12.4.simruntime/Contents/Resources/RuntimeRoot/System/Library/Frameworks/OpenGLES.framework" DYLD_FALLBACK_FRAMEWORK_PATH="/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 12.4.simruntime/Contents/Resources/RuntimeRoot/System/Library/Frameworks" CORRADE_TEST_COLOR=ON ctest -V -C Release -E "GLTest|GLBenchmark"
+
+# Test install, after running the tests as for them it shouldn't be needed
+set -o pipefail && cmake --build . --config Release --target install | xcbeautify