travis: Add macOS 10.5.5. and Xcode 12.0

.travis.yml

@@ -1,29 +1,34 @@
 language: cpp
 
-os: linux
-
-# Use the latest supported distro, Focal, released in April 2020…
+os:
+  - linux
+  - osx
 dist: focal
-
-git:
-  depth: 1
+osx_image: xcode12
 
 compiler:
-  - clang
   - gcc
+  - clang
 
 env:
-  matrix:
-    - BUILD_TYPE="Release"
-    - BUILD_TYPE="Debug"
+  - BUILD_TYPE="Release"
+  - BUILD_TYPE="Debug"
+
+jobs:
+  exclude:
+    - os: osx
+      compiler: gcc
+
+git:
+  depth: 1
 
 before_install:
-  - sudo apt-get install -y libassimp-dev
-  - sudo apt-get install -y libglfw3-dev
+  - if [ "$TRAVIS_OS_NAME" = "linux" ]; then sudo apt-get install -y libassimp-dev libglfw3-dev; fi
 
 script:
   - mkdir build || exit 1
+  - if [ "$TRAVIS_OS_NAME" = "osx" ]; then generator='Xcode'; else generator='Ninja'; fi
   - pushd build && { cmake -DCMAKE_CXX_FLAGS="-Wall" \
                            -DCMAKE_BUILD_TYPE="${BUILD_TYPE}" \
-                           -G Ninja ..; popd; } || exit 1
+                           -G "$generator" ..; popd; } || exit 1
   - cmake --build build || exit 1