Improved Android Building (#930)

Added in a check for x86 and x86_64 branches of android

Added in $(OS) checks to see if we're running on windows or *nix

Added a default location for android ndks and sdks at /usr/lib/android

src/Makefile

@@ -160,15 +160,23 @@ ifeq ($(PLATFORM),PLATFORM_ANDROID)
     # Android architecture: ARM64
     # Starting at 2019 using ARM64 is mandatory for published apps
     ANDROID_ARCH ?= ARM
-    ANDROID_API_VERSION = 21
+    ANDROID_API_VERSION = 26
 
     # Android required path variables
     # NOTE: Android NDK is just required to generate the standalone toolchain,
     # in case is not already provided
-    ANDROID_NDK = C:/android-ndk
+    ifeq ($(OS),Windows_NT)
+        ANDROID_NDK = C:/android-ndk
+    else
+        ANDROID_NDK = /usr/lib/android/ndk
+    endif
 
     # Android standalone toolchain path
-    ANDROID_TOOLCHAIN = C:/android_toolchain_$(ANDROID_ARCH)_API$(ANDROID_API_VERSION)
+    ifeq ($(OS),Windows_NT)
+        ANDROID_TOOLCHAIN = C:/android_toolchain_$(ANDROID_ARCH)_API$(ANDROID_API_VERSION)
+    else
+        ANDROID_TOOLCHAIN = /usr/lib/android/toolchain_$(ANDROID_ARCH)_API$(ANDROID_API_VERSION)
+    endif
 
     ifeq ($(ANDROID_ARCH),ARM)
         ANDROID_ARCH_NAME = armeabi-v7a
@@ -176,6 +184,12 @@ ifeq ($(PLATFORM),PLATFORM_ANDROID)
     ifeq ($(ANDROID_ARCH),ARM64)
         ANDROID_ARCH_NAME = arm64-v8a
     endif
+    ifeq ($(ANDROID_ARCH),x86)
+        ANDROID_ARCH_NAME = i686
+    endif
+    ifeq ($(ANDROID_ARCH),x86_64)
+        ANDROID_ARCH_NAME = x86_64
+    endif
 endif
 
 # Define raylib source code path
@@ -242,6 +256,14 @@ ifeq ($(PLATFORM),PLATFORM_ANDROID)
         CC = $(ANDROID_TOOLCHAIN)/bin/aarch64-linux-android-clang
         AR = $(ANDROID_TOOLCHAIN)/bin/aarch64-linux-android-ar
     endif
+    ifeq ($(ANDROID_ARCH),x86)
+        CC = $(ANDROID_TOOLCHAIN)/bin/i686-linux-android$(ANDROID_API_VERSION)-clang
+        AR = $(ANDROID_TOOLCHAIN)/bin/i686-linux-android-ar
+    endif
+    ifeq ($(ANDROID_ARCH),x86_64)
+        CC = $(ANDROID_TOOLCHAIN)/bin/x86_64-linux-android$(ANDROID_API_VERSION)-clang
+        AR = $(ANDROID_TOOLCHAIN)/bin/x86_64-linux-android-ar
+    endif
 endif
 
 
@@ -305,6 +327,12 @@ ifeq ($(PLATFORM),PLATFORM_ANDROID)
     ifeq ($(ANDROID_ARCH),ARM64)
         CFLAGS += -target aarch64 -mfix-cortex-a53-835769
     endif
+    ifeq ($(ANDROID_ARCH), x86)
+        CFLAGS += -march=i686
+    endif
+    ifeq ($(ANDROID_ARCH), x86_64)
+        CFLAGS += -march=x86-64
+    endif
     # Compilation functions attributes options
     CFLAGS += -ffunction-sections -funwind-tables -fstack-protector-strong -fPIE -fPIC
     # Compiler options for the linker
@@ -356,11 +384,12 @@ ifeq ($(PLATFORM),PLATFORM_RPI)
     INCLUDE_PATHS += -I$(RPI_TOOLCHAIN_SYSROOT)/opt/vc/include/interface/vcos/pthreads
 endif
 ifeq ($(PLATFORM),PLATFORM_ANDROID)
+    NATIVE_APP_GLUE = $(RAYLIB_RELEASE_PATH)/external/android/native_app_glue
+    #NATIVE_APP_GLUE = $(ANDROID_NDK)/sources/android/native_app_glue
     # Android required libraries
     INCLUDE_PATHS += -I$(ANDROID_TOOLCHAIN)/sysroot/usr/include
     # Include android_native_app_glue.h
-    INCLUDE_PATHS += -Iexternal/android/native_app_glue
-    #INCLUDE_PATHS += -I$(ANDROID_NDK)/sources/android/native_app_glue
+    INCLUDE_PATHS += -I$(NATIVE_APP_GLUE)
 endif
 
 # Define linker options
@@ -635,6 +664,6 @@ else
 	rm -fv *.o $(RAYLIB_RELEASE_PATH)/libraylib.a $(RAYLIB_RELEASE_PATH)/libraylib.bc $(RAYLIB_RELEASE_PATH)/libraylib.so*
 endif
 ifeq ($(PLATFORM),PLATFORM_ANDROID)
-	rm -rf $(ANDROID_TOOLCHAIN)
+	rm -rf $(ANDROID_TOOLCHAIN) $(NATIVE_APP_GLUE)/android_native_app_glue.o
 endif
 	@echo "removed all generated files!"