[ion/sdl] Clean the Android build system

ion/src/sdl/android/Makefile

@@ -6,10 +6,59 @@ $(call object_for,ion/src/sdl/shared/main.cpp) : SFLAGS += -DEPSILON_SDL_FULLSCR
 
 LDFLAGS += -ljnigraphics -llog
 
-ANDROID_LIB_PATH = ion/src/sdl/android/libs
+# If NDK_ABI is not defined, we will re-trigger a build for each avaialble ABI.
+# This is used to build APKs, which needs to embbed a binary for each ABI.
 
-$(ANDROID_LIB_PATH)/%/libepsilon.so:
-ion/src/sdl/android/libs/%/libepsilon.so:
-	$(Q) $(MAKE) MODEL=android NDK_ABI=$* clean
-	$(Q) $(MAKE) MODEL=android NDK_ABI=$* epsilon.so
-	$(Q) mv epsilon.so $@
+ifdef NDK_ABI
+
+.PHONY: epsilon.apk
+epsilon.apk:
+	echo "To make epsilon.apk, to not define NDK_ABI"
+
+else
+
+# Cross-ABI libepsilon.so
+# This file is loaded is loaded only once, which prevents us from tracking
+# dependencies across ABIs. As a shortcut, we simply force a re-make of
+# libepsilon.so for each ABI.
+
+.PHONY: force_remake
+
+$(BUILD_DIR)/app/libs/%/libepsilon.so: force_remake $$(@D)/.
+	$(Q) echo "MAKE    NDK_ABI=$*"
+	$(Q) $(MAKE) NDK_ABI=$* epsilon.so
+	$(Q) cp $(BUILD_DIR)/$*/epsilon.so $@
+
+# Android resources
+# Some android resources needs to be filtered through ImageMagick. Others are
+# simply copied over.
+
+$(BUILD_DIR)/app/res/mipmap/ic_launcher.png: ion/src/sdl/assets/logo.svg | $$(@D)/.
+	@echo "CONVERT $@"
+	$(Q) convert -background "#FFB734" $< $@
+
+$(BUILD_DIR)/app/res/mipmap-v26/ic_launcher_foreground.png: ion/src/sdl/assets/logo.svg | $$(@D)/.
+	@echo "CONVERT $@"
+	$(Q) convert -background none $< -resize 512x512 -gravity center -background none -extent 1024x1024 $@
+
+$(BUILD_DIR)/app/res/%: ion/src/sdl/android/src/res/% $$(@D)/.
+	@echo "COPY    $@"
+	$(Q) cp $< $@
+
+NDK_ABIS = arm64-v8a x86_64
+
+epsilon_apk_deps = $(patsubst %,$(BUILD_DIR)/app/libs/%/libepsilon.so,$(NDK_ABIS))
+epsilon_apk_deps += $(subst ion/src/sdl/android/src/res,$(BUILD_DIR)/app/res,$(wildcard ion/src/sdl/android/src/res/*/*))
+epsilon_apk_deps += $(addprefix $(BUILD_DIR)/app/res/,mipmap/ic_launcher.png mipmap-v26/ic_launcher_foreground.png)
+
+.PHONY: epsilon.apk
+epsilon.apk: $(epsilon_apk_deps)
+	@echo "GRADLE ion/src/sdl/android/build.gradle"
+	$(Q) ANDROID_HOME=/usr/local/android gradle -b ion/src/sdl/android/build.gradle assembleRelease
+
+.PHONY: epsilon_run
+epsilon_run: $(epsilon_apk_deps)
+	@echo "GRADLE ion/src/sdl/android/build.gradle"
+	$(Q) ANDROID_HOME=/usr/local/android gradle -b ion/src/sdl/android/build.gradle installDebug
+
+endif

ion/src/sdl/android/build.gradle

@@ -34,13 +34,13 @@ android {
   buildTypes {
     release {
       minifyEnabled false
-      proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+      proguardFiles getDefaultProguardFile('proguard-android.txt')
     }
   }
   sourceSets{
     main {
       manifest.srcFile 'src/AndroidManifest.xml'
-      res.srcDir 'src/res'
+      res.srcDir BUILD_DIR + '/res'
       java.srcDir 'src'
       jniLibs.srcDir BUILD_DIR + '/libs'
       assets.srcDir '../assets'

ion/src/sdl/android/src/res/mipmap-v26/ic_launcher.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+  <background android:drawable="@color/yellow" />
+  <foreground android:drawable="@mipmap/ic_launcher_foreground" />
+</adaptive-icon>

ion/src/sdl/android/src/res/values/colors.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+  <color name="yellow">#FFB734</color>
+  <color name="lightGray">#F7F7F7</color>
+</resources>

ion/src/sdl/android/src/res/values/strings.xml

@@ -0,0 +1,3 @@
+<resources>
+  <string name="app_name">NumWorks</string>
+</resources>

ion/src/sdl/assets/logo.svg

@@ -0,0 +1,3 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1024 1024">
+  <path d="M744.7 189c-27.1 0-49.2 20.1-49.2 44.8v431.8l-369.8-457c-9.9-12.2-25.9-19.6-42.7-19.6-29.2 0-53 21.5-53 47.9v553.3c0 24.7 22.1 44.8 49.3 44.8 27.1 0 49.2-20.1 49.2-44.8V358.6l369.9 458.2c9.2 11.4 24 18.2 39.7 18.2h6.7c27.1 0 49.2-20.1 49.2-44.8V233.8c0-24.7-22.1-44.8-49.3-44.8z" fill="#fff" stroke="none" />
+</svg>

scripts/targets.sdl.android.mak

@@ -1,22 +0,0 @@
-# Makefile is loaded for a single architecture at once. If NDK_ABI is not
-# defined, we assume we want to build all of them. But in that case, we cannot
-# track per-ABI dependencies. So as a shortcut, we force a re-make of each ABI.
-
-.PHONY: force_rebuild_libepsilon
-
-$(BUILD_DIR)/app/libs/%/libepsilon.so: force_rebuild_libepsilon $$(@D)/.
-	$(Q) echo "MAKE    NDK_ABI=$*"
-	$(Q) $(MAKE) NDK_ABI=$* epsilon.so
-	$(Q) cp $(BUILD_DIR)/$*/epsilon.so $@
-
-NDK_ABIS = arm64-v8a x86_64
-
-.PHONY: epsilon.apk
-epsilon.apk: $(patsubst %,$(BUILD_DIR)/app/libs/%/libepsilon.so,$(NDK_ABIS))
-	@echo "GRADLE ion/src/sdl/android/build.gradle"
-	$(Q) ANDROID_HOME=/usr/local/android gradle -b ion/src/sdl/android/build.gradle assembleRelease
-
-.PHONY: epsilon_run
-epsilon_run: $(patsubst %,$(BUILD_DIR)/app/libs/%/libepsilon.so,$(NDK_ABIS))
-	@echo "GRADLE ion/src/sdl/android/build.gradle"
-	$(Q) ANDROID_HOME=/usr/local/android gradle -b ion/src/sdl/android/build.gradle installDebug