android: extend secondary display presentation

tests/engine/android_secondary_present.lua

@@ -0,0 +1,36 @@
+local function read(path)
+  local file = assert(io.open(path, "rb"))
+  local source = file:read("*a")
+  file:close()
+  return source
+end
+
+local function check(value, message)
+  if not value then error(message, 2) end
+end
+
+local java = read(
+  "mobile/android/love/src/main/java/org/love2d/android/GameActivity.java")
+local cpp = read("mobile/android/love/src/jni/love/src/common/android.cpp")
+
+check(java:find("hasSecondaryDisplayCandidate", 1, true)
+    and java:find("findSecondaryDisplay(self, false)", 1, true)
+    and java:find("now %- secondaryDetectionAt < 500"),
+  "Android exposes cached physical detection before Presentation is ready")
+check(java:find("presentSecondaryFrame", 1, true)
+    and java:find("secondaryFrame = new byte", 1, true)
+    and java:find("rgba.get(secondaryFrame", 1, true),
+  "extended presentation reuses a retained frame buffer")
+check(java:find("java.nio.ByteBuffer.wrap(secondaryFrame)", 1, true),
+  "a recreated Presentation receives the retained frame")
+check(java:find("0xFF000000 | (color & 0x00FFFFFF)", 1, true),
+  "RGB companion backgrounds become opaque Android colors")
+check(java:find("Math.max((float) vw / fw, (float) vh / fh)", 1, true)
+    and java:find("Math.floor(fit)", 1, true),
+  "FrameView supports cover and pixel-friendly contain fits")
+check(cpp:find("love_android_secondary_detected", 1, true)
+    and cpp:find("love_android_present_secondary", 1, true)
+    and cpp:find('"(Ljava/nio/ByteBuffer;IIIZ)Z"', 1, true),
+  "JNI exports the optional detected and presentation calls")
+
+print("android secondary presentation: ok")