tilesize declaration refactoring

src/net/torvald/terrarum/TerrarumGLinfo.kt

@@ -0,0 +1,41 @@
+package net.torvald.terrarum
+
+import com.badlogic.gdx.Gdx
+import com.badlogic.gdx.utils.GdxRuntimeException
+import org.lwjgl.opengl.GL11
+
+class TerrarumGLinfo {
+    private var _initialised = false
+
+    // some JVMs don't have this property, but they probably don't have "sun.misc.Unsafe" either, so it's no big issue \_(ツ)_/
+    val MINIMAL_GL_VERSION = 320
+
+    var GL_VERSION = -1; private set
+        get() = if (_initialised) field else throw UninitializedPropertyAccessException()
+    var GL_MAX_TEXTURE_SIZE = -1; private set
+        get() = if (_initialised) field else throw UninitializedPropertyAccessException()
+
+    fun create() {
+        _initialised = true
+
+
+        val glInfo = Gdx.graphics.glVersion.debugVersionString
+
+        GL_VERSION = Gdx.graphics.glVersion.majorVersion * 100 + Gdx.graphics.glVersion.minorVersion * 10 +
+                               Gdx.graphics.glVersion.releaseVersion
+
+        println("GL_VERSION = $GL_VERSION")
+        println("GL info:\n$glInfo") // debug info
+
+
+
+        if (GL_VERSION < MINIMAL_GL_VERSION) {
+            // TODO notify properly
+            throw GdxRuntimeException("Graphics device not capable -- device's GL_VERSION: $GL_VERSION, required: $MINIMAL_GL_VERSION")
+        }
+
+        GL_MAX_TEXTURE_SIZE = GL11.glGetInteger(GL11.GL_MAX_TEXTURE_SIZE)
+        println("Maximum Texture Size: $GL_MAX_TEXTURE_SIZE")
+    }
+
+}