Move some functions to there own file

1 files changed, 126 insertions, 0 deletions

diff --git a/dmagick/Utils.d b/dmagick/Utils.d
new file mode 100644
index 0000000..f853350
--- /dev/null
+++ b/dmagick/Utils.d
@@ -0,0 +1,126 @@
+/**
+ * A collection of helper functions used in DMagick.
+ *
+ * Copyright: Mike Wey 2011
+ * License:   To be determined
+ * Authors:   Mike Wey
+ */
+
+module dmagick.Utils;
+
+import std.math;
+
+import dmagick.c.memory;
+import dmagick.c.magickString;
+import dmagick.c.magickType;
+
+/**
+ * Copy a string into a static array used
+ * by ImageMagick for some atributes.
+ */
+private void copyString(ref char[MaxTextExtent] dest, string source)
+{
+	if ( source.length < MaxTextExtent )
+		throw new Exception("text is to long"); //TODO: a proper exception.
+
+	dest[0 .. source.length] = source;
+	dest[source.length] = '\0';
+}
+
+/**
+ * Our implementation of ImageMagick's CloneString.
+ *
+ * We use this since using CloneString forces us to
+ * append a \0 to the end of the string, and the realocation
+ * whould be wastefull if we are just going to copy it
+ */
+private void copyString(ref char* dest, string source)
+{
+	if ( source is null )
+	{
+		if ( dest !is null )
+			DestroyString(dest);
+		return;
+	}
+
+	if ( ~source.length < MaxTextExtent )
+		throw new Exception("UnableToAcquireString"); //TODO: a proper exception.
+
+	if ( dest is null )
+		dest = cast(char*)AcquireQuantumMemory(source.length+MaxTextExtent, dest.sizeof);
+	else
+		dest = cast(char*)ResizeQuantumMemory(dest, source.length+MaxTextExtent, dest.sizeof);
+
+	if ( dest is null )
+		throw new Exception("UnableToAcquireString"); //TODO: a proper exception.
+
+	if ( source.length > 0 )
+		dest[0 .. source.length] = source;
+
+	dest[source.length] = '\0';
+}
+
+real degreesToRadians(real deg)
+{
+	return deg*PI/180;
+}
+
+struct RefCounted(alias pred, T)
+	if ( !is(T == class) && is(typeof(pred(null)) == void) )
+{
+	T* payload;
+
+	private bool isInitialized;
+	private size_t* refcount;
+
+	alias payload this;
+
+	this(T* payload)
+	{
+		this.payload = payload;
+
+		refcount  = new size_t;
+		*refcount = 1;
+
+		isInitialized = true;
+	}
+
+	this(this)
+	{
+		if ( isInitialized )
+			(*refcount)++;
+	}
+
+	~this()
+	{
+		(*refcount)--;
+
+		if ( *refcount == 0 )
+			pred(payload);
+	}
+
+	@property size_t refCount()
+	{
+		return *refcount;
+	}
+}
+
+unittest
+{
+	int x = 10;
+	int y = 20;
+
+	alias RefCounted!( (void* t){ x = 20; }, int ) IntRef;
+
+	auto a = IntRef(&x);
+	assert( a.refCount == 1 );
+	auto b = a;
+	assert( a.refCount == 2 );
+
+	b = IntRef(&y);
+	assert( a.refCount == 1 );
+	assert( b.refCount == 1 );
+	a = b;
+	assert( b.refCount == 2 );
+	assert( x == 20 );
+}