Added crop image function.

Fixed 'difference' symbol type.

doc/type/double.txt

@@ -2,7 +2,7 @@ Primitive type: real number
 
 Real or floating point numbers are numbers with a decimal point.
 
-Conversio from integer to real numbers happens automatically in scripting.
+Conversion from integer to real numbers happens automatically in scripting.
 
 --File syntax--
 > something: 123

src/gfx/generated_image.cpp

@@ -185,15 +185,15 @@ bool SetCombineImage::operator == (const GeneratedImage& that) const {
 Image EnlargeImage::generate(const Options& opt) const {
 	// generate 'sub' image
 	Options sub_opt
-		( opt.width  * (border_size < 0.5 ? 1 - 2 * border_size : 0)
-		, opt.height * (border_size < 0.5 ? 1 - 2 * border_size : 0)
+		( int(opt.width  * (border_size < 0.5 ? 1 - 2 * border_size : 0))
+		, int(opt.height * (border_size < 0.5 ? 1 - 2 * border_size : 0))
 		, opt.package
 		, opt.local_package
 		, opt.preserve_aspect);
 	Image img = image->generate(sub_opt);
 	// size of generated image
 	int w  = img.GetWidth(),  h = img.GetHeight();  // original image size
-	int dw = w * border_size, dh = h * border_size; // delta
+	int dw = int(w * border_size), dh = int(h * border_size); // delta
 	int w2 = w + dw + dw,     h2 = h + dh + dh;     // new image size
 	Image larger(w2,h2);
 	larger.InitAlpha();
@@ -221,6 +221,21 @@ bool EnlargeImage::operator == (const GeneratedImage& that) const {
 	             && border_size == that2->border_size;
 }
 
+// ----------------------------------------------------------------------------- : CropImage
+
+Image CropImage::generate(const Options& opt) const {
+	return image->generate(opt).Size(wxSize((int)width, (int)height), wxPoint(-(int)offset_x, -(int)offset_y));
+}
+ImageCombine CropImage::combine() const {
+	return image->combine();
+}
+bool CropImage::operator == (const GeneratedImage& that) const {
+	const CropImage* that2 = dynamic_cast<const CropImage*>(&that);
+	return that2 && *image      == *that2->image
+	             && width    == that2->width    && height   == that2->height
+	             && offset_x == that2->offset_x && offset_y == that2->offset_y;
+}
+
 // ----------------------------------------------------------------------------- : DropShadowImage
 
 /// Preform a gaussian blur, from the image in of w*h bytes to out
@@ -287,7 +302,7 @@ Image DropShadowImage::generate(const Options& opt) const {
 	UInt total = 255 * gaussian_blur(alpha, shadow, w, h, shadow_blur_radius);
 	// combine
 	Byte* data = img.GetData();
-	int dw = w * offset_x, dh = h * offset_y;
+	int dw = int(w * offset_x), dh = int(h * offset_y);
 	int x_start = max(0,   dw), y_start = max(0,   dh);
 	int x_end   = min(w, w+dw), y_end   = min(h, h+dh);
 	int delta = dw + w * dh;

src/gfx/generated_image.hpp

@@ -180,6 +180,23 @@ class EnlargeImage : public GeneratedImage {
 	double border_size;
 };
 
+// ----------------------------------------------------------------------------- : CropImage
+
+/// Crop an image at a certain point, to a certain size
+class CropImage : public GeneratedImage {
+  public:
+	inline CropImage(const GeneratedImageP& image, double width, double height, double offset_x, double offset_y)
+		: image(image), width(width), height(height), offset_x(offset_x), offset_y(offset_y)
+	{}
+	virtual Image generate(const Options& opt) const;
+	virtual ImageCombine combine() const;
+	virtual bool operator == (const GeneratedImage& that) const;
+  private:
+	GeneratedImageP image;
+	double width, height;
+	double offset_x, offset_y;
+};
+
 // ----------------------------------------------------------------------------- : DropShadowImage
 
 /// Add a drop shadow to an image

src/gui/symbol/window.cpp

@@ -246,14 +246,14 @@ void SymbolWindow::onFileExit(wxCommandEvent& ev) {
 
 
 void SymbolWindow::onEditUndo(wxCommandEvent& ev) {
-	if (!control->isEditing()) {
+	if (!control->isEditing() && control->getSymbol()->actions.canUndo()) {
 		control->getSymbol()->actions.undo();
 		control->Refresh(false);
 	}
 }
 
 void SymbolWindow::onEditRedo(wxCommandEvent& ev) {
-	if (!control->isEditing()) {
+	if (!control->isEditing() && control->getSymbol()->actions.canRedo()) {
 		control->getSymbol()->actions.redo();
 		control->Refresh(false);
 	}

src/render/symbol/viewer.cpp

@@ -242,7 +242,7 @@ void SymbolViewer::combineSymbolShape(const SymbolShape& shape, DC& border, DC&
 			break;
 		} case SYMBOL_COMBINE_DIFFERENCE: {
 			interior.SetLogicalFunction(wxXOR);
-			drawSymbolShape(shape, &border, &interior, 0, ~interiorCol, directB, true);
+			drawSymbolShape(shape, &border, &interior, 0, interiorCol, directB, true);
 			interior.SetLogicalFunction(wxCOPY);
 			break;
 		} case SYMBOL_COMBINE_BORDER: {

src/script/functions/image.cpp

@@ -84,6 +84,15 @@ SCRIPT_FUNCTION(enlarge) {
 	return new_intrusive2<EnlargeImage>(input, border_size);
 }
 
+SCRIPT_FUNCTION(crop) {
+	SCRIPT_PARAM(GeneratedImageP, input);
+	SCRIPT_PARAM_N(int, _("width"),       width);
+	SCRIPT_PARAM_N(int, _("height"),      height);
+	SCRIPT_PARAM_N(double, _("offset x"), offset_x);
+	SCRIPT_PARAM_N(double, _("offset y"), offset_y);
+	return new_intrusive5<CropImage>(input, width, height, offset_x, offset_y);
+}
+
 SCRIPT_FUNCTION(drop_shadow) {
 	SCRIPT_PARAM(GeneratedImageP, input);
 	SCRIPT_OPTIONAL_PARAM_N_(double, _("offset x"),    offset_x);
@@ -161,6 +170,7 @@ void init_script_image_functions(Context& ctx) {
 	ctx.setVariable(_("set alpha"),        script_set_alpha);
 	ctx.setVariable(_("set combine"),      script_set_combine);
 	ctx.setVariable(_("enlarge"),          script_enlarge);
+	ctx.setVariable(_("crop"),             script_crop);
 	ctx.setVariable(_("drop shadow"),      script_drop_shadow);
 	ctx.setVariable(_("symbol variation"), script_symbol_variation);
 	ctx.setVariable(_("built in image"),   script_built_in_image);