feat: initial implementation for to_card_image() function (closes #33)

src/gfx/generated_image.cpp

@@ -443,6 +443,17 @@ bool BuiltInImage::operator == (const GeneratedImage& that) const {
   return that2 && name == that2->name;
 }
 
+// ----------------------------------------------------------------------------- : ArbitraryImage
+
+Image ArbitraryImage::generate(const Options& opt) const {
+  return image;
+}
+bool ArbitraryImage::operator == (const GeneratedImage& that) const {
+  const ArbitraryImage* that2 = dynamic_cast<const ArbitraryImage*>(&that);
+  return that2 && image.IsSameAs(that2->image);
+}
+
+
 // ----------------------------------------------------------------------------- : SymbolToImage
 
 SymbolToImage::SymbolToImage(bool is_local, const LocalFileName& filename, Age age, const SymbolVariationP& variation)

src/gfx/generated_image.hpp

@@ -348,6 +348,19 @@ private:
   String name;
 };
 
+// ----------------------------------------------------------------------------- : Arbitrary
+
+class ArbitraryImage : public GeneratedImage {
+public:
+    inline ArbitraryImage(const Image image)
+        : image(image)
+    {}
+    Image generate(const Options& opt) const override;
+    bool operator == (const GeneratedImage& that) const override;
+private:
+    Image image;
+};
+
 // ----------------------------------------------------------------------------- : SymbolToImage
 
 /// Use a symbol as an image

src/script/functions/image.cpp

@@ -16,6 +16,7 @@
 #include <data/stylesheet.hpp>
 #include <data/symbol.hpp>
 #include <data/field/symbol.hpp>
+#include <data/format/formats.hpp>
 #include <gfx/generated_image.hpp>
 #include <render/symbol/filter.hpp>
 
@@ -28,6 +29,12 @@ SCRIPT_FUNCTION(to_image) {
   return input;
 }
 
+SCRIPT_FUNCTION(to_card_image) {
+  SCRIPT_PARAM(Set*, set);
+  SCRIPT_PARAM(CardP, input);
+  return make_intrusive<ArbitraryImage>(export_bitmap(set, input).ConvertToImage());
+}
+
 // ----------------------------------------------------------------------------- : Image functions
 
 SCRIPT_FUNCTION(linear_blend) {
@@ -210,6 +217,7 @@ SCRIPT_FUNCTION(built_in_image) {
 
 void init_script_image_functions(Context& ctx) {
   ctx.setVariable(_("to_image"),         script_to_image);
+  ctx.setVariable(_("to_card_image"),    script_to_card_image);
   ctx.setVariable(_("linear_blend"),     script_linear_blend);
   ctx.setVariable(_("masked_blend"),     script_masked_blend);
   ctx.setVariable(_("combine_blend"),    script_combine_blend);