1 files changed, 84 insertions, 0 deletions
diff --git a/olpcgames/svgsprite.py b/olpcgames/svgsprite.py
new file mode 100755
index 0000000..ad247dd
--- /dev/null
+++ b/olpcgames/svgsprite.py
@@ -0,0 +1,84 @@
+"""RSVG/Cairo-based rendering of SVG into Pygame Images"""
+from pygame import sprite, Rect
+from olpcgames import _cairoimage
+
+class SVGSprite( sprite.Sprite ):
+    """Sprite class which renders SVG source-code as a Pygame image
+    
+    Note:
+    
+        Currently this sprite class is a bit over-engineered, it gets in the way 
+        if you want to, e.g. animate among a number of SVG drawings, as it 
+        assumes that setSVG will always set a single SVG file for rendering.
+    """
+    rect = image = None
+    resolution = None
+    def __init__( 
+        self, svg=None, size=None, *args
+    ):
+        """Initialise the svg sprite
+        
+        svg -- svg source text (i.e. content of an svg file)
+        size -- optional, to constrain size, (width,height), leaving one 
+            as None or 0 causes proportional scaling, leaving both 
+            as None or 0 causes natural scaling (screen resolution)
+        args -- if present, groups to which to automatically add
+        """
+        self.size = size
+        super( SVGSprite, self ).__init__( *args )
+        if svg:
+            self.setSVG( svg )
+    def setSVG( self, svg ):
+        """Set our SVG source"""
+        self.svg = svg
+        # XXX could delay this until actually asked to display...
+        if self.size:
+            width,height = self.size
+        else:
+            width,height = None,None
+        self.image = self._render( width,height ).convert_alpha()
+        rect = self.image.get_rect()
+        if self.rect:
+            rect.move( self.rect ) # should let something higher-level do that...
+        self.rect = rect 
+
+    def _render( self, width, height ):
+        """Render our SVG to a Pygame image"""
+        import rsvg
+        handle = rsvg.Handle( data = self.svg )
+        originalSize = (width,height)
+        scale = 1.0
+        hw,hh = handle.get_dimension_data()[:2]
+        if hw and hh:
+            if not width:
+                if not height:
+                    width,height = hw,hh 
+                else:
+                    scale = float(height)/hh
+                    width = hh/float(hw) * height
+            elif not height:
+                scale = float(width)/hw
+                height = hw/float(hh) * width
+            else:
+                # scale only, only rendering as large as it is...
+                if width/height > hw/hh:
+                    # want it taller than it is...
+                    width = hh/float(hw) * height
+                else:
+                    height = hw/float(hh) * width
+                scale = float(height)/hh
+            
+            csrf, ctx = _cairoimage.newContext( int(width), int(height) )
+            ctx.scale( scale, scale )
+            handle.render_cairo( ctx )
+            return _cairoimage.asImage( csrf )
+        return None
+    def copy( self ):
+        """Create a copy of this sprite without reloading the svg image"""
+        result = self.__class__(
+            size = self.size
+        )
+        result.image = self.image 
+        result.rect = Rect(self.rect)
+        result.resolution = self.resolution
+        return result