--- rxvt-unicode/src/rxvtimg.C	2012/06/08 21:41:45	1.65
+++ rxvt-unicode/src/rxvtimg.C	2012/06/10 07:51:45	1.75
@@ -51,6 +51,7 @@
   return img;
 }
 
+# if HAVE_PIXBUF
 rxvt_img *
 rxvt_img::new_from_pixbuf (rxvt_screen *s, GdkPixbuf *pb)
 {
@@ -168,6 +169,7 @@
 
   return img;
 }
+# endif
 
 void
 rxvt_img::destroy ()
@@ -317,64 +319,120 @@
 }
 
 static Picture
-create_xrender_mask (Display *dpy, Drawable drawable, Bool argb)
+create_xrender_mask (Display *dpy, Drawable drawable, Bool argb, Bool component_alpha)
 {
   Pixmap pixmap = XCreatePixmap (dpy, drawable, 1, 1, argb ? 32 : 8);
 
   XRenderPictFormat *format = XRenderFindStandardFormat (dpy, argb ? PictStandardARGB32 : PictStandardA8);
   XRenderPictureAttributes pa;
-  pa.repeat = True;
-  Picture mask = XRenderCreatePicture (dpy, pixmap, format, CPRepeat, &pa);
+  pa.repeat = RepeatNormal;
+  pa.component_alpha = component_alpha;
+  Picture mask = XRenderCreatePicture (dpy, pixmap, format, CPRepeat | CPComponentAlpha, &pa);
 
   XFreePixmap (dpy, pixmap);
 
   return mask;
 }
 
+static void
+extract (int32_t cl0, int32_t cl1, int32_t &c, unsigned short &xc)
+{
+  int32_t x = clamp (c, cl0, cl1);
+  c -= x;
+  xc = x;
+}
+
+static bool
+extract (int32_t cl0, int32_t cl1, int32_t &r, int32_t &g, int32_t &b, int32_t &a, unsigned short &xr, unsigned short &xg, unsigned short &xb, unsigned short &xa)
+{
+  extract (cl0, cl1, r, xr);
+  extract (cl0, cl1, g, xg);
+  extract (cl0, cl1, b, xb);
+  extract (cl0, cl1, a, xa);
+
+  return xr | xg | xb | xa;
+}
+
 void
-rxvt_img::brightness (uint16_t r, uint16_t g, uint16_t b, uint16_t a)
+rxvt_img::brightness (int32_t r, int32_t g, int32_t b, int32_t a)
 {
+  unshare ();
+
   Display *dpy = s->display->dpy;
-  Picture src = create_xrender_mask (dpy, pm, True);
   Picture dst = XRenderCreatePicture (dpy, pm, format, 0, 0);
 
-  XRenderColor mask_c;
-  mask_c.red   = r;
-  mask_c.green = g;
-  mask_c.blue  = b;
-  mask_c.alpha = a;
-  XRenderFillRectangle (dpy, PictOpSrc, src, &mask_c, 0, 0, 1, 1);
+  // loop should not be needed for brightness, as only -1..1 makes sense
+  //while (r | g | b | a)
+    {
+      unsigned short xr, xg, xb, xa;
+      XRenderColor mask_c;
 
-  XRenderComposite (dpy, PictOpAdd, src, None, dst, 0, 0, 0, 0, 0, 0, w, h);
+      if (extract (0, 65535, r, g, b, a, mask_c.red, mask_c.green, mask_c.blue, mask_c.alpha))
+        XRenderFillRectangle (dpy, PictOpAdd, dst, &mask_c, 0, 0, w, h);
+
+      if (extract (-65535, 0, r, g, b, a, mask_c.red, mask_c.green, mask_c.blue, mask_c.alpha))
+        {
+          XRenderColor mask_w = { 65535, 65535, 65535, 65535 };
+          XRenderFillRectangle (dpy, PictOpDifference, dst, &mask_w, 0, 0, w, h);
+          mask_c.red   = -mask_c.red; //TODO: verify that doing clamp, assign, and negation does the right thing
+          mask_c.green = -mask_c.green;
+          mask_c.blue  = -mask_c.blue;
+          mask_c.alpha = -mask_c.alpha;
+          XRenderFillRectangle (dpy, PictOpAdd, dst, &mask_c, 0, 0, w, h);
+          XRenderFillRectangle (dpy, PictOpDifference, dst, &mask_w, 0, 0, w, h);
+        }
+    }
 
-  XRenderFreePicture (dpy, src);
   XRenderFreePicture (dpy, dst);
 }
 
 void
-rxvt_img::contrast (uint16_t r, uint16_t g, uint16_t b, uint16_t a)
+rxvt_img::contrast (int32_t r, int32_t g, int32_t b, int32_t a)
 {
-  if (!(s->display->flags & DISPLAY_HAS_RENDER_MUL))
-    {
-      rxvt_warn ("rxvt_img::contrast operation not supported on this display, RENDER extension too old.\n");
-      return;
-    }
+  if (r < 0 || g < 0 || b < 0 || a < 0)
+    rxvt_fatal ("rxvt_img::contrast does not support negative values.\n");
+
+  rxvt_img *img = new rxvt_img (s, format, x, y, w, h, repeat);
+  img->alloc ();
+
+  {
+    rxvt_color empty;
+    empty.set (s, rgba (0, 0, 0, 0));
+    img->fill (empty);
+  }
+
+  // premultiply (yeah, these are not exact, sue me or fix it)
+  r = (r * (a >> 8)) >> 8;
+  g = (g * (a >> 8)) >> 8;
+  b = (b * (a >> 8)) >> 8;
 
   Display *dpy = s->display->dpy;
-  Picture src = create_xrender_mask (dpy, pm, True);
-  Picture dst = XRenderCreatePicture (dpy, pm, format, 0, 0);
 
-  XRenderColor mask_c;
-  mask_c.red   = r;
-  mask_c.green = g;
-  mask_c.blue  = b;
-  mask_c.alpha = a;
-  XRenderFillRectangle (dpy, PictOpSrc, src, &mask_c, 0, 0, 1, 1);
+  Picture src = src_picture ();
+  Picture dst = XRenderCreatePicture (dpy, img->pm, format, 0, 0);
+  Picture mul = create_xrender_mask (dpy, pm, True, True);
 
-  XRenderComposite (dpy, PictOpMultiply, src, None, dst, 0, 0, 0, 0, 0, 0, w, h);
+  //TODO: this operator does not yet implement some useful contrast
+  while (r | g | b | a)
+    {
+      unsigned short xr, xg, xb, xa;
+      XRenderColor mask_c;
 
-  XRenderFreePicture (dpy, src);
+      if (extract (0, 65535, r, g, b, a, mask_c.red, mask_c.green, mask_c.blue, mask_c.alpha))
+        {
+          XRenderFillRectangle (dpy, PictOpSrc, mul, &mask_c, 0, 0, 1, 1);
+          XRenderComposite (dpy, PictOpAdd, src, mul, dst, 0, 0, 0, 0, 0, 0, w, h);
+        }
+    }
+
+  XRenderFreePicture (dpy, mul);
   XRenderFreePicture (dpy, dst);
+  XRenderFreePicture (dpy, src);
+
+  ::swap (img->ref, ref);
+  ::swap (img->pm , pm );
+
+  delete img;
 }
 
 rxvt_img *
@@ -474,10 +532,8 @@
     for (int j = 0; j < 3; ++j)
       xfrm.matrix [i][j] = XDoubleToFixed (matrix [i * 3 + j]);
 
-#if 0
   xfrm.matrix [0][2] -= XDoubleToFixed (x);//TODO
   xfrm.matrix [1][2] -= XDoubleToFixed (y);
-#endif
 
   XRenderSetPictureFilter (dpy, src, "good", 0, 0);
   XRenderSetPictureTransform (dpy, src, &xfrm);
@@ -568,7 +624,7 @@
   Display *dpy = s->display->dpy;
   Picture src = img->src_picture ();
   Picture dst = XRenderCreatePicture (dpy, img2->pm, img2->format, 0, 0);
-  Picture mask = create_xrender_mask (dpy, img->pm, False);
+  Picture mask = create_xrender_mask (dpy, img->pm, False, False);
 
   XRenderColor mask_c;