--- rxvt-unicode/src/rxvtimg.C	2012/06/07 21:28:10	1.59
+++ rxvt-unicode/src/rxvtimg.C	2012/06/10 10:29:26	1.76
@@ -51,6 +51,7 @@
   return img;
 }
 
+# if HAVE_PIXBUF
 rxvt_img *
 rxvt_img::new_from_pixbuf (rxvt_screen *s, GdkPixbuf *pb)
 {
@@ -64,7 +65,6 @@
 
   // since we require rgb24/argb32 formats from xrender we assume
   // that both 24 and 32 bpp MUST be supported by any screen that supports xrender
-  int depth = gdk_pixbuf_get_has_alpha (pb) ? 32 : 24;
 
   int byte_order = ecb_big_endian () ? MSBFirst : LSBFirst;
 
@@ -78,7 +78,7 @@
   xi.bitmap_unit      = 0;         //XY only, unused
   xi.bitmap_bit_order = 0;         //XY only, unused
   xi.bitmap_pad       = BitmapPad (dpy);
-  xi.depth            = depth;
+  xi.depth            = 32;
   xi.bytes_per_line   = 0;
   xi.bits_per_pixel   = 32;         //Z only
   xi.red_mask         = 0x00000000; //Z only, unused
@@ -97,9 +97,9 @@
   xi.data = (char *)rxvt_malloc (height * xi.bytes_per_line);
 
   int rowstride = gdk_pixbuf_get_rowstride (pb);
-
-  assert (3 + (depth == 32) == gdk_pixbuf_get_n_channels (pb));
+  bool pb_has_alpha = gdk_pixbuf_get_has_alpha (pb);
   unsigned char *row = gdk_pixbuf_get_pixels (pb);
+
   char *line = xi.data;
 
   for (int y = 0; y < height; y++)
@@ -107,14 +107,14 @@
       unsigned char *src = row;
       uint32_t      *dst = (uint32_t *)line;
 
-      if (depth == 24)
+      if (!pb_has_alpha)
         for (int x = 0; x < width; x++)
           {
             uint8_t r = *src++;
             uint8_t g = *src++;
             uint8_t b = *src++;
 
-            uint32_t v = (r << 16) | (g << 8) | b;
+            uint32_t v = (255 << 24) | (r << 16) | (g << 8) | b;
             
             if (ecb_big_endian () ? !byte_order_mismatch : byte_order_mismatch)
               v = ecb_bswap32 (v);
@@ -141,7 +141,7 @@
       line += xi.bytes_per_line;
     }
 
-  rxvt_img *img = new rxvt_img (s, XRenderFindStandardFormat (dpy, depth == 24 ? PictStandardRGB24 : PictStandardARGB32), 0, 0, width, height);
+  rxvt_img *img = new rxvt_img (s, XRenderFindStandardFormat (dpy, PictStandardARGB32), 0, 0, width, height);
   img->alloc ();
 
   GC gc = XCreateGC (dpy, img->pm, 0, 0);
@@ -168,6 +168,7 @@
 
   return img;
 }
+# endif
 
 void
 rxvt_img::destroy ()
@@ -211,7 +212,6 @@
   if (ref->cnt == 1 && ref->ours)
     return;
 
-  //TODO: maybe should reify instead
   Pixmap pm2 = XCreatePixmap (s->display->dpy, s->display->root, ref->w, ref->h, format->depth);
   GC gc = XCreateGC (s->display->dpy, pm, 0, 0);
   XCopyArea (s->display->dpy, pm, pm2, gc, 0, 0, ref->w, ref->h, 0, 0);
@@ -267,11 +267,10 @@
   rxvt_img *img = new rxvt_img (s, format, x, y, w, h, repeat);
   img->alloc ();
 
-  Picture src = src_picture ();
-
   XRenderPictureAttributes pa;
   pa.repeat = RepeatPad;
-  Picture dst = XRenderCreatePicture (dpy, img->pm, format, CPRepeat, &pa);
+  Picture src = XRenderCreatePicture (dpy, pm, format, CPRepeat, &pa);
+  Picture dst = XRenderCreatePicture (dpy, img->pm, format, 0, 0);
 
   Pixmap tmp_pm = XCreatePixmap (dpy, pm, w, h, format->depth);
   Picture tmp = XRenderCreatePicture (dpy, tmp_pm , format, CPRepeat, &pa);
@@ -297,7 +296,7 @@
       get_gaussian_kernel (rv, size, kernel, params);
       ::swap (params[0], params[1]);
 
-      XRenderSetPictureFilter (dpy, src, FilterConvolution, params, size+2);
+      XRenderSetPictureFilter (dpy, tmp, FilterConvolution, params, size+2);
       XRenderComposite (dpy,
                         PictOpSrc,
                         tmp,
@@ -319,61 +318,120 @@
 }
 
 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 (unsigned short r, unsigned short g, unsigned short b, unsigned short 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 (unsigned short r, unsigned short g, unsigned short b, unsigned short a)
+rxvt_img::contrast (int32_t r, int32_t g, int32_t b, int32_t a)
 {
-  if (!(s->display->flags & DISPLAY_HAS_RENDER_MUL))
-    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 *
@@ -410,9 +468,10 @@
 
   Display *dpy = s->display->dpy;
 
-  bool alpha = !format->direct.alphaMask
-               && (x || y)
-               && repeat == RepeatNone;
+  // add an alpha channel if...
+  bool alpha = !format->direct.alphaMask // pixmap has none yet
+               && (x || y)               // we need one because of non-zero offset
+               && repeat == RepeatNone;  // and we have no good pixels to fill with
 
   rxvt_img *img = new rxvt_img (s, alpha ? find_alpha_format_for (dpy, format) : format, 0, 0, w, h, repeat);
   img->alloc ();
@@ -472,10 +531,8 @@
     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);
@@ -566,7 +623,7 @@
   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;