[poppler] poppler/CairoOutputDev.cc

[Carlos Garcia Campos]

 poppler/CairoOutputDev.cc |   37 +++++++++++++++++++------------------
 1 file changed, 19 insertions(+), 18 deletions(-)

New commits:
commit 3c2a92b06a6541071bd1e555606bb2096de17ef6
Author: Carlos Garcia Campos <carlosgc at gnome.org>
Date:   Sat Apr 20 16:41:56 2013 +0200

    cairo: Always use the trasnfer function if present in setSoftMask
    
    "If the subtype is Alpha, the transparency group XObject G shall be
    evaluated to compute a group alpha only. The colours of the constituent
    objects shall be ignored and the colour compositing computations shall
    not be performed. The transfer function TR shall then be applied to the
    computed group alpha to produce the mask values."
    
    We were using the transfer function only for luminosity soft masks.
    
    https://bugs.freedesktop.org/show_bug.cgi?id=63587

diff --git a/poppler/CairoOutputDev.cc b/poppler/CairoOutputDev.cc
index 2ff84b6..37e0f1c 100644
--- a/poppler/CairoOutputDev.cc
+++ b/poppler/CairoOutputDev.cc
@@ -1577,7 +1577,7 @@ void CairoOutputDev::setSoftMask(GfxState * state, double * bbox, GBool alpha,
 
   LOG(printf ("set softMask\n"));
 
-  if (alpha == false) {
+  if (!alpha || transferFunc) {
     /* We need to mask according to the luminocity of the group.
      * So we paint the group to an image surface convert it to a luminocity map
      * and then use that as the mask. */
@@ -1620,13 +1620,15 @@ void CairoOutputDev::setSoftMask(GfxState * state, double * bbox, GBool alpha,
     cairo_t *maskCtx = cairo_create(source);
 
     //XXX: hopefully this uses the correct color space */
-    GfxRGB backdropColorRGB;
-    groupColorSpaceStack->cs->getRGB(backdropColor, &backdropColorRGB);
-    /* paint the backdrop */
-    cairo_set_source_rgb(maskCtx,
-			 colToDbl(backdropColorRGB.r),
-			 colToDbl(backdropColorRGB.g),
-			 colToDbl(backdropColorRGB.b));
+    if (!alpha) {
+      GfxRGB backdropColorRGB;
+      groupColorSpaceStack->cs->getRGB(backdropColor, &backdropColorRGB);
+      /* paint the backdrop */
+      cairo_set_source_rgb(maskCtx,
+                           colToDbl(backdropColorRGB.r),
+                           colToDbl(backdropColorRGB.g),
+                           colToDbl(backdropColorRGB.b));
+    }
     cairo_paint(maskCtx);
 
     /* Copy source ctm to mask ctm and translate origin so that the
@@ -1653,15 +1655,14 @@ void CairoOutputDev::setSoftMask(GfxState * state, double * bbox, GBool alpha,
     int stride = cairo_image_surface_get_stride(source)/4;
     for (int y=0; y<height; y++) {
       for (int x=0; x<width; x++) {
-	int lum;
-	lum = luminocity(source_data[y*stride + x]);
-	if (transferFunc) {
-	  double lum_in, lum_out;
-	  lum_in = lum/256.0;
-	  transferFunc->transform(&lum_in, &lum_out);
-	  lum = (int)(lum_out * 255.0 + 0.5);
-	}
-	source_data[y*stride + x] = lum << 24;
+	int lum = alpha ? fill_opacity : luminocity(source_data[y*stride + x]);
+        if (transferFunc) {
+          double lum_in, lum_out;
+          lum_in = lum/256.0;
+          transferFunc->transform(&lum_in, &lum_out);
+          lum = (int)(lum_out * 255.0 + 0.5);
+        }
+        source_data[y*stride + x] = lum << 24;
       }
     }
     cairo_surface_mark_dirty (source);
@@ -1681,7 +1682,7 @@ void CairoOutputDev::setSoftMask(GfxState * state, double * bbox, GBool alpha,
     }
 
     cairo_surface_destroy(source);
-  } else {
+  } else if (alpha) {
     mask = cairo_pattern_reference(group);
     cairo_get_matrix(cairo, &mask_matrix);
   }