From 101d09ea6dfede5a35986264ddb18ec830dd6808 Mon Sep 17 00:00:00 2001
From: Adrian Johnson <ajohnson@redneon.com>
Date: Sat, 8 Oct 2011 19:15:50 +1030
Subject: [PATCH 5/5] cairo: implement transfer function in setSoftMask

---
 poppler/CairoOutputDev.cc |   22 +++++++++-------------
 1 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/poppler/CairoOutputDev.cc b/poppler/CairoOutputDev.cc
index c2b6445..fae0136 100644
--- a/poppler/CairoOutputDev.cc
+++ b/poppler/CairoOutputDev.cc
@@ -1497,14 +1497,14 @@ void CairoOutputDev::paintTransparencyGroup(GfxState * /*state*/, double * /*bbo
   popTransparencyGroup();
 }
 
-static uint32_t luminocity(uint32_t x)
+static int luminocity(uint32_t x)
 {
   int r = (x >> 16) & 0xff;
   int g = (x >>  8) & 0xff;
   int b = (x >>  0) & 0xff;
   // an arbitrary integer approximation of .3*r + .59*g + .11*b
   int y = (r*19661+g*38666+b*7209 + 32829)>>16;
-  return y << 24;
+  return y;
 }
 
 
@@ -1591,19 +1591,15 @@ 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++) {
-	source_data[y*stride + x] = luminocity(source_data[y*stride + x]);
-
-#if 0
-	here is how splash deals with the transferfunction we should deal with this
-	  at some point
+	int lum;
+	lum = luminocity(source_data[y*stride + x]);
 	if (transferFunc) {
-	  transferFunc->transform(&lum, &lum2);
-	} else {
-	  lum2 = lum;
+	  double lum_in, lum_out;
+	  lum_in = lum/256.0;
+	  transferFunc->transform(&lum_in, &lum_out);
+	  lum = (int)(lum_out * 255.0 + 0.5);
 	}
-	p[x] = (int)(lum2 * 255.0 + 0.5);
-#endif
-
+	source_data[y*stride + x] = lum << 24;
       }
     }
     cairo_surface_mark_dirty (source);
-- 
1.7.4.1