[patch] Patch fixes scaling problem

poppler-0.12.3-fdo#5589.patch (text/plain), 4.63 KB, created by Marcin Rybarski on 2010-02-06 23:48:57 UTC

diff -up poppler-0.12.3/poppler/CairoOutputDev.cc.rex poppler-0.12.3/poppler/CairoOutputDev.cc
--- poppler-0.12.3/poppler/CairoOutputDev.cc.rex	2009-12-24 04:41:22.000000000 -0600
+++ poppler-0.12.3/poppler/CairoOutputDev.cc	2010-01-19 12:14:33.210386122 -0600
@@ -97,6 +97,69 @@ void CairoImage::setImage (cairo_surface
   this->image = cairo_surface_reference (image);
 }
 
+// basic 2D box filter 
+void PrescaleARGB(unsigned int * source,int width,int height,int stride,unsigned int * dest,int scaledWidth,int scaledHeight,int scaledStride)
+{
+ stride/=4;
+ scaledStride/=4;
+ // sanity check
+ if (scaledHeight>height || scaledWidth>width || scaledHeight<=0 || scaledWidth<=0 || stride<width || scaledStride<scaledWidth) return;
+ if (source==NULL || dest==NULL) return;
+
+ unsigned int * pLine,*pt;
+
+ int x,y,z;
+ unsigned int sum1,sum2,sum3,sum4;
+ int sx,sy,oy;
+ int count,dx,dy;
+
+ // calculate pixelwidths
+ int * pixelwidth=new int[scaledWidth];
+ int n,l=0;
+ for(x=0;x<scaledWidth;x++) 
+ {
+  n=((x+1)*width-1)/scaledWidth;
+  pixelwidth[x]=n-l;
+ // assert(pixelwidth[x]);
+  l=n;
+ }
+
+ pLine=source; 
+ oy=0;
+ for(y=0;y<scaledHeight;y++)
+  { // column
+   z=y*scaledStride;
+   pLine=source+oy*stride;
+   n=((y+1)*height-1)/scaledHeight;
+   dy=n-oy;
+   for(x=0;x<scaledWidth;x++) 
+    { // row
+     dx=pixelwidth[x];
+     pt=pLine; // temp storage line pointer
+     sum1=sum2=sum3=sum4=0;
+     for(sy=0;sy<dy;sy++) 
+     { // sum y
+      for(sx=0;sx<dx;sx++)
+      { // sum x
+       sum1+=pLine[sx]&0xFF;
+       sum2+=(pLine[sx]>>8)&0xFF;
+       sum3+=(pLine[sx]>>16)&0xFF;
+       sum4+=pLine[sx]>>24;
+      } // sum x
+      pLine+=stride;
+     } // sum y
+     pLine=pt+dx;
+     count=dx*dy;
+     dest[z++]=sum1/count+(sum2/count<<8)+(sum3/count<<16)+(sum4/count<<24);
+    } // row
+   oy+=dy;
+  }
+
+ delete [] pixelwidth; 
+}
+
+
+
 //------------------------------------------------------------------------
 // CairoOutputDev
 //------------------------------------------------------------------------
@@ -1975,13 +2038,40 @@ void CairoOutputDev::drawImage(GfxState 
 		   ((GfxICCBasedColorSpace*)colorMap->getColorSpace())->getAlt()->getMode() == csDeviceRGB);
 #endif
 
+  int scaledWidth,scaledHeight,scaledStride;
+  unsigned char * scaledBuffer;
+
+  cairo_get_matrix(cairo, &matrix);
+  scaledWidth=fabs(matrix.xx+matrix.yx)+0.5;
+  scaledHeight=fabs(matrix.xy+matrix.yy)+0.5;
+
+  if (printing || scaledWidth>=width || scaledHeight>=height)  
+  { // no prescaling => render directly to cairo_image
+    scaledWidth=width;
+    scaledHeight=height;
+  }
+  else
+   { // first render to ARGB buffer then downsample to cairo_image
+    stride = width*4; 
+    buffer = new unsigned char [stride*height]; 
+   } 
+
   image = cairo_image_surface_create (maskColors ?
 				      CAIRO_FORMAT_ARGB32 :
 				      CAIRO_FORMAT_RGB24,
-				      width, height);
+				      scaledWidth, scaledHeight);
   if (cairo_surface_status (image))
     goto cleanup;
+ 
+  scaledBuffer = cairo_image_surface_get_data (image);
+  scaledStride = cairo_image_surface_get_stride (image);
 
+  if (scaledWidth>=width || scaledHeight>=height)  
+  { // no prescaling => render directly to cairo_image
+    stride = scaledStride;
+    buffer = scaledBuffer;
+  }
+ 
   // special case for one-channel (monochrome/gray/separation) images:
   // build a lookup table here
   if (colorMap->getNumPixelComps() == 1) {
@@ -1994,11 +2084,9 @@ void CairoOutputDev::drawImage(GfxState 
       pix = (Guchar)i;
 
       colorMap->getRGB(&pix, &lookup[i]);
-    }
-  }
+    }   
+  } 
 
-  buffer = cairo_image_surface_get_data (image);
-  stride = cairo_image_surface_get_stride (image);
   for (int y = 0; y < height; y++) {
     uint32_t *dest = (uint32_t *) (buffer + y * stride);
     Guchar *pix = imgStr->getLine();
@@ -2040,6 +2128,12 @@ void CairoOutputDev::drawImage(GfxState 
   }
   gfree(lookup);
 
+  if (scaledWidth<width)
+  {
+   PrescaleARGB((unsigned int *)buffer,width,height,stride,(unsigned int *)scaledBuffer,scaledWidth,scaledHeight,scaledStride);
+   delete [] buffer;
+  }
+
   cairo_surface_mark_dirty (image);
   pattern = cairo_pattern_create_for_surface (image);
   cairo_surface_destroy (image);
@@ -2053,8 +2147,8 @@ void CairoOutputDev::drawImage(GfxState 
 			    CAIRO_FILTER_BILINEAR : CAIRO_FILTER_FAST);
   cairo_pattern_set_extend (pattern, CAIRO_EXTEND_PAD);
 
-  cairo_matrix_init_translate (&matrix, 0, height);
-  cairo_matrix_scale (&matrix, width, -height);
+  cairo_matrix_init_translate (&matrix, 0, scaledHeight);
+  cairo_matrix_scale (&matrix, scaledWidth, -scaledHeight);
   cairo_pattern_set_matrix (pattern, &matrix);
 
   if (!mask && fill_opacity != 1.0) {