Changeset 1027 for trunk/include/mapnik/image_util.hpp

Timestamp:

03/29/09 07:05:20 (16 months ago)

Author:

artem

Message:

+ applied "hill shading" patch from Marcin Rudowski

a) Raster opacity
b) Raster merging modes (TODO:add more modes, consider agg impl)
c) Raster scaling algos: fast,bilinear,bilinear8

(TODO: add alpha support in bilinear8)

d) improvements to png256

*Great work, thanks!*

Files:

• trunk/include/mapnik/image_util.hpp (modified) (1 diff)

trunk/include/mapnik/image_util.hpp

@@ -273 +273 @@
    }
    
+   template <typename Image>
+   inline void scale_image_bilinear (Image& target,const Image& source)
+   {
+
+      int source_width=source.width();
+      int source_height=source.height();
+
+      int target_width=target.width();
+      int target_height=target.height();
+
+      if (source_width<1 || source_height<1 ||
+          target_width<1 || target_height<1) return;
+      int x=0,y=0,xs=0,ys=0;
+      int tw2 = target_width/2;
+      int th2 = target_height/2;
+
+
+      for (y=0;y<target_height;++y)
+      {
+        ys = y*source_height/target_height;
+        int ys1 = ys+1;
+        if (ys1>=source_height)
+            ys1--;
+        unsigned yprt = y*source_height%target_height;
+        unsigned yprt1 = target_height-yprt;
+        for (x=0;x<target_width;++x)
+        {
+            xs = x*source_width/target_width;
+            if (source_width>=target_width || source_height>=target_height){
+                target(x,y)=source(xs,ys);
+                continue;
+            }
+            unsigned xprt = x*source_width%target_width;
+            unsigned xprt1 = target_width-xprt;
+            int xs1 = xs+1;
+            if (xs1>=source_width)
+                xs1--;
+
+            unsigned a = source(xs,ys);
+            unsigned b = source(xs1,ys);
+            unsigned c = source(xs,ys1);
+            unsigned d = source(xs1,ys1);
+            unsigned out=0;
+            unsigned t = 0;
+
+            for(int i=0; i<4; i++){
+                unsigned p,r,s;
+                // X axis
+                p = a&0xff;
+                r = b&0xff;
+                if (p!=r)
+                    r = (r*xprt+p*xprt1+tw2)/target_width;
+                p = c&0xff;
+                s = d&0xff;
+                if (p!=s)
+                    s = (s*xprt+p*xprt1+tw2)/target_width;
+                // Y axis
+                if (r!=s)
+                    r = (s*yprt+r*yprt1+th2)/target_height;
+                // channel up
+                out |= r << t;
+                t += 8;
+                a >>= 8;
+                b >>= 8;
+                c >>= 8;
+                d >>= 8;
+            }
+            target(x,y)=out;
+        }
+     }
+   }
+
+   template <typename Image>
+   inline void scale_image_bilinear8 (Image& target,const Image& source)
+   {
+
+      int source_width=source.width();
+      int source_height=source.height();
+
+      int target_width=target.width();
+      int target_height=target.height();
+
+      if (source_width<1 || source_height<1 ||
+          target_width<1 || target_height<1) return;
+      int x=0,y=0,xs=0,ys=0;
+      int tw2 = target_width/2;
+      int th2 = target_height/2;
+
+
+      for (y=0;y<target_height;++y)
+      {
+        ys = y*source_height/target_height;
+        int ys1 = ys+1;
+        if (ys1>=source_height)
+            ys1--;
+        unsigned yprt = y*source_height%target_height;
+        unsigned yprt1 = target_height-yprt;
+        for (x=0;x<target_width;++x)
+        {
+            xs = x*source_width/target_width;
+            if (source_width>=target_width || source_height>=target_height){
+                target(x,y)=source(xs,ys);
+                continue;
+            }
+            unsigned xprt = x*source_width%target_width;
+            unsigned xprt1 = target_width-xprt;
+            int xs1 = xs+1;
+            if (xs1>=source_width)
+                xs1--;
+
+            unsigned a = source(xs,ys);
+            unsigned b = source(xs1,ys);
+            unsigned c = source(xs,ys1);
+            unsigned d = source(xs1,ys1);
+            unsigned p,r,s;
+            // X axis
+            p = a&0xff;
+            r = b&0xff;
+            if (p!=r)
+                r = (r*xprt+p*xprt1+tw2)/target_width;
+            p = c&0xff;
+            s = d&0xff;
+            if (p!=s)
+                s = (s*xprt+p*xprt1+tw2)/target_width;
+            // Y axis
+            if (r!=s)
+                r = (s*yprt+r*yprt1+th2)/target_height;
+            target(x,y)=(0xff<<24) | (r<<16) | (r<<8) | r;
+        }
+     }
+   }
+
    inline MAPNIK_DECL void save_to_file (Image32 const& image,
                                          std::string const& file,