Doc: Add filter examples from the doc

The filter code is a copy and paste from the doc.
Maybe the code should be in an include file, so we're sure the
preview and the documentation code are the same?

doc/previews/Makefile.am

@@ -27,7 +27,7 @@ noinst_PROGRAMS = preview_text_filter
 DATADIR = ${top_srcdir}/doc/previews/img
 HTMLDIR = ${top_srcdir}/doc/html
 
-PREVIEWS =
+PREVIEWS = blend blur bump curve grow mask transform
 
 previews-data:
 	$(MKDIR_P) $(DATADIR)

doc/previews/filter_blend.sh

@@ -0,0 +1,5 @@
+TEXT="Blend"
+FONT="Sans:style=bold"
+SIZE=32
+FILTER="blend (color = #3399FF);"
+

doc/previews/filter_blur.sh

@@ -0,0 +1,8 @@
+TEXT="Blur"
+FONT="Sans:style=bold"
+SIZE=32
+FILTER="
+blur (10, color = black, oy = 5, ox = 5);
+blend ();
+"
+

doc/previews/filter_bump.sh

@@ -0,0 +1,8 @@
+TEXT="Bump"
+FONT="Sans:style=bold"
+SIZE=64
+FILTER="
+buffer : a (alpha);
+blur (5, dst = a);
+bump (map = a, compensate = yes, color = cyan, specular = 10.0);
+"

doc/previews/filter_curve.sh

@@ -0,0 +1,9 @@
+TEXT="Curve"
+FONT="Sans:style=bold"
+SIZE=64
+FILTER="
+buffer : a (alpha);
+blur (4, dst = a);
+curve (0:0 - 20:0 - 60:255 - 160:255 - 200:0 - 255:0, src = a, dst = a);
+blend(src = a, color = black);
+"

doc/previews/filter_example_1.sh

@@ -0,0 +1,10 @@
+TEXT="Evas Filters"
+FONT="Sans"
+SIZE=50
+FILTER="
+buffer : fat (alpha);
+grow (8, dst = fat);
+blur (12, src = fat, color = darkblue);
+blur (4, color = cyan);
+blend ();
+"

doc/previews/filter_grow.sh

@@ -0,0 +1,9 @@
+TEXT="Grow - Contour"
+FONT="Sans:style=bold"
+SIZE=32
+FILTER="
+buffer : fat (alpha);
+grow (4, dst = fat);
+blend (src = fat, color = black);
+blend (color = white);
+"

doc/previews/filter_mask.sh

@@ -0,0 +1,10 @@
+TEXT="Mask"
+FONT="Sans:style=bold"
+SIZE=64
+FILTER="
+buffer: a (alpha);
+blur(5, dst = a);
+curve(points = 0:255 - 128:255 - 255:0, src = a, dst = a);
+blend(color = black);
+mask(mask = a, color = cyan);
+"

doc/previews/filter_transform.sh

@@ -0,0 +1,9 @@
+TEXT="Transform - Mirror effect"
+FONT="Sans"
+SIZE=50
+FILTER="
+buffer : t (alpha);
+transform (oy = 20, dst = t);
+blend (src = t, color = silver);
+blend (color = white);
+"