1 files changed, 134 insertions, 0 deletions
diff --git a/src/toys/mesh-grad.cpp b/src/toys/mesh-grad.cpp
new file mode 100644
index 0000000..c71f5f0
--- /dev/null
+++ b/src/toys/mesh-grad.cpp
@@ -0,0 +1,134 @@
+/**
+ * Generate approximate mesh gradients for blurring technique suggested by bbyak.
+ * (njh)
+ */
+#include <2geom/d2.h>
+#include <2geom/sbasis.h>
+#include <2geom/sbasis-2d.h>
+#include <2geom/bezier-to-sbasis.h>
+#include <2geom/path.h>
+
+#include <toys/path-cairo.h>
+#include <toys/toy-framework-2.h>
+
+
+#include <vector>
+using std::vector;
+using namespace Geom;
+
+unsigned total_pieces_sub;
+unsigned total_pieces_inc;
+
+const double u_subs = 5,
+             v_subs = 5,
+             fudge = .01;
+
+const double inv_u_subs = 1 / u_subs,
+             inv_v_subs = 1 / v_subs;
+
+class Sb2d2: public Toy {
+public:
+    PointSetHandle hand;
+    Sb2d2() {
+        handles.push_back(&hand);
+    }
+    void draw(cairo_t *cr, std::ostringstream *notify, int width, int height, bool save, std::ostringstream *timer_stream) override {
+        D2<SBasis2d> sb2;
+        for(unsigned dim = 0; dim < 2; dim++) {
+            sb2[dim].us = 2;
+            sb2[dim].vs = 2;
+            const int depth = sb2[dim].us*sb2[dim].vs;
+            sb2[dim].resize(depth, Linear2d(0));
+        }
+        Geom::Point dir(1,-2);
+        if(hand.pts.empty()) {
+            for(unsigned vi = 0; vi < sb2[0].vs; vi++)
+                for(unsigned ui = 0; ui < sb2[0].us; ui++)
+                    for(unsigned iv = 0; iv < 2; iv++)
+                        for(unsigned iu = 0; iu < 2; iu++)
+                            hand.pts.emplace_back((2*(iu+ui)/(2.*ui+1)+1)*width/4.,
+                                                          (2*(iv+vi)/(2.*vi+1)+1)*width/4.);
+        
+        }
+        
+        for(int dim = 0; dim < 2; dim++) {
+            Geom::Point dir(0,0);
+            dir[dim] = 1;
+            for(unsigned vi = 0; vi < sb2[dim].vs; vi++)
+                for(unsigned ui = 0; ui < sb2[dim].us; ui++)
+                    for(unsigned iv = 0; iv < 2; iv++)
+                        for(unsigned iu = 0; iu < 2; iu++) {
+                            unsigned corner = iu + 2*iv;
+                            unsigned i = ui + vi*sb2[dim].us;
+                            Geom::Point base((2*(iu+ui)/(2.*ui+1)+1)*width/4.,
+                                             (2*(iv+vi)/(2.*vi+1)+1)*width/4.);
+                            if(vi == 0 && ui == 0) {
+                                base = Geom::Point(width/4., width/4.);
+                            }
+                            double dl = dot((hand.pts[corner+4*i] - base), dir)/dot(dir,dir);
+                            sb2[dim][i][corner] = dl/(width/2)*pow(4.0,(double)ui+vi);
+                        }
+        }
+        cairo_d2_sb2d(cr, sb2, dir*0.1, width);
+        cairo_set_source_rgba (cr, 0., 0., 0, 0.5);
+        cairo_stroke(cr);
+        for(unsigned vi = 0; vi < v_subs; vi++) {
+            double tv = vi * inv_v_subs;
+            for(unsigned ui = 0; ui < u_subs; ui++) {
+                double tu = ui * inv_u_subs;
+                
+                Geom::Path pb;
+                D2<SBasis> B;
+                D2<SBasis> tB;
+                
+                B[0] = Linear(tu-fudge, tu+fudge + inv_u_subs );
+                B[1] = Linear(tv-fudge, tv-fudge);
+                tB = compose_each(sb2, B);
+                tB = tB*(width/2) + Geom::Point(width/4, width/4);
+                pb.append(tB);
+                
+                B[0] = Linear(tu+fudge + inv_u_subs , tu+fudge + inv_u_subs);
+                B[1] = Linear(tv-fudge,               tv+fudge + inv_v_subs);
+                tB = compose_each(sb2, B);
+                tB = tB*(width/2) + Geom::Point(width/4, width/4);
+                pb.append(tB);
+                
+                B[0] = Linear(tu+fudge + inv_u_subs, tu-fudge);
+                B[1] = Linear(tv+fudge + inv_v_subs, tv+fudge + inv_v_subs);
+                tB = compose_each(sb2, B);
+                tB = tB*(width/2) + Geom::Point(width/4, width/4);
+                pb.append(tB);
+                
+                B[0] = Linear(tu-fudge,              tu-fudge);
+                B[1] = Linear(tv+fudge + inv_v_subs, tv-fudge);
+                tB = compose_each(sb2, B);
+                tB = tB*(width/2) + Geom::Point(width/4, width/4);
+                pb.append(tB);
+                
+                cairo_path(cr, pb);
+                
+                //std::cout <<  pb.peek().end() - pb.peek().begin() << std::endl;
+                cairo_set_source_rgba (cr, tu, tv, 0, 1);
+                cairo_fill(cr);
+            }
+        }
+        //*notify << "bo = " << sb2.index(0,0);
+        Toy::draw(cr, notify, width, height, save,timer_stream);
+    }
+};
+
+int main(int argc, char **argv) {
+    init(argc, argv, new Sb2d2);
+    return 0;
+}
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :