Add new parameters for motionblur. Enable linear, constant and hyperbolic sub-samples.

Patch thanks to Brendon Higgins

diff --git a/synfig-core/src/synfig/layer_motionblur.cpp b/synfig-core/src/synfig/layer_motionblur.cpp
index 59f90f7..eb489d9 100644 (file)
--- a/synfig-core/src/synfig/layer_motionblur.cpp
+++ b/synfig-core/src/synfig/layer_motionblur.cpp
@@ -61,8 +61,12 @@ SYNFIG_LAYER_SET_CVS_ID(Layer_MotionBlur,"$Id$");
 /* === M E M B E R S ======================================================= */
 
 Layer_MotionBlur::Layer_MotionBlur():
-       Layer_Composite (1.0,Color::BLEND_STRAIGHT),
-       aperture                (0)
+       Layer_Composite         (1.0,Color::BLEND_STRAIGHT),
+       aperture                        (0),
+       subsamples_factor       (1.0),
+       subsampling_type        (SUBSAMPLING_CONSTANT),
+       subsample_start         (0.0),
+       subsample_end           (1.0)
 {
 }
 
@@ -71,13 +75,21 @@ Layer_MotionBlur::set_param(const String &param, const ValueBase &value)
 {
 
        IMPORT(aperture);
+       IMPORT(subsamples_factor);
+       IMPORT(subsampling_type);
+       IMPORT(subsample_start);
+       IMPORT(subsample_end);
        return Layer_Composite::set_param(param,value);
 }
 
 ValueBase
 Layer_MotionBlur::get_param(const String &param)const
 {
-       EXPORT(aperture);
+       EXPORT(aperture);
+       EXPORT(subsamples_factor);
+       EXPORT(subsampling_type);
+       EXPORT(subsample_start);
+       EXPORT(subsample_end);
 
        EXPORT_NAME();
        EXPORT_VERSION();
@@ -123,6 +135,30 @@ Layer_MotionBlur::get_param_vocab()const
                .set_description(_("Shutter Time"))
        );
 
+       ret.push_back(ParamDesc("subsamples_factor")
+               .set_local_name(_("Subsamples Factor"))
+               .set_description(_("Multiplies The Number Of Subsamples Rendered"))
+       );
+
+       ret.push_back(ParamDesc("subsampling_type")
+               .set_local_name(_("Subsampling Type"))
+               .set_description(_("Curve Type For Weighting Subsamples"))
+               .set_hint("enum")
+               .add_enum_value(SUBSAMPLING_CONSTANT,"constant",_("Constant"))
+               .add_enum_value(SUBSAMPLING_LINEAR,"linear",_("Linear"))
+               .add_enum_value(SUBSAMPLING_HYPERBOLIC,"hyperbolic",_("Hyperbolic"))
+       );
+
+       ret.push_back(ParamDesc("subsample_start")
+               .set_local_name(_("Subsample Start Amount"))
+               .set_description(_("Relative Amount Of The First Subsample, For Linear Weighting"))
+       );
+
+       ret.push_back(ParamDesc("subsample_end")
+               .set_local_name(_("Subsample End Amount"))
+               .set_description(_("Relative Amount Of The Last Subsample, For Linear Weighting"))
+       );
+
        return ret;
 }
 
@@ -170,7 +206,17 @@ Layer_MotionBlur::accelerated_render(Context context,Surface *surface,int qualit
 
                }
 
-               if (samples == 1) return context.accelerated_render(surface,quality,renddesc,cb);
+               samples *= subsamples_factor;
+
+               if (samples <= 1) return context.accelerated_render(surface,quality,renddesc,cb);
+
+               // Only in modes where subsample_start/end matters...
+               if(subsampling_type == SUBSAMPLING_LINEAR)
+               {
+                       // We won't render when the scale==0, so we'll use those samples elsewhere
+                       if(subsample_start == 0) samples++;
+                       if(subsample_end == 0) samples++;
+               }
 
                Surface tmp;
                int i;
@@ -179,14 +225,32 @@ Layer_MotionBlur::accelerated_render(Context context,Surface *surface,int qualit
                surface->set_wh(renddesc.get_w(),renddesc.get_h());
                surface->clear();
 
+               // Render subsamples from time_cur-aperture to time_cur
                for(i=0;i<samples;i++)
                {
+                       float pos = i/(samples-1.0);
+                       float ipos = 1.0-pos;
+                       switch(subsampling_type)
+                       {
+                               case SUBSAMPLING_LINEAR:
+                                       scale = ipos*subsample_start + pos*subsample_end;
+                                       break;
+                               case SUBSAMPLING_HYPERBOLIC:
+                                       scale = 1.0/(samples-i);
+                                       break;
+                               case SUBSAMPLING_CONSTANT:
+                               default:
+                                       scale = 1.0; // Weights don't matter for constant overall subsampling.
+                                       break;
+                       }
+                       // Don't bother rendering if scale is zero
+                       if(scale==0)
+                               continue;
+                       divisor += scale;
                        subimagecb=SuperCallback(cb,i*(5000/samples),(i+1)*(5000/samples),5000);
-                       context.set_time(time_cur-(aperture*(samples-1-i)/(samples-1)));
+                       context.set_time(time_cur-aperture*ipos);
                        if(!context.accelerated_render(&tmp,quality,renddesc,&subimagecb))
                                return false;
-                       scale = 1.0/(samples-i);
-                       divisor += scale;
                        for(int y=0;y<renddesc.get_h();y++)
                                for(int x=0;x<renddesc.get_w();x++)
                                        (*surface)[y][x]+=tmp[y][x].premult_alpha()*scale;

diff --git a/synfig-core/src/synfig/layer_motionblur.h b/synfig-core/src/synfig/layer_motionblur.h
index b476f59..9b4391c 100644 (file)
--- a/synfig-core/src/synfig/layer_motionblur.h
+++ b/synfig-core/src/synfig/layer_motionblur.h
@@ -39,8 +39,21 @@ class Layer_MotionBlur : public synfig::Layer_Composite
 {
        SYNFIG_LAYER_MODULE_EXT
 
+       enum SubsamplingType
+       {
+           SUBSAMPLING_CONSTANT=0,             //!< weight each subsample equally
+           SUBSAMPLING_LINEAR=1,               //!< fade in subsamples linearly
+           SUBSAMPLING_HYPERBOLIC=2,   //!< fade in subsamples by a hyperbolic curve (default style of 0.62 and previous)
+
+           SUBSAMPLING_END=2                           //!< \internal
+       };
+
 private:
        Time aperture;
+       Real subsamples_factor;
+       SubsamplingType subsampling_type;
+       Real subsample_start;
+       Real subsample_end;
        mutable Time time_cur;
 
 public: