Fix 1684240 (as it applies to conical gradients): Conical Gradient layers suffer...

[synfig.git] / synfig-core / trunk / src / modules / mod_gradient / conicalgradient.cpp

diff --git a/synfig-core/trunk/src/modules/mod_gradient/conicalgradient.cpp b/synfig-core/trunk/src/modules/mod_gradient/conicalgradient.cpp
index 7a6ba1c..c4c2e62 100644 (file)
--- a/synfig-core/trunk/src/modules/mod_gradient/conicalgradient.cpp
+++ b/synfig-core/trunk/src/modules/mod_gradient/conicalgradient.cpp
@@ -2,19 +2,20 @@
 /*!    \file conicalgradient.cpp
 **     \brief Template Header
 **
-**     $Id: conicalgradient.cpp,v 1.1.1.1 2005/01/04 01:23:10 darco Exp $
+**     $Id$
 **
 **     \legal
-**     Copyright (c) 2002 Robert B. Quattlebaum Jr.
+**     Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
 **
-**     This software and associated documentation
-**     are CONFIDENTIAL and PROPRIETARY property of
-**     the above-mentioned copyright holder.
+**     This package is free software; you can redistribute it and/or
+**     modify it under the terms of the GNU General Public License as
+**     published by the Free Software Foundation; either version 2 of
+**     the License, or (at your option) any later version.
 **
-**     You may not copy, print, publish, or in any
-**     other way distribute this software without
-**     a prior written agreement with
-**     the copyright holder.
+**     This package is distributed in the hope that it will be useful,
+**     but WITHOUT ANY WARRANTY; without even the implied warranty of
+**     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+**     General Public License for more details.
 **     \endlegal
 */
 /* ========================================================================= */
@@ -55,7 +56,7 @@ SYNFIG_LAYER_SET_NAME(ConicalGradient,"conical_gradient");
 SYNFIG_LAYER_SET_LOCAL_NAME(ConicalGradient,_("Conical Gradient"));
 SYNFIG_LAYER_SET_CATEGORY(ConicalGradient,_("Gradients"));
 SYNFIG_LAYER_SET_VERSION(ConicalGradient,"0.1");
-SYNFIG_LAYER_SET_CVS_ID(ConicalGradient,"$Id: conicalgradient.cpp,v 1.1.1.1 2005/01/04 01:23:10 darco Exp $");
+SYNFIG_LAYER_SET_CVS_ID(ConicalGradient,"$Id$");
 
 /* === P R O C E D U R E S ================================================= */
 
@@ -71,7 +72,7 @@ ConicalGradient::ConicalGradient():
        symmetric(false)
 {
 }
-       
+
 bool
 ConicalGradient::set_param(const String & param, const ValueBase &value)
 {
@@ -92,15 +93,15 @@ ConicalGradient::get_param(const String &param)const
 
        EXPORT_NAME();
        EXPORT_VERSION();
-               
-       return Layer_Composite::get_param(param);       
+
+       return Layer_Composite::get_param(param);
 }
 
 Layer::Vocab
 ConicalGradient::get_param_vocab()const
 {
        Layer::Vocab ret(Layer_Composite::get_param_vocab());
-       
+
        ret.push_back(ParamDesc("gradient")
                .set_local_name(_("Gradient"))
        );
@@ -108,7 +109,7 @@ ConicalGradient::get_param_vocab()const
        ret.push_back(ParamDesc("center")
                .set_local_name(_("Center"))
        );
-       
+
        ret.push_back(ParamDesc("angle")
                .set_local_name(_("Angle"))
                .set_origin("center")
@@ -117,7 +118,7 @@ ConicalGradient::get_param_vocab()const
        ret.push_back(ParamDesc("symmetric")
                .set_local_name(_("Symmetric"))
        );
-       
+
        return ret;
 }
 
@@ -128,7 +129,7 @@ ConicalGradient::color_func(const Point &pos, float supersample)const
        Angle::rot a=Angle::tan(-centered[1],centered[0]).mod();
        a+=angle;
        Real dist(a.mod().get());
-       
+
        dist-=floor(dist);
 
        if(symmetric)
@@ -167,14 +168,18 @@ ConicalGradient::color_func(const Point &pos, float supersample)const
 */
        if(dist+supersample*0.5>1.0)
        {
-               Color pool(gradient(dist,supersample*0.5).premult_alpha()*(1.0-(dist-supersample*0.5)));
-               pool+=gradient((dist+supersample*0.5)-1.0,supersample*0.5).premult_alpha()*((dist+supersample*0.5)-1.0);
+               float  left(supersample*0.5-(dist-1.0));
+               float right(supersample*0.5+(dist-1.0));
+               Color pool(gradient(1.0-(left*0.5),left).premult_alpha()*left/supersample);
+               pool+=gradient(right*0.5,right).premult_alpha()*right/supersample;
                return pool.demult_alpha();
        }
        if(dist-supersample*0.5<0.0)
        {
-               Color pool(gradient(dist,supersample*0.5).premult_alpha()*(dist+supersample*0.5));
-               pool+=gradient(1.0-(dist-supersample*0.5),supersample*0.5).premult_alpha()*(-(dist-supersample*0.5));
+               float  left(supersample*0.5-dist);
+               float right(supersample*0.5+dist);
+               Color pool(gradient(right*0.5,right).premult_alpha()*right/supersample);
+               pool+=gradient(1.0-left*0.5,left).premult_alpha()*left/supersample;
                return pool.demult_alpha();
        }
 
@@ -206,13 +211,13 @@ Color
 ConicalGradient::get_color(Context context, const Point &pos)const
 {
        const Color color(color_func(pos));
-       
+
        if(get_amount()==1.0 && get_blend_method()==Color::BLEND_STRAIGHT)
                return color;
        else
                return Color::blend(color,context.get_color(pos),get_amount(),get_blend_method());
 }
-       
+
 bool
 ConicalGradient::accelerated_render(Context context,Surface *surface,int quality, const RendDesc &renddesc, ProgressCallback *cb)const
 {
@@ -230,7 +235,7 @@ ConicalGradient::accelerated_render(Context context,Surface *surface,int quality
                        return true;
        }
 
-               
+
        int x,y;
 
        Surface::pen pen(surface->begin());
@@ -239,7 +244,7 @@ ConicalGradient::accelerated_render(Context context,Surface *surface,int quality
        Point tl(renddesc.get_tl());
        const int w(surface->get_w());
        const int h(surface->get_h());
-       
+
        if(get_amount()==1.0 && get_blend_method()==Color::BLEND_STRAIGHT)
        {
                if(quality<9)