add Stan Melax' ImplicitCloth demo

examples/Experiments/ImplicitCloth/stan/Cloth.cpp

@@ -0,0 +1,96 @@
+
+//-----------------------------------------------------------------------------------------------
+//
+// The remainder of this file shows how to use the spring network class with backward integration
+// in order to implement a cloth system within a 3D game environment.
+// The cloth class extends the springnetwork class in order to provide
+// import/export, rendering support, and hooks into the game.
+//
+
+#include "Cloth.h"
+
+Array<Cloth*> cloths;
+
+Cloth::Cloth(const char *_name,int _n):SpringNetwork(_n),
+							color(0,0.5f,1.0f)
+{
+      
+       cloths.Add(this);
+}
+Cloth::~Cloth()
+{
+       cloths.Remove(this);
+}
+
+//
+// I/O support for serialization of our springnetwork and cloth objects.
+//
+
+
+
+
+int   cloth_showbbox = 0;  // for debug visualization  shows bounding box.
+float cloth_showvert = 0.025f; // size of box to put around current vert selected, 0 turns off
+
+
+
+Cloth *ClothCreate(int w,int h,float size)
+{
+       // simple cloth generation routine that creates a typical square cloth.
+       // better to use a real pipeline to generate these, this is just for testing.
+       int i,j;
+       Cloth *cloth = new Cloth("cloth",w*h);
+       cloth->w=w;
+       cloth->h=h; // later for rendering.
+       for(i=0;i<h;i++)
+        for(j=0;j<w;j++)
+       {
+               cloth->X[i*w+j] = (float3(-0.5f,-0.5f,0)+float3((float)j/(w-1.0f),1.0f-(float)i/(h-1.0f),0)) * size;
+       }
+       for(i=0;i<h;i++)
+        for(j=0;j<w;j++)
+       {
+               if(i<h-1)        cloth->CreateSpring(SPRING_STRUCT,i*w+j,(i+1)*w+j);     // structural
+               if(j<w-1)        cloth->CreateSpring(SPRING_STRUCT,i*w+j,i*w+(j+1));     // structural
+               if(j<w-1&&i<h-1) cloth->CreateSpring(SPRING_SHEAR ,i*w+j,(i+1)*w+(j+1)); // shear
+               if(j>0  &&i<h-1) cloth->CreateSpring(SPRING_SHEAR ,i*w+j,(i+1)*w+(j-1)); // shear
+               if(i<h-2)        cloth->CreateSpring(SPRING_BEND  ,i*w+j,(i+2)*w+j);     // benders
+               if(j<w-2)        cloth->CreateSpring(SPRING_BEND  ,i*w+j,i*w+(j+2));     // benders
+       }
+       cloth->UpdateLimits();
+       return cloth;
+}
+
+
+int    cloth_tess = 20;
+float3 cloth_spawnpoint(0,3,5.0f);
+
+
+/*
+static void ClothDrawSprings(Cloth *cloth)
+{
+       static const float3 color[3]={float3(1,1,0),float3(1,0,1),float3(0,1,1)};
+       float3N &X = cloth->X;
+       for(int i=0;i<cloth->springs.count;i++)
+       {
+               SpringNetwork::Spring &s = cloth->springs[i];
+               extern void Line(const float3 &,const float3 &,const float3 &color_rgb);
+               Line(X[s.a],X[s.b],color[s.type]);
+       }
+}
+*/
+int cloth_showsprings=0;
+
+void DoCloths()
+{
+       int i;
+       for(i=0;i<cloths.count;i++)
+       {
+               Cloth *cloth=cloths[i];
+               
+             //  cloth->Simulate((cloth->cloth_step<0)?DeltaT:cloth->cloth_step);
+               //if(cloth_showsprings)
+               //        ClothDrawSprings(cloth); // debug visualization
+               
+       }
+}