View difference between Paste ID: SJhs8ntt and emij5Hmz

 //N-Body simulation
 //Algorithm based on: http://http.developer.nvidia.com/GPUGems3/gpugems3_ch31.html
 
 #define BLOCK_SIZE 128
 
 cbuffer data						: register(b0)
 {
 	uint num_particles;
 	uint num_blocks;
 	float deltaTime;
 	float damping;
 };
 
 struct PosVel
 {
 	float4 pos; //xyz = pos, w = weight
 	float4 vel; //only xyz
 };
 
 StructuredBuffer<PosVel>	oldPar	: register(t0);
 RWStructuredBuffer<PosVel> 	newPar	: register(u0);
 
 static float g_FG = 6.67300e-11f;
 static float g_softeningFactorSq =  0.0012500000*0.0012500000;
 static float g_fParticleMass = 10000.0f * 10000.0f * 10000.0f;
 
 groupshared float4 sh_Positions[BLOCK_SIZE];
 
 void body_body_interaction(inout float3 ai, float4 bi, float4 bj)
 {
 	float3 r = bj.xyz - bi.xyz;
 
     float distSqr = dot(r, r);
     distSqr += g_softeningFactorSq;
 
 	float distInvCube = 1.0f / sqrt(distSqr * distSqr * distSqr);
 
-	//ai += g_FG * /*g_fParticleMass*/bj.w * distInvCube * r;
+	//ai += g_FG * bj.w * distInvCube * r;
 	ai += g_FG *g_fParticleMass * distInvCube * r;
 }
 
 [numthreads(BLOCK_SIZE,1,1)]
 void CS(uint3 DTid : SV_DispatchThreadID, uint indexGroup : SV_GroupIndex, uint3 Gid : SV_GroupID)
 {
 	float3 accel = float3(0.0f, 0.0f, 0.0f);
 
 	PosVel myParticle = oldPar[DTid.x];
 
 	[loop]
 	for(uint block=0; block< num_blocks; ++block)
 	{
 		//Fetch positions to shared cache
 		sh_Positions[indexGroup] = oldPar[block * BLOCK_SIZE + indexGroup].pos;
 		GroupMemoryBarrierWithGroupSync();
 
 		[unroll]
 		for(uint i = 0; i<BLOCK_SIZE; i+=8)
 		{
 			body_body_interaction(accel, myParticle.pos, sh_Positions[i]);
 			body_body_interaction(accel, myParticle.pos, sh_Positions[i+1]);
 			body_body_interaction(accel, myParticle.pos, sh_Positions[i+2]);
 			body_body_interaction(accel, myParticle.pos, sh_Positions[i+3]);
 			body_body_interaction(accel, myParticle.pos, sh_Positions[i+4]);
 			body_body_interaction(accel, myParticle.pos, sh_Positions[i+5]);
 			body_body_interaction(accel, myParticle.pos, sh_Positions[i+6]);
 			body_body_interaction(accel, myParticle.pos, sh_Positions[i+7]);
 		}
 
 		GroupMemoryBarrierWithGroupSync();
 	}
 
 	//CS returns 0 for memory access out of range (write out of memory are NOPs)
 	//So we calculated gravity for many particles from position (0,0,0), because num_particles != spawned_threads in certain scenarios
 	//We need to subtract it now
 	uint particleDifference = (num_blocks * BLOCK_SIZE) - num_particles;
 	float3 a = float3(0.0f, 0.0f, 0.0f);
 
 	body_body_interaction(a, myParticle.pos, float4(0.0f, 0.0f, 0.0f, 0.0f));
 	accel -= particleDifference * a;
 
 	//Calculate new position and velocity
 	myParticle.vel.xyz += accel * deltaTime;
 	myParticle.pos.xyz += myParticle.vel.xyz * deltaTime;
 
 	//Save to global memory
 	if(DTid.x < num_particles)
 	{
 		newPar[DTid.x].pos = myParticle.pos;
 		newPar[DTid.x].vel = myParticle.vel;
 	}
 }