semilagranianfluidnewdiffuse.fp

PDE simulator on GPU.

!!FP1.0
#2d FLUID Diffuse for Density or Velocity or Pressure
DECLARE TexPARA = {0,0,0,0};
#TEX0 -- OldValue
#TEX1 -- NewValue
ADDH H0, f[WPOS].xyxy, {1,0,-1,0};
#U(i+1,j)
TEX R1, H0.xyww, TEX1, RECT;

#U(i-1,j)
TEX R2, H0.zwww, TEX1, RECT;
ADD R2, R1, R2;

ADDH H0, f[WPOS].xyxy, {0,1,0,-1};
#U(i,j+1)
TEX R1, H0.xyww, TEX1, RECT;
ADD R2, R1, R2;

#U(i,j-1)-->R5
TEX R1, H0.zwww, TEX1, RECT;
ADD R2, R1, R2;

TEX R0, f[WPOS], TEX0, RECT;
MAD R0, R2, TexPARA.xxzz, R0;
MUL R0, R0, TexPARA.yyww;

#Tex2 --BoundaryConditionTexID
TEX R1, f[WPOS], TEX2, RECT;

MUL o[COLR], R0, R1;

END