diff options
| -rw-r--r-- | .gitignore | 1 | ||||
| -rw-r--r-- | filter.bqn | 4 | ||||
| -rw-r--r-- | lib.c | 56 | ||||
| -rw-r--r-- | makefile | 6 |
4 files changed, 67 insertions, 0 deletions
diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..5325f56 --- /dev/null +++ b/.gitignore @@ -0,0 +1 @@ +lib.so @@ -56,6 +56,10 @@ Filter ← { r }¨ 𝕩 }⎉1 +{𝕤 + fi ← "lib.so" (•BQN"•FFI"){𝔽} "&"‿"filter"∾∾("u64"⋈∾⟜"f64")¨"&**" + Filter ↩ Fi∘{ ∾≠⊸⋈¨ ⟨𝕩⟩∾𝕨 }⎉1 +}⎊⊢@ _f ← { !∘0⊘(𝔽⊸Filter) } # Compute the frequency response from coefficients @@ -0,0 +1,56 @@ +#include <stdlib.h> + +typedef long long I; +typedef double D; + +#define DO(n,stm) {I i=0,_n=(n); for(;i<_n;i++){stm}} +#define DECL_ARR(t, v, l) t *v = malloc(sizeof(t)*(l)) + +void filter11(I,D*,D,D); +void filter21(I,D*,D,D,D); +void filter32(I,D*,D,D,D,D,D); +void filter(I length, D* a, I lx, D* xc, I ly, D* yc) { + if (lx==1 && ly==1) { return filter11(length,a,xc[0],yc[0]); } + if (lx==2 && ly==1) { return filter21(length,a,xc[0],xc[1],yc[0]); } + if (lx==3 && ly==2) { return filter32(length,a,xc[0],xc[1],xc[2],yc[0],yc[1]); } + DECL_ARR(D, x, lx); DECL_ARR(D, y, ly); + DO(lx, x[i]=0;); DO(ly, y[i]=0;); + int j, ix=0, iy=0; + for (j=0; j<length; j++) { + x[ix++] = a[j]; ix%=lx; + a[j] = 0; + DO(lx, a[j] += x[(ix+i)%lx] * xc[i];); + DO(ly, a[j] += y[(iy+i)%ly] * yc[i];); + y[iy++] = a[j]; iy%=ly; + } + free(x); free(y); + return; +} + +void filter11(I length, D* a, D xc0, D yc0) { + D x0=0, y0=0; int j; + for (j=0; j<length; j++) { + x0 = a[j]; + a[j] = x0*xc0 + y0*yc0; + y0 = a[j]; + } + return; +} +void filter21(I length, D* a, D xc0, D xc1, D yc0) { + D x0=0, x1=0, y0=0; int j; + for (j=0; j<length; j++) { + x0 = x1; x1 = a[j]; + a[j] = x0*xc0 + x1*xc1 + y0*yc0; + y0 = a[j]; + } + return; +} +void filter32(I length, D* a, D xc0, D xc1, D xc2, D yc0, D yc1) { + D x0=0, x1=0, x2=0, y0=0, y1=0; int j; + for (j=0; j<length; j++) { + x0 = x1; x1 = x2; x2 = a[j]; + a[j] = x0*xc0 + x1*xc1 + x2*xc2 + y0*yc0 + y1*yc1; + y0 = y1; y1 = a[j]; + } + return; +} diff --git a/makefile b/makefile new file mode 100644 index 0000000..e8c7e82 --- /dev/null +++ b/makefile @@ -0,0 +1,6 @@ +CFLAGS = -O3 -fPIC -ffast-math -march=native +FLAGS = -shared +TARGET = lib.so + +$(TARGET): lib.c + cc lib.c $(CFLAGS) $(FLAGS) -o $(TARGET) |