tmpinterp_wip

1 files changed, 18 insertions, 5 deletions

diff --git a/transfer.c b/transfer.c
index 6db1ad2..aa1fd89 100644
--- a/transfer.c
+++ b/transfer.c
@@ -122,23 +122,36 @@ static int transfer_factors_lagrange(GridTransferContext *ctx, unsigned int dim)
         return -ENOMEM;
 
     for (ptrdiff_t idx_dst = 0; idx_dst < ctx->dst.size[dim]; idx_dst++) {
-        const ptrdiff_t idx_src = (ptrdiff_t)(scale * (idx_dst + ctx->dst.start[dim])) - ctx->src.start[dim] - (priv->stencil / 2 - 1);
+        double *fact = priv->fact[dim] + priv->stencil * idx_dst;
         const double coord_dst  = (idx_dst + ctx->dst.start[dim]) * step_dst;
 
-        double *fact = priv->fact[dim] + priv->stencil * idx_dst;
+        unsigned int stencil;
+        ptrdiff_t idx_src;
+
+        stencil = priv->stencil;
+        idx_src = (ptrdiff_t)(scale * (idx_dst + ctx->dst.start[dim])) - ctx->src.start[dim] - (stencil / 2 - 1);
+        //while (idx_src < 0 && stencil >= 4) {
+        //    stencil -= 2;
+        //    idx_src = (ptrdiff_t)(scale * idx_dst) - (stencil / 2 - 1);
+        //}
+        //if (idx_src < 0) {
+        //    mg2di_assert(stencil == 2);
+        //}
 
-        for (int i = 0; i < priv->stencil; i++)
+        for (int i = 0; i < stencil; i++)
             coord_src[i] = (idx_src + ctx->src.start[dim] + i) * step_src;
 
-        for (int i = 0; i < priv->stencil; i++) {
+        for (int i = 0; i < stencil; i++) {
             fact[i] = 1.0;
-            for (int j = 0; j < priv->stencil; j++) {
+            for (int j = 0; j < stencil; j++) {
                 if (i == j)
                     continue;
 
                 fact[i] *= (coord_dst - coord_src[j]) / (coord_src[i] - coord_src[j]);
             }
         }
+        for (int i = stencil; i < priv->stencil; i++)
+            fact[i] = 0.0;
 
         priv->idx[dim][idx_dst] = idx_src;
     }