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| author | Soumith Chintala <soumith@gmail.com> | 2015-06-14 05:30:43 +0300 |
|---|---|---|
| committer | Soumith Chintala <soumith@gmail.com> | 2015-06-14 05:30:43 +0300 |
| commit | e7c3cdb97d5bc890f7d7fff1144bb273ffdc37f3 (patch) | |
| tree | 84467389e7c7b0023f079d987832aee9577f27c7 | |
| parent | 6df44fb23fba5861fdefa6fb0885675ddc35e338 (diff) | |
| parent | f9ca80c3fb62cfc11b2504e004805caa431dcfb2 (diff) | |
Merge pull request #72 from Maratyszcza/patch-1
Avoid recomputing sin/cos in rotate main loop
| -rwxr-xr-x | generic/image.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/generic/image.c b/generic/image.c index 8aa77f0..27469ab 100755 --- a/generic/image.c +++ b/generic/image.c @@ -257,6 +257,7 @@ static int image_(Main_rotate)(lua_State *L) THTensor *Tsrc = luaT_checkudata(L, 1, torch_Tensor); THTensor *Tdst = luaT_checkudata(L, 2, torch_Tensor); float theta = luaL_checknumber(L, 3); + float cos_theta, sin_theta; real *src, *dst; long dst_stride0, dst_stride1, dst_stride2, dst_width, dst_height, dst_depth; long src_stride0, src_stride1, src_stride2, src_width, src_height, src_depth; @@ -302,14 +303,17 @@ static int image_(Main_rotate)(lua_State *L) xc=src_width/2.0; yc=src_height/2.0; + sin_theta = sinf(theta); + cos_theta = cosf(theta); + for(j = 0; j < dst_height; j++) { jd=j; for(i = 0; i < dst_width; i++) { float val = -1; id= i; - ii=(long)( cos(theta)*(id-xc)-sin(theta)*(jd-yc) ); - jj=(long)( cos(theta)*(jd-yc)+sin(theta)*(id-xc) ); + ii=(long)( cos_theta*(id-xc)-sin_theta*(jd-yc) ); + jj=(long)( cos_theta*(jd-yc)+sin_theta*(id-xc) ); ii+=(long) xc; jj+=(long) yc; /* rotated corners are blank */ |