diff options
Diffstat (limited to 'src/kernels/forwardproject.cl')
| -rw-r--r-- | src/kernels/forwardproject.cl | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/src/kernels/forwardproject.cl b/src/kernels/forwardproject.cl index 1022ede..18a8019 100644 --- a/src/kernels/forwardproject.cl +++ b/src/kernels/forwardproject.cl @@ -24,6 +24,7 @@ constant sampler_t sampler = CLK_NORMALIZED_COORDS_FALSE | kernel void forwardproject(read_only image2d_t slice, global float *sinogram, + float axis_pos, float angle_step) { const int idx = get_global_id(0); @@ -32,9 +33,9 @@ forwardproject(read_only image2d_t slice, const float angle = idy * angle_step; /* radius of object circle */ - const float r = slice_width / 2.0f; + const float r = fmin (axis_pos, slice_width - axis_pos); /* positive/negative distance from detector center */ - const float d = idx - r; + const float d = idx - axis_pos + 0.5f; /* length of the cut through the circle */ const float l = sqrt(4.0f*r*r - 4.0f*d*d); @@ -46,7 +47,7 @@ forwardproject(read_only image2d_t slice, const float2 N = (float2) (D.y, -D.x); /* sample point in the circle traveling along N */ - float2 sample = d * D - l/2.0f * N + ((float2) (r, r)); + float2 sample = d * D - l/2.0f * N + ((float2) (axis_pos, axis_pos)); float sum = 0.0f; for (int i = 0; i < l; i++) { |