summaryrefslogtreecommitdiff
path: root/src/random.h
diff options
context:
space:
mode:
Diffstat (limited to 'src/random.h')
-rw-r--r--src/random.h85
1 files changed, 45 insertions, 40 deletions
diff --git a/src/random.h b/src/random.h
index 6abc415..e9d2e75 100644
--- a/src/random.h
+++ b/src/random.h
@@ -5,76 +5,81 @@
#include "physical_constants.h"
-__device__ float uniform(curandState *s, const float &low, const float &high)
+__device__ float
+uniform(curandState *s, const float &low, const float &high)
{
- return low + curand_uniform(s)*(high-low);
+ return low + curand_uniform(s)*(high-low);
}
-__device__ float3 uniform_sphere(curandState *s)
+__device__ float3
+uniform_sphere(curandState *s)
{
- float theta = uniform(s, 0.0f, 2*PI);
- float u = uniform(s, -1.0f, 1.0f);
- float c = sqrtf(1.0f-u*u);
+ float theta = uniform(s, 0.0f, 2*PI);
+ float u = uniform(s, -1.0f, 1.0f);
+ float c = sqrtf(1.0f-u*u);
- return make_float3(c*cosf(theta), c*sinf(theta), u);
+ return make_float3(c*cosf(theta), c*sinf(theta), u);
}
// Draw a random sample given a cumulative distribution function
// Assumptions: ncdf >= 2, cdf_y[0] is 0.0, and cdf_y[ncdf-1] is 1.0
-__device__ float sample_cdf(curandState *rng, int ncdf,
- float *cdf_x, float *cdf_y)
+__device__ float
+sample_cdf(curandState *rng, int ncdf, float *cdf_x, float *cdf_y)
{
- float u = curand_uniform(rng);
-
- // Find u in cdf_y with binary search
- // list must contain at least 2 elements: 0.0 and 1.0
- int lower=0;
- int upper=ncdf-1;
- while(lower < upper-1) {
- int half = (lower+upper) / 2;
- if (u < cdf_y[half])
- upper = half;
- else
- lower = half;
- }
+ float u = curand_uniform(rng);
+
+ // Find u in cdf_y with binary search
+ // list must contain at least 2 elements: 0.0 and 1.0
+ int lower=0;
+ int upper=ncdf-1;
+ while(lower < upper-1) {
+ int half = (lower+upper) / 2;
+ if (u < cdf_y[half])
+ upper = half;
+ else
+ lower = half;
+ }
- float frac = (u - cdf_y[lower]) / (cdf_y[upper] - cdf_y[lower]);
- return cdf_x[lower] * frac + cdf_x[upper] * (1.0f - frac);
+ float frac = (u - cdf_y[lower]) / (cdf_y[upper] - cdf_y[lower]);
+ return cdf_x[lower] * frac + cdf_x[upper] * (1.0f - frac);
}
-
extern "C"
{
-__global__ void init_rng(int nthreads, curandState *s, unsigned long long seed, unsigned long long offset)
+__global__ void
+init_rng(int nthreads, curandState *s, unsigned long long seed,
+ unsigned long long offset)
{
- int id = blockIdx.x*blockDim.x + threadIdx.x;
+ int id = blockIdx.x*blockDim.x + threadIdx.x;
- if (id >= nthreads)
- return;
+ if (id >= nthreads)
+ return;
- curand_init(seed, id, offset, &s[id]);
+ curand_init(seed, id, offset, &s[id]);
}
-__global__ void fill_uniform(int nthreads, curandState *s, float *a, float low, float high)
+__global__ void
+fill_uniform(int nthreads, curandState *s, float *a, float low, float high)
{
- int id = blockIdx.x*blockDim.x + threadIdx.x;
+ int id = blockIdx.x*blockDim.x + threadIdx.x;
- if (id >= nthreads)
- return;
+ if (id >= nthreads)
+ return;
- a[id] = uniform(&s[id], low, high);
+ a[id] = uniform(&s[id], low, high);
}
-__global__ void fill_uniform_sphere(int nthreads, curandState *s, float3 *a)
+__global__ void
+fill_uniform_sphere(int nthreads, curandState *s, float3 *a)
{
- int id = blockIdx.x*blockDim.x + threadIdx.x;
+ int id = blockIdx.x*blockDim.x + threadIdx.x;
- if (id >= nthreads)
- return;
+ if (id >= nthreads)
+ return;
- a[id] = uniform_sphere(&s[id]);
+ a[id] = uniform_sphere(&s[id]);
}
} // extern "c"