blender/intern/cycles/util/math_float2.h
Lukas Stockner e308b891c8 Cycles: Use faster and exact GGX VNDF sampling algorithm
Based on "Sampling the GGX Distribution of Visible Normals" by Eric Heitz
(https://jcgt.org/published/0007/04/01/).

Also, this removes the lambdaI computation from the Beckmann sampling code and
just recomputes it below. We already need to recompute for two other cases
(GGX and clearcoat), so this makes the code more consistent.

In terms of performance, I don't expect a notable impact since the earlier
computation also was non-trivial, and while it probably was slightly more
accurate, I'd argue that being consistent between evaluation and sampling is
more important than absolute numerical accuracy anyways.

Differential Revision: https://developer.blender.org/D17100
2023-01-24 17:59:29 +01:00

220 lines
4.3 KiB
C

/* SPDX-License-Identifier: Apache-2.0
* Copyright 2011-2022 Blender Foundation */
#ifndef __UTIL_MATH_FLOAT2_H__
#define __UTIL_MATH_FLOAT2_H__
#ifndef __UTIL_MATH_H__
# error "Do not include this file directly, include util/types.h instead."
#endif
CCL_NAMESPACE_BEGIN
ccl_device_inline float2 zero_float2()
{
return make_float2(0.0f, 0.0f);
}
ccl_device_inline float2 one_float2()
{
return make_float2(1.0f, 1.0f);
}
#if !defined(__KERNEL_METAL__)
ccl_device_inline float2 operator-(const float2 &a)
{
return make_float2(-a.x, -a.y);
}
ccl_device_inline float2 operator*(const float2 a, const float2 b)
{
return make_float2(a.x * b.x, a.y * b.y);
}
ccl_device_inline float2 operator*(const float2 a, float f)
{
return make_float2(a.x * f, a.y * f);
}
ccl_device_inline float2 operator*(float f, const float2 a)
{
return make_float2(a.x * f, a.y * f);
}
ccl_device_inline float2 operator/(float f, const float2 a)
{
return make_float2(f / a.x, f / a.y);
}
ccl_device_inline float2 operator/(const float2 a, float f)
{
float invf = 1.0f / f;
return make_float2(a.x * invf, a.y * invf);
}
ccl_device_inline float2 operator/(const float2 a, const float2 b)
{
return make_float2(a.x / b.x, a.y / b.y);
}
ccl_device_inline float2 operator+(const float2 a, const float2 b)
{
return make_float2(a.x + b.x, a.y + b.y);
}
ccl_device_inline float2 operator+(const float2 a, const float f)
{
return a + make_float2(f, f);
}
ccl_device_inline float2 operator-(const float2 a, const float2 b)
{
return make_float2(a.x - b.x, a.y - b.y);
}
ccl_device_inline float2 operator-(const float2 a, const float f)
{
return a - make_float2(f, f);
}
ccl_device_inline float2 operator+=(float2 &a, const float2 b)
{
return a = a + b;
}
ccl_device_inline float2 operator*=(float2 &a, const float2 b)
{
return a = a * b;
}
ccl_device_inline float2 operator*=(float2 &a, float f)
{
return a = a * f;
}
ccl_device_inline float2 operator/=(float2 &a, const float2 b)
{
return a = a / b;
}
ccl_device_inline float2 operator/=(float2 &a, float f)
{
float invf = 1.0f / f;
return a = a * invf;
}
ccl_device_inline bool operator==(const float2 a, const float2 b)
{
return (a.x == b.x && a.y == b.y);
}
ccl_device_inline bool operator!=(const float2 a, const float2 b)
{
return !(a == b);
}
ccl_device_inline bool is_zero(const float2 a)
{
return (a.x == 0.0f && a.y == 0.0f);
}
ccl_device_inline float average(const float2 a)
{
return (a.x + a.y) * (1.0f / 2.0f);
}
ccl_device_inline float dot(const float2 a, const float2 b)
{
return a.x * b.x + a.y * b.y;
}
#endif
ccl_device_inline float len(const float2 a)
{
return sqrtf(dot(a, a));
}
ccl_device_inline float len_squared(const float2 a)
{
return dot(a, a);
}
#if !defined(__KERNEL_METAL__)
ccl_device_inline float distance(const float2 a, const float2 b)
{
return len(a - b);
}
ccl_device_inline float cross(const float2 a, const float2 b)
{
return (a.x * b.y - a.y * b.x);
}
ccl_device_inline float2 normalize(const float2 a)
{
return a / len(a);
}
ccl_device_inline float2 normalize_len(const float2 a, ccl_private float *t)
{
*t = len(a);
return a / (*t);
}
ccl_device_inline float2 safe_normalize(const float2 a)
{
float t = len(a);
return (t != 0.0f) ? a / t : a;
}
ccl_device_inline float2 min(const float2 a, const float2 b)
{
return make_float2(min(a.x, b.x), min(a.y, b.y));
}
ccl_device_inline float2 max(const float2 a, const float2 b)
{
return make_float2(max(a.x, b.x), max(a.y, b.y));
}
ccl_device_inline float2 clamp(const float2 a, const float2 mn, const float2 mx)
{
return min(max(a, mn), mx);
}
ccl_device_inline float2 fabs(const float2 a)
{
return make_float2(fabsf(a.x), fabsf(a.y));
}
ccl_device_inline float2 as_float2(const float4 &a)
{
return make_float2(a.x, a.y);
}
ccl_device_inline float2 interp(const float2 a, const float2 b, float t)
{
return a + t * (b - a);
}
ccl_device_inline float2 mix(const float2 a, const float2 b, float t)
{
return a + t * (b - a);
}
ccl_device_inline float2 floor(const float2 a)
{
return make_float2(floorf(a.x), floorf(a.y));
}
#endif /* !__KERNEL_METAL__ */
ccl_device_inline float2 safe_divide_float2_float(const float2 a, const float b)
{
return (b != 0.0f) ? a / b : zero_float2();
}
CCL_NAMESPACE_END
#endif /* __UTIL_MATH_FLOAT2_H__ */