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/*
* Parts adapted from Open Shading Language with this license:
*
* Copyright (c) 2009-2010 Sony Pictures Imageworks Inc., et al.
* All Rights Reserved.
*
* Modifications Copyright 2011, Blender Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of Sony Pictures Imageworks nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef __KERNEL_PROJECTION_CL__
#define __KERNEL_PROJECTION_CL__
CCL_NAMESPACE_BEGIN
/* Spherical coordinates <-> Cartesian direction */
ccl_device float2 direction_to_spherical(float3 dir)
{
float theta = safe_acosf(dir.z);
float phi = atan2f(dir.x, dir.y);
return make_float2(theta, phi);
}
ccl_device float3 spherical_to_direction(float theta, float phi)
{
return make_float3(
sinf(theta)*cosf(phi),
sinf(theta)*sinf(phi),
cosf(theta));
}
/* Equirectangular coordinates <-> Cartesian direction */
ccl_device float2 direction_to_equirectangular_range(float3 dir, float4 range)
{
float u = (atan2f(dir.y, dir.x) - range.y) / range.x;
float v = (acosf(dir.z / len(dir)) - range.w) / range.z;
return make_float2(u, v);
}
ccl_device float3 equirectangular_range_to_direction(float u, float v, float4 range)
{
float phi = range.x*u + range.y;
float theta = range.z*v + range.w;
return make_float3(
sinf(theta)*cosf(phi),
sinf(theta)*sinf(phi),
cosf(theta));
}
ccl_device float2 direction_to_equirectangular(float3 dir)
{
return direction_to_equirectangular_range(dir, make_float4(-M_2PI_F, M_PI_F, -M_PI_F, M_PI_F));
}
ccl_device float3 equirectangular_to_direction(float u, float v)
{
return equirectangular_range_to_direction(u, v, make_float4(-M_2PI_F, M_PI_F, -M_PI_F, M_PI_F));
}
/* Fisheye <-> Cartesian direction */
ccl_device float2 direction_to_fisheye(float3 dir, float fov)
{
float r = atan2f(sqrtf(dir.y*dir.y + dir.z*dir.z), dir.x) / fov;
float phi = atan2f(dir.z, dir.y);
float u = r * cosf(phi) + 0.5f;
float v = r * sinf(phi) + 0.5f;
return make_float2(u, v);
}
ccl_device float3 fisheye_to_direction(float u, float v, float fov)
{
u = (u - 0.5f) * 2.0f;
v = (v - 0.5f) * 2.0f;
float r = sqrtf(u*u + v*v);
if(r > 1.0f)
return make_float3(0.0f, 0.0f, 0.0f);
float phi = safe_acosf((r != 0.0f)? u/r: 0.0f);
float theta = r * fov * 0.5f;
if(v < 0.0f) phi = -phi;
return make_float3(
cosf(theta),
-cosf(phi)*sinf(theta),
sinf(phi)*sinf(theta)
);
}
ccl_device float2 direction_to_fisheye_equisolid(float3 dir, float lens, float width, float height)
{
float theta = safe_acosf(dir.x);
float r = 2.0f * lens * sinf(theta * 0.5f);
float phi = atan2f(dir.z, dir.y);
float u = r * cosf(phi) / width + 0.5f;
float v = r * sinf(phi) / height + 0.5f;
return make_float2(u, v);
}
ccl_device float3 fisheye_equisolid_to_direction(float u, float v, float lens, float fov, float width, float height)
{
u = (u - 0.5f) * width;
v = (v - 0.5f) * height;
float rmax = 2.0f * lens * sinf(fov * 0.25f);
float r = sqrtf(u*u + v*v);
if(r > rmax)
return make_float3(0.0f, 0.0f, 0.0f);
float phi = safe_acosf((r != 0.0f)? u/r: 0.0f);
float theta = 2.0f * asinf(r/(2.0f * lens));
if(v < 0.0f) phi = -phi;
return make_float3(
cosf(theta),
-cosf(phi)*sinf(theta),
sinf(phi)*sinf(theta)
);
}
/* Mirror Ball <-> Cartesion direction */
ccl_device float3 mirrorball_to_direction(float u, float v)
{
/* point on sphere */
float3 dir;
dir.x = 2.0f*u - 1.0f;
dir.z = 2.0f*v - 1.0f;
if(dir.x*dir.x + dir.z*dir.z > 1.0f)
return make_float3(0.0f, 0.0f, 0.0f);
dir.y = -sqrtf(max(1.0f - dir.x*dir.x - dir.z*dir.z, 0.0f));
/* reflection */
float3 I = make_float3(0.0f, -1.0f, 0.0f);
return 2.0f*dot(dir, I)*dir - I;
}
ccl_device float2 direction_to_mirrorball(float3 dir)
{
/* inverse of mirrorball_to_direction */
dir.y -= 1.0f;
float div = 2.0f*sqrtf(max(-0.5f*dir.y, 0.0f));
if(div > 0.0f)
dir /= div;
float u = 0.5f*(dir.x + 1.0f);
float v = 0.5f*(dir.z + 1.0f);
return make_float2(u, v);
}
ccl_device float3 panorama_to_direction(KernelGlobals *kg, float u, float v)
{
switch(kernel_data.cam.panorama_type) {
case PANORAMA_EQUIRECTANGULAR:
return equirectangular_range_to_direction(u, v, kernel_data.cam.equirectangular_range);
case PANORAMA_MIRRORBALL:
return mirrorball_to_direction(u, v);
case PANORAMA_FISHEYE_EQUIDISTANT:
return fisheye_to_direction(u, v, kernel_data.cam.fisheye_fov);
case PANORAMA_FISHEYE_EQUISOLID:
default:
return fisheye_equisolid_to_direction(u, v, kernel_data.cam.fisheye_lens,
kernel_data.cam.fisheye_fov, kernel_data.cam.sensorwidth, kernel_data.cam.sensorheight);
}
}
ccl_device float2 direction_to_panorama(KernelGlobals *kg, float3 dir)
{
switch(kernel_data.cam.panorama_type) {
case PANORAMA_EQUIRECTANGULAR:
return direction_to_equirectangular_range(dir, kernel_data.cam.equirectangular_range);
case PANORAMA_MIRRORBALL:
return direction_to_mirrorball(dir);
case PANORAMA_FISHEYE_EQUIDISTANT:
return direction_to_fisheye(dir, kernel_data.cam.fisheye_fov);
case PANORAMA_FISHEYE_EQUISOLID:
default:
return direction_to_fisheye_equisolid(dir, kernel_data.cam.fisheye_lens,
kernel_data.cam.sensorwidth, kernel_data.cam.sensorheight);
}
}
CCL_NAMESPACE_END
#endif /* __KERNEL_PROJECTION_CL__ */
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