forked from bartvdbraak/blender
b9ce231060
More information in this post: http://code.blender.org/ Thanks to all contributes for giving their permission!
99 lines
3.8 KiB
C
99 lines
3.8 KiB
C
/*
|
|
* 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 CCL_OSLUTIL_H
|
|
#define CCL_OSLUTIL_H
|
|
|
|
/* NB: must match the value in kernel_types.h */
|
|
#define RAMP_TABLE_SIZE 256
|
|
|
|
// Return wireframe opacity factor [0, 1] given a geometry type in
|
|
// ("triangles", "polygons" or "patches"), and a line_width in raster
|
|
// or world space depending on the last (raster) boolean argument.
|
|
//
|
|
float wireframe(string edge_type, float line_width, int raster)
|
|
{
|
|
// ray differentials are so big in diffuse context that this function would always return "wire"
|
|
if (raytype("path:diffuse")) return 0.0;
|
|
|
|
int np = 0;
|
|
point p[64];
|
|
float pixelWidth = 1;
|
|
|
|
if (edge_type == "triangles")
|
|
{
|
|
np = 3;
|
|
if (!getattribute("geom:trianglevertices", p))
|
|
return 0.0;
|
|
}
|
|
else if (edge_type == "polygons" || edge_type == "patches")
|
|
{
|
|
getattribute("geom:numpolyvertices", np);
|
|
if (np < 3 || !getattribute("geom:polyvertices", p))
|
|
return 0.0;
|
|
}
|
|
|
|
if (raster)
|
|
{
|
|
// Project the derivatives of P to the viewing plane defined
|
|
// by I so we have a measure of how big is a pixel at this point
|
|
float pixelWidthX = length(Dx(P) - dot(Dx(P), I) * I);
|
|
float pixelWidthY = length(Dy(P) - dot(Dy(P), I) * I);
|
|
// Take the average of both axis' length
|
|
pixelWidth = (pixelWidthX + pixelWidthY) / 2;
|
|
}
|
|
|
|
// Use half the width as the neighbor face will render the
|
|
// other half. And take the square for fast comparison
|
|
pixelWidth *= 0.5 * line_width;
|
|
pixelWidth *= pixelWidth;
|
|
for (int i = 0; i < np; i++)
|
|
{
|
|
int i2 = i ? i - 1 : np - 1;
|
|
vector dir = P - p[i];
|
|
vector edge = p[i] - p[i2];
|
|
vector crs = cross(edge, dir);
|
|
// At this point dot(crs, crs) / dot(edge, edge) is
|
|
// the square of area / length(edge) == square of the
|
|
// distance to the edge.
|
|
if (dot(crs, crs) < (dot(edge, edge) * pixelWidth))
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
float wireframe(string edge_type, float line_width) { return wireframe(edge_type, line_width, 1); }
|
|
float wireframe(string edge_type) { return wireframe(edge_type, 1.0, 1); }
|
|
float wireframe() { return wireframe("polygons", 1.0, 1); }
|
|
|
|
#endif /* CCL_OSLUTIL_H */
|