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Diffstat (limited to 'intern/cycles/kernel/shaders/oslutil.h')
| -rw-r--r-- | intern/cycles/kernel/shaders/oslutil.h | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/intern/cycles/kernel/shaders/oslutil.h b/intern/cycles/kernel/shaders/oslutil.h new file mode 100644 index 00000000000..6c91684d9a6 --- /dev/null +++ b/intern/cycles/kernel/shaders/oslutil.h @@ -0,0 +1,94 @@ +///////////////////////////////////////////////////////////////////////////// +// Copyright (c) 2009-2010 Sony Pictures Imageworks Inc., et al. All Rights Reserved. +// +// 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 */ |