108 lines
3.4 KiB
C
108 lines
3.4 KiB
C
/* SPDX-FileCopyrightText: 2009-2010 Sony Pictures Imageworks Inc., et al. All Rights Reserved.
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* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
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*
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* SPDX-License-Identifier: BSD-3-Clause
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*
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* Adapted code from Open Shading Language. */
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#pragma once
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CCL_NAMESPACE_BEGIN
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/* Wireframe Node */
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ccl_device_inline float wireframe(KernelGlobals kg,
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ccl_private ShaderData *sd,
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const differential3 dP,
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float size,
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int pixel_size,
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ccl_private float3 *P)
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{
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#if defined(__HAIR__) || defined(__POINTCLOUD__)
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if (sd->prim != PRIM_NONE && sd->type & PRIMITIVE_TRIANGLE)
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#else
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if (sd->prim != PRIM_NONE)
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#endif
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{
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float3 Co[3];
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float pixelwidth = 1.0f;
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/* Triangles */
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int np = 3;
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if (sd->type & PRIMITIVE_MOTION) {
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motion_triangle_vertices(kg, sd->object, sd->prim, sd->time, Co);
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}
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else {
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triangle_vertices(kg, sd->prim, Co);
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}
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if (!(sd->object_flag & SD_OBJECT_TRANSFORM_APPLIED)) {
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object_position_transform(kg, sd, &Co[0]);
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object_position_transform(kg, sd, &Co[1]);
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object_position_transform(kg, sd, &Co[2]);
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}
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if (pixel_size) {
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// Project the derivatives of P to the viewing plane defined
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// by I so we have a measure of how big is a pixel at this point
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float pixelwidth_x = len(dP.dx - dot(dP.dx, sd->wi) * sd->wi);
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float pixelwidth_y = len(dP.dy - dot(dP.dy, sd->wi) * sd->wi);
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// Take the average of both axis' length
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pixelwidth = (pixelwidth_x + pixelwidth_y) * 0.5f;
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}
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// Use half the width as the neighbor face will render the
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// other half. And take the square for fast comparison
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pixelwidth *= 0.5f * size;
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pixelwidth *= pixelwidth;
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for (int i = 0; i < np; i++) {
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int i2 = i ? i - 1 : np - 1;
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float3 dir = *P - Co[i];
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float3 edge = Co[i] - Co[i2];
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float3 crs = cross(edge, dir);
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// At this point dot(crs, crs) / dot(edge, edge) is
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// the square of area / length(edge) == square of the
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// distance to the edge.
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if (dot(crs, crs) < (dot(edge, edge) * pixelwidth)) {
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return 1.0f;
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}
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}
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}
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return 0.0f;
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}
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ccl_device_noinline void svm_node_wireframe(KernelGlobals kg,
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ccl_private ShaderData *sd,
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ccl_private float *stack,
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uint4 node)
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{
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uint in_size = node.y;
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uint out_fac = node.z;
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uint use_pixel_size, bump_offset;
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svm_unpack_node_uchar2(node.w, &use_pixel_size, &bump_offset);
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/* Input Data */
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float size = stack_load_float(stack, in_size);
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int pixel_size = (int)use_pixel_size;
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/* Calculate wireframe */
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const differential3 dP = differential_from_compact(sd->Ng, sd->dP);
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float f = wireframe(kg, sd, dP, size, pixel_size, &sd->P);
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/* TODO(sergey): Think of faster way to calculate derivatives. */
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if (bump_offset == NODE_BUMP_OFFSET_DX) {
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float3 Px = sd->P - dP.dx;
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f += (f - wireframe(kg, sd, dP, size, pixel_size, &Px)) / len(dP.dx);
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}
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else if (bump_offset == NODE_BUMP_OFFSET_DY) {
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float3 Py = sd->P - dP.dy;
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f += (f - wireframe(kg, sd, dP, size, pixel_size, &Py)) / len(dP.dy);
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}
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if (stack_valid(out_fac))
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stack_store_float(stack, out_fac, f);
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}
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CCL_NAMESPACE_END
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