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Diffstat (limited to 'intern/cycles/kernel/geom/patch.h')
-rw-r--r-- | intern/cycles/kernel/geom/patch.h | 470 |
1 files changed, 470 insertions, 0 deletions
diff --git a/intern/cycles/kernel/geom/patch.h b/intern/cycles/kernel/geom/patch.h new file mode 100644 index 00000000000..7d24937a41e --- /dev/null +++ b/intern/cycles/kernel/geom/patch.h @@ -0,0 +1,470 @@ +/* + * Based on code from OpenSubdiv released under this license: + * + * Copyright 2013 Pixar + * + * Licensed under the Apache License, Version 2.0 (the "Apache License") + * with the following modification; you may not use this file except in + * compliance with the Apache License and the following modification to it: + * Section 6. Trademarks. is deleted and replaced with: + * + * 6. Trademarks. This License does not grant permission to use the trade + * names, trademarks, service marks, or product names of the Licensor + * and its affiliates, except as required to comply with Section 4(c) of + * the License and to reproduce the content of the NOTICE file. + * + * You may obtain a copy of the Apache License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the Apache License with the above modification is + * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the Apache License for the specific + * language governing permissions and limitations under the Apache License. + */ + +#pragma once + +#include "util/color.h" + +CCL_NAMESPACE_BEGIN + +typedef struct PatchHandle { + int array_index, patch_index, vert_index; +} PatchHandle; + +ccl_device_inline int patch_map_resolve_quadrant(float median, + ccl_private float *u, + ccl_private float *v) +{ + int quadrant = -1; + + if (*u < median) { + if (*v < median) { + quadrant = 0; + } + else { + quadrant = 1; + *v -= median; + } + } + else { + if (*v < median) { + quadrant = 3; + } + else { + quadrant = 2; + *v -= median; + } + *u -= median; + } + + return quadrant; +} + +/* retrieve PatchHandle from patch coords */ + +ccl_device_inline PatchHandle +patch_map_find_patch(KernelGlobals kg, int object, int patch, float u, float v) +{ + PatchHandle handle; + + kernel_assert((u >= 0.0f) && (u <= 1.0f) && (v >= 0.0f) && (v <= 1.0f)); + + int node = (object_patch_map_offset(kg, object) + patch) / 2; + float median = 0.5f; + + for (int depth = 0; depth < 0xff; depth++) { + float delta = median * 0.5f; + + int quadrant = patch_map_resolve_quadrant(median, &u, &v); + kernel_assert(quadrant >= 0); + + uint child = kernel_tex_fetch(__patches, node + quadrant); + + /* is the quadrant a hole? */ + if (!(child & PATCH_MAP_NODE_IS_SET)) { + handle.array_index = -1; + return handle; + } + + uint index = child & PATCH_MAP_NODE_INDEX_MASK; + + if (child & PATCH_MAP_NODE_IS_LEAF) { + handle.array_index = kernel_tex_fetch(__patches, index + 0); + handle.patch_index = kernel_tex_fetch(__patches, index + 1); + handle.vert_index = kernel_tex_fetch(__patches, index + 2); + + return handle; + } + else { + node = index; + } + + median = delta; + } + + /* no leaf found */ + kernel_assert(0); + + handle.array_index = -1; + return handle; +} + +ccl_device_inline void patch_eval_bspline_weights(float t, + ccl_private float *point, + ccl_private float *deriv) +{ + /* The four uniform cubic B-Spline basis functions evaluated at t */ + float inv_6 = 1.0f / 6.0f; + + float t2 = t * t; + float t3 = t * t2; + + point[0] = inv_6 * (1.0f - 3.0f * (t - t2) - t3); + point[1] = inv_6 * (4.0f - 6.0f * t2 + 3.0f * t3); + point[2] = inv_6 * (1.0f + 3.0f * (t + t2 - t3)); + point[3] = inv_6 * t3; + + /* Derivatives of the above four basis functions at t */ + deriv[0] = -0.5f * t2 + t - 0.5f; + deriv[1] = 1.5f * t2 - 2.0f * t; + deriv[2] = -1.5f * t2 + t + 0.5f; + deriv[3] = 0.5f * t2; +} + +ccl_device_inline void patch_eval_adjust_boundary_weights(uint bits, + ccl_private float *s, + ccl_private float *t) +{ + int boundary = ((bits >> 8) & 0xf); + + if (boundary & 1) { + t[2] -= t[0]; + t[1] += 2 * t[0]; + t[0] = 0; + } + + if (boundary & 2) { + s[1] -= s[3]; + s[2] += 2 * s[3]; + s[3] = 0; + } + + if (boundary & 4) { + t[1] -= t[3]; + t[2] += 2 * t[3]; + t[3] = 0; + } + + if (boundary & 8) { + s[2] -= s[0]; + s[1] += 2 * s[0]; + s[0] = 0; + } +} + +ccl_device_inline int patch_eval_depth(uint patch_bits) +{ + return (patch_bits & 0xf); +} + +ccl_device_inline float patch_eval_param_fraction(uint patch_bits) +{ + bool non_quad_root = (patch_bits >> 4) & 0x1; + int depth = patch_eval_depth(patch_bits); + + if (non_quad_root) { + return 1.0f / (float)(1 << (depth - 1)); + } + else { + return 1.0f / (float)(1 << depth); + } +} + +ccl_device_inline void patch_eval_normalize_coords(uint patch_bits, + ccl_private float *u, + ccl_private float *v) +{ + float frac = patch_eval_param_fraction(patch_bits); + + int iu = (patch_bits >> 22) & 0x3ff; + int iv = (patch_bits >> 12) & 0x3ff; + + /* top left corner */ + float pu = (float)iu * frac; + float pv = (float)iv * frac; + + /* normalize uv coordinates */ + *u = (*u - pu) / frac; + *v = (*v - pv) / frac; +} + +/* retrieve patch control indices */ + +ccl_device_inline int patch_eval_indices(KernelGlobals kg, + ccl_private const PatchHandle *handle, + int channel, + int indices[PATCH_MAX_CONTROL_VERTS]) +{ + int index_base = kernel_tex_fetch(__patches, handle->array_index + 2) + handle->vert_index; + + /* XXX: regular patches only */ + for (int i = 0; i < 16; i++) { + indices[i] = kernel_tex_fetch(__patches, index_base + i); + } + + return 16; +} + +/* evaluate patch basis functions */ + +ccl_device_inline void patch_eval_basis(KernelGlobals kg, + ccl_private const PatchHandle *handle, + float u, + float v, + float weights[PATCH_MAX_CONTROL_VERTS], + float weights_du[PATCH_MAX_CONTROL_VERTS], + float weights_dv[PATCH_MAX_CONTROL_VERTS]) +{ + uint patch_bits = kernel_tex_fetch(__patches, handle->patch_index + 1); /* read patch param */ + float d_scale = 1 << patch_eval_depth(patch_bits); + + bool non_quad_root = (patch_bits >> 4) & 0x1; + if (non_quad_root) { + d_scale *= 0.5f; + } + + patch_eval_normalize_coords(patch_bits, &u, &v); + + /* XXX: regular patches only for now. */ + + float s[4], t[4], ds[4], dt[4]; + + patch_eval_bspline_weights(u, s, ds); + patch_eval_bspline_weights(v, t, dt); + + patch_eval_adjust_boundary_weights(patch_bits, s, t); + patch_eval_adjust_boundary_weights(patch_bits, ds, dt); + + for (int k = 0; k < 4; k++) { + for (int l = 0; l < 4; l++) { + weights[4 * k + l] = s[l] * t[k]; + weights_du[4 * k + l] = ds[l] * t[k] * d_scale; + weights_dv[4 * k + l] = s[l] * dt[k] * d_scale; + } + } +} + +/* generic function for evaluating indices and weights from patch coords */ + +ccl_device_inline int patch_eval_control_verts(KernelGlobals kg, + int object, + int patch, + float u, + float v, + int channel, + int indices[PATCH_MAX_CONTROL_VERTS], + float weights[PATCH_MAX_CONTROL_VERTS], + float weights_du[PATCH_MAX_CONTROL_VERTS], + float weights_dv[PATCH_MAX_CONTROL_VERTS]) +{ + PatchHandle handle = patch_map_find_patch(kg, object, patch, u, v); + kernel_assert(handle.array_index >= 0); + + int num_control = patch_eval_indices(kg, &handle, channel, indices); + patch_eval_basis(kg, &handle, u, v, weights, weights_du, weights_dv); + + return num_control; +} + +/* functions for evaluating attributes on patches */ + +ccl_device float patch_eval_float(KernelGlobals kg, + ccl_private const ShaderData *sd, + int offset, + int patch, + float u, + float v, + int channel, + ccl_private float *du, + ccl_private float *dv) +{ + int indices[PATCH_MAX_CONTROL_VERTS]; + float weights[PATCH_MAX_CONTROL_VERTS]; + float weights_du[PATCH_MAX_CONTROL_VERTS]; + float weights_dv[PATCH_MAX_CONTROL_VERTS]; + + int num_control = patch_eval_control_verts( + kg, sd->object, patch, u, v, channel, indices, weights, weights_du, weights_dv); + + float val = 0.0f; + if (du) + *du = 0.0f; + if (dv) + *dv = 0.0f; + + for (int i = 0; i < num_control; i++) { + float v = kernel_tex_fetch(__attributes_float, offset + indices[i]); + + val += v * weights[i]; + if (du) + *du += v * weights_du[i]; + if (dv) + *dv += v * weights_dv[i]; + } + + return val; +} + +ccl_device float2 patch_eval_float2(KernelGlobals kg, + ccl_private const ShaderData *sd, + int offset, + int patch, + float u, + float v, + int channel, + ccl_private float2 *du, + ccl_private float2 *dv) +{ + int indices[PATCH_MAX_CONTROL_VERTS]; + float weights[PATCH_MAX_CONTROL_VERTS]; + float weights_du[PATCH_MAX_CONTROL_VERTS]; + float weights_dv[PATCH_MAX_CONTROL_VERTS]; + + int num_control = patch_eval_control_verts( + kg, sd->object, patch, u, v, channel, indices, weights, weights_du, weights_dv); + + float2 val = make_float2(0.0f, 0.0f); + if (du) + *du = make_float2(0.0f, 0.0f); + if (dv) + *dv = make_float2(0.0f, 0.0f); + + for (int i = 0; i < num_control; i++) { + float2 v = kernel_tex_fetch(__attributes_float2, offset + indices[i]); + + val += v * weights[i]; + if (du) + *du += v * weights_du[i]; + if (dv) + *dv += v * weights_dv[i]; + } + + return val; +} + +ccl_device float3 patch_eval_float3(KernelGlobals kg, + ccl_private const ShaderData *sd, + int offset, + int patch, + float u, + float v, + int channel, + ccl_private float3 *du, + ccl_private float3 *dv) +{ + int indices[PATCH_MAX_CONTROL_VERTS]; + float weights[PATCH_MAX_CONTROL_VERTS]; + float weights_du[PATCH_MAX_CONTROL_VERTS]; + float weights_dv[PATCH_MAX_CONTROL_VERTS]; + + int num_control = patch_eval_control_verts( + kg, sd->object, patch, u, v, channel, indices, weights, weights_du, weights_dv); + + float3 val = make_float3(0.0f, 0.0f, 0.0f); + if (du) + *du = make_float3(0.0f, 0.0f, 0.0f); + if (dv) + *dv = make_float3(0.0f, 0.0f, 0.0f); + + for (int i = 0; i < num_control; i++) { + float3 v = float4_to_float3(kernel_tex_fetch(__attributes_float3, offset + indices[i])); + + val += v * weights[i]; + if (du) + *du += v * weights_du[i]; + if (dv) + *dv += v * weights_dv[i]; + } + + return val; +} + +ccl_device float4 patch_eval_float4(KernelGlobals kg, + ccl_private const ShaderData *sd, + int offset, + int patch, + float u, + float v, + int channel, + ccl_private float4 *du, + ccl_private float4 *dv) +{ + int indices[PATCH_MAX_CONTROL_VERTS]; + float weights[PATCH_MAX_CONTROL_VERTS]; + float weights_du[PATCH_MAX_CONTROL_VERTS]; + float weights_dv[PATCH_MAX_CONTROL_VERTS]; + + int num_control = patch_eval_control_verts( + kg, sd->object, patch, u, v, channel, indices, weights, weights_du, weights_dv); + + float4 val = make_float4(0.0f, 0.0f, 0.0f, 0.0f); + if (du) + *du = make_float4(0.0f, 0.0f, 0.0f, 0.0f); + if (dv) + *dv = make_float4(0.0f, 0.0f, 0.0f, 0.0f); + + for (int i = 0; i < num_control; i++) { + float4 v = kernel_tex_fetch(__attributes_float3, offset + indices[i]); + + val += v * weights[i]; + if (du) + *du += v * weights_du[i]; + if (dv) + *dv += v * weights_dv[i]; + } + + return val; +} + +ccl_device float4 patch_eval_uchar4(KernelGlobals kg, + ccl_private const ShaderData *sd, + int offset, + int patch, + float u, + float v, + int channel, + ccl_private float4 *du, + ccl_private float4 *dv) +{ + int indices[PATCH_MAX_CONTROL_VERTS]; + float weights[PATCH_MAX_CONTROL_VERTS]; + float weights_du[PATCH_MAX_CONTROL_VERTS]; + float weights_dv[PATCH_MAX_CONTROL_VERTS]; + + int num_control = patch_eval_control_verts( + kg, sd->object, patch, u, v, channel, indices, weights, weights_du, weights_dv); + + float4 val = make_float4(0.0f, 0.0f, 0.0f, 0.0f); + if (du) + *du = make_float4(0.0f, 0.0f, 0.0f, 0.0f); + if (dv) + *dv = make_float4(0.0f, 0.0f, 0.0f, 0.0f); + + for (int i = 0; i < num_control; i++) { + float4 v = color_srgb_to_linear_v4( + color_uchar4_to_float4(kernel_tex_fetch(__attributes_uchar4, offset + indices[i]))); + + val += v * weights[i]; + if (du) + *du += v * weights_du[i]; + if (dv) + *dv += v * weights_dv[i]; + } + + return val; +} + +CCL_NAMESPACE_END |