Add Chromium-only Blender WebEngine parity work

blender-5.2.0/intern/cycles/kernel/bake/bake.h

@@ -0,0 +1,236 @@
+/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
+ *
+ * SPDX-License-Identifier: Apache-2.0 */
+
+#pragma once
+
+#include "kernel/globals.h"
+
+#include "kernel/camera/projection.h"
+#include "kernel/integrator/displacement_shader.h"
+#include "kernel/integrator/state.h"
+#include "kernel/integrator/surface_shader.h"
+#include "kernel/integrator/volume_shader.h"
+
+#include "kernel/geom/object.h"
+#include "kernel/geom/shader_data.h"
+
+#include "kernel/util/colorspace.h"
+
+CCL_NAMESPACE_BEGIN
+
+ccl_device void kernel_displace_evaluate(KernelGlobals kg,
+                                         const ccl_global KernelShaderEvalInput *input,
+                                         ccl_global float *output,
+                                         ccl_global uint *cache_miss,
+                                         const int offset)
+{
+  /* Setup shader data. */
+  const KernelShaderEvalInput in = input[offset];
+
+  ShaderData sd;
+  shader_setup_from_displace(kg, &sd, in.object, in.prim, in.u, in.v);
+
+  /* Evaluate displacement shader. */
+  ConstIntegratorBakeState state;
+  const float3 P = sd.P;
+  displacement_shader_eval(kg, state, &sd);
+  float3 D = sd.P - P;
+  if (sd.flag & SD_CACHE_MISS) {
+    *cache_miss = true;
+  }
+  object_inverse_dir_transform(kg, &sd, &D);
+
+#ifdef __KERNEL_DEBUG_NAN__
+  if (!isfinite_safe(D)) {
+    kernel_assert(!"Cycles displacement with non-finite value detected");
+  }
+#endif
+
+  /* Ensure finite displacement, preventing BVH from becoming degenerate and avoiding possible
+   * traversal issues caused by non-finite math. */
+  D = ensure_finite(D);
+
+  /* Write output. */
+  output[offset * 3 + 0] = D.x;
+  output[offset * 3 + 1] = D.y;
+  output[offset * 3 + 2] = D.z;
+}
+
+ccl_device void kernel_background_evaluate(KernelGlobals kg,
+                                           const ccl_global KernelShaderEvalInput *input,
+                                           ccl_global float *output,
+                                           ccl_global uint *cache_miss,
+                                           const int offset)
+{
+  /* Setup ray */
+  const KernelShaderEvalInput in = input[offset];
+  const float3 ray_P = zero_float3();
+  const float3 ray_D = equirectangular_to_direction(in.u, in.v);
+  const float ray_time = 0.5f;
+
+  /* Compute ray differential from resolution passed via object and prim fields. */
+  const float du = 1.0f / in.object;
+  const float dv = 1.0f / in.prim;
+  const float3 ray_D_du = equirectangular_to_direction(in.u + du, in.v);
+  const float3 ray_D_dv = equirectangular_to_direction(in.u, in.v + dv);
+  const float ray_dD = 0.5f * (len(ray_D_du - ray_D) + len(ray_D_dv - ray_D));
+
+  /* Setup shader data. */
+  ShaderData sd;
+  shader_setup_from_background(kg, &sd, ray_P, ray_D, ray_dD, ray_time);
+
+  /* Evaluate shader.
+   * This is being evaluated for all BSDFs, so path flag does not contain a specific type.
+   * However, we want to flag the ray visibility to ignore the sun in the background map. */
+  ConstIntegratorBakeState state;
+  const uint32_t path_flag = PATH_RAY_EMISSION | PATH_RAY_IMPORTANCE_BAKE;
+  surface_shader_eval<KERNEL_FEATURE_NODE_MASK_SURFACE_LIGHT &
+                      ~(KERNEL_FEATURE_NODE_RAYTRACE | KERNEL_FEATURE_NODE_LIGHT_PATH)>(
+      kg, state, &sd, nullptr, PATH_RAY_VISIBILITY_NONE, path_flag);
+  if (sd.flag & SD_CACHE_MISS) {
+    *cache_miss = true;
+  }
+
+  Spectrum color = surface_shader_background(&sd);
+
+#ifdef __KERNEL_DEBUG_NAN__
+  if (!isfinite_safe(color)) {
+    kernel_assert(!"Cycles background with non-finite value detected");
+  }
+#endif
+
+  /* Ensure finite color, avoiding possible numerical instabilities in the path tracing kernels. */
+  color = ensure_finite(color);
+
+  const float3 color_rgb = spectrum_to_rgb(color);
+
+  /* Write output. */
+  output[offset * 3 + 0] = color_rgb.x;
+  output[offset * 3 + 1] = color_rgb.y;
+  output[offset * 3 + 2] = color_rgb.z;
+}
+
+ccl_device void kernel_curve_shadow_transparency_evaluate(
+    KernelGlobals kg,
+    const ccl_global KernelShaderEvalInput *input,
+    ccl_global float *output,
+    ccl_global uint *cache_miss,
+    const int offset)
+{
+#ifdef __HAIR__
+  /* Setup shader data. */
+  const KernelShaderEvalInput in = input[offset];
+
+  ShaderData sd;
+  shader_setup_from_curve(kg, &sd, in.object, in.prim, __float_as_int(in.v), in.u);
+
+  /* Evaluate transparency. */
+  ConstIntegratorBakeState state;
+  surface_shader_eval<KERNEL_FEATURE_NODE_MASK_SURFACE_SHADOW &
+                      ~(KERNEL_FEATURE_NODE_RAYTRACE | KERNEL_FEATURE_NODE_LIGHT_PATH)>(
+      kg, state, &sd, nullptr, PATH_RAY_VISIBILITY_SHADOW, PATH_RAY_FLAG_NONE);
+
+  if (sd.flag & SD_CACHE_MISS) {
+    *cache_miss = true;
+  }
+
+  /* Write output. */
+  output[offset] = clamp(average(surface_shader_transparency(&sd)), 0.0f, 1.0f);
+#endif
+}
+
+ccl_device void kernel_volume_density_evaluate(KernelGlobals kg,
+                                               ccl_global const KernelShaderEvalInput *input,
+                                               ccl_global float *output,
+                                               ccl_global uint *cache_miss,
+                                               const int offset)
+{
+#ifdef __VOLUME__
+  if (input[offset * 2 + 1].object == SHADER_NONE) {
+    return;
+  }
+
+  KernelShaderEvalInput in = input[offset * 2];
+
+  /* Setup ray. */
+  Ray ray;
+  ray.P = make_float3(__int_as_float(in.prim), in.u, in.v);
+  ray.D = zero_float3();
+  ray.tmin = 0.0f;
+  /* Motion blur is ignored when computing the extrema of the density, but we also don't expect the
+   * value to change a lot in one frame. */
+  ray.time = 0.5f;
+
+  /* Setup shader data. */
+  ShaderData sd;
+  shader_setup_from_volume(&sd, &ray, in.object);
+  sd.flag = SD_IS_VOLUME_SHADER_EVAL;
+  /* For stochastic texture sampling. */
+  sd.lcg_state = lcg_state_init(offset, 0, 0, 0x15b4f88d);
+
+  /* Evaluate extinction and emission without allocating closures. */
+  sd.num_closure_left = 0;
+  /* Evaluate density for camera ray because it usually makes the most visual impact. For shaders
+   * that depends on ray types, the extrema are estimated on the fly. */
+  /* TODO(weizhen): Volume invisible to camera ray might appear noisy. We can at least build a
+   * separate octree for shadow ray. */
+  const PathRayVisibility path_visibility = PATH_RAY_VISIBILITY_CAMERA;
+  const uint32_t path_flag = PATH_RAY_FLAG_NONE;
+
+  /* Setup volume stack entry. */
+  in = input[offset * 2 + 1];
+  const int shader = in.object;
+  const VolumeStack entry = {sd.object, shader};
+
+  const float3 voxel_size = make_float3(__int_as_float(in.prim), in.u, in.v);
+  Extrema<float> extrema = {FLT_MAX, -FLT_MAX};
+  /* For heterogeneous volume, we take 16 samples per grid;
+   * for homogeneous volume, only 1 sample is needed. */
+  const int num_samples = volume_is_homogeneous(kg, entry) ? 1 : 16;
+
+  const bool need_transformation = !(kernel_data_fetch(object_flag, sd.object) &
+                                     SD_OBJECT_TRANSFORM_APPLIED);
+  const Transform tfm = need_transformation ?
+                            object_fetch_transform(kg, sd.object, OBJECT_TRANSFORM) :
+                            Transform();
+  for (int sample = 0; sample < num_samples; sample++) {
+    /* Blue noise indexing. The sequence length is the number of samples. */
+    const uint3 index = make_uint3(sample + offset * num_samples, 0, 0xffffffff);
+
+    /* Sample a random position inside the voxel. */
+    const float3 rand_p = sobol_burley_sample_3D(
+        index.x, PRNG_BAKE_VOLUME_DENSITY_EVAL, index.y, index.z);
+    sd.P = ray.P + rand_p * voxel_size;
+    if (need_transformation) {
+      /* Convert to world space. */
+      sd.P = transform_point(&tfm, sd.P);
+    }
+    sd.closure_transparent_extinction = zero_float3();
+    sd.closure_emission_background = zero_float3();
+
+    /* Evaluate volume coefficients. */
+    ConstIntegratorBakeState state;
+    volume_shader_eval_entry<false,
+                             KERNEL_FEATURE_NODE_MASK_VOLUME & ~KERNEL_FEATURE_NODE_LIGHT_PATH>(
+        kg, state, &sd, entry, path_visibility, path_flag);
+
+    if (sd.flag & SD_CACHE_MISS) {
+      /* Note we keep rendering other samples so we find all cache misses in one go. */
+      *cache_miss = true;
+    }
+
+    const float sigma = reduce_max(sd.closure_transparent_extinction);
+    const float emission = reduce_max(sd.closure_emission_background);
+
+    extrema = merge(extrema, fmaxf(sigma, emission));
+  }
+
+  /* Write output. */
+  const float scale = object_volume_density(kg, sd.object);
+  output[offset * 2 + 0] = extrema.min / scale;
+  output[offset * 2 + 1] = extrema.max / scale;
+#endif
+}
+
+CCL_NAMESPACE_END