blender/intern/cycles/kernel/svm/svm_brick.h

/*
 * Copyright 2011-2013 Blender Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

CCL_NAMESPACE_BEGIN

/* Brick */

ccl_device_noinline float brick_noise(uint n) /* fast integer noise */
{
  uint nn;
  n = (n + 1013) & 0x7fffffff;
  n = (n >> 13) ^ n;
  nn = (n * (n * n * 60493 + 19990303) + 1376312589) & 0x7fffffff;
  return 0.5f * ((float)nn / 1073741824.0f);
}

ccl_device_noinline float2 svm_brick(float3 p,
                                     float mortar_size,
                                     float mortar_smooth,
                                     float bias,
                                     float brick_width,
                                     float row_height,
                                     float offset_amount,
                                     int offset_frequency,
                                     float squash_amount,
                                     int squash_frequency)
{
  int bricknum, rownum;
  float offset = 0.0f;
  float x, y;

  rownum = floor_to_int(p.y / row_height);

  if (offset_frequency && squash_frequency) {
    brick_width *= (rownum % squash_frequency) ? 1.0f : squash_amount;           /* squash */
    offset = (rownum % offset_frequency) ? 0.0f : (brick_width * offset_amount); /* offset */
  }

  bricknum = floor_to_int((p.x + offset) / brick_width);

  x = (p.x + offset) - brick_width * bricknum;
  y = p.y - row_height * rownum;

  float tint = saturate((brick_noise((rownum << 16) + (bricknum & 0xFFFF)) + bias));
  float min_dist = min(min(x, y), min(brick_width - x, row_height - y));

  float mortar;
  if (min_dist >= mortar_size) {
    mortar = 0.0f;
  }
  else if (mortar_smooth == 0.0f) {
    mortar = 1.0f;
  }
  else {
    min_dist = 1.0f - min_dist / mortar_size;
    mortar = (min_dist < mortar_smooth) ? smoothstepf(min_dist / mortar_smooth) : 1.0f;
  }

  return make_float2(tint, mortar);
}

ccl_device void svm_node_tex_brick(
    KernelGlobals *kg, ShaderData *sd, float *stack, uint4 node, int *offset)
{
  uint4 node2 = read_node(kg, offset);
  uint4 node3 = read_node(kg, offset);
  uint4 node4 = read_node(kg, offset);

  /* Input and Output Sockets */
  uint co_offset, color1_offset, color2_offset, mortar_offset, scale_offset;
  uint mortar_size_offset, bias_offset, brick_width_offset, row_height_offset;
  uint color_offset, fac_offset, mortar_smooth_offset;

  /* RNA properties */
  uint offset_frequency, squash_frequency;

  decode_node_uchar4(node.y, &co_offset, &color1_offset, &color2_offset, &mortar_offset);
  decode_node_uchar4(
      node.z, &scale_offset, &mortar_size_offset, &bias_offset, &brick_width_offset);
  decode_node_uchar4(
      node.w, &row_height_offset, &color_offset, &fac_offset, &mortar_smooth_offset);

  decode_node_uchar4(node2.x, &offset_frequency, &squash_frequency, NULL, NULL);

  float3 co = stack_load_float3(stack, co_offset);

  float3 color1 = stack_load_float3(stack, color1_offset);
  float3 color2 = stack_load_float3(stack, color2_offset);
  float3 mortar = stack_load_float3(stack, mortar_offset);

  float scale = stack_load_float_default(stack, scale_offset, node2.y);
  float mortar_size = stack_load_float_default(stack, mortar_size_offset, node2.z);
  float mortar_smooth = stack_load_float_default(stack, mortar_smooth_offset, node4.x);
  float bias = stack_load_float_default(stack, bias_offset, node2.w);
  float brick_width = stack_load_float_default(stack, brick_width_offset, node3.x);
  float row_height = stack_load_float_default(stack, row_height_offset, node3.y);
  float offset_amount = __int_as_float(node3.z);
  float squash_amount = __int_as_float(node3.w);

  float2 f2 = svm_brick(co * scale,
                        mortar_size,
                        mortar_smooth,
                        bias,
                        brick_width,
                        row_height,
                        offset_amount,
                        offset_frequency,
                        squash_amount,
                        squash_frequency);

  float tint = f2.x;
  float f = f2.y;

  if (f != 1.0f) {
    float facm = 1.0f - tint;
    color1 = facm * color1 + tint * color2;
  }

  if (stack_valid(color_offset))
    stack_store_float3(stack, color_offset, color1 * (1.0f - f) + mortar * f);
  if (stack_valid(fac_offset))
    stack_store_float(stack, fac_offset, f);
}

CCL_NAMESPACE_END