/*
 * Copyright 2011-2017 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

#define ccl_get_feature(buffer, pass) (buffer)[(pass)*pass_stride]

/* Loop over the pixels in the range [low.x, high.x) x [low.y, high.y).
 * pixel_buffer always points to the current pixel in the first pass. */
#define FOR_PIXEL_WINDOW     pixel_buffer = buffer + (low.y - rect.y)*buffer_w + (low.x - rect.x); \
                             for(pixel.y = low.y; pixel.y < high.y; pixel.y++) { \
                                 for(pixel.x = low.x; pixel.x < high.x; pixel.x++, pixel_buffer++) {

#define END_FOR_PIXEL_WINDOW     } \
                                 pixel_buffer += buffer_w - (high.x - low.x); \
                             }

ccl_device_inline void filter_get_features(int2 pixel,
                                           const ccl_global float *ccl_restrict buffer,
                                           float *features,
                                           const float *ccl_restrict mean,
                                           int pass_stride)
{
	features[0] = pixel.x;
	features[1] = pixel.y;
	features[2] = fabsf(ccl_get_feature(buffer, 0));
	features[3] = ccl_get_feature(buffer, 1);
	features[4] = ccl_get_feature(buffer, 2);
	features[5] = ccl_get_feature(buffer, 3);
	features[6] = ccl_get_feature(buffer, 4);
	features[7] = ccl_get_feature(buffer, 5);
	features[8] = ccl_get_feature(buffer, 6);
	features[9] = ccl_get_feature(buffer, 7);
	if(mean) {
		for(int i = 0; i < DENOISE_FEATURES; i++)
			features[i] -= mean[i];
	}
}

ccl_device_inline void filter_get_feature_scales(int2 pixel,
                                                 const ccl_global float *ccl_restrict buffer,
                                                 float *scales,
                                                 const float *ccl_restrict mean,
                                                 int pass_stride)
{
	scales[0] = fabsf(pixel.x - mean[0]);
	scales[1] = fabsf(pixel.y - mean[1]);
	scales[2] = fabsf(fabsf(ccl_get_feature(buffer, 0)) - mean[2]);
	scales[3] = len_squared(make_float3(ccl_get_feature(buffer, 1) - mean[3],
	                                    ccl_get_feature(buffer, 2) - mean[4],
	                                    ccl_get_feature(buffer, 3) - mean[5]));
	scales[4] = fabsf(ccl_get_feature(buffer, 4) - mean[6]);
	scales[5] = len_squared(make_float3(ccl_get_feature(buffer, 5) - mean[7],
	                                    ccl_get_feature(buffer, 6) - mean[8],
	                                    ccl_get_feature(buffer, 7) - mean[9]));
}

ccl_device_inline void filter_calculate_scale(float *scale)
{
	scale[0] = 1.0f/max(scale[0], 0.01f);
	scale[1] = 1.0f/max(scale[1], 0.01f);
	scale[2] = 1.0f/max(scale[2], 0.01f);
	scale[6] = 1.0f/max(scale[4], 0.01f);
	scale[7] = scale[8] = scale[9] = 1.0f/max(sqrtf(scale[5]), 0.01f);
	scale[3] = scale[4] = scale[5] = 1.0f/max(sqrtf(scale[3]), 0.01f);
}

ccl_device_inline float3 filter_get_color(const ccl_global float *ccl_restrict buffer,
                                          int pass_stride)
{
	return make_float3(ccl_get_feature(buffer, 8), ccl_get_feature(buffer, 9), ccl_get_feature(buffer, 10));
}

ccl_device_inline void design_row_add(float *design_row,
                                      int rank,
                                      const ccl_global float *ccl_restrict transform,
                                      int stride,
                                      int row,
                                      float feature)
{
	for(int i = 0; i < rank; i++) {
		design_row[1+i] += transform[(row*DENOISE_FEATURES + i)*stride]*feature;
	}
}

/* Fill the design row. */
ccl_device_inline void filter_get_design_row_transform(int2 p_pixel,
                                                       const ccl_global float *ccl_restrict p_buffer,
                                                       int2 q_pixel,
                                                       const ccl_global float *ccl_restrict q_buffer,
                                                       int pass_stride,
                                                       int rank,
                                                       float *design_row,
                                                       const ccl_global float *ccl_restrict transform,
                                                       int stride)
{
	design_row[0] = 1.0f;
	math_vector_zero(design_row+1, rank);
	design_row_add(design_row, rank, transform, stride, 0, q_pixel.x - p_pixel.x);
	design_row_add(design_row, rank, transform, stride, 1, q_pixel.y - p_pixel.y);
	design_row_add(design_row, rank, transform, stride, 2, fabsf(ccl_get_feature(q_buffer, 0)) - fabsf(ccl_get_feature(p_buffer, 0)));
	design_row_add(design_row, rank, transform, stride, 3, ccl_get_feature(q_buffer, 1) - ccl_get_feature(p_buffer, 1));
	design_row_add(design_row, rank, transform, stride, 4, ccl_get_feature(q_buffer, 2) - ccl_get_feature(p_buffer, 2));
	design_row_add(design_row, rank, transform, stride, 5, ccl_get_feature(q_buffer, 3) - ccl_get_feature(p_buffer, 3));
	design_row_add(design_row, rank, transform, stride, 6, ccl_get_feature(q_buffer, 4) - ccl_get_feature(p_buffer, 4));
	design_row_add(design_row, rank, transform, stride, 7, ccl_get_feature(q_buffer, 5) - ccl_get_feature(p_buffer, 5));
	design_row_add(design_row, rank, transform, stride, 8, ccl_get_feature(q_buffer, 6) - ccl_get_feature(p_buffer, 6));
	design_row_add(design_row, rank, transform, stride, 9, ccl_get_feature(q_buffer, 7) - ccl_get_feature(p_buffer, 7));
}

CCL_NAMESPACE_END