/*
 * Copyright 2011-2015 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

/* TODO(sergey): Think of making it more generic volume-type attribute
 * sampler.
 */
ccl_device void svm_node_tex_voxel(KernelGlobals *kg,
                                   ShaderData *sd,
                                   float *stack,
                                   uint4 node,
                                   int *offset)
{
	uint co_offset, density_out_offset, color_out_offset, space;
	decode_node_uchar4(node.z, &co_offset, &density_out_offset, &color_out_offset, &space);
#ifdef __VOLUME__
	int id = node.y;
	float3 co = stack_load_float3(stack, co_offset);
	if(space == NODE_TEX_VOXEL_SPACE_OBJECT) {
		co = volume_normalized_position(kg, sd, co);
	}
	else {
		kernel_assert(space == NODE_TEX_VOXEL_SPACE_WORLD);
		Transform tfm;
		tfm.x = read_node_float(kg, offset);
		tfm.y = read_node_float(kg, offset);
		tfm.z = read_node_float(kg, offset);
		tfm.w = read_node_float(kg, offset);
		co = transform_point(&tfm, co);
	}
	float4 r;
#  if defined(__KERNEL_GPU__)
#    if __CUDA_ARCH__ >= 300
	CUtexObject tex = kernel_tex_fetch(__bindless_mapping, id);
	if(id < 2048) /* TODO(dingto): Make this a variable */
		r = kernel_tex_image_interp_3d_float4(tex, co.x, co.y, co.z);
	else {
		float f = kernel_tex_image_interp_3d_float(tex, co.x, co.y, co.z);
		r = make_float4(f, f, f, 1.0f);
	}
#    else /* __CUDA_ARCH__ >= 300 */
	r = volume_image_texture_3d(id, co.x, co.y, co.z);
#    endif
#  else /* __KERNEL_GPU__ */
	r = kernel_tex_image_interp_3d(id, co.x, co.y, co.z);
#  endif
#else
	float4 r = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
#endif
	if(stack_valid(density_out_offset))
		stack_store_float(stack, density_out_offset, r.w);
	if(stack_valid(color_out_offset))
		stack_store_float3(stack, color_out_offset, make_float3(r.x, r.y, r.z));
}

CCL_NAMESPACE_END
