#line 2 "sampler_types.cl"

/***************************************************************************
 * Copyright 1998-2013 by authors (see AUTHORS.txt)                        *
 *                                                                         *
 *   This file is part of LuxRender.                                       *
 *                                                                         *
 * 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.                                          *
 ***************************************************************************/

//------------------------------------------------------------------------------
// Indices of Sample related u[] array
//------------------------------------------------------------------------------

#if defined(SLG_OPENCL_KERNEL)

#define IDX_SCREEN_X 0
#define IDX_SCREEN_Y 1
#if defined(PARAM_CAMERA_HAS_DOF) && defined(PARAM_HAS_PASSTHROUGH)
#define IDX_EYE_PASSTHROUGH 2
#define IDX_DOF_X 3
#define IDX_DOF_Y 4
#define IDX_BSDF_OFFSET 5
#elif defined(PARAM_CAMERA_HAS_DOF)
#define IDX_DOF_X 2
#define IDX_DOF_Y 3
#define IDX_BSDF_OFFSET 4
#elif defined(PARAM_HAS_PASSTHROUGH)
#define IDX_EYE_PASSTHROUGH 2
#define IDX_BSDF_OFFSET 3
#else
#define IDX_BSDF_OFFSET 2
#endif

// Relative to IDX_BSDF_OFFSET + PathDepth * VERTEX_SAMPLE_SIZE
#if defined(PARAM_HAS_PASSTHROUGH)

#define IDX_PASSTHROUGH 0
#define IDX_BSDF_X 1
#define IDX_BSDF_Y 2
#define IDX_DIRECTLIGHT_X 3
#define IDX_DIRECTLIGHT_Y 4
#define IDX_DIRECTLIGHT_Z 5
#define IDX_DIRECTLIGHT_W 6
#define IDX_DIRECTLIGHT_A 7
#define IDX_RR 8

#define VERTEX_SAMPLE_SIZE 9

#else

#define IDX_BSDF_X 0
#define IDX_BSDF_Y 1
#define IDX_DIRECTLIGHT_X 2
#define IDX_DIRECTLIGHT_Y 3
#define IDX_DIRECTLIGHT_Z 4
#define IDX_DIRECTLIGHT_W 5
#define IDX_RR 6

#define VERTEX_SAMPLE_SIZE 7
#endif

#if (PARAM_SAMPLER_TYPE == 0) || (PARAM_SAMPLER_TYPE == 2)
#define TOTAL_U_SIZE 2
#endif

#if (PARAM_SAMPLER_TYPE == 1)
#define TOTAL_U_SIZE (IDX_BSDF_OFFSET + PARAM_MAX_PATH_DEPTH * VERTEX_SAMPLE_SIZE)
#endif

#endif

//------------------------------------------------------------------------------
// Sample data types
//------------------------------------------------------------------------------

// This is defined only under OpenCL because of variable size structures
#if defined(SLG_OPENCL_KERNEL)

typedef struct {
	SampleResult result;
} RandomSample;

typedef struct {
	SampleResult result;

	float totalI;

	// Using ushort here totally freeze the ATI driver
	unsigned int largeMutationCount, smallMutationCount;
	unsigned int current, proposed, consecutiveRejects;

	float weight;
	SampleResult currentResult;
} MetropolisSample;

typedef struct {
	float rng0, rng1;
	unsigned int pixelIndex, pass;

	SampleResult result;
} SobolSample;

#if (PARAM_SAMPLER_TYPE == 0)
typedef RandomSample Sample;
#endif

#if (PARAM_SAMPLER_TYPE == 1)
typedef MetropolisSample Sample;
#endif

#if (PARAM_SAMPLER_TYPE == 2)
typedef SobolSample Sample;
#endif

#endif

//------------------------------------------------------------------------------
// Sampler data types
//------------------------------------------------------------------------------

typedef enum {
	RANDOM = 0,
	METROPOLIS = 1,
	SOBOL = 2
} SamplerType;

typedef struct {
	SamplerType type;
	union {
		struct {
			float largeMutationProbability, imageMutationRange;
			unsigned int maxRejects;
		} metropolis;
	};
} Sampler;

#define SOBOL_BITS 32
#define SOBOL_MAX_DIMENSIONS 21201