#ifndef _RRRASTERIZER_HPP
#define _RRRASTERIZER_HPP
/*-------------------------------------------------------------------------
 * drawElements Quality Program Reference Renderer
 * -----------------------------------------------
 *
 * Copyright 2014 The Android Open Source Project
 *
 * 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.
 *
 *//*!
 * \file
 * \brief Reference rasterizer
 *//*--------------------------------------------------------------------*/

#include "rrDefs.hpp"
#include "tcuVector.hpp"
#include "rrRenderState.hpp"
#include "rrFragmentPacket.hpp"


namespace rr
{

//! Rasterizer configuration
enum
{
	RASTERIZER_SUBPIXEL_BITS			= 8,
	RASTERIZER_MAX_SAMPLES_PER_FRAGMENT	= 16
};

//! Get coverage bit value.
inline deUint64 getCoverageBit (int numSamples, int x, int y, int sampleNdx)
{
	const int	numBits		= (int)sizeof(deUint64)*8;
	const int	maxSamples	= numBits/4;
	DE_STATIC_ASSERT(maxSamples >= RASTERIZER_MAX_SAMPLES_PER_FRAGMENT);
	DE_ASSERT(de::inRange(numSamples, 1, maxSamples) && de::inBounds(x, 0, 2) && de::inBounds(y, 0, 2));
	return 1ull << ((x*2 + y)*numSamples + sampleNdx);
}

//! Get all sample bits for fragment
inline deUint64 getCoverageFragmentSampleBits (int numSamples, int x, int y)
{
	DE_ASSERT(de::inBounds(x, 0, 2) && de::inBounds(y, 0, 2));
	const deUint64 fragMask = (1ull << numSamples) - 1;
	return fragMask << (x*2 + y)*numSamples;
}

//! Set bit in coverage mask.
inline deUint64 setCoverageValue (deUint64 mask, int numSamples, int x, int y, int sampleNdx, bool val)
{
	const deUint64 bit = getCoverageBit(numSamples, x, y, sampleNdx);
	return val ? (mask | bit) : (mask & ~bit);
}

//! Get coverage bit value in mask.
inline bool getCoverageValue (deUint64 mask, int numSamples, int x, int y, int sampleNdx)
{
	return (mask & getCoverageBit(numSamples, x, y, sampleNdx)) != 0;
}

//! Test if any sample for fragment is live
inline bool getCoverageAnyFragmentSampleLive (deUint64 mask, int numSamples, int x, int y)
{
	return (mask & getCoverageFragmentSampleBits(numSamples, x, y)) != 0;
}

//! Get position of first coverage bit of fragment - equivalent to deClz64(getCoverageFragmentSampleBits(numSamples, x, y)).
inline int getCoverageOffset (int numSamples, int x, int y)
{
	return (x*2 + y)*numSamples;
}

/*--------------------------------------------------------------------*//*!
 * \brief Edge function
 *
 * Edge function can be evaluated for point P (in fixed-point coordinates
 * with SUBPIXEL_BITS fractional part) by computing
 *  D = a*Px + b*Py + c
 *
 * D will be fixed-point value where lower (SUBPIXEL_BITS*2) bits will
 * be fractional part.
 *
 * a and b are stored with SUBPIXEL_BITS fractional part, while c is stored
 * with SUBPIXEL_BITS*2 fractional bits.
 *//*--------------------------------------------------------------------*/
struct EdgeFunction
{
	inline EdgeFunction (void) : a(0), b(0), c(0), inclusive(false) {}

	deInt64			a;
	deInt64			b;
	deInt64			c;
	bool			inclusive;	//!< True if edge is inclusive according to fill rules.
};

/*--------------------------------------------------------------------*//*!
 * \brief Triangle rasterizer
 *
 * Triangle rasterizer implements following features:
 *  - Rasterization using fixed-point coordinates
 *  - 1, 4, and 16 -sample rasterization
 *  - Depth interpolation
 *  - Perspective-correct barycentric computation for interpolation
 *  - Visible face determination
 *
 * It does not (and will not) implement following:
 *  - Triangle setup
 *  - Clipping
 *  - Degenerate elimination
 *  - Coordinate transformation (inputs are in screen-space)
 *  - Culling - logic can be implemented outside by querying visible face
 *  - Scissoring (this can be done by controlling viewport rectangle)
 *  - Any per-fragment operations
 *//*--------------------------------------------------------------------*/
class TriangleRasterizer
{
public:
							TriangleRasterizer		(const tcu::IVec4& viewport, const int numSamples, const RasterizationState& state);

	void					init					(const tcu::Vec4& v0, const tcu::Vec4& v1, const tcu::Vec4& v2);

	// Following functions are only available after init()
	FaceType				getVisibleFace			(void) const { return m_face; }
	void					rasterize				(FragmentPacket* const fragmentPackets, float* const depthValues, const int maxFragmentPackets, int& numPacketsRasterized);

private:
	void					rasterizeSingleSample	(FragmentPacket* const fragmentPackets, float* const depthValues, const int maxFragmentPackets, int& numPacketsRasterized);

	template<int NumSamples>
	void					rasterizeMultiSample	(FragmentPacket* const fragmentPackets, float* const depthValues, const int maxFragmentPackets, int& numPacketsRasterized);

	// Constant rasterization state.
	const tcu::IVec4		m_viewport;
	const int				m_numSamples;
	const Winding			m_winding;
	const HorizontalFill	m_horizontalFill;
	const VerticalFill		m_verticalFill;

	// Per-triangle rasterization state.
	tcu::Vec4				m_v0;
	tcu::Vec4				m_v1;
	tcu::Vec4				m_v2;
	EdgeFunction			m_edge01;
	EdgeFunction			m_edge12;
	EdgeFunction			m_edge20;
	FaceType				m_face;					//!< Triangle orientation, eg. visible face.
	tcu::IVec2				m_bboxMin;				//!< Bounding box min (inclusive).
	tcu::IVec2				m_bboxMax;				//!< Bounding box max (inclusive).
	tcu::IVec2				m_curPos;				//!< Current rasterization position.
	ViewportOrientation		m_viewportOrientation;	//!< Direction of +x+y axis
} DE_WARN_UNUSED_TYPE;


/*--------------------------------------------------------------------*//*!
 * \brief Single sample line rasterizer
 *
 * Line rasterizer implements following features:
 *  - Rasterization using fixed-point coordinates
 *  - Depth interpolation
 *  - Perspective-correct interpolation
 *
 * It does not (and will not) implement following:
 *  - Clipping
 *  - Multisampled line rasterization
 *//*--------------------------------------------------------------------*/
class SingleSampleLineRasterizer
{
public:
									SingleSampleLineRasterizer	(const tcu::IVec4& viewport);
									~SingleSampleLineRasterizer	(void);

	void							init						(const tcu::Vec4& v0, const tcu::Vec4& v1, float lineWidth);

	// only available after init()
	void							rasterize					(FragmentPacket* const fragmentPackets, float* const depthValues, const int maxFragmentPackets, int& numPacketsRasterized);

private:
									SingleSampleLineRasterizer	(const SingleSampleLineRasterizer&); // not allowed
	SingleSampleLineRasterizer&		operator=					(const SingleSampleLineRasterizer&); // not allowed

	// Constant rasterization state.
	const tcu::IVec4				m_viewport;

	// Per-line rasterization state.
	tcu::Vec4						m_v0;
	tcu::Vec4						m_v1;
	tcu::IVec2						m_bboxMin;			//!< Bounding box min (inclusive).
	tcu::IVec2						m_bboxMax;			//!< Bounding box max (inclusive).
	tcu::IVec2						m_curPos;			//!< Current rasterization position.
	deInt32							m_curRowFragment;	//!< Current rasterization position of one fragment in column of lineWidth fragments
	float							m_lineWidth;
} DE_WARN_UNUSED_TYPE;


/*--------------------------------------------------------------------*//*!
 * \brief Multisampled line rasterizer
 *
 * Line rasterizer implements following features:
 *  - Rasterization using fixed-point coordinates
 *  - Depth interpolation
 *  - Perspective-correct interpolation
 *
 * It does not (and will not) implement following:
 *  - Clipping
 *  - Aliased line rasterization
 *//*--------------------------------------------------------------------*/
class MultiSampleLineRasterizer
{
public:
								MultiSampleLineRasterizer	(const int numSamples, const tcu::IVec4& viewport);
								~MultiSampleLineRasterizer	();

	void						init						(const tcu::Vec4& v0, const tcu::Vec4& v1, float lineWidth);

	// only available after init()
	void						rasterize					(FragmentPacket* const fragmentPackets, float* const depthValues, const int maxFragmentPackets, int& numPacketsRasterized);

private:
								MultiSampleLineRasterizer	(const MultiSampleLineRasterizer&); // not allowed
	MultiSampleLineRasterizer&	operator=					(const MultiSampleLineRasterizer&); // not allowed

	// Constant rasterization state.
	const int					m_numSamples;

	// Per-line rasterization state.
	TriangleRasterizer			m_triangleRasterizer0; //!< not in array because we want to initialize these in the initialization list
	TriangleRasterizer			m_triangleRasterizer1;
} DE_WARN_UNUSED_TYPE;


/*--------------------------------------------------------------------*//*!
 * \brief Pixel diamond
 *
 * Structure representing a diamond a line exits.
 *//*--------------------------------------------------------------------*/
struct LineExitDiamond
{
	tcu::IVec2	position;
};

/*--------------------------------------------------------------------*//*!
 * \brief Line exit diamond generator
 *
 * For a given line, generates list of diamonds the line exits using the
 * line-exit rules of the line rasterization. Does not do scissoring.
 *
 * \note Not used by rr, but provided to prevent test cases requiring
 *       accurate diamonds from abusing SingleSampleLineRasterizer.
 *//*--------------------------------------------------------------------*/
class LineExitDiamondGenerator
{
public:
									LineExitDiamondGenerator	(void);
									~LineExitDiamondGenerator	(void);

	void							init						(const tcu::Vec4& v0, const tcu::Vec4& v1);

	// only available after init()
	void							rasterize					(LineExitDiamond* const lineDiamonds, const int maxDiamonds, int& numWritten);

private:
									LineExitDiamondGenerator	(const LineExitDiamondGenerator&); // not allowed
	LineExitDiamondGenerator&		operator=					(const LineExitDiamondGenerator&); // not allowed

	// Per-line rasterization state.
	tcu::Vec4						m_v0;
	tcu::Vec4						m_v1;
	tcu::IVec2						m_bboxMin;			//!< Bounding box min (inclusive).
	tcu::IVec2						m_bboxMax;			//!< Bounding box max (inclusive).
	tcu::IVec2						m_curPos;			//!< Current rasterization position.
};

} // rr

#endif // _RRRASTERIZER_HPP