1/*-------------------------------------------------------------------------
2 * drawElements Quality Program Reference Renderer
3 * -----------------------------------------------
4 *
5 * Copyright 2014 The Android Open Source Project
6 *
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
10 *
11 *      http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 *
19 *//*!
20 * \file
21 * \brief Reference rasterizer
22 *//*--------------------------------------------------------------------*/
23
24#include "rrRasterizer.hpp"
25#include "deMath.h"
26#include "tcuVectorUtil.hpp"
27
28namespace rr
29{
30
31inline deInt64 toSubpixelCoord (float v, int bits)
32{
33	return (deInt64)(v * (float)(1 << bits) + (v < 0.f ? -0.5f : 0.5f));
34}
35
36inline deInt64 toSubpixelCoord (deInt32 v, int bits)
37{
38	return v << bits;
39}
40
41inline deInt32 ceilSubpixelToPixelCoord (deInt64 coord, int bits, bool fillEdge)
42{
43	if (coord >= 0)
44		return (deInt32)((coord + ((1ll << bits) - (fillEdge ? 0 : 1))) >> bits);
45	else
46		return (deInt32)((coord + (fillEdge ? 1 : 0)) >> bits);
47}
48
49inline deInt32 floorSubpixelToPixelCoord (deInt64 coord, int bits, bool fillEdge)
50{
51	if (coord >= 0)
52		return (deInt32)((coord - (fillEdge ? 1 : 0)) >> bits);
53	else
54		return (deInt32)((coord - ((1ll << bits) - (fillEdge ? 0 : 1))) >> bits);
55}
56
57static inline void initEdgeCCW (EdgeFunction& edge, const HorizontalFill horizontalFill, const VerticalFill verticalFill, const deInt64 x0, const deInt64 y0, const deInt64 x1, const deInt64 y1)
58{
59	// \note See EdgeFunction documentation for details.
60
61	const deInt64	xd			= x1-x0;
62	const deInt64	yd			= y1-y0;
63	bool			inclusive	= false;	//!< Inclusive in CCW orientation.
64
65	if (yd == 0)
66		inclusive = verticalFill == FILL_BOTTOM ? xd >= 0 : xd <= 0;
67	else
68		inclusive = horizontalFill == FILL_LEFT ? yd <= 0 : yd >= 0;
69
70	edge.a			= (y0 - y1);
71	edge.b			= (x1 - x0);
72	edge.c			= x0*y1 - y0*x1;
73	edge.inclusive	= inclusive; //!< \todo [pyry] Swap for CW triangles
74}
75
76static inline void reverseEdge (EdgeFunction& edge)
77{
78	edge.a			= -edge.a;
79	edge.b			= -edge.b;
80	edge.c			= -edge.c;
81	edge.inclusive	= !edge.inclusive;
82}
83
84static inline deInt64 evaluateEdge (const EdgeFunction& edge, const deInt64 x, const deInt64 y)
85{
86	return edge.a*x + edge.b*y + edge.c;
87}
88
89static inline bool isInsideCCW (const EdgeFunction& edge, const deInt64 edgeVal)
90{
91	return edge.inclusive ? (edgeVal >= 0) : (edgeVal > 0);
92}
93
94namespace LineRasterUtil
95{
96
97struct SubpixelLineSegment
98{
99	const tcu::Vector<deInt64,2>	m_v0;
100	const tcu::Vector<deInt64,2>	m_v1;
101
102	SubpixelLineSegment (const tcu::Vector<deInt64,2>& v0, const tcu::Vector<deInt64,2>& v1)
103		: m_v0(v0)
104		, m_v1(v1)
105	{
106	}
107
108	tcu::Vector<deInt64,2> direction (void) const
109	{
110		return m_v1 - m_v0;
111	}
112};
113
114enum LINE_SIDE
115{
116	LINE_SIDE_INTERSECT = 0,
117	LINE_SIDE_LEFT,
118	LINE_SIDE_RIGHT
119};
120
121static tcu::Vector<deInt64,2> toSubpixelVector (const tcu::Vec2& v, int bits)
122{
123	return tcu::Vector<deInt64,2>(toSubpixelCoord(v.x(), bits), toSubpixelCoord(v.y(), bits));
124}
125
126static tcu::Vector<deInt64,2> toSubpixelVector (const tcu::IVec2& v, int bits)
127{
128	return tcu::Vector<deInt64,2>(toSubpixelCoord(v.x(), bits), toSubpixelCoord(v.y(), bits));
129}
130
131#if defined(DE_DEBUG)
132static bool isTheCenterOfTheFragment (const tcu::Vector<deInt64,2>& a, int bits)
133{
134	const deUint64 pixelSize = 1ll << bits;
135	const deUint64 halfPixel = 1ll << (bits - 1);
136	return	((a.x() & (pixelSize-1)) == halfPixel &&
137				(a.y() & (pixelSize-1)) == halfPixel);
138}
139
140static bool inViewport (const tcu::IVec2& p, const tcu::IVec4& viewport)
141{
142	return	p.x() >= viewport.x() &&
143			p.y() >= viewport.y() &&
144			p.x() <  viewport.x() + viewport.z() &&
145			p.y() <  viewport.y() + viewport.w();
146}
147#endif // DE_DEBUG
148
149// returns true if vertex is on the left side of the line
150static bool vertexOnLeftSideOfLine (const tcu::Vector<deInt64,2>& p, const SubpixelLineSegment& l)
151{
152	const tcu::Vector<deInt64,2> u = l.direction();
153	const tcu::Vector<deInt64,2> v = ( p - l.m_v0);
154	const deInt64 crossProduct = (u.x() * v.y() - u.y() * v.x());
155	return crossProduct < 0;
156}
157
158// returns true if vertex is on the right side of the line
159static bool vertexOnRightSideOfLine (const tcu::Vector<deInt64,2>& p, const SubpixelLineSegment& l)
160{
161	const tcu::Vector<deInt64,2> u = l.direction();
162	const tcu::Vector<deInt64,2> v = ( p - l.m_v0);
163	const deInt64 crossProduct = (u.x() * v.y() - u.y() * v.x());
164	return crossProduct > 0;
165}
166
167// returns true if vertex is on the line
168static bool vertexOnLine (const tcu::Vector<deInt64,2>& p, const SubpixelLineSegment& l)
169{
170	const tcu::Vector<deInt64,2> u = l.direction();
171	const tcu::Vector<deInt64,2> v = ( p - l.m_v0);
172	const deInt64 crossProduct = (u.x() * v.y() - u.y() * v.x());
173	return crossProduct == 0; // cross product == 0
174}
175
176// returns true if vertex is on the line segment
177static bool vertexOnLineSegment (const tcu::Vector<deInt64,2>& p, const SubpixelLineSegment& l)
178{
179	if (!vertexOnLine(p, l))
180		return false;
181
182	const tcu::Vector<deInt64,2> v	= l.direction();
183	const tcu::Vector<deInt64,2> u1	= ( p - l.m_v0);
184	const tcu::Vector<deInt64,2> u2	= ( p - l.m_v1);
185
186	if (v.x() == 0 && v.y() == 0)
187		return false;
188
189	return	tcu::dot( v, u1) >= 0 &&
190			tcu::dot(-v, u2) >= 0; // dot (A->B, A->V) >= 0 and dot (B->A, B->V) >= 0
191}
192
193static LINE_SIDE getVertexSide (const tcu::Vector<deInt64,2>& v, const SubpixelLineSegment& l)
194{
195	if (vertexOnLeftSideOfLine(v, l))
196		return LINE_SIDE_LEFT;
197	else if (vertexOnRightSideOfLine(v, l))
198		return LINE_SIDE_RIGHT;
199	else if (vertexOnLine(v, l))
200		return LINE_SIDE_INTERSECT;
201	else
202	{
203		DE_ASSERT(false);
204		return LINE_SIDE_INTERSECT;
205	}
206}
207
208// returns true if angle between line and given cornerExitNormal is in range (-45, 45)
209bool lineInCornerAngleRange (const SubpixelLineSegment& line, const tcu::Vector<deInt64,2>& cornerExitNormal)
210{
211	// v0 -> v1 has angle difference to cornerExitNormal in range (-45, 45)
212	const tcu::Vector<deInt64,2> v = line.direction();
213	const deInt64 dotProduct = dot(v, cornerExitNormal);
214
215	// dotProduct > |v1-v0|*|cornerExitNormal|/sqrt(2)
216	if (dotProduct < 0)
217		return false;
218	return 2 * dotProduct * dotProduct > tcu::lengthSquared(v)*tcu::lengthSquared(cornerExitNormal);
219}
220
221// returns true if angle between line and given cornerExitNormal is in range (-135, 135)
222bool lineInCornerOutsideAngleRange (const SubpixelLineSegment& line, const tcu::Vector<deInt64,2>& cornerExitNormal)
223{
224	// v0 -> v1 has angle difference to cornerExitNormal in range (-135, 135)
225	const tcu::Vector<deInt64,2> v = line.direction();
226	const deInt64 dotProduct = dot(v, cornerExitNormal);
227
228	// dotProduct > -|v1-v0|*|cornerExitNormal|/sqrt(2)
229	if (dotProduct >= 0)
230		return true;
231	return 2 * (-dotProduct) * (-dotProduct) < tcu::lengthSquared(v)*tcu::lengthSquared(cornerExitNormal);
232}
233
234bool doesLineSegmentExitDiamond (const SubpixelLineSegment& line, const tcu::Vector<deInt64,2>& diamondCenter, int bits)
235{
236	DE_ASSERT(isTheCenterOfTheFragment(diamondCenter, bits));
237
238	// Diamond Center is at diamondCenter in subpixel coords
239
240	const deInt64 halfPixel = 1ll << (bits - 1);
241
242	// Reject distant diamonds early
243	{
244		const tcu::Vector<deInt64,2>	u				= line.direction();
245		const tcu::Vector<deInt64,2>	v				= (diamondCenter - line.m_v0);
246		const deInt64					crossProduct	= (u.x() * v.y() - u.y() * v.x());
247
248		// crossProduct = |p| |l| sin(theta)
249		// distanceFromLine = |p| sin(theta)
250		// => distanceFromLine = crossProduct / |l|
251		//
252		// |distanceFromLine| > C
253		// => distanceFromLine^2 > C^2
254		// => crossProduct^2 / |l|^2 > C^2
255		// => crossProduct^2 > |l|^2 * C^2
256
257		const deInt64	floorSqrtMaxInt64			= 3037000499LL; //!< floor(sqrt(MAX_INT64))
258
259		const deInt64	broadRejectDistance			= 2 * halfPixel;
260		const deInt64	broadRejectDistanceSquared	= broadRejectDistance * broadRejectDistance;
261		const bool		crossProductOverflows		= (crossProduct > floorSqrtMaxInt64 || crossProduct < -floorSqrtMaxInt64);
262		const deInt64	crossProductSquared			= (crossProductOverflows) ? (0) : (crossProduct * crossProduct); // avoid overflow
263		const deInt64	lineLengthSquared			= tcu::lengthSquared(u);
264		const bool		limitValueCouldOverflow		= ((64 - deClz64(lineLengthSquared)) + (64 - deClz64(broadRejectDistanceSquared))) > 63;
265		const deInt64	limitValue					= (limitValueCouldOverflow) ? (0) : (lineLengthSquared * broadRejectDistanceSquared); // avoid overflow
266
267		// only cross overflows
268		if (crossProductOverflows && !limitValueCouldOverflow)
269			return false;
270
271		// both representable
272		if (!crossProductOverflows && !limitValueCouldOverflow)
273		{
274			if (crossProductSquared > limitValue)
275				return false;
276		}
277	}
278
279	const struct DiamondBound
280	{
281		tcu::Vector<deInt64,2>	p0;
282		tcu::Vector<deInt64,2>	p1;
283		bool					edgeInclusive; // would a point on the bound be inside of the region
284	} bounds[] =
285	{
286		{ diamondCenter + tcu::Vector<deInt64,2>(0,				-halfPixel),	diamondCenter + tcu::Vector<deInt64,2>(-halfPixel,	0),				 false	},
287		{ diamondCenter + tcu::Vector<deInt64,2>(-halfPixel,	0),				diamondCenter + tcu::Vector<deInt64,2>(0,			halfPixel),		 false	},
288		{ diamondCenter + tcu::Vector<deInt64,2>(0,				halfPixel),		diamondCenter + tcu::Vector<deInt64,2>(halfPixel,	0),				 true	},
289		{ diamondCenter + tcu::Vector<deInt64,2>(halfPixel,		0),				diamondCenter + tcu::Vector<deInt64,2>(0,			-halfPixel),	 true	},
290	};
291
292	const struct DiamondCorners
293	{
294		enum CORNER_EDGE_CASE_BEHAVIOR
295		{
296			CORNER_EDGE_CASE_NONE,							// if the line intersects just a corner, no entering or exiting
297			CORNER_EDGE_CASE_HIT,							// if the line intersects just a corner, entering and exit
298			CORNER_EDGE_CASE_HIT_FIRST_QUARTER,				// if the line intersects just a corner and the line has either endpoint in (+X,-Y) direction (preturbing moves the line inside)
299			CORNER_EDGE_CASE_HIT_SECOND_QUARTER				// if the line intersects just a corner and the line has either endpoint in (+X,+Y) direction (preturbing moves the line inside)
300		};
301		enum CORNER_START_CASE_BEHAVIOR
302		{
303			CORNER_START_CASE_NONE,							// the line starting point is outside, no exiting
304			CORNER_START_CASE_OUTSIDE,						// exit, if line does not intersect the region (preturbing moves the start point inside)
305			CORNER_START_CASE_POSITIVE_Y_45,				// exit, if line the angle of line vector and X-axis is in range (0, 45] in positive Y side.
306			CORNER_START_CASE_NEGATIVE_Y_45					// exit, if line the angle of line vector and X-axis is in range [0, 45] in negative Y side.
307		};
308		enum CORNER_END_CASE_BEHAVIOR
309		{
310			CORNER_END_CASE_NONE,							// end is inside, no exiting (preturbing moves the line end inside)
311			CORNER_END_CASE_DIRECTION,						// exit, if line intersected the region (preturbing moves the line end outside)
312			CORNER_END_CASE_DIRECTION_AND_FIRST_QUARTER,	// exit, if line intersected the region, or line originates from (+X,-Y) direction (preturbing moves the line end outside)
313			CORNER_END_CASE_DIRECTION_AND_SECOND_QUARTER	// exit, if line intersected the region, or line originates from (+X,+Y) direction (preturbing moves the line end outside)
314		};
315
316		tcu::Vector<deInt64,2>		dp;
317		bool						pointInclusive;			// would a point in this corner intersect with the region
318		CORNER_EDGE_CASE_BEHAVIOR	lineBehavior;			// would a line segment going through this corner intersect with the region
319		CORNER_START_CASE_BEHAVIOR	startBehavior;			// how the corner behaves if the start point at the corner
320		CORNER_END_CASE_BEHAVIOR	endBehavior;			// how the corner behaves if the end point at the corner
321	} corners[] =
322	{
323		{ tcu::Vector<deInt64,2>(0,				-halfPixel),	false,	DiamondCorners::CORNER_EDGE_CASE_HIT_SECOND_QUARTER,	DiamondCorners::CORNER_START_CASE_POSITIVE_Y_45,	DiamondCorners::CORNER_END_CASE_DIRECTION_AND_SECOND_QUARTER},
324		{ tcu::Vector<deInt64,2>(-halfPixel,	0),				false,	DiamondCorners::CORNER_EDGE_CASE_NONE,					DiamondCorners::CORNER_START_CASE_NONE,				DiamondCorners::CORNER_END_CASE_DIRECTION					},
325		{ tcu::Vector<deInt64,2>(0,				halfPixel),		false,	DiamondCorners::CORNER_EDGE_CASE_HIT_FIRST_QUARTER,		DiamondCorners::CORNER_START_CASE_NEGATIVE_Y_45,	DiamondCorners::CORNER_END_CASE_DIRECTION_AND_FIRST_QUARTER	},
326		{ tcu::Vector<deInt64,2>(halfPixel,		0),				true,	DiamondCorners::CORNER_EDGE_CASE_HIT,					DiamondCorners::CORNER_START_CASE_OUTSIDE,			DiamondCorners::CORNER_END_CASE_NONE						},
327	};
328
329	// Corner cases at the corners
330	for (int ndx = 0; ndx < DE_LENGTH_OF_ARRAY(corners); ++ndx)
331	{
332		const tcu::Vector<deInt64,2> p	= diamondCenter + corners[ndx].dp;
333		const bool intersectsAtCorner	= LineRasterUtil::vertexOnLineSegment(p, line);
334
335		if (!intersectsAtCorner)
336			continue;
337
338		// line segment body intersects with the corner
339		if (p != line.m_v0 && p != line.m_v1)
340		{
341			if (corners[ndx].lineBehavior == DiamondCorners::CORNER_EDGE_CASE_HIT)
342				return true;
343
344			// endpoint in (+X, -Y) (X or Y may be 0) direction <==> x*y <= 0
345			if (corners[ndx].lineBehavior == DiamondCorners::CORNER_EDGE_CASE_HIT_FIRST_QUARTER &&
346				(line.direction().x() * line.direction().y()) <= 0)
347				return true;
348
349			// endpoint in (+X, +Y) (Y > 0) direction <==> x*y > 0
350			if (corners[ndx].lineBehavior == DiamondCorners::CORNER_EDGE_CASE_HIT_SECOND_QUARTER &&
351				(line.direction().x() * line.direction().y()) > 0)
352				return true;
353		}
354
355		// line exits the area at the corner
356		if (lineInCornerAngleRange(line, corners[ndx].dp))
357		{
358			const bool startIsInside = corners[ndx].pointInclusive || p != line.m_v0;
359			const bool endIsOutside = !corners[ndx].pointInclusive || p != line.m_v1;
360
361			// starting point is inside the region and end endpoint is outside
362			if (startIsInside && endIsOutside)
363				return true;
364		}
365
366		// line end is at the corner
367		if (p == line.m_v1)
368		{
369			if (corners[ndx].endBehavior == DiamondCorners::CORNER_END_CASE_DIRECTION ||
370				corners[ndx].endBehavior == DiamondCorners::CORNER_END_CASE_DIRECTION_AND_FIRST_QUARTER ||
371				corners[ndx].endBehavior == DiamondCorners::CORNER_END_CASE_DIRECTION_AND_SECOND_QUARTER)
372			{
373				// did the line intersect the region
374				if (lineInCornerAngleRange(line, corners[ndx].dp))
375					return true;
376			}
377
378			// due to the perturbed endpoint, lines at this the angle will cause and enter-exit pair
379			if (corners[ndx].endBehavior == DiamondCorners::CORNER_END_CASE_DIRECTION_AND_FIRST_QUARTER &&
380				line.direction().x() < 0 &&
381				line.direction().y() > 0)
382				return true;
383			if (corners[ndx].endBehavior == DiamondCorners::CORNER_END_CASE_DIRECTION_AND_SECOND_QUARTER &&
384				line.direction().x() > 0 &&
385				line.direction().y() > 0)
386				return true;
387		}
388
389		// line start is at the corner
390		if (p == line.m_v0)
391		{
392			if (corners[ndx].startBehavior == DiamondCorners::CORNER_START_CASE_OUTSIDE)
393			{
394				// if the line is not going inside, it will exit
395				if (lineInCornerOutsideAngleRange(line, corners[ndx].dp))
396					return true;
397			}
398
399			// exit, if line the angle between line vector and X-axis is in range (0, 45] in positive Y side.
400			if (corners[ndx].startBehavior == DiamondCorners::CORNER_START_CASE_POSITIVE_Y_45 &&
401				line.direction().x() > 0 &&
402				line.direction().y() > 0 &&
403				line.direction().y() <= line.direction().x())
404				return true;
405
406			// exit, if line the angle between line vector and X-axis is in range [0, 45] in negative Y side.
407			if (corners[ndx].startBehavior == DiamondCorners::CORNER_START_CASE_NEGATIVE_Y_45 &&
408				 line.direction().x() > 0 &&
409				 line.direction().y() <= 0 &&
410				-line.direction().y() <= line.direction().x())
411				return true;
412		}
413	}
414
415	// Does the line intersect boundary at the left == exits the diamond
416	for (int ndx = 0; ndx < DE_LENGTH_OF_ARRAY(bounds); ++ndx)
417	{
418		const bool startVertexInside =	LineRasterUtil::vertexOnLeftSideOfLine						(line.m_v0, LineRasterUtil::SubpixelLineSegment(bounds[ndx].p0, bounds[ndx].p1)) ||
419										(bounds[ndx].edgeInclusive && LineRasterUtil::vertexOnLine	(line.m_v0, LineRasterUtil::SubpixelLineSegment(bounds[ndx].p0, bounds[ndx].p1)));
420		const bool endVertexInside =	LineRasterUtil::vertexOnLeftSideOfLine						(line.m_v1, LineRasterUtil::SubpixelLineSegment(bounds[ndx].p0, bounds[ndx].p1)) ||
421										(bounds[ndx].edgeInclusive && LineRasterUtil::vertexOnLine	(line.m_v1, LineRasterUtil::SubpixelLineSegment(bounds[ndx].p0, bounds[ndx].p1)));
422
423		// start must be on inside this half space (left or at the inclusive boundary)
424		if (!startVertexInside)
425			continue;
426
427		// end must be outside of this half-space (right or at non-inclusive boundary)
428		if (endVertexInside)
429			continue;
430
431		// Does the line via v0 and v1 intersect the line segment p0-p1
432		// <==> p0 and p1 are the different sides (LEFT, RIGHT) of the v0-v1 line.
433		// Corners are not allowed, they are checked already
434		LineRasterUtil::LINE_SIDE sideP0 = LineRasterUtil::getVertexSide(bounds[ndx].p0, line);
435		LineRasterUtil::LINE_SIDE sideP1 = LineRasterUtil::getVertexSide(bounds[ndx].p1, line);
436
437		if (sideP0 != LineRasterUtil::LINE_SIDE_INTERSECT &&
438			sideP1 != LineRasterUtil::LINE_SIDE_INTERSECT &&
439			sideP0 != sideP1)
440			return true;
441	}
442
443	return false;
444}
445
446} // LineRasterUtil
447
448TriangleRasterizer::TriangleRasterizer (const tcu::IVec4& viewport, const int numSamples, const RasterizationState& state, const int subpixelBits)
449	: m_viewport				(viewport)
450	, m_numSamples				(numSamples)
451	, m_winding					(state.winding)
452	, m_horizontalFill			(state.horizontalFill)
453	, m_verticalFill			(state.verticalFill)
454	, m_subpixelBits			(subpixelBits)
455	, m_face					(FACETYPE_LAST)
456	, m_viewportOrientation		(state.viewportOrientation)
457{
458}
459
460/*--------------------------------------------------------------------*//*!
461 * \brief Initialize triangle rasterization
462 * \param v0 Screen-space coordinates (x, y, z) and 1/w for vertex 0.
463 * \param v1 Screen-space coordinates (x, y, z) and 1/w for vertex 1.
464 * \param v2 Screen-space coordinates (x, y, z) and 1/w for vertex 2.
465 *//*--------------------------------------------------------------------*/
466void TriangleRasterizer::init (const tcu::Vec4& v0, const tcu::Vec4& v1, const tcu::Vec4& v2)
467{
468	m_v0 = v0;
469	m_v1 = v1;
470	m_v2 = v2;
471
472	// Positions in fixed-point coordinates.
473	const deInt64	x0		= toSubpixelCoord(v0.x(), m_subpixelBits);
474	const deInt64	y0		= toSubpixelCoord(v0.y(), m_subpixelBits);
475	const deInt64	x1		= toSubpixelCoord(v1.x(), m_subpixelBits);
476	const deInt64	y1		= toSubpixelCoord(v1.y(), m_subpixelBits);
477	const deInt64	x2		= toSubpixelCoord(v2.x(), m_subpixelBits);
478	const deInt64	y2		= toSubpixelCoord(v2.y(), m_subpixelBits);
479
480	// Initialize edge functions.
481	if (m_winding == WINDING_CCW)
482	{
483		initEdgeCCW(m_edge01, m_horizontalFill, m_verticalFill, x0, y0, x1, y1);
484		initEdgeCCW(m_edge12, m_horizontalFill, m_verticalFill, x1, y1, x2, y2);
485		initEdgeCCW(m_edge20, m_horizontalFill, m_verticalFill, x2, y2, x0, y0);
486	}
487	else
488	{
489		// Reverse edges
490		initEdgeCCW(m_edge01, m_horizontalFill, m_verticalFill, x1, y1, x0, y0);
491		initEdgeCCW(m_edge12, m_horizontalFill, m_verticalFill, x2, y2, x1, y1);
492		initEdgeCCW(m_edge20, m_horizontalFill, m_verticalFill, x0, y0, x2, y2);
493	}
494
495	// Determine face.
496	const deInt64	s				= evaluateEdge(m_edge01, x2, y2);
497	const bool		positiveArea	= (m_winding == WINDING_CCW) ? (s > 0) : (s < 0);
498
499	if (m_viewportOrientation == VIEWPORTORIENTATION_UPPER_LEFT)
500		m_face = positiveArea ? FACETYPE_BACK : FACETYPE_FRONT;
501	else
502		m_face = positiveArea ? FACETYPE_FRONT : FACETYPE_BACK;
503
504	if (!positiveArea)
505	{
506		// Reverse edges so that we can use CCW area tests & interpolation
507		reverseEdge(m_edge01);
508		reverseEdge(m_edge12);
509		reverseEdge(m_edge20);
510	}
511
512	// Bounding box
513	const deInt64	xMin	= de::min(de::min(x0, x1), x2);
514	const deInt64	xMax	= de::max(de::max(x0, x1), x2);
515	const deInt64	yMin	= de::min(de::min(y0, y1), y2);
516	const deInt64	yMax	= de::max(de::max(y0, y1), y2);
517
518	m_bboxMin.x() = floorSubpixelToPixelCoord	(xMin, m_subpixelBits, m_horizontalFill	== FILL_LEFT);
519	m_bboxMin.y() = floorSubpixelToPixelCoord	(yMin, m_subpixelBits, m_verticalFill	== FILL_BOTTOM);
520	m_bboxMax.x() = ceilSubpixelToPixelCoord	(xMax, m_subpixelBits, m_horizontalFill	== FILL_RIGHT);
521	m_bboxMax.y() = ceilSubpixelToPixelCoord	(yMax, m_subpixelBits, m_verticalFill	== FILL_TOP);
522
523	// Clamp to viewport
524	const int		wX0		= m_viewport.x();
525	const int		wY0		= m_viewport.y();
526	const int		wX1		= wX0 + m_viewport.z() - 1;
527	const int		wY1		= wY0 + m_viewport.w() -1;
528
529	m_bboxMin.x() = de::clamp(m_bboxMin.x(), wX0, wX1);
530	m_bboxMin.y() = de::clamp(m_bboxMin.y(), wY0, wY1);
531	m_bboxMax.x() = de::clamp(m_bboxMax.x(), wX0, wX1);
532	m_bboxMax.y() = de::clamp(m_bboxMax.y(), wY0, wY1);
533
534	m_curPos = m_bboxMin;
535}
536
537void TriangleRasterizer::rasterizeSingleSample (FragmentPacket* const fragmentPackets, float* const depthValues, const int maxFragmentPackets, int& numPacketsRasterized)
538{
539	DE_ASSERT(maxFragmentPackets > 0);
540
541	const deUint64	halfPixel	= 1ll << (m_subpixelBits - 1);
542	int				packetNdx	= 0;
543
544	// For depth interpolation; given barycentrics A, B, C = (1 - A - B)
545	// we can reformulate the usual z = z0*A + z1*B + z2*C into more
546	// stable equation z = A*(z0 - z2) + B*(z1 - z2) + z2.
547	const float		za			= m_v0.z()-m_v2.z();
548	const float		zb			= m_v1.z()-m_v2.z();
549	const float		zc			= m_v2.z();
550
551	while (m_curPos.y() <= m_bboxMax.y() && packetNdx < maxFragmentPackets)
552	{
553		const int		x0		= m_curPos.x();
554		const int		y0		= m_curPos.y();
555
556		// Subpixel coords
557		const deInt64	sx0		= toSubpixelCoord(x0,   m_subpixelBits)	+ halfPixel;
558		const deInt64	sx1		= toSubpixelCoord(x0+1, m_subpixelBits)	+ halfPixel;
559		const deInt64	sy0		= toSubpixelCoord(y0,   m_subpixelBits)	+ halfPixel;
560		const deInt64	sy1		= toSubpixelCoord(y0+1, m_subpixelBits)	+ halfPixel;
561
562		const deInt64	sx[4]	= { sx0, sx1, sx0, sx1 };
563		const deInt64	sy[4]	= { sy0, sy0, sy1, sy1 };
564
565		// Viewport test
566		const bool		outX1	= x0+1 == m_viewport.x()+m_viewport.z();
567		const bool		outY1	= y0+1 == m_viewport.y()+m_viewport.w();
568
569		DE_ASSERT(x0 < m_viewport.x()+m_viewport.z());
570		DE_ASSERT(y0 < m_viewport.y()+m_viewport.w());
571
572		// Edge values
573		tcu::Vector<deInt64, 4>	e01;
574		tcu::Vector<deInt64, 4>	e12;
575		tcu::Vector<deInt64, 4>	e20;
576
577		// Coverage
578		deUint64		coverage	= 0;
579
580		// Evaluate edge values
581		for (int i = 0; i < 4; i++)
582		{
583			e01[i] = evaluateEdge(m_edge01, sx[i], sy[i]);
584			e12[i] = evaluateEdge(m_edge12, sx[i], sy[i]);
585			e20[i] = evaluateEdge(m_edge20, sx[i], sy[i]);
586		}
587
588		// Compute coverage mask
589		coverage = setCoverageValue(coverage, 1, 0, 0, 0,						isInsideCCW(m_edge01, e01[0]) && isInsideCCW(m_edge12, e12[0]) && isInsideCCW(m_edge20, e20[0]));
590		coverage = setCoverageValue(coverage, 1, 1, 0, 0, !outX1 &&				isInsideCCW(m_edge01, e01[1]) && isInsideCCW(m_edge12, e12[1]) && isInsideCCW(m_edge20, e20[1]));
591		coverage = setCoverageValue(coverage, 1, 0, 1, 0, !outY1 &&				isInsideCCW(m_edge01, e01[2]) && isInsideCCW(m_edge12, e12[2]) && isInsideCCW(m_edge20, e20[2]));
592		coverage = setCoverageValue(coverage, 1, 1, 1, 0, !outX1 && !outY1 &&	isInsideCCW(m_edge01, e01[3]) && isInsideCCW(m_edge12, e12[3]) && isInsideCCW(m_edge20, e20[3]));
593
594		// Advance to next location
595		m_curPos.x() += 2;
596		if (m_curPos.x() > m_bboxMax.x())
597		{
598			m_curPos.y() += 2;
599			m_curPos.x()  = m_bboxMin.x();
600		}
601
602		if (coverage == 0)
603			continue; // Discard.
604
605		// Floating-point edge values for barycentrics etc.
606		const tcu::Vec4		e01f	= e01.asFloat();
607		const tcu::Vec4		e12f	= e12.asFloat();
608		const tcu::Vec4		e20f	= e20.asFloat();
609
610		// Compute depth values.
611		if (depthValues)
612		{
613			const tcu::Vec4		edgeSum	= e01f + e12f + e20f;
614			const tcu::Vec4		z0		= e12f / edgeSum;
615			const tcu::Vec4		z1		= e20f / edgeSum;
616
617			depthValues[packetNdx*4+0] = z0[0]*za + z1[0]*zb + zc;
618			depthValues[packetNdx*4+1] = z0[1]*za + z1[1]*zb + zc;
619			depthValues[packetNdx*4+2] = z0[2]*za + z1[2]*zb + zc;
620			depthValues[packetNdx*4+3] = z0[3]*za + z1[3]*zb + zc;
621		}
622
623		// Compute barycentrics and write out fragment packet
624		{
625			FragmentPacket& packet = fragmentPackets[packetNdx];
626
627			const tcu::Vec4		b0		= e12f * m_v0.w();
628			const tcu::Vec4		b1		= e20f * m_v1.w();
629			const tcu::Vec4		b2		= e01f * m_v2.w();
630			const tcu::Vec4		bSum	= b0 + b1 + b2;
631
632			packet.position			= tcu::IVec2(x0, y0);
633			packet.coverage			= coverage;
634			packet.barycentric[0]	= b0 / bSum;
635			packet.barycentric[1]	= b1 / bSum;
636			packet.barycentric[2]	= 1.0f - packet.barycentric[0] - packet.barycentric[1];
637
638			packetNdx += 1;
639		}
640	}
641
642	DE_ASSERT(packetNdx <= maxFragmentPackets);
643	numPacketsRasterized = packetNdx;
644}
645
646// Sample positions - ordered as (x, y) list.
647static const float s_samplePts2[] =
648{
649	0.3f, 0.3f,
650	0.7f, 0.7f
651};
652
653static const float s_samplePts4[] =
654{
655	0.25f, 0.25f,
656	0.75f, 0.25f,
657	0.25f, 0.75f,
658	0.75f, 0.75f
659};
660
661static const float s_samplePts8[] =
662{
663	7.f  / 16.f,  9.f / 16.f,
664	9.f  / 16.f, 13.f / 16.f,
665	11.f / 16.f,  3.f / 16.f,
666	13.f / 16.f, 11.f / 16.f,
667	1.f  / 16.f,  7.f / 16.f,
668	5.f  / 16.f,  1.f / 16.f,
669	15.f / 16.f,  5.f / 16.f,
670	3.f  / 16.f, 15.f / 16.f
671};
672
673static const float s_samplePts16[] =
674{
675	1.f / 8.f, 1.f / 8.f,
676	3.f / 8.f, 1.f / 8.f,
677	5.f / 8.f, 1.f / 8.f,
678	7.f / 8.f, 1.f / 8.f,
679	1.f / 8.f, 3.f / 8.f,
680	3.f / 8.f, 3.f / 8.f,
681	5.f / 8.f, 3.f / 8.f,
682	7.f / 8.f, 3.f / 8.f,
683	1.f / 8.f, 5.f / 8.f,
684	3.f / 8.f, 5.f / 8.f,
685	5.f / 8.f, 5.f / 8.f,
686	7.f / 8.f, 5.f / 8.f,
687	1.f / 8.f, 7.f / 8.f,
688	3.f / 8.f, 7.f / 8.f,
689	5.f / 8.f, 7.f / 8.f,
690	7.f / 8.f, 7.f / 8.f
691};
692
693template<int NumSamples>
694void TriangleRasterizer::rasterizeMultiSample (FragmentPacket* const fragmentPackets, float* const depthValues, const int maxFragmentPackets, int& numPacketsRasterized)
695{
696	DE_ASSERT(maxFragmentPackets > 0);
697
698	// Big enough to hold maximum multisample count
699	deInt64			samplePos[DE_LENGTH_OF_ARRAY(s_samplePts16)];
700	const float *	samplePts	= DE_NULL;
701	const deUint64	halfPixel	= 1ll << (m_subpixelBits - 1);
702	int				packetNdx	= 0;
703
704	// For depth interpolation, see rasterizeSingleSample
705	const float		za			= m_v0.z()-m_v2.z();
706	const float		zb			= m_v1.z()-m_v2.z();
707	const float		zc			= m_v2.z();
708
709	switch (NumSamples)
710	{
711		case 2:		samplePts = s_samplePts2;	break;
712		case 4:		samplePts = s_samplePts4;	break;
713		case 8:		samplePts = s_samplePts8;	break;
714		case 16:	samplePts = s_samplePts16;	break;
715		default:
716			DE_ASSERT(false);
717	}
718
719	for (int c = 0; c < NumSamples * 2; ++c)
720		samplePos[c] = toSubpixelCoord(samplePts[c], m_subpixelBits);
721
722	while (m_curPos.y() <= m_bboxMax.y() && packetNdx < maxFragmentPackets)
723	{
724		const int		x0		= m_curPos.x();
725		const int		y0		= m_curPos.y();
726
727		// Base subpixel coords
728		const deInt64	sx0		= toSubpixelCoord(x0,   m_subpixelBits);
729		const deInt64	sx1		= toSubpixelCoord(x0+1, m_subpixelBits);
730		const deInt64	sy0		= toSubpixelCoord(y0,   m_subpixelBits);
731		const deInt64	sy1		= toSubpixelCoord(y0+1, m_subpixelBits);
732
733		const deInt64	sx[4]	= { sx0, sx1, sx0, sx1 };
734		const deInt64	sy[4]	= { sy0, sy0, sy1, sy1 };
735
736		// Viewport test
737		const bool		outX1	= x0+1 == m_viewport.x()+m_viewport.z();
738		const bool		outY1	= y0+1 == m_viewport.y()+m_viewport.w();
739
740		DE_ASSERT(x0 < m_viewport.x()+m_viewport.z());
741		DE_ASSERT(y0 < m_viewport.y()+m_viewport.w());
742
743		// Edge values
744		tcu::Vector<deInt64, 4>	e01[NumSamples];
745		tcu::Vector<deInt64, 4>	e12[NumSamples];
746		tcu::Vector<deInt64, 4>	e20[NumSamples];
747
748		// Coverage
749		deUint64		coverage	= 0;
750
751		// Evaluate edge values at sample positions
752		for (int sampleNdx = 0; sampleNdx < NumSamples; sampleNdx++)
753		{
754			const deInt64 ox = samplePos[sampleNdx*2 + 0];
755			const deInt64 oy = samplePos[sampleNdx*2 + 1];
756
757			for (int fragNdx = 0; fragNdx < 4; fragNdx++)
758			{
759				e01[sampleNdx][fragNdx] = evaluateEdge(m_edge01, sx[fragNdx] + ox, sy[fragNdx] + oy);
760				e12[sampleNdx][fragNdx] = evaluateEdge(m_edge12, sx[fragNdx] + ox, sy[fragNdx] + oy);
761				e20[sampleNdx][fragNdx] = evaluateEdge(m_edge20, sx[fragNdx] + ox, sy[fragNdx] + oy);
762			}
763		}
764
765		// Compute coverage mask
766		for (int sampleNdx = 0; sampleNdx < NumSamples; sampleNdx++)
767		{
768			coverage = setCoverageValue(coverage, NumSamples, 0, 0, sampleNdx,						isInsideCCW(m_edge01, e01[sampleNdx][0]) && isInsideCCW(m_edge12, e12[sampleNdx][0]) && isInsideCCW(m_edge20, e20[sampleNdx][0]));
769			coverage = setCoverageValue(coverage, NumSamples, 1, 0, sampleNdx, !outX1 &&			isInsideCCW(m_edge01, e01[sampleNdx][1]) && isInsideCCW(m_edge12, e12[sampleNdx][1]) && isInsideCCW(m_edge20, e20[sampleNdx][1]));
770			coverage = setCoverageValue(coverage, NumSamples, 0, 1, sampleNdx, !outY1 &&			isInsideCCW(m_edge01, e01[sampleNdx][2]) && isInsideCCW(m_edge12, e12[sampleNdx][2]) && isInsideCCW(m_edge20, e20[sampleNdx][2]));
771			coverage = setCoverageValue(coverage, NumSamples, 1, 1, sampleNdx, !outX1 && !outY1 &&	isInsideCCW(m_edge01, e01[sampleNdx][3]) && isInsideCCW(m_edge12, e12[sampleNdx][3]) && isInsideCCW(m_edge20, e20[sampleNdx][3]));
772		}
773
774		// Advance to next location
775		m_curPos.x() += 2;
776		if (m_curPos.x() > m_bboxMax.x())
777		{
778			m_curPos.y() += 2;
779			m_curPos.x()  = m_bboxMin.x();
780		}
781
782		if (coverage == 0)
783			continue; // Discard.
784
785		// Compute depth values.
786		if (depthValues)
787		{
788			for (int sampleNdx = 0; sampleNdx < NumSamples; sampleNdx++)
789			{
790				// Floating-point edge values at sample coordinates.
791				const tcu::Vec4&	e01f	= e01[sampleNdx].asFloat();
792				const tcu::Vec4&	e12f	= e12[sampleNdx].asFloat();
793				const tcu::Vec4&	e20f	= e20[sampleNdx].asFloat();
794
795				const tcu::Vec4		edgeSum	= e01f + e12f + e20f;
796				const tcu::Vec4		z0		= e12f / edgeSum;
797				const tcu::Vec4		z1		= e20f / edgeSum;
798
799				depthValues[(packetNdx*4+0)*NumSamples + sampleNdx] = z0[0]*za + z1[0]*zb + zc;
800				depthValues[(packetNdx*4+1)*NumSamples + sampleNdx] = z0[1]*za + z1[1]*zb + zc;
801				depthValues[(packetNdx*4+2)*NumSamples + sampleNdx] = z0[2]*za + z1[2]*zb + zc;
802				depthValues[(packetNdx*4+3)*NumSamples + sampleNdx] = z0[3]*za + z1[3]*zb + zc;
803			}
804		}
805
806		// Compute barycentrics and write out fragment packet
807		{
808			FragmentPacket& packet = fragmentPackets[packetNdx];
809
810			// Floating-point edge values at pixel center.
811			tcu::Vec4			e01f;
812			tcu::Vec4			e12f;
813			tcu::Vec4			e20f;
814
815			for (int i = 0; i < 4; i++)
816			{
817				e01f[i] = float(evaluateEdge(m_edge01, sx[i] + halfPixel, sy[i] + halfPixel));
818				e12f[i] = float(evaluateEdge(m_edge12, sx[i] + halfPixel, sy[i] + halfPixel));
819				e20f[i] = float(evaluateEdge(m_edge20, sx[i] + halfPixel, sy[i] + halfPixel));
820			}
821
822			// Barycentrics & scale.
823			const tcu::Vec4		b0		= e12f * m_v0.w();
824			const tcu::Vec4		b1		= e20f * m_v1.w();
825			const tcu::Vec4		b2		= e01f * m_v2.w();
826			const tcu::Vec4		bSum	= b0 + b1 + b2;
827
828			packet.position			= tcu::IVec2(x0, y0);
829			packet.coverage			= coverage;
830			packet.barycentric[0]	= b0 / bSum;
831			packet.barycentric[1]	= b1 / bSum;
832			packet.barycentric[2]	= 1.0f - packet.barycentric[0] - packet.barycentric[1];
833
834			packetNdx += 1;
835		}
836	}
837
838	DE_ASSERT(packetNdx <= maxFragmentPackets);
839	numPacketsRasterized = packetNdx;
840}
841
842void TriangleRasterizer::rasterize (FragmentPacket* const fragmentPackets, float* const depthValues, const int maxFragmentPackets, int& numPacketsRasterized)
843{
844	DE_ASSERT(maxFragmentPackets > 0);
845
846	switch (m_numSamples)
847	{
848		case 1:		rasterizeSingleSample		(fragmentPackets, depthValues, maxFragmentPackets, numPacketsRasterized);	break;
849		case 2:		rasterizeMultiSample<2>		(fragmentPackets, depthValues, maxFragmentPackets, numPacketsRasterized);	break;
850		case 4:		rasterizeMultiSample<4>		(fragmentPackets, depthValues, maxFragmentPackets, numPacketsRasterized);	break;
851		case 8:		rasterizeMultiSample<8>		(fragmentPackets, depthValues, maxFragmentPackets, numPacketsRasterized);	break;
852		case 16:	rasterizeMultiSample<16>	(fragmentPackets, depthValues, maxFragmentPackets, numPacketsRasterized);	break;
853		default:
854			DE_ASSERT(DE_FALSE);
855	}
856}
857
858SingleSampleLineRasterizer::SingleSampleLineRasterizer (const tcu::IVec4& viewport, const int subpixelBits)
859	: m_viewport		(viewport)
860	, m_subpixelBits	(subpixelBits)
861	, m_curRowFragment	(0)
862	, m_lineWidth		(0.0f)
863	, m_stippleCounter  (0)
864{
865}
866
867SingleSampleLineRasterizer::~SingleSampleLineRasterizer (void)
868{
869}
870
871void SingleSampleLineRasterizer::init (const tcu::Vec4& v0, const tcu::Vec4& v1, float lineWidth, deUint32 stippleFactor, deUint16 stipplePattern)
872{
873	const bool						isXMajor		= de::abs((v1 - v0).x()) >= de::abs((v1 - v0).y());
874
875	// Bounding box \note: with wide lines, the line is actually moved as in the spec
876	const deInt32					lineWidthPixels	= (lineWidth > 1.0f) ? (deInt32)floor(lineWidth + 0.5f) : 1;
877
878	const tcu::Vector<deInt64,2>	widthOffset		= (isXMajor ? tcu::Vector<deInt64,2>(0, -1) : tcu::Vector<deInt64,2>(-1, 0)) * (toSubpixelCoord(lineWidthPixels - 1, m_subpixelBits) / 2);
879
880	const deInt64					x0				= toSubpixelCoord(v0.x(), m_subpixelBits) + widthOffset.x();
881	const deInt64					y0				= toSubpixelCoord(v0.y(), m_subpixelBits) + widthOffset.y();
882	const deInt64					x1				= toSubpixelCoord(v1.x(), m_subpixelBits) + widthOffset.x();
883	const deInt64					y1				= toSubpixelCoord(v1.y(), m_subpixelBits) + widthOffset.y();
884
885	// line endpoints might be perturbed, add some margin
886	const deInt64					xMin			= de::min(x0, x1) - toSubpixelCoord(1, m_subpixelBits);
887	const deInt64					xMax			= de::max(x0, x1) + toSubpixelCoord(1, m_subpixelBits);
888	const deInt64					yMin			= de::min(y0, y1) - toSubpixelCoord(1, m_subpixelBits);
889	const deInt64					yMax			= de::max(y0, y1) + toSubpixelCoord(1, m_subpixelBits);
890
891	// Remove invisible area
892
893	if (isXMajor)
894	{
895		// clamp to viewport in major direction
896		m_bboxMin.x() = de::clamp(floorSubpixelToPixelCoord(xMin, m_subpixelBits, true), m_viewport.x(), m_viewport.x() + m_viewport.z() - 1);
897		m_bboxMax.x() = de::clamp(ceilSubpixelToPixelCoord (xMax, m_subpixelBits, true), m_viewport.x(), m_viewport.x() + m_viewport.z() - 1);
898
899		// clamp to padded viewport in minor direction (wide lines might bleed over viewport in minor direction)
900		m_bboxMin.y() = de::clamp(floorSubpixelToPixelCoord(yMin, m_subpixelBits, true), m_viewport.y() - lineWidthPixels, m_viewport.y() + m_viewport.w() - 1);
901		m_bboxMax.y() = de::clamp(ceilSubpixelToPixelCoord (yMax, m_subpixelBits, true), m_viewport.y() - lineWidthPixels, m_viewport.y() + m_viewport.w() - 1);
902	}
903	else
904	{
905		// clamp to viewport in major direction
906		m_bboxMin.y() = de::clamp(floorSubpixelToPixelCoord(yMin, m_subpixelBits, true), m_viewport.y(), m_viewport.y() + m_viewport.w() - 1);
907		m_bboxMax.y() = de::clamp(ceilSubpixelToPixelCoord (yMax, m_subpixelBits, true), m_viewport.y(), m_viewport.y() + m_viewport.w() - 1);
908
909		// clamp to padded viewport in minor direction (wide lines might bleed over viewport in minor direction)
910		m_bboxMin.x() = de::clamp(floorSubpixelToPixelCoord(xMin, m_subpixelBits, true), m_viewport.x() - lineWidthPixels, m_viewport.x() + m_viewport.z() - 1);
911		m_bboxMax.x() = de::clamp(ceilSubpixelToPixelCoord (xMax, m_subpixelBits, true), m_viewport.x() - lineWidthPixels, m_viewport.x() + m_viewport.z() - 1);
912	}
913
914	m_lineWidth = lineWidth;
915
916	m_v0 = v0;
917	m_v1 = v1;
918
919	// Choose direction of traversal and whether to start at bbox min or max. Direction matters
920    // for the stipple counter.
921	int											xDelta				= (m_v1 - m_v0).x() > 0 ? 1 : -1;
922	int											yDelta				= (m_v1 - m_v0).y() > 0 ? 1 : -1;
923
924	m_curPos.x() = xDelta > 0 ? m_bboxMin.x() : m_bboxMax.x();
925	m_curPos.y() = yDelta > 0 ? m_bboxMin.y() : m_bboxMax.y();
926
927	m_curRowFragment = 0;
928	m_stippleFactor = stippleFactor;
929	m_stipplePattern = stipplePattern;
930}
931
932void SingleSampleLineRasterizer::rasterize (FragmentPacket* const fragmentPackets, float* const depthValues, const int maxFragmentPackets, int& numPacketsRasterized)
933{
934	DE_ASSERT(maxFragmentPackets > 0);
935
936	const deInt64								halfPixel			= 1ll << (m_subpixelBits - 1);
937	const deInt32								lineWidth			= (m_lineWidth > 1.0f) ? deFloorFloatToInt32(m_lineWidth + 0.5f) : 1;
938	const bool									isXMajor			= de::abs((m_v1 - m_v0).x()) >= de::abs((m_v1 - m_v0).y());
939	const tcu::IVec2							minorDirection		= (isXMajor) ? (tcu::IVec2(0, 1)) : (tcu::IVec2(1, 0));
940	const int									minViewportLimit	= (isXMajor) ? (m_viewport.y()) : (m_viewport.x());
941	const int									maxViewportLimit	= (isXMajor) ? (m_viewport.y() + m_viewport.w()) : (m_viewport.x() + m_viewport.z());
942	const tcu::Vector<deInt64,2>				widthOffset			= -minorDirection.cast<deInt64>() * (toSubpixelCoord(lineWidth - 1, m_subpixelBits) / 2);
943	const tcu::Vector<deInt64,2>				pa					= LineRasterUtil::toSubpixelVector(m_v0.xy(), m_subpixelBits) + widthOffset;
944	const tcu::Vector<deInt64,2>				pb					= LineRasterUtil::toSubpixelVector(m_v1.xy(), m_subpixelBits) + widthOffset;
945	const LineRasterUtil::SubpixelLineSegment	line				= LineRasterUtil::SubpixelLineSegment(pa, pb);
946
947	int											packetNdx			= 0;
948	int											xDelta				= (m_v1 - m_v0).x() > 0 ? 1 : -1;
949	int											yDelta				= (m_v1 - m_v0).y() > 0 ? 1 : -1;
950
951	while (m_curPos.y() <= m_bboxMax.y() && m_curPos.y() >= m_bboxMin.y() && packetNdx < maxFragmentPackets)
952	{
953		const tcu::Vector<deInt64,2> diamondPosition = LineRasterUtil::toSubpixelVector(m_curPos, m_subpixelBits) + tcu::Vector<deInt64,2>(halfPixel,halfPixel);
954
955		// Should current fragment be drawn? == does the segment exit this diamond?
956		if (LineRasterUtil::doesLineSegmentExitDiamond(line, diamondPosition, m_subpixelBits))
957		{
958			const tcu::Vector<deInt64,2>	pr					= diamondPosition;
959			const float						t					= tcu::dot((pr - pa).asFloat(), (pb - pa).asFloat()) / tcu::lengthSquared(pb.asFloat() - pa.asFloat());
960
961			// Rasterize on only fragments that are would end up in the viewport (i.e. visible)
962			const int						fragmentLocation	= (isXMajor) ? (m_curPos.y()) : (m_curPos.x());
963			const int						rowFragBegin		= de::max(0, minViewportLimit - fragmentLocation);
964			const int						rowFragEnd			= de::min(maxViewportLimit - fragmentLocation, lineWidth);
965
966			int stippleBit = (m_stippleCounter / m_stippleFactor) % 16;
967			bool stipplePass = (m_stipplePattern & (1 << stippleBit)) != 0;
968			m_stippleCounter++;
969
970			if (stipplePass)
971			{
972				// Wide lines require multiple fragments.
973				for (; rowFragBegin + m_curRowFragment < rowFragEnd; m_curRowFragment++)
974				{
975					const int			replicationId	= rowFragBegin + m_curRowFragment;
976					const tcu::IVec2	fragmentPos		= m_curPos + minorDirection * replicationId;
977
978					// We only rasterize visible area
979					DE_ASSERT(LineRasterUtil::inViewport(fragmentPos, m_viewport));
980
981					// Compute depth values.
982					if (depthValues)
983					{
984						const float za = m_v0.z();
985						const float zb = m_v1.z();
986
987						depthValues[packetNdx*4+0] = (1 - t) * za + t * zb;
988						depthValues[packetNdx*4+1] = 0;
989						depthValues[packetNdx*4+2] = 0;
990						depthValues[packetNdx*4+3] = 0;
991					}
992
993					{
994						// output this fragment
995						// \note In order to make consistent output with multisampled line rasterization, output "barycentric" coordinates
996						FragmentPacket& packet = fragmentPackets[packetNdx];
997
998						const tcu::Vec4		b0		= tcu::Vec4(1 - t);
999						const tcu::Vec4		b1		= tcu::Vec4(t);
1000						const tcu::Vec4		ooSum	= 1.0f / (b0 + b1);
1001
1002						packet.position			= fragmentPos;
1003						packet.coverage			= getCoverageBit(1, 0, 0, 0);
1004						packet.barycentric[0]	= b0 * ooSum;
1005						packet.barycentric[1]	= b1 * ooSum;
1006						packet.barycentric[2]	= tcu::Vec4(0.0f);
1007
1008						packetNdx += 1;
1009					}
1010
1011					if (packetNdx == maxFragmentPackets)
1012					{
1013						m_curRowFragment++; // don't redraw this fragment again next time
1014						m_stippleCounter--; // reuse same stipple counter next time
1015						numPacketsRasterized = packetNdx;
1016						return;
1017					}
1018				}
1019
1020				m_curRowFragment = 0;
1021			}
1022		}
1023
1024		m_curPos.x() += xDelta;
1025		if (m_curPos.x() > m_bboxMax.x() || m_curPos.x() < m_bboxMin.x())
1026		{
1027			m_curPos.y() += yDelta;
1028			m_curPos.x() = xDelta > 0 ? m_bboxMin.x() : m_bboxMax.x();
1029		}
1030	}
1031
1032	DE_ASSERT(packetNdx <= maxFragmentPackets);
1033	numPacketsRasterized = packetNdx;
1034}
1035
1036MultiSampleLineRasterizer::MultiSampleLineRasterizer (const int numSamples, const tcu::IVec4& viewport, const int subpixelBits)
1037	: m_numSamples			(numSamples)
1038	, m_triangleRasterizer0 (viewport, m_numSamples, RasterizationState(), subpixelBits)
1039	, m_triangleRasterizer1 (viewport, m_numSamples, RasterizationState(), subpixelBits)
1040{
1041}
1042
1043MultiSampleLineRasterizer::~MultiSampleLineRasterizer ()
1044{
1045}
1046
1047void MultiSampleLineRasterizer::init (const tcu::Vec4& v0, const tcu::Vec4& v1, float lineWidth)
1048{
1049	// allow creation of single sampled rasterizer objects but do not allow using them
1050	DE_ASSERT(m_numSamples > 1);
1051
1052	const tcu::Vec2 lineVec		= tcu::Vec2(tcu::Vec4(v1).xy()) - tcu::Vec2(tcu::Vec4(v0).xy());
1053	const tcu::Vec2 normal2		= tcu::normalize(tcu::Vec2(-lineVec[1], lineVec[0]));
1054	const tcu::Vec4 normal4		= tcu::Vec4(normal2.x(), normal2.y(), 0, 0);
1055	const float offset			= lineWidth / 2.0f;
1056
1057	const tcu::Vec4 p0 = v0 + normal4 * offset;
1058	const tcu::Vec4 p1 = v0 - normal4 * offset;
1059	const tcu::Vec4 p2 = v1 - normal4 * offset;
1060	const tcu::Vec4 p3 = v1 + normal4 * offset;
1061
1062	// Edge 0 -> 1 is always along the line and edge 1 -> 2 is in 90 degree angle to the line
1063	m_triangleRasterizer0.init(p0, p3, p2);
1064	m_triangleRasterizer1.init(p2, p1, p0);
1065}
1066
1067void MultiSampleLineRasterizer::rasterize (FragmentPacket* const fragmentPackets, float* const depthValues, const int maxFragmentPackets, int& numPacketsRasterized)
1068{
1069	DE_ASSERT(maxFragmentPackets > 0);
1070
1071	m_triangleRasterizer0.rasterize(fragmentPackets, depthValues, maxFragmentPackets, numPacketsRasterized);
1072
1073	// Remove 3rd barycentric value and rebalance. Lines do not have non-zero barycentric at index 2
1074	for (int packNdx = 0; packNdx < numPacketsRasterized; ++packNdx)
1075	for (int fragNdx = 0; fragNdx < 4; fragNdx++)
1076	{
1077		float removedValue = fragmentPackets[packNdx].barycentric[2][fragNdx];
1078		fragmentPackets[packNdx].barycentric[2][fragNdx] = 0.0f;
1079		fragmentPackets[packNdx].barycentric[1][fragNdx] += removedValue;
1080	}
1081
1082	// rasterizer 0 filled the whole buffer?
1083	if (numPacketsRasterized == maxFragmentPackets)
1084		return;
1085
1086	{
1087		FragmentPacket* const nextFragmentPackets	= fragmentPackets + numPacketsRasterized;
1088		float* nextDepthValues						= (depthValues) ? (depthValues+4*numPacketsRasterized*m_numSamples) : (DE_NULL);
1089		int numPacketsRasterized2					= 0;
1090
1091		m_triangleRasterizer1.rasterize(nextFragmentPackets, nextDepthValues, maxFragmentPackets - numPacketsRasterized, numPacketsRasterized2);
1092
1093		numPacketsRasterized += numPacketsRasterized2;
1094
1095		// Fix swapped barycentrics in the second triangle
1096		for (int packNdx = 0; packNdx < numPacketsRasterized2; ++packNdx)
1097		for (int fragNdx = 0; fragNdx < 4; fragNdx++)
1098		{
1099			float removedValue = nextFragmentPackets[packNdx].barycentric[2][fragNdx];
1100			nextFragmentPackets[packNdx].barycentric[2][fragNdx] = 0.0f;
1101			nextFragmentPackets[packNdx].barycentric[1][fragNdx] += removedValue;
1102
1103			// edge has reversed direction
1104			std::swap(nextFragmentPackets[packNdx].barycentric[0][fragNdx], nextFragmentPackets[packNdx].barycentric[1][fragNdx]);
1105		}
1106	}
1107}
1108
1109LineExitDiamondGenerator::LineExitDiamondGenerator (const int subpixelBits)
1110	: m_subpixelBits(subpixelBits)
1111{
1112}
1113
1114LineExitDiamondGenerator::~LineExitDiamondGenerator (void)
1115{
1116}
1117
1118void LineExitDiamondGenerator::init (const tcu::Vec4& v0, const tcu::Vec4& v1)
1119{
1120	const deInt64					x0				= toSubpixelCoord(v0.x(), m_subpixelBits);
1121	const deInt64					y0				= toSubpixelCoord(v0.y(), m_subpixelBits);
1122	const deInt64					x1				= toSubpixelCoord(v1.x(), m_subpixelBits);
1123	const deInt64					y1				= toSubpixelCoord(v1.y(), m_subpixelBits);
1124
1125	// line endpoints might be perturbed, add some margin
1126	const deInt64					xMin			= de::min(x0, x1) - toSubpixelCoord(1, m_subpixelBits);
1127	const deInt64					xMax			= de::max(x0, x1) + toSubpixelCoord(1, m_subpixelBits);
1128	const deInt64					yMin			= de::min(y0, y1) - toSubpixelCoord(1, m_subpixelBits);
1129	const deInt64					yMax			= de::max(y0, y1) + toSubpixelCoord(1, m_subpixelBits);
1130
1131	m_bboxMin.x() = floorSubpixelToPixelCoord(xMin, m_subpixelBits, true);
1132	m_bboxMin.y() = floorSubpixelToPixelCoord(yMin, m_subpixelBits, true);
1133	m_bboxMax.x() = ceilSubpixelToPixelCoord (xMax, m_subpixelBits, true);
1134	m_bboxMax.y() = ceilSubpixelToPixelCoord (yMax, m_subpixelBits, true);
1135
1136	m_v0 = v0;
1137	m_v1 = v1;
1138
1139	m_curPos = m_bboxMin;
1140}
1141
1142void LineExitDiamondGenerator::rasterize (LineExitDiamond* const lineDiamonds, const int maxDiamonds, int& numWritten)
1143{
1144	DE_ASSERT(maxDiamonds > 0);
1145
1146	const deInt64								halfPixel			= 1ll << (m_subpixelBits - 1);
1147	const tcu::Vector<deInt64,2>				pa					= LineRasterUtil::toSubpixelVector(m_v0.xy(), m_subpixelBits);
1148	const tcu::Vector<deInt64,2>				pb					= LineRasterUtil::toSubpixelVector(m_v1.xy(), m_subpixelBits);
1149	const LineRasterUtil::SubpixelLineSegment	line				= LineRasterUtil::SubpixelLineSegment(pa, pb);
1150
1151	int											diamondNdx			= 0;
1152
1153	while (m_curPos.y() <= m_bboxMax.y() && diamondNdx < maxDiamonds)
1154	{
1155		const tcu::Vector<deInt64,2> diamondPosition = LineRasterUtil::toSubpixelVector(m_curPos, m_subpixelBits) + tcu::Vector<deInt64,2>(halfPixel,halfPixel);
1156
1157		if (LineRasterUtil::doesLineSegmentExitDiamond(line, diamondPosition, m_subpixelBits))
1158		{
1159			LineExitDiamond& packet = lineDiamonds[diamondNdx];
1160			packet.position = m_curPos;
1161			++diamondNdx;
1162		}
1163
1164		++m_curPos.x();
1165		if (m_curPos.x() > m_bboxMax.x())
1166		{
1167			++m_curPos.y();
1168			m_curPos.x() = m_bboxMin.x();
1169		}
1170	}
1171
1172	DE_ASSERT(diamondNdx <= maxDiamonds);
1173	numWritten = diamondNdx;
1174}
1175
1176} // rr
1177