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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 
28 namespace rr
29 {
30 
toSubpixelCoord(float v)31 inline deInt64 toSubpixelCoord (float v)
32 {
33 	return (deInt64)(v * (1<<RASTERIZER_SUBPIXEL_BITS) + (v < 0.f ? -0.5f : 0.5f));
34 }
35 
toSubpixelCoord(deInt32 v)36 inline deInt64 toSubpixelCoord (deInt32 v)
37 {
38 	return v << RASTERIZER_SUBPIXEL_BITS;
39 }
40 
ceilSubpixelToPixelCoord(deInt64 coord,bool fillEdge)41 inline deInt32 ceilSubpixelToPixelCoord (deInt64 coord, bool fillEdge)
42 {
43 	if (coord >= 0)
44 		return (deInt32)((coord + ((1ll<<RASTERIZER_SUBPIXEL_BITS) - (fillEdge ? 0 : 1))) >> RASTERIZER_SUBPIXEL_BITS);
45 	else
46 		return (deInt32)((coord + (fillEdge ? 1 : 0)) >> RASTERIZER_SUBPIXEL_BITS);
47 }
48 
floorSubpixelToPixelCoord(deInt64 coord,bool fillEdge)49 inline deInt32 floorSubpixelToPixelCoord (deInt64 coord, bool fillEdge)
50 {
51 	if (coord >= 0)
52 		return (deInt32)((coord - (fillEdge ? 1 : 0)) >> RASTERIZER_SUBPIXEL_BITS);
53 	else
54 		return (deInt32)((coord - ((1ll<<RASTERIZER_SUBPIXEL_BITS) - (fillEdge ? 0 : 1))) >> RASTERIZER_SUBPIXEL_BITS);
55 }
56 
initEdgeCCW(EdgeFunction & edge,const HorizontalFill horizontalFill,const VerticalFill verticalFill,const deInt64 x0,const deInt64 y0,const deInt64 x1,const deInt64 y1)57 static 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 
reverseEdge(EdgeFunction & edge)76 static 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 
evaluateEdge(const EdgeFunction & edge,const deInt64 x,const deInt64 y)84 static 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 
isInsideCCW(const EdgeFunction & edge,const deInt64 edgeVal)89 static inline bool isInsideCCW (const EdgeFunction& edge, const deInt64 edgeVal)
90 {
91 	return edge.inclusive ? (edgeVal >= 0) : (edgeVal > 0);
92 }
93 
94 namespace LineRasterUtil
95 {
96 
97 struct SubpixelLineSegment
98 {
99 	const tcu::Vector<deInt64,2>	m_v0;
100 	const tcu::Vector<deInt64,2>	m_v1;
101 
SubpixelLineSegmentrr::LineRasterUtil::SubpixelLineSegment102 	SubpixelLineSegment (const tcu::Vector<deInt64,2>& v0, const tcu::Vector<deInt64,2>& v1)
103 		: m_v0(v0)
104 		, m_v1(v1)
105 	{
106 	}
107 
directionrr::LineRasterUtil::SubpixelLineSegment108 	tcu::Vector<deInt64,2> direction (void) const
109 	{
110 		return m_v1 - m_v0;
111 	}
112 };
113 
114 enum LINE_SIDE
115 {
116 	LINE_SIDE_INTERSECT = 0,
117 	LINE_SIDE_LEFT,
118 	LINE_SIDE_RIGHT
119 };
120 
toSubpixelVector(const tcu::Vec2 & v)121 static tcu::Vector<deInt64,2> toSubpixelVector (const tcu::Vec2& v)
122 {
123 	return tcu::Vector<deInt64,2>(toSubpixelCoord(v.x()), toSubpixelCoord(v.y()));
124 }
125 
toSubpixelVector(const tcu::IVec2 & v)126 static tcu::Vector<deInt64,2> toSubpixelVector (const tcu::IVec2& v)
127 {
128 	return tcu::Vector<deInt64,2>(toSubpixelCoord(v.x()), toSubpixelCoord(v.y()));
129 }
130 
131 #if defined(DE_DEBUG)
isTheCenterOfTheFragment(const tcu::Vector<deInt64,2> & a)132 static bool isTheCenterOfTheFragment (const tcu::Vector<deInt64,2>& a)
133 {
134 	const deUint64 pixelSize = 1ll << (RASTERIZER_SUBPIXEL_BITS);
135 	const deUint64 halfPixel = 1ll << (RASTERIZER_SUBPIXEL_BITS-1);
136 	return	((a.x() & (pixelSize-1)) == halfPixel &&
137 				(a.y() & (pixelSize-1)) == halfPixel);
138 }
139 
inViewport(const tcu::IVec2 & p,const tcu::IVec4 & viewport)140 static 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
vertexOnLeftSideOfLine(const tcu::Vector<deInt64,2> & p,const SubpixelLineSegment & l)150 static 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
vertexOnRightSideOfLine(const tcu::Vector<deInt64,2> & p,const SubpixelLineSegment & l)159 static 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
vertexOnLine(const tcu::Vector<deInt64,2> & p,const SubpixelLineSegment & l)168 static 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
vertexOnLineSegment(const tcu::Vector<deInt64,2> & p,const SubpixelLineSegment & l)177 static 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 
getVertexSide(const tcu::Vector<deInt64,2> & v,const SubpixelLineSegment & l)193 static 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)
lineInCornerAngleRange(const SubpixelLineSegment & line,const tcu::Vector<deInt64,2> & cornerExitNormal)209 bool 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)
lineInCornerOutsideAngleRange(const SubpixelLineSegment & line,const tcu::Vector<deInt64,2> & cornerExitNormal)222 bool 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 
doesLineSegmentExitDiamond(const SubpixelLineSegment & line,const tcu::Vector<deInt64,2> & diamondCenter)234 bool doesLineSegmentExitDiamond (const SubpixelLineSegment& line, const tcu::Vector<deInt64,2>& diamondCenter)
235 {
236 	DE_ASSERT(isTheCenterOfTheFragment(diamondCenter));
237 
238 	// Diamond Center is at diamondCenter in subpixel coords
239 
240 	const deInt64 halfPixel = 1ll << (RASTERIZER_SUBPIXEL_BITS-1);
241 
242 	const struct DiamondBound
243 	{
244 		tcu::Vector<deInt64,2>	p0;
245 		tcu::Vector<deInt64,2>	p1;
246 		bool					edgeInclusive; // would a point on the bound be inside of the region
247 	} bounds[] =
248 	{
249 		{ diamondCenter + tcu::Vector<deInt64,2>(0,				-halfPixel),	diamondCenter + tcu::Vector<deInt64,2>(-halfPixel,	0),				 false	},
250 		{ diamondCenter + tcu::Vector<deInt64,2>(-halfPixel,	0),				diamondCenter + tcu::Vector<deInt64,2>(0,			halfPixel),		 false	},
251 		{ diamondCenter + tcu::Vector<deInt64,2>(0,				halfPixel),		diamondCenter + tcu::Vector<deInt64,2>(halfPixel,	0),				 true	},
252 		{ diamondCenter + tcu::Vector<deInt64,2>(halfPixel,		0),				diamondCenter + tcu::Vector<deInt64,2>(0,			-halfPixel),	 true	},
253 	};
254 
255 	const struct DiamondCorners
256 	{
257 		enum CORNER_EDGE_CASE_BEHAVIOR
258 		{
259 			CORNER_EDGE_CASE_NONE,							// if the line intersects just a corner, no entering or exiting
260 			CORNER_EDGE_CASE_HIT,							// if the line intersects just a corner, entering and exit
261 			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)
262 			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)
263 		};
264 		enum CORNER_START_CASE_BEHAVIOR
265 		{
266 			CORNER_START_CASE_NONE,							// the line starting point is outside, no exiting
267 			CORNER_START_CASE_OUTSIDE,						// exit, if line does not intersect the region (preturbing moves the start point inside)
268 			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.
269 			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.
270 		};
271 		enum CORNER_END_CASE_BEHAVIOR
272 		{
273 			CORNER_END_CASE_NONE,							// end is inside, no exiting (preturbing moves the line end inside)
274 			CORNER_END_CASE_DIRECTION,						// exit, if line intersected the region (preturbing moves the line end outside)
275 			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)
276 			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)
277 		};
278 
279 		tcu::Vector<deInt64,2>		dp;
280 		bool						pointInclusive;			// would a point in this corner intersect with the region
281 		CORNER_EDGE_CASE_BEHAVIOR	lineBehavior;			// would a line segment going through this corner intersect with the region
282 		CORNER_START_CASE_BEHAVIOR	startBehavior;			// how the corner behaves if the start point at the corner
283 		CORNER_END_CASE_BEHAVIOR	endBehavior;			// how the corner behaves if the end point at the corner
284 
285 	} corners[] =
286 	{
287 		{ 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},
288 		{ tcu::Vector<deInt64,2>(-halfPixel,	0),				false,	DiamondCorners::CORNER_EDGE_CASE_NONE,					DiamondCorners::CORNER_START_CASE_NONE,				DiamondCorners::CORNER_END_CASE_DIRECTION					},
289 		{ 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	},
290 		{ tcu::Vector<deInt64,2>(halfPixel,		0),				true,	DiamondCorners::CORNER_EDGE_CASE_HIT,					DiamondCorners::CORNER_START_CASE_OUTSIDE,			DiamondCorners::CORNER_END_CASE_NONE						},
291 	};
292 
293 	// Corner cases at the corners
294 	for (int ndx = 0; ndx < DE_LENGTH_OF_ARRAY(corners); ++ndx)
295 	{
296 		const tcu::Vector<deInt64,2> p	= diamondCenter + corners[ndx].dp;
297 		const bool intersectsAtCorner	= LineRasterUtil::vertexOnLineSegment(p, line);
298 
299 		if (!intersectsAtCorner)
300 			continue;
301 
302 		// line segment body intersects with the corner
303 		if (p != line.m_v0 && p != line.m_v1)
304 		{
305 			if (corners[ndx].lineBehavior == DiamondCorners::CORNER_EDGE_CASE_HIT)
306 				return true;
307 
308 			// endpoint in (+X, -Y) (X or Y may be 0) direction <==> x*y <= 0
309 			if (corners[ndx].lineBehavior == DiamondCorners::CORNER_EDGE_CASE_HIT_FIRST_QUARTER &&
310 				(line.direction().x() * line.direction().y()) <= 0)
311 				return true;
312 
313 			// endpoint in (+X, +Y) (Y > 0) direction <==> x*y > 0
314 			if (corners[ndx].lineBehavior == DiamondCorners::CORNER_EDGE_CASE_HIT_SECOND_QUARTER &&
315 				(line.direction().x() * line.direction().y()) > 0)
316 				return true;
317 		}
318 
319 		// line exits the area at the corner
320 		if (lineInCornerAngleRange(line, corners[ndx].dp))
321 		{
322 			const bool startIsInside = corners[ndx].pointInclusive || p != line.m_v0;
323 			const bool endIsOutside = !corners[ndx].pointInclusive || p != line.m_v1;
324 
325 			// starting point is inside the region and end endpoint is outside
326 			if (startIsInside && endIsOutside)
327 				return true;
328 		}
329 
330 		// line end is at the corner
331 		if (p == line.m_v1)
332 		{
333 			if (corners[ndx].endBehavior == DiamondCorners::CORNER_END_CASE_DIRECTION ||
334 				corners[ndx].endBehavior == DiamondCorners::CORNER_END_CASE_DIRECTION_AND_FIRST_QUARTER ||
335 				corners[ndx].endBehavior == DiamondCorners::CORNER_END_CASE_DIRECTION_AND_SECOND_QUARTER)
336 			{
337 				// did the line intersect the region
338 				if (lineInCornerAngleRange(line, corners[ndx].dp))
339 					return true;
340 			}
341 
342 			// due to the perturbed endpoint, lines at this the angle will cause and enter-exit pair
343 			if (corners[ndx].endBehavior == DiamondCorners::CORNER_END_CASE_DIRECTION_AND_FIRST_QUARTER &&
344 				line.direction().x() < 0 &&
345 				line.direction().y() > 0)
346 				return true;
347 			if (corners[ndx].endBehavior == DiamondCorners::CORNER_END_CASE_DIRECTION_AND_SECOND_QUARTER &&
348 				line.direction().x() > 0 &&
349 				line.direction().y() > 0)
350 				return true;
351 		}
352 
353 		// line start is at the corner
354 		if (p == line.m_v0)
355 		{
356 			if (corners[ndx].startBehavior == DiamondCorners::CORNER_START_CASE_OUTSIDE)
357 			{
358 				// if the line is not going inside, it will exit
359 				if (lineInCornerOutsideAngleRange(line, corners[ndx].dp))
360 					return true;
361 			}
362 
363 			// exit, if line the angle between line vector and X-axis is in range (0, 45] in positive Y side.
364 			if (corners[ndx].startBehavior == DiamondCorners::CORNER_START_CASE_POSITIVE_Y_45 &&
365 				line.direction().x() > 0 &&
366 				line.direction().y() > 0 &&
367 				line.direction().y() <= line.direction().x())
368 				return true;
369 
370 			// exit, if line the angle between line vector and X-axis is in range [0, 45] in negative Y side.
371 			if (corners[ndx].startBehavior == DiamondCorners::CORNER_START_CASE_NEGATIVE_Y_45 &&
372 				 line.direction().x() > 0 &&
373 				 line.direction().y() <= 0 &&
374 				-line.direction().y() <= line.direction().x())
375 				return true;
376 		}
377 	}
378 
379 	// Does the line intersect boundary at the left == exits the diamond
380 	for (int ndx = 0; ndx < DE_LENGTH_OF_ARRAY(bounds); ++ndx)
381 	{
382 		const bool startVertexInside =	LineRasterUtil::vertexOnLeftSideOfLine						(line.m_v0, LineRasterUtil::SubpixelLineSegment(bounds[ndx].p0, bounds[ndx].p1)) ||
383 										(bounds[ndx].edgeInclusive && LineRasterUtil::vertexOnLine	(line.m_v0, LineRasterUtil::SubpixelLineSegment(bounds[ndx].p0, bounds[ndx].p1)));
384 		const bool endVertexInside =	LineRasterUtil::vertexOnLeftSideOfLine						(line.m_v1, LineRasterUtil::SubpixelLineSegment(bounds[ndx].p0, bounds[ndx].p1)) ||
385 										(bounds[ndx].edgeInclusive && LineRasterUtil::vertexOnLine	(line.m_v1, LineRasterUtil::SubpixelLineSegment(bounds[ndx].p0, bounds[ndx].p1)));
386 
387 		// start must be on inside this half space (left or at the inclusive boundary)
388 		if (!startVertexInside)
389 			continue;
390 
391 		// end must be outside of this half-space (right or at non-inclusive boundary)
392 		if (endVertexInside)
393 			continue;
394 
395 		// Does the line via v0 and v1 intersect the line segment p0-p1
396 		// <==> p0 and p1 are the different sides (LEFT, RIGHT) of the v0-v1 line.
397 		// Corners are not allowed, they are checked already
398 		LineRasterUtil::LINE_SIDE sideP0 = LineRasterUtil::getVertexSide(bounds[ndx].p0, line);
399 		LineRasterUtil::LINE_SIDE sideP1 = LineRasterUtil::getVertexSide(bounds[ndx].p1, line);
400 
401 		if (sideP0 != LineRasterUtil::LINE_SIDE_INTERSECT &&
402 			sideP1 != LineRasterUtil::LINE_SIDE_INTERSECT &&
403 			sideP0 != sideP1)
404 			return true;
405 	}
406 
407 	return false;
408 }
409 
410 } // LineRasterUtil
411 
TriangleRasterizer(const tcu::IVec4 & viewport,const int numSamples,const RasterizationState & state)412 TriangleRasterizer::TriangleRasterizer (const tcu::IVec4& viewport, const int numSamples, const RasterizationState& state)
413 	: m_viewport		(viewport)
414 	, m_numSamples		(numSamples)
415 	, m_winding			(state.winding)
416 	, m_horizontalFill	(state.horizontalFill)
417 	, m_verticalFill	(state.verticalFill)
418 	, m_face			(FACETYPE_LAST)
419 {
420 }
421 
422 /*--------------------------------------------------------------------*//*!
423  * \brief Initialize triangle rasterization
424  * \param v0 Screen-space coordinates (x, y, z) and 1/w for vertex 0.
425  * \param v1 Screen-space coordinates (x, y, z) and 1/w for vertex 1.
426  * \param v2 Screen-space coordinates (x, y, z) and 1/w for vertex 2.
427  *//*--------------------------------------------------------------------*/
init(const tcu::Vec4 & v0,const tcu::Vec4 & v1,const tcu::Vec4 & v2)428 void TriangleRasterizer::init (const tcu::Vec4& v0, const tcu::Vec4& v1, const tcu::Vec4& v2)
429 {
430 	m_v0 = v0;
431 	m_v1 = v1;
432 	m_v2 = v2;
433 
434 	// Positions in fixed-point coordinates.
435 	const deInt64	x0		= toSubpixelCoord(v0.x());
436 	const deInt64	y0		= toSubpixelCoord(v0.y());
437 	const deInt64	x1		= toSubpixelCoord(v1.x());
438 	const deInt64	y1		= toSubpixelCoord(v1.y());
439 	const deInt64	x2		= toSubpixelCoord(v2.x());
440 	const deInt64	y2		= toSubpixelCoord(v2.y());
441 
442 	// Initialize edge functions.
443 	if (m_winding == WINDING_CCW)
444 	{
445 		initEdgeCCW(m_edge01, m_horizontalFill, m_verticalFill, x0, y0, x1, y1);
446 		initEdgeCCW(m_edge12, m_horizontalFill, m_verticalFill, x1, y1, x2, y2);
447 		initEdgeCCW(m_edge20, m_horizontalFill, m_verticalFill, x2, y2, x0, y0);
448 	}
449 	else
450 	{
451 		// Reverse edges
452 		initEdgeCCW(m_edge01, m_horizontalFill, m_verticalFill, x1, y1, x0, y0);
453 		initEdgeCCW(m_edge12, m_horizontalFill, m_verticalFill, x2, y2, x1, y1);
454 		initEdgeCCW(m_edge20, m_horizontalFill, m_verticalFill, x0, y0, x2, y2);
455 	}
456 
457 	// Determine face.
458 	const deInt64	s				= evaluateEdge(m_edge01, x2, y2);
459 	const bool		positiveArea	= (m_winding == WINDING_CCW) ? (s > 0) : (s < 0);
460 	m_face = positiveArea ? FACETYPE_FRONT : FACETYPE_BACK;
461 
462 	if (!positiveArea)
463 	{
464 		// Reverse edges so that we can use CCW area tests & interpolation
465 		reverseEdge(m_edge01);
466 		reverseEdge(m_edge12);
467 		reverseEdge(m_edge20);
468 	}
469 
470 	// Bounding box
471 	const deInt64	xMin	= de::min(de::min(x0, x1), x2);
472 	const deInt64	xMax	= de::max(de::max(x0, x1), x2);
473 	const deInt64	yMin	= de::min(de::min(y0, y1), y2);
474 	const deInt64	yMax	= de::max(de::max(y0, y1), y2);
475 
476 	m_bboxMin.x() = floorSubpixelToPixelCoord	(xMin, m_horizontalFill	== FILL_LEFT);
477 	m_bboxMin.y() = floorSubpixelToPixelCoord	(yMin, m_verticalFill	== FILL_BOTTOM);
478 	m_bboxMax.x() = ceilSubpixelToPixelCoord	(xMax, m_horizontalFill	== FILL_RIGHT);
479 	m_bboxMax.y() = ceilSubpixelToPixelCoord	(yMax, m_verticalFill	== FILL_TOP);
480 
481 	// Clamp to viewport
482 	const int		wX0		= m_viewport.x();
483 	const int		wY0		= m_viewport.y();
484 	const int		wX1		= wX0 + m_viewport.z() - 1;
485 	const int		wY1		= wY0 + m_viewport.w() -1;
486 
487 	m_bboxMin.x() = de::clamp(m_bboxMin.x(), wX0, wX1);
488 	m_bboxMin.y() = de::clamp(m_bboxMin.y(), wY0, wY1);
489 	m_bboxMax.x() = de::clamp(m_bboxMax.x(), wX0, wX1);
490 	m_bboxMax.y() = de::clamp(m_bboxMax.y(), wY0, wY1);
491 
492 	m_curPos = m_bboxMin;
493 }
494 
rasterizeSingleSample(FragmentPacket * const fragmentPackets,float * const depthValues,const int maxFragmentPackets,int & numPacketsRasterized)495 void TriangleRasterizer::rasterizeSingleSample (FragmentPacket* const fragmentPackets, float* const depthValues, const int maxFragmentPackets, int& numPacketsRasterized)
496 {
497 	DE_ASSERT(maxFragmentPackets > 0);
498 
499 	const deUint64	halfPixel	= 1ll << (RASTERIZER_SUBPIXEL_BITS-1);
500 	int				packetNdx	= 0;
501 
502 	while (m_curPos.y() <= m_bboxMax.y() && packetNdx < maxFragmentPackets)
503 	{
504 		const int		x0		= m_curPos.x();
505 		const int		y0		= m_curPos.y();
506 
507 		// Subpixel coords
508 		const deInt64	sx0		= toSubpixelCoord(x0)	+ halfPixel;
509 		const deInt64	sx1		= toSubpixelCoord(x0+1)	+ halfPixel;
510 		const deInt64	sy0		= toSubpixelCoord(y0)	+ halfPixel;
511 		const deInt64	sy1		= toSubpixelCoord(y0+1)	+ halfPixel;
512 
513 		const deInt64	sx[4]	= { sx0, sx1, sx0, sx1 };
514 		const deInt64	sy[4]	= { sy0, sy0, sy1, sy1 };
515 
516 		// Viewport test
517 		const bool		outX1	= x0+1 == m_viewport.x()+m_viewport.z();
518 		const bool		outY1	= y0+1 == m_viewport.y()+m_viewport.w();
519 
520 		DE_ASSERT(x0 < m_viewport.x()+m_viewport.z());
521 		DE_ASSERT(y0 < m_viewport.y()+m_viewport.w());
522 
523 		// Edge values
524 		tcu::Vector<deInt64, 4>	e01;
525 		tcu::Vector<deInt64, 4>	e12;
526 		tcu::Vector<deInt64, 4>	e20;
527 
528 		// Coverage
529 		deUint64		coverage	= 0;
530 
531 		// Evaluate edge values
532 		for (int i = 0; i < 4; i++)
533 		{
534 			e01[i] = evaluateEdge(m_edge01, sx[i], sy[i]);
535 			e12[i] = evaluateEdge(m_edge12, sx[i], sy[i]);
536 			e20[i] = evaluateEdge(m_edge20, sx[i], sy[i]);
537 		}
538 
539 		// Compute coverage mask
540 		coverage = setCoverageValue(coverage, 1, 0, 0, 0,						isInsideCCW(m_edge01, e01[0]) && isInsideCCW(m_edge12, e12[0]) && isInsideCCW(m_edge20, e20[0]));
541 		coverage = setCoverageValue(coverage, 1, 1, 0, 0, !outX1 &&				isInsideCCW(m_edge01, e01[1]) && isInsideCCW(m_edge12, e12[1]) && isInsideCCW(m_edge20, e20[1]));
542 		coverage = setCoverageValue(coverage, 1, 0, 1, 0, !outY1 &&				isInsideCCW(m_edge01, e01[2]) && isInsideCCW(m_edge12, e12[2]) && isInsideCCW(m_edge20, e20[2]));
543 		coverage = setCoverageValue(coverage, 1, 1, 1, 0, !outX1 && !outY1 &&	isInsideCCW(m_edge01, e01[3]) && isInsideCCW(m_edge12, e12[3]) && isInsideCCW(m_edge20, e20[3]));
544 
545 		// Advance to next location
546 		m_curPos.x() += 2;
547 		if (m_curPos.x() > m_bboxMax.x())
548 		{
549 			m_curPos.y() += 2;
550 			m_curPos.x()  = m_bboxMin.x();
551 		}
552 
553 		if (coverage == 0)
554 			continue; // Discard.
555 
556 		// Floating-point edge values for barycentrics etc.
557 		const tcu::Vec4		e01f	= e01.asFloat();
558 		const tcu::Vec4		e12f	= e12.asFloat();
559 		const tcu::Vec4		e20f	= e20.asFloat();
560 
561 		// Compute depth values.
562 		if (depthValues)
563 		{
564 			const tcu::Vec4		ooSum	= 1.0f / (e01f + e12f + e20f);
565 			const tcu::Vec4		z0		= e12f * ooSum;
566 			const tcu::Vec4		z1		= e20f * ooSum;
567 			const tcu::Vec4		z2		= e01f * ooSum;
568 
569 			depthValues[packetNdx*4+0] = z0[0]*m_v0.z() + z1[0]*m_v1.z() + z2[0]*m_v2.z();
570 			depthValues[packetNdx*4+1] = z0[1]*m_v0.z() + z1[1]*m_v1.z() + z2[1]*m_v2.z();
571 			depthValues[packetNdx*4+2] = z0[2]*m_v0.z() + z1[2]*m_v1.z() + z2[2]*m_v2.z();
572 			depthValues[packetNdx*4+3] = z0[3]*m_v0.z() + z1[3]*m_v1.z() + z2[3]*m_v2.z();
573 		}
574 
575 		// Compute barycentrics and write out fragment packet
576 		{
577 			FragmentPacket& packet = fragmentPackets[packetNdx];
578 
579 			const tcu::Vec4		b0		= e12f * m_v0.w();
580 			const tcu::Vec4		b1		= e20f * m_v1.w();
581 			const tcu::Vec4		b2		= e01f * m_v2.w();
582 			const tcu::Vec4		ooSum	= 1.0f / (b0 + b1 + b2);
583 
584 			packet.position			= tcu::IVec2(x0, y0);
585 			packet.coverage			= coverage;
586 			packet.barycentric[0]	= b0 * ooSum;
587 			packet.barycentric[1]	= b1 * ooSum;
588 			packet.barycentric[2]	= 1.0f - packet.barycentric[0] - packet.barycentric[1];
589 
590 			packetNdx += 1;
591 		}
592 	}
593 
594 	DE_ASSERT(packetNdx <= maxFragmentPackets);
595 	numPacketsRasterized = packetNdx;
596 }
597 
598 // Sample positions - ordered as (x, y) list.
599 
600 // \note Macros are used to eliminate function calls even in debug builds.
601 #define SAMPLE_POS_TO_SUBPIXEL_COORD(POS)	\
602 	(deInt64)((POS) * (1<<RASTERIZER_SUBPIXEL_BITS) + 0.5f)
603 
604 #define SAMPLE_POS(X, Y)	\
605 	SAMPLE_POS_TO_SUBPIXEL_COORD(X), SAMPLE_POS_TO_SUBPIXEL_COORD(Y)
606 
607 static const deInt64 s_samplePos2[] =
608 {
609 	SAMPLE_POS(0.3f, 0.3f),
610 	SAMPLE_POS(0.7f, 0.7f)
611 };
612 
613 static const deInt64 s_samplePos4[] =
614 {
615 	SAMPLE_POS(0.25f, 0.25f),
616 	SAMPLE_POS(0.75f, 0.25f),
617 	SAMPLE_POS(0.25f, 0.75f),
618 	SAMPLE_POS(0.75f, 0.75f)
619 };
620 DE_STATIC_ASSERT(DE_LENGTH_OF_ARRAY(s_samplePos4) == 4*2);
621 
622 static const deInt64 s_samplePos8[] =
623 {
624 	SAMPLE_POS( 7.f/16.f,  9.f/16.f),
625 	SAMPLE_POS( 9.f/16.f, 13.f/16.f),
626 	SAMPLE_POS(11.f/16.f,  3.f/16.f),
627 	SAMPLE_POS(13.f/16.f, 11.f/16.f),
628 	SAMPLE_POS( 1.f/16.f,  7.f/16.f),
629 	SAMPLE_POS( 5.f/16.f,  1.f/16.f),
630 	SAMPLE_POS(15.f/16.f,  5.f/16.f),
631 	SAMPLE_POS( 3.f/16.f, 15.f/16.f)
632 };
633 DE_STATIC_ASSERT(DE_LENGTH_OF_ARRAY(s_samplePos8) == 8*2);
634 
635 static const deInt64 s_samplePos16[] =
636 {
637 	SAMPLE_POS(1.f/8.f, 1.f/8.f),
638 	SAMPLE_POS(3.f/8.f, 1.f/8.f),
639 	SAMPLE_POS(5.f/8.f, 1.f/8.f),
640 	SAMPLE_POS(7.f/8.f, 1.f/8.f),
641 	SAMPLE_POS(1.f/8.f, 3.f/8.f),
642 	SAMPLE_POS(3.f/8.f, 3.f/8.f),
643 	SAMPLE_POS(5.f/8.f, 3.f/8.f),
644 	SAMPLE_POS(7.f/8.f, 3.f/8.f),
645 	SAMPLE_POS(1.f/8.f, 5.f/8.f),
646 	SAMPLE_POS(3.f/8.f, 5.f/8.f),
647 	SAMPLE_POS(5.f/8.f, 5.f/8.f),
648 	SAMPLE_POS(7.f/8.f, 5.f/8.f),
649 	SAMPLE_POS(1.f/8.f, 7.f/8.f),
650 	SAMPLE_POS(3.f/8.f, 7.f/8.f),
651 	SAMPLE_POS(5.f/8.f, 7.f/8.f),
652 	SAMPLE_POS(7.f/8.f, 7.f/8.f)
653 };
654 DE_STATIC_ASSERT(DE_LENGTH_OF_ARRAY(s_samplePos16) == 16*2);
655 
656 #undef SAMPLE_POS
657 #undef SAMPLE_POS_TO_SUBPIXEL_COORD
658 
659 template<int NumSamples>
rasterizeMultiSample(FragmentPacket * const fragmentPackets,float * const depthValues,const int maxFragmentPackets,int & numPacketsRasterized)660 void TriangleRasterizer::rasterizeMultiSample (FragmentPacket* const fragmentPackets, float* const depthValues, const int maxFragmentPackets, int& numPacketsRasterized)
661 {
662 	DE_ASSERT(maxFragmentPackets > 0);
663 
664 	const deInt64*	samplePos	= DE_NULL;
665 	const deUint64	halfPixel	= 1ll << (RASTERIZER_SUBPIXEL_BITS-1);
666 	int				packetNdx	= 0;
667 
668 	switch (NumSamples)
669 	{
670 		case 2:		samplePos = s_samplePos2;	break;
671 		case 4:		samplePos = s_samplePos4;	break;
672 		case 8:		samplePos = s_samplePos8;	break;
673 		case 16:	samplePos = s_samplePos16;	break;
674 		default:
675 			DE_ASSERT(false);
676 	}
677 
678 	while (m_curPos.y() <= m_bboxMax.y() && packetNdx < maxFragmentPackets)
679 	{
680 		const int		x0		= m_curPos.x();
681 		const int		y0		= m_curPos.y();
682 
683 		// Base subpixel coords
684 		const deInt64	sx0		= toSubpixelCoord(x0);
685 		const deInt64	sx1		= toSubpixelCoord(x0+1);
686 		const deInt64	sy0		= toSubpixelCoord(y0);
687 		const deInt64	sy1		= toSubpixelCoord(y0+1);
688 
689 		const deInt64	sx[4]	= { sx0, sx1, sx0, sx1 };
690 		const deInt64	sy[4]	= { sy0, sy0, sy1, sy1 };
691 
692 		// Viewport test
693 		const bool		outX1	= x0+1 == m_viewport.x()+m_viewport.z();
694 		const bool		outY1	= y0+1 == m_viewport.y()+m_viewport.w();
695 
696 		DE_ASSERT(x0 < m_viewport.x()+m_viewport.z());
697 		DE_ASSERT(y0 < m_viewport.y()+m_viewport.w());
698 
699 		// Edge values
700 		tcu::Vector<deInt64, 4>	e01[NumSamples];
701 		tcu::Vector<deInt64, 4>	e12[NumSamples];
702 		tcu::Vector<deInt64, 4>	e20[NumSamples];
703 
704 		// Coverage
705 		deUint64		coverage	= 0;
706 
707 		// Evaluate edge values at sample positions
708 		for (int sampleNdx = 0; sampleNdx < NumSamples; sampleNdx++)
709 		{
710 			const deInt64 ox = samplePos[sampleNdx*2 + 0];
711 			const deInt64 oy = samplePos[sampleNdx*2 + 1];
712 
713 			for (int fragNdx = 0; fragNdx < 4; fragNdx++)
714 			{
715 				e01[sampleNdx][fragNdx] = evaluateEdge(m_edge01, sx[fragNdx] + ox, sy[fragNdx] + oy);
716 				e12[sampleNdx][fragNdx] = evaluateEdge(m_edge12, sx[fragNdx] + ox, sy[fragNdx] + oy);
717 				e20[sampleNdx][fragNdx] = evaluateEdge(m_edge20, sx[fragNdx] + ox, sy[fragNdx] + oy);
718 			}
719 		}
720 
721 		// Compute coverage mask
722 		for (int sampleNdx = 0; sampleNdx < NumSamples; sampleNdx++)
723 		{
724 			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]));
725 			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]));
726 			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]));
727 			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]));
728 		}
729 
730 		// Advance to next location
731 		m_curPos.x() += 2;
732 		if (m_curPos.x() > m_bboxMax.x())
733 		{
734 			m_curPos.y() += 2;
735 			m_curPos.x()  = m_bboxMin.x();
736 		}
737 
738 		if (coverage == 0)
739 			continue; // Discard.
740 
741 		// Compute depth values.
742 		if (depthValues)
743 		{
744 			for (int sampleNdx = 0; sampleNdx < NumSamples; sampleNdx++)
745 			{
746 				// Floating-point edge values at sample coordinates.
747 				const tcu::Vec4&	e01f	= e01[sampleNdx].asFloat();
748 				const tcu::Vec4&	e12f	= e12[sampleNdx].asFloat();
749 				const tcu::Vec4&	e20f	= e20[sampleNdx].asFloat();
750 
751 				const tcu::Vec4		ooSum	= 1.0f / (e01f + e12f + e20f);
752 				const tcu::Vec4		z0		= e12f * ooSum;
753 				const tcu::Vec4		z1		= e20f * ooSum;
754 				const tcu::Vec4		z2		= e01f * ooSum;
755 
756 				depthValues[(packetNdx*4+0)*NumSamples + sampleNdx] = z0[0]*m_v0.z() + z1[0]*m_v1.z() + z2[0]*m_v2.z();
757 				depthValues[(packetNdx*4+1)*NumSamples + sampleNdx] = z0[1]*m_v0.z() + z1[1]*m_v1.z() + z2[1]*m_v2.z();
758 				depthValues[(packetNdx*4+2)*NumSamples + sampleNdx] = z0[2]*m_v0.z() + z1[2]*m_v1.z() + z2[2]*m_v2.z();
759 				depthValues[(packetNdx*4+3)*NumSamples + sampleNdx] = z0[3]*m_v0.z() + z1[3]*m_v1.z() + z2[3]*m_v2.z();
760 			}
761 		}
762 
763 		// Compute barycentrics and write out fragment packet
764 		{
765 			FragmentPacket& packet = fragmentPackets[packetNdx];
766 
767 			// Floating-point edge values at pixel center.
768 			tcu::Vec4			e01f;
769 			tcu::Vec4			e12f;
770 			tcu::Vec4			e20f;
771 
772 			for (int i = 0; i < 4; i++)
773 			{
774 				e01f[i] = float(evaluateEdge(m_edge01, sx[i] + halfPixel, sy[i] + halfPixel));
775 				e12f[i] = float(evaluateEdge(m_edge12, sx[i] + halfPixel, sy[i] + halfPixel));
776 				e20f[i] = float(evaluateEdge(m_edge20, sx[i] + halfPixel, sy[i] + halfPixel));
777 			}
778 
779 			// Barycentrics & scale.
780 			const tcu::Vec4		b0		= e12f * m_v0.w();
781 			const tcu::Vec4		b1		= e20f * m_v1.w();
782 			const tcu::Vec4		b2		= e01f * m_v2.w();
783 			const tcu::Vec4		ooSum	= 1.0f / (b0 + b1 + b2);
784 
785 			packet.position			= tcu::IVec2(x0, y0);
786 			packet.coverage			= coverage;
787 			packet.barycentric[0]	= b0 * ooSum;
788 			packet.barycentric[1]	= b1 * ooSum;
789 			packet.barycentric[2]	= 1.0f - packet.barycentric[0] - packet.barycentric[1];
790 
791 			packetNdx += 1;
792 		}
793 	}
794 
795 	DE_ASSERT(packetNdx <= maxFragmentPackets);
796 	numPacketsRasterized = packetNdx;
797 }
798 
rasterize(FragmentPacket * const fragmentPackets,float * const depthValues,const int maxFragmentPackets,int & numPacketsRasterized)799 void TriangleRasterizer::rasterize (FragmentPacket* const fragmentPackets, float* const depthValues, const int maxFragmentPackets, int& numPacketsRasterized)
800 {
801 	DE_ASSERT(maxFragmentPackets > 0);
802 
803 	switch (m_numSamples)
804 	{
805 		case 1:		rasterizeSingleSample		(fragmentPackets, depthValues, maxFragmentPackets, numPacketsRasterized);	break;
806 		case 2:		rasterizeMultiSample<2>		(fragmentPackets, depthValues, maxFragmentPackets, numPacketsRasterized);	break;
807 		case 4:		rasterizeMultiSample<4>		(fragmentPackets, depthValues, maxFragmentPackets, numPacketsRasterized);	break;
808 		case 8:		rasterizeMultiSample<8>		(fragmentPackets, depthValues, maxFragmentPackets, numPacketsRasterized);	break;
809 		case 16:	rasterizeMultiSample<16>	(fragmentPackets, depthValues, maxFragmentPackets, numPacketsRasterized);	break;
810 		default:
811 			DE_ASSERT(DE_FALSE);
812 	}
813 }
814 
SingleSampleLineRasterizer(const tcu::IVec4 & viewport)815 SingleSampleLineRasterizer::SingleSampleLineRasterizer (const tcu::IVec4& viewport)
816 	: m_viewport		(viewport)
817 	, m_curRowFragment	(0)
818 	, m_lineWidth		(0.0f)
819 {
820 }
821 
~SingleSampleLineRasterizer()822 SingleSampleLineRasterizer::~SingleSampleLineRasterizer	()
823 {
824 }
825 
init(const tcu::Vec4 & v0,const tcu::Vec4 & v1,float lineWidth)826 void SingleSampleLineRasterizer::init (const tcu::Vec4& v0, const tcu::Vec4& v1, float lineWidth)
827 {
828 	const bool						isXMajor		= de::abs((v1 - v0).x()) >= de::abs((v1 - v0).y());
829 
830 	// Bounding box \note: with wide lines, the line is actually moved as in the spec
831 	const deInt32					lineWidthPixels	= (lineWidth > 1.0f) ? (deInt32)floor(lineWidth + 0.5f) : 1;
832 
833 	const tcu::IVec2				minorDirection	= (isXMajor ? tcu::IVec2(0, 1) : tcu::IVec2(1, 0));
834 	const tcu::Vector<deInt64,2>	widthOffset		= (isXMajor ? tcu::Vector<deInt64,2>(0, -1) : tcu::Vector<deInt64,2>(-1, 0)) * (toSubpixelCoord(lineWidthPixels - 1) / 2);
835 
836 	const deInt64					x0				= toSubpixelCoord(v0.x()) + widthOffset.x();
837 	const deInt64					y0				= toSubpixelCoord(v0.y()) + widthOffset.y();
838 	const deInt64					x1				= toSubpixelCoord(v1.x()) + widthOffset.x();
839 	const deInt64					y1				= toSubpixelCoord(v1.y()) + widthOffset.y();
840 
841 	// line endpoints might be perturbed, add some margin
842 	const deInt64					xMin			= de::min(x0, x1) - toSubpixelCoord(1);
843 	const deInt64					xMax			= de::max(x0, x1) + toSubpixelCoord(1);
844 	const deInt64					yMin			= de::min(y0, y1) - toSubpixelCoord(1);
845 	const deInt64					yMax			= de::max(y0, y1) + toSubpixelCoord(1);
846 
847 	// Remove invisible area
848 
849 	if (isXMajor)
850 	{
851 		// clamp to viewport in major direction
852 		m_bboxMin.x() = de::clamp(floorSubpixelToPixelCoord(xMin, true), m_viewport.x(), m_viewport.x() + m_viewport.z() - 1);
853 		m_bboxMax.x() = de::clamp(ceilSubpixelToPixelCoord (xMax, true), m_viewport.x(), m_viewport.x() + m_viewport.z() - 1);
854 
855 		// clamp to padded viewport in minor direction (wide lines might bleed over viewport in minor direction)
856 		m_bboxMin.y() = de::clamp(floorSubpixelToPixelCoord(yMin, true), m_viewport.y() - lineWidthPixels, m_viewport.y() + m_viewport.w() - 1);
857 		m_bboxMax.y() = de::clamp(ceilSubpixelToPixelCoord (yMax, true), m_viewport.y() - lineWidthPixels, m_viewport.y() + m_viewport.w() - 1);
858 	}
859 	else
860 	{
861 		// clamp to viewport in major direction
862 		m_bboxMin.y() = de::clamp(floorSubpixelToPixelCoord(yMin, true), m_viewport.y(), m_viewport.y() + m_viewport.w() - 1);
863 		m_bboxMax.y() = de::clamp(ceilSubpixelToPixelCoord (yMax, true), m_viewport.y(), m_viewport.y() + m_viewport.w() - 1);
864 
865 		// clamp to padded viewport in minor direction (wide lines might bleed over viewport in minor direction)
866 		m_bboxMin.x() = de::clamp(floorSubpixelToPixelCoord(xMin, true), m_viewport.x() - lineWidthPixels, m_viewport.x() + m_viewport.z() - 1);
867 		m_bboxMax.x() = de::clamp(ceilSubpixelToPixelCoord (xMax, true), m_viewport.x() - lineWidthPixels, m_viewport.x() + m_viewport.z() - 1);
868 	}
869 
870 	m_lineWidth = lineWidth;
871 
872 	m_v0 = v0;
873 	m_v1 = v1;
874 
875 	m_curPos = m_bboxMin;
876 	m_curRowFragment = 0;
877 }
878 
rasterize(FragmentPacket * const fragmentPackets,float * const depthValues,const int maxFragmentPackets,int & numPacketsRasterized)879 void SingleSampleLineRasterizer::rasterize (FragmentPacket* const fragmentPackets, float* const depthValues, const int maxFragmentPackets, int& numPacketsRasterized)
880 {
881 	DE_ASSERT(maxFragmentPackets > 0);
882 
883 	const deInt64								halfPixel		= 1ll << (RASTERIZER_SUBPIXEL_BITS-1);
884 	const deInt32								lineWidth		= (m_lineWidth > 1.0f) ? (deInt32)floor(m_lineWidth + 0.5f) : 1;
885 	const bool									isXMajor		= de::abs((m_v1 - m_v0).x()) >= de::abs((m_v1 - m_v0).y());
886 	const tcu::IVec2							minorDirection	= (isXMajor ? tcu::IVec2(0, 1) : tcu::IVec2(1, 0));
887 	const tcu::Vector<deInt64,2>				widthOffset		= (isXMajor ? tcu::Vector<deInt64,2>(0, -1) : tcu::Vector<deInt64,2>(-1, 0)) * (toSubpixelCoord(lineWidth - 1) / 2);
888 	const tcu::Vector<deInt64,2>				pa				= LineRasterUtil::toSubpixelVector(m_v0.xy()) + widthOffset;
889 	const tcu::Vector<deInt64,2>				pb				= LineRasterUtil::toSubpixelVector(m_v1.xy()) + widthOffset;
890 	const LineRasterUtil::SubpixelLineSegment	line			= LineRasterUtil::SubpixelLineSegment(pa, pb);
891 
892 	int											packetNdx 		= 0;
893 
894 	while (m_curPos.y() <= m_bboxMax.y() && packetNdx < maxFragmentPackets)
895 	{
896 		const tcu::Vector<deInt64,2> diamondPosition = LineRasterUtil::toSubpixelVector(m_curPos) + tcu::Vector<deInt64,2>(halfPixel,halfPixel);
897 
898 		// Should current fragment be drawn? == does the segment exit this diamond?
899 		if (LineRasterUtil::doesLineSegmentExitDiamond(line, diamondPosition))
900 		{
901 			const tcu::Vector<deInt64,2> 	pr					= diamondPosition;
902 			const float 					t					= tcu::dot((pr - pa).asFloat(), (pb - pa).asFloat()) / tcu::lengthSquared(pb.asFloat() - pa.asFloat());
903 
904 			// Rasterize on only fragments that are would end up in the viewport (i.e. visible)
905 			const int						minViewportLimit	= (isXMajor) ? (m_viewport.y())                  : (m_viewport.x());
906 			const int						maxViewportLimit	= (isXMajor) ? (m_viewport.y() + m_viewport.w()) : (m_viewport.x() + m_viewport.z());
907 			const int						fragmentLocation	= (isXMajor) ? (m_curPos.y())                    : (m_curPos.x());
908 
909 			const int						rowFragBegin		= de::max(0, minViewportLimit - fragmentLocation);
910 			const int						rowFragEnd			= de::min(maxViewportLimit - fragmentLocation, lineWidth);
911 
912 			// Wide lines require multiple fragments.
913 			for (; rowFragBegin + m_curRowFragment < rowFragEnd; m_curRowFragment++)
914 			{
915 				const tcu::IVec2 fragmentPos = m_curPos + minorDirection * (rowFragBegin + m_curRowFragment);
916 
917 				// We only rasterize visible area
918 				DE_ASSERT(LineRasterUtil::inViewport(fragmentPos, m_viewport));
919 
920 				// Compute depth values.
921 				if (depthValues)
922 				{
923 					const float za = m_v0.z();
924 					const float zb = m_v1.z();
925 
926 					depthValues[packetNdx*4+0] = (1 - t) * za + t * zb;
927 					depthValues[packetNdx*4+1] = 0;
928 					depthValues[packetNdx*4+2] = 0;
929 					depthValues[packetNdx*4+3] = 0;
930 				}
931 
932 				{
933 					// output this fragment
934 					// \note In order to make consistent output with multisampled line rasterization, output "barycentric" coordinates
935 					FragmentPacket& packet = fragmentPackets[packetNdx];
936 
937 					const tcu::Vec4		b0		= tcu::Vec4(1 - t);
938 					const tcu::Vec4		b1		= tcu::Vec4(t);
939 					const tcu::Vec4		ooSum	= 1.0f / (b0 + b1);
940 
941 					packet.position			= fragmentPos;
942 					packet.coverage			= getCoverageBit(1, 0, 0, 0);
943 					packet.barycentric[0]	= b0 * ooSum;
944 					packet.barycentric[1]	= b1 * ooSum;
945 					packet.barycentric[2]	= tcu::Vec4(0.0f);
946 
947 					packetNdx += 1;
948 				}
949 
950 				if (packetNdx == maxFragmentPackets)
951 				{
952 					m_curRowFragment++; // don't redraw this fragment again next time
953 					numPacketsRasterized = packetNdx;
954 					return;
955 				}
956 			}
957 
958 			m_curRowFragment = 0;
959 		}
960 
961 		++m_curPos.x();
962 		if (m_curPos.x() > m_bboxMax.x())
963 		{
964 			++m_curPos.y();
965 			m_curPos.x() = m_bboxMin.x();
966 		}
967 	}
968 
969 	DE_ASSERT(packetNdx <= maxFragmentPackets);
970 	numPacketsRasterized = packetNdx;
971 }
972 
MultiSampleLineRasterizer(const int numSamples,const tcu::IVec4 & viewport)973 MultiSampleLineRasterizer::MultiSampleLineRasterizer (const int numSamples, const tcu::IVec4& viewport)
974 	: m_numSamples			(numSamples)
975 	, m_triangleRasterizer0 (viewport, m_numSamples, RasterizationState())
976 	, m_triangleRasterizer1 (viewport, m_numSamples, RasterizationState())
977 {
978 }
979 
~MultiSampleLineRasterizer()980 MultiSampleLineRasterizer::~MultiSampleLineRasterizer ()
981 {
982 }
983 
init(const tcu::Vec4 & v0,const tcu::Vec4 & v1,float lineWidth)984 void MultiSampleLineRasterizer::init (const tcu::Vec4& v0, const tcu::Vec4& v1, float lineWidth)
985 {
986 	// allow creation of single sampled rasterizer objects but do not allow using them
987 	DE_ASSERT(m_numSamples > 1);
988 
989 	const tcu::Vec2 lineVec		= tcu::Vec2(tcu::Vec4(v1).xy()) - tcu::Vec2(tcu::Vec4(v0).xy());
990 	const tcu::Vec2 normal2		= tcu::normalize(tcu::Vec2(-lineVec[1], lineVec[0]));
991 	const tcu::Vec4 normal4		= tcu::Vec4(normal2.x(), normal2.y(), 0, 0);
992 	const float offset			= lineWidth / 2.0f;
993 
994 	const tcu::Vec4 p0 = v0 + normal4 * offset;
995 	const tcu::Vec4 p1 = v0 - normal4 * offset;
996 	const tcu::Vec4 p2 = v1 - normal4 * offset;
997 	const tcu::Vec4 p3 = v1 + normal4 * offset;
998 
999 	// Edge 0 -> 1 is always along the line and edge 1 -> 2 is in 90 degree angle to the line
1000 	m_triangleRasterizer0.init(p0, p3, p2);
1001 	m_triangleRasterizer1.init(p2, p1, p0);
1002 }
1003 
rasterize(FragmentPacket * const fragmentPackets,float * const depthValues,const int maxFragmentPackets,int & numPacketsRasterized)1004 void MultiSampleLineRasterizer::rasterize (FragmentPacket* const fragmentPackets, float* const depthValues, const int maxFragmentPackets, int& numPacketsRasterized)
1005 {
1006 	DE_ASSERT(maxFragmentPackets > 0);
1007 
1008 	m_triangleRasterizer0.rasterize(fragmentPackets, depthValues, maxFragmentPackets, numPacketsRasterized);
1009 
1010 	// Remove 3rd barycentric value and rebalance. Lines do not have non-zero barycentric at index 2
1011 	for (int packNdx = 0; packNdx < numPacketsRasterized; ++packNdx)
1012 	for (int fragNdx = 0; fragNdx < 4; fragNdx++)
1013 	{
1014 		float removedValue = fragmentPackets[packNdx].barycentric[2][fragNdx];
1015 		fragmentPackets[packNdx].barycentric[2][fragNdx] = 0.0f;
1016 		fragmentPackets[packNdx].barycentric[1][fragNdx] += removedValue;
1017 	}
1018 
1019 	// rasterizer 0 filled the whole buffer?
1020 	if (numPacketsRasterized == maxFragmentPackets)
1021 		return;
1022 
1023 	{
1024 		FragmentPacket* const nextFragmentPackets	= fragmentPackets + numPacketsRasterized;
1025 		float* nextDepthValues						= (depthValues) ? (depthValues+4*numPacketsRasterized*m_numSamples) : (DE_NULL);
1026 		int numPacketsRasterized2					= 0;
1027 
1028 		m_triangleRasterizer1.rasterize(nextFragmentPackets, nextDepthValues, maxFragmentPackets - numPacketsRasterized, numPacketsRasterized2);
1029 
1030 		numPacketsRasterized += numPacketsRasterized2;
1031 
1032 		// Fix swapped barycentrics in the second triangle
1033 		for (int packNdx = 0; packNdx < numPacketsRasterized2; ++packNdx)
1034 		for (int fragNdx = 0; fragNdx < 4; fragNdx++)
1035 		{
1036 			float removedValue = nextFragmentPackets[packNdx].barycentric[2][fragNdx];
1037 			nextFragmentPackets[packNdx].barycentric[2][fragNdx] = 0.0f;
1038 			nextFragmentPackets[packNdx].barycentric[1][fragNdx] += removedValue;
1039 
1040 			// edge has reversed direction
1041 			std::swap(nextFragmentPackets[packNdx].barycentric[0][fragNdx], nextFragmentPackets[packNdx].barycentric[1][fragNdx]);
1042 		}
1043 	}
1044 }
1045 
1046 } // rr
1047