framework/referencerenderer/rrRasterizer.cpp

   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
  31 inline deInt64 toSubpixelCoord (float v)
  32 {
  33         return (deInt64)(v * (1<<RASTERIZER_SUBPIXEL_BITS) + (v < 0.f ? -0.5f : 0.5f));
  34 }
  35
  36 inline deInt64 toSubpixelCoord (deInt32 v)
  37 {
  38         return v << RASTERIZER_SUBPIXEL_BITS;
  39 }
  40
  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
  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
  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
  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
  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
  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
 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
 114 enum LINE_SIDE
 115 {
 116         LINE_SIDE_INTERSECT = 0,
 117         LINE_SIDE_LEFT,
 118         LINE_SIDE_RIGHT
 119 };
 120
 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
 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)
 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
 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
 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
 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
 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
 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
 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)
 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)
 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
 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
 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  *//*--------------------------------------------------------------------*/
 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
 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>
 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
 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
 815 SingleSampleLineRasterizer::SingleSampleLineRasterizer (const tcu::IVec4& viewport)
 816         : m_viewport            (viewport)
 817         , m_curRowFragment      (0)
 818         , m_lineWidth           (0.0f)
 819 {
 820 }
 821
 822 SingleSampleLineRasterizer::~SingleSampleLineRasterizer ()
 823 {
 824 }
 825
 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
 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
 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
 980 MultiSampleLineRasterizer::~MultiSampleLineRasterizer ()
 981 {
 982 }
 983
 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
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