Relaxes line rasterization tolerances

Components: Framework
VK-GL-CTS Issue: 2033

Affects:
dEQP-VK.rasterization.*

Change-Id: Ib41552b1bb6d9aa2b25d0cbc6f02d51ce997f4e3

diff --git a/framework/common/tcuRasterizationVerifier.cpp b/framework/common/tcuRasterizationVerifier.cpp
index dd8ff86..b4a4937 100644 (file)
--- a/framework/common/tcuRasterizationVerifier.cpp
+++ b/framework/common/tcuRasterizationVerifier.cpp
@@ -2103,7 +2103,7 @@ CoverageType calculateTriangleCoverage (const tcu::Vec4& p0, const tcu::Vec4& p1
        typedef tcu::Vector<deInt64, 2> I64Vec2;
 
        const deUint64          numSubPixels                                            = ((deUint64)1) << subpixelBits;
-       const deUint64          pixelHitBoxSize                                         = (multisample) ? (numSubPixels) : (2+2);       //!< allow 4 central (2x2) for non-multisample pixels. Rounding may move edges 1 subpixel to any direction.
+       const deUint64          pixelHitBoxSize                                         = (multisample) ? (numSubPixels) : 5;           //!< 5 = ceil(6 * sqrt(2) / 2) to account for a 3 subpixel fuzz around pixel center
        const bool                      order                                                           = isTriangleClockwise(p0, p1, p2);                      //!< clockwise / counter-clockwise
        const tcu::Vec4&        orderedP0                                                       = p0;                                                                           //!< vertices of a clockwise triangle
        const tcu::Vec4&        orderedP1                                                       = (order) ? (p1) : (p2);
@@ -2137,12 +2137,13 @@ CoverageType calculateTriangleCoverage (const tcu::Vec4& p0, const tcu::Vec4& p1
 
        // Broad triangle - pixel area intersection
        {
-               const I64Vec2 pixelCenterPosition = I64Vec2(pixel.x(), pixel.y()) * I64Vec2(numSubPixels, numSubPixels) + I64Vec2(numSubPixels / 2, numSubPixels / 2);
-               const I64Vec2 triangleSubPixelSpaceRound[3] =
+               const DVec2 pixelCenterPosition                 =       DVec2((double)pixel.x(), (double)pixel.y()) * DVec2((double)numSubPixels, (double)numSubPixels) +
+                                                                                                       DVec2((double)numSubPixels / 2, (double)numSubPixels / 2);
+               const DVec2 triangleSubPixelSpace[3]    =
                {
-                       I64Vec2(deRoundFloatToInt32(triangleScreenSpace[0].x() * (float)numSubPixels), deRoundFloatToInt32(triangleScreenSpace[0].y() * (float)numSubPixels)),
-                       I64Vec2(deRoundFloatToInt32(triangleScreenSpace[1].x() * (float)numSubPixels), deRoundFloatToInt32(triangleScreenSpace[1].y() * (float)numSubPixels)),
-                       I64Vec2(deRoundFloatToInt32(triangleScreenSpace[2].x() * (float)numSubPixels), deRoundFloatToInt32(triangleScreenSpace[2].y() * (float)numSubPixels)),
+                       DVec2(triangleScreenSpace[0].x() * (double)numSubPixels, triangleScreenSpace[0].y() * (double)numSubPixels),
+                       DVec2(triangleScreenSpace[1].x() * (double)numSubPixels, triangleScreenSpace[1].y() * (double)numSubPixels),
+                       DVec2(triangleScreenSpace[2].x() * (double)numSubPixels, triangleScreenSpace[2].y() * (double)numSubPixels),
                };
 
                // Check (using cross product) if pixel center is
@@ -2152,10 +2153,10 @@ CoverageType calculateTriangleCoverage (const tcu::Vec4& p0, const tcu::Vec4& p1
                for (int vtxNdx = 0; vtxNdx < 3; ++vtxNdx)
                {
                        const int               otherVtxNdx                             = (vtxNdx + 1) % 3;
-                       const deInt64   maxPixelDistanceSquared = pixelHitBoxSize*pixelHitBoxSize; // Max distance from the pixel center from within the pixel is (sqrt(2) * boxWidth/2). Use 2x value for rounding tolerance
-                       const I64Vec2   edge                                    = triangleSubPixelSpaceRound[otherVtxNdx]       - triangleSubPixelSpaceRound[vtxNdx];
-                       const I64Vec2   v                                               = pixelCenterPosition                                           - triangleSubPixelSpaceRound[vtxNdx];
-                       const deInt64   crossProduct                    = (edge.x() * v.y() - edge.y() * v.x());
+                       const double    maxPixelDistanceSquared = (double)(pixelHitBoxSize * pixelHitBoxSize); // Max distance from the pixel center from within the pixel is (sqrt(2) * boxWidth/2). Use 2x value for rounding tolerance
+                       const DVec2             edge                                    = triangleSubPixelSpace[otherVtxNdx]    - triangleSubPixelSpace[vtxNdx];
+                       const DVec2             v                                               = pixelCenterPosition                                   - triangleSubPixelSpace[vtxNdx];
+                       const double    crossProduct                    = (edge.x() * v.y() - edge.y() * v.x());
 
                        // distance from edge: (edge x v) / |edge|
                        //     (edge x v) / |edge| > maxPixelDistance
@@ -2181,12 +2182,14 @@ CoverageType calculateTriangleCoverage (const tcu::Vec4& p0, const tcu::Vec4& p1
                        I64Vec2((pixel.x()+1) * numSubPixels, (pixel.y()+1) * numSubPixels),
                        I64Vec2((pixel.x()+0) * numSubPixels, (pixel.y()+1) * numSubPixels),
                };
+
+               // 3 subpixel tolerance around pixel center to account for accumulated errors during various line rasterization methods
                const I64Vec2 pixelCenterCorners[4] =
                {
-                       I64Vec2(pixel.x() * numSubPixels + numSubPixels/2 + 0, pixel.y() * numSubPixels + numSubPixels/2 + 0),
-                       I64Vec2(pixel.x() * numSubPixels + numSubPixels/2 + 1, pixel.y() * numSubPixels + numSubPixels/2 + 0),
-                       I64Vec2(pixel.x() * numSubPixels + numSubPixels/2 + 1, pixel.y() * numSubPixels + numSubPixels/2 + 1),
-                       I64Vec2(pixel.x() * numSubPixels + numSubPixels/2 + 0, pixel.y() * numSubPixels + numSubPixels/2 + 1),
+                       I64Vec2(pixel.x() * numSubPixels + numSubPixels/2 - 3, pixel.y() * numSubPixels + numSubPixels/2 - 3),
+                       I64Vec2(pixel.x() * numSubPixels + numSubPixels/2 + 3, pixel.y() * numSubPixels + numSubPixels/2 - 3),
+                       I64Vec2(pixel.x() * numSubPixels + numSubPixels/2 + 3, pixel.y() * numSubPixels + numSubPixels/2 + 3),
+                       I64Vec2(pixel.x() * numSubPixels + numSubPixels/2 - 3, pixel.y() * numSubPixels + numSubPixels/2 + 3),
                };
 
                // both rounding directions