Restore fuzzyCompare() sample rate

Commit 57c002a31612855e744c33ac698590da0e3d02d3 changed how the stride
was calculated for sampling values in order to avoid double-counting
values. However, it also reduced the number of values sampled and
that's resulting in both GLES and Vulkan failures.

This patch restores the original stride calculation, but changes the
parameters to rnd.getInt() to ensure that 0 is never returned from it.

Components: Framework

VK-GL-CTS issue: 658

Change-Id: I4c7e6d39017bbfc38bcd155037d3b4d40ce46ca7

diff --git a/framework/common/tcuFuzzyImageCompare.cpp b/framework/common/tcuFuzzyImageCompare.cpp
index 4e76476dc1c132440a39e298c12e7875dbdb931a..6aa62ab069eaf72737b61af2d148b8951d3eb77b 100644 (file)
--- a/framework/common/tcuFuzzyImageCompare.cpp
+++ b/framework/common/tcuFuzzyImageCompare.cpp
@@ -318,7 +318,7 @@ float fuzzyCompare (const FuzzyCompareParams& params, const ConstPixelBufferAcce
 
        for (int y = 1; y < height-1; y++)
        {
-               for (int x = 1; x < width-1; x += 1 + (int)rnd.getInt(0, params.maxSampleSkip))
+               for (int x = 1; x < width-1; x += params.maxSampleSkip > 0 ? (int)rnd.getInt(1, params.maxSampleSkip) : 1)
                {
                        const deUint32  minDist2RefToCmp        = distSquaredToNeighbor<4>(rnd, readUnorm8<4>(refAccess, x, y), cmpAccess, x, y);
                        const deUint32  minDist2CmpToRef        = distSquaredToNeighbor<4>(rnd, readUnorm8<4>(cmpAccess, x, y), refAccess, x, y);