Add threshold to rasterization order depth checks

These tests compared floating point depth values expecting exact
matches, which was causing trouble for some implementations. This commit
adds an error threshold to the check.

Affected tests:
dEQP-VK.rasterization.rasterization_order_attachment_access.depth.*

Components: Vulkan
VK-GL-CTS issue: 3711

Change-Id: If6798dfd473f57341775e83d68188e39bdf27caa

diff --git a/external/vulkancts/modules/vulkan/rasterization/vktRasterizationOrderAttachmentAccessTests.cpp b/external/vulkancts/modules/vulkan/rasterization/vktRasterizationOrderAttachmentAccessTests.cpp
index 1b4df33..263a487 100644 (file)
--- a/external/vulkancts/modules/vulkan/rasterization/vktRasterizationOrderAttachmentAccessTests.cpp
+++ b/external/vulkancts/modules/vulkan/rasterization/vktRasterizationOrderAttachmentAccessTests.cpp
@@ -559,22 +559,27 @@ void AttachmentAccessOrderDepthTestCase::addShadersInternal(SourceCollections& p
                                << "            out0.y = curIndex + 1 + gl_SampleID + zero;\n";
        if (m_sampleCount != VK_SAMPLE_COUNT_1_BIT)
        {
-               fragShader      << "    gl_FragDepth = 0.125 * (float(curIndex) / float(total)) + gl_SampleID / 128.0;\n";
+               fragShader      << "            gl_FragDepth = 0.125 * (float(curIndex) / float(total)) + gl_SampleID / 128.0;\n";
        }
        fragShader      << "    }\n"
-                               << "    else if (ds.x == 0.125 * float(curIndex - 1) / float(total) + gl_SampleID / 128.0)\n"
+                               << "    else\n"
                                << "    {\n"
-                               << "            out0.x = color.x;\n"
-                               << "            out0.y = curIndex + 1 + gl_SampleID + zero;\n";
+                               << "            const float expected = 0.125 * float(curIndex - 1) / float(total) + gl_SampleID / 128.0;\n"
+                               << "            const float threshold = 0.0000001;\n"
+                               << "            if (ds.x >= expected - threshold && ds.x <= expected + threshold)\n"
+                               << "            {\n"
+                               << "                    out0.x = color.x;\n"
+                               << "                    out0.y = curIndex + 1 + gl_SampleID + zero;\n";
        if (m_sampleCount != VK_SAMPLE_COUNT_1_BIT)
        {
-               fragShader      << "    gl_FragDepth = 0.125 * (float(curIndex) / float(total)) + gl_SampleID / 128.0;\n";
+               fragShader      << "                    gl_FragDepth = 0.125 * (float(curIndex) / float(total)) + gl_SampleID / 128.0;\n";
        }
-       fragShader      << "    }\n"
-                               << "    else\n"
-                               << "    {\n"
-                               << "            out0.y = 0;\n"
-                               << "            out0.x = 1u;\n"
+       fragShader      << "            }\n"
+                               << "            else\n"
+                               << "            {\n"
+                               << "                    out0.y = 0;\n"
+                               << "                    out0.x = 1u;\n"
+                               << "            }\n"
                                << "    }\n"
                                << "}\n";